Tokamak assembly

The size and weight of the major components, the tiny tolerances and careful handling required for the assembly of huge and unique systems, the diversity of manufacturers, the tight schedule, complex interfaces ... all of these elements combine to make the assembly of the ��ϲʸ�� tokamak an engineering and logistics challenge of enormous proportions.

Core machine assembly is proceeding from bottom to top. Beginning with the heaviest single component—the 1,250-tonne cryostat base, installed in May 2020—assembly contractors are executing the sequence as planned: lower poloidal field coils, cryostat lower cylinder and thermal shield and, over the next years, the nine vacuum vessel modules, subsequent ring coils, components at the top of the machine, central solenoid and, finally, the cryostat lid.

1

Components enter the Assembly Hall through the Cleaning Facility, where they are unpacked and cleaned with compressed air, pressurized demineralized water, or specialty detergents. The Cleaning Facility operates as an airlock between the Hall and the outside environment.

2

The overhead crane system transfers the newly arrived loads to temporary laydown areas, or zones reserved for sub-assembly activities. Then, in the order determined by assembly sequences, the components or assemblies are transported to the Tokamak pit, a 30-metre-deep concrete cylinder in the centre of the Tokamak Building.

3

The ��ϲʸ�� Organization is using a number of other warehouse spaces on site to receive, inspect and prepare the largest components for handling in the Assembly Hall. Each ��ϲʸ�� component is absolutely unique—and in many cases has required ten years to design, prototype and manufacture. Every possible precaution is taken in their unloading and transport.

4

Contractors working under the supervision of the ��ϲʸ�� Organization are carrying out the thousands of complex lifting, positioning, joining, and inspection activities of ��ϲʸ�� machine assembly.

These contractors are carrying out the day-to-day work of machine assembly under the oversight of the ��ϲʸ�� Organization:

Tokamak in-cryostat assembly

The CNPE Consortium (China Nuclear Power Engineering; China Nuclear Industry 23 Construction Company Ltd.; Southwestern Institute of Physics; Institute of Plasma Physics, Chinese Academy of Sciences ASIPP; and Framatome) is responsible for tokamak machine assembly (assembly of the cryostat and cryostat thermal shield; magnet feeders; the central solenoid, poloidal field and correction coil magnets; and cooling structures and instrumentation).

Vacuum vessel assembly

The CNPE Consortium is responsible for Sector Module Sub-Assembly, SMSA (assembly of the vacuum vessel sectors with toroidal field coils and vacuum vessel thermal shielding). In partnership with SIMIC S.p.A., the CNPE-Consortium is also executing the contract for Sector Module Assembly in Pit, SMPA (aligning and using intercoil structures to connect the nine sector modules in the pit).

Vacuum vessel & port welding

The ��ϲʸ�� Organization is in the process of finalizing a negotiation with the multinational company Westinghouse for vacuum vessel welding (production phase in the tokamak pit). In the meantime, in order to develop and finalize the correct technologies and processes to be used, a contract covering welding process qualification (engineering and qualification of all processes and new tools required for nine-sector simultaneous welding) was placed with the company in September 2024. The Indian firm Larsen & Toubro has been awarded a contract for port positioning alignment and welding (engineering, qualification and tools and in-pit welding of vacuum vessel ports and bellows).

Gallery

Sector 7: thermal shield in place

2024-11-19

With thermal shield panels already in place around sector #7, workers are installing the lower adapters on the wings of the tool for the pair of toroidal field coils that will be rotated inward towards the sector.

With experience, the process will be faster

2024-11-18

The assembly teams have already benefitted from the assembly, and disassembly, of the vacuum vessel #6 which had to be removed from the tokamak pit for repair. That experience, as well as improvements made in the overhead cranes, the process workflow, and contract management, should result in the acceleration of the sub-assembly process for each sector by a factor of 2.5 or 3.

Two sectors in sub-assembly tooling

2024-11-18

Two giant sectors of the ��ϲʸ�� vacuum vessel are suspended vertically in tooling. One has been fully repaired and is being re-assembled into a "sector module" (with thermal shield panels and two D-shaped superconducting magnets). The other is in the last stage of repair.

Last stage of repair for sector #6

2024-11-12

Sector module #6, which was extracted from the tokamak pit in July 2023, is presently in the last stages of repair, with one side already completed and the other to be finalized in the coming days.

Sector 7 will be the first to re-enter the pit

2024-11-12

Assembly operations on sector module #7 began in September 2024 and should be completed in the first quarter of 2025—a seven-and-a-half month process compared to the 18 months spent on the initial assembly of sector module #6.

Sector 5, unveiled

2024-11-08

The first vacuum vessel sector delivered by Europe, sector 5, arrived two weeks ago. Since then, it has been settled into a space in the former Cryostat Workshop on its transport frame and unpacked.

Automatic welding robot at work on sector 8

2024-10-28

Following close to three months of metal build-up, machining has started on the bevels of vacuum vessel sector #8. Two machining tools, driven by computer numerical control are presently at work. Three others are scheduled to join in the coming weeks.

First the robots, then the hands

2024-10-28

Adapted and equipped for the specific task of metal filling and build-up, the welding robot has now completed its task on one side of vacuum vessel sector #8. The mechanized process, however, represents only 25 percent of the total metal build-up required. For reasons of accessibility and flexibility, the remaining 75 percent must be done manually.

Thermal shield panel: ready for reintegration

2024-09-17

A repaired thermal shield panel is inspected in the former Cryostat Workshop. It will soon join vacuum vessel sector #7 in sub-assembly tooling.

Highly polished

2024-09-17

The original silver coating has been removed and the surface has been polished to mirror-like perfection (less than 80 microns rugosity). Ultra-high polishing ensures a similar performance (low emissivity) as the former silver coating.

Sector #7 is the first to be repaired

2024-09-15

The first-repaired sector of the ��ϲʸ�� vacuum vessel is sector #7 (pictured). The bevel joint region has been brought back to its nominal dimensions and the work to create a sector module (sector + thermal shield panels + toroidal field coils) can proceed.

Vacuum vessel assembly restarts

2024-09-15

Close to two years have passed since vacuum vessel assembly was halted when defects were identified in the ��ϲʸ�� tokamak's vacuum vessel sectors and thermal shield. In September 2024, sector module assembly restarts.

Ready to rotate

2024-09-13

A thermal shield panel (protected in yellow) has been installed on the wings of the assembly tool to be rotated toward sector #7. The sector is now free of the dense scaffolding that had kept it hidden for the better part of the year.

Keeping components clean

2024-09-06

��ϲʸ�� is working with outside provider OHB (Germany) to implement specific cleaning and protective protocols for ��ϲʸ�� components that must be kept free of contamination while construction work is taking place all around. In this picture, textile coverings are being installed on components in the Tokamak pit.

Repairs on sector #8

2024-09-05

In the former Cryostat Workshop, the bevel joint region of vacuum vessel sector #8 (side one) is being repaired while the 440-tonne component is in a horizontal position. It will need to be "flipped" and the sequence of operations repeated on the other side.

Seen from the rafters

2024-07-18

Vacuum vessel sectors #7 and #6 supported in vertical tooling as their joint regions are repaired. Work on sector #7 (left) is expected to be completed in late August.

Metal build-up

2024-07-15

Metal build-up (here on sector #8) is a delicate operation that demands extreme concentration to achieve uniformity, homogeneity and reliability.

Horizontal repair for sector #8

2024-07-15

As both sub-assembly tools in the Assembly Hall are mobilized for the repair of sectors #6 and #7, there is no other option than to repair sector #8 in a horizontal position. Repairs have started on the first side of sector #8 in the former Cryostat Workshop.

Automatic welding on sector #8

2024-07-15

Whereas approximately 24 kgs of metal fill are needed for sectors #7 and #6, the quantity required for sector #8 is significantly higher. As a consequence, with the exception of a few initial passes (pictured here), the process will be automated.

Shaving

2024-07-15

A close-up of one of the milling machines working along the bevel region of sector #7.

Restoring vacuum vessel geometry

2024-07-15

Up to three automatic milling machines can be positioned along a sector's joint (bevel) region to shave off excess material and return the component to nominal. Work on sector #6 (photo) will conclude this autumn.

Hundreds learn more about ��ϲʸ�� machine assembly

2024-05-27

Participants to ��ϲʸ��'s Private Sector Fusion Workshop in late May had the opportunity to visit the Assembly Hall and the Tokamak pit in small groups. A new visitors platform in the Assembly Hall provides for excellent viewing. (Photo Christian Lünig)

Activity on the cryobridge

2024-05-17

In the bridge that connects the cryoplant to the Tokamak Complex, contractors are installing multipurpose cryolines, spool by spool.

Welding two cryoline spools

2024-05-17

The welders' task is difficult, the space constricted, the body contortions sometimes painful but the work gets done, millimetre after millimetre. The cryoline network spans several kilometres.

A challenging operation

2024-05-17

One of the most challenging operations of the whole cryoline installation process: the precise positioning of a 9-tonne spool designed to decouple displacements between the cryobridge and the Tokamak Building in case of a seismic event.

Close-up of feeder joints

2024-04-18

The criticality of the superconducting feeder joints stems from the fact that they can only be truly tested once the machine is up and running. Hence the exceptionnaly demanding qualification programs for the technicians who realize joint assemblies.

Precise work: creating feeder joints

2024-04-18

Twenty-one magnet feeders must be installed at B2 basement level, each one formed from three segments. Here, highly trained workers from the CNPE consortium are finalizing the joints connecting two segments of the feeder that will deliver cryogens and electricity to the lowest central solenoid module.

Peeking in on Tokamak assembly

2024-04-13

During a public event on 13 April, groups were taken into one of two port cells leading to the Tokamak pit, where guides explained what has already been installed and what we are expecting next.

Lifting central solenoid module #3

2024-04-11

The specialized lifting tool, in yellow, exerts radial pressure to "grasp" the cylindrical module. Redundent lifting slings and support blocks are installed ensure to ensure operation security.

Almost there

2024-04-11

Module 3 will be positioned on the two-module stack with a slight radial offset to provide room for equipment and connection work.

Heading to the stack

2024-04-11

The third independent superconducting magnet for the ��ϲʸ�� central solenoid has been lifted off its temporary platform and is heading toward the stack.

Work ahead

2024-04-11

One of the main tasks ahead is the completion of superconducting electrical connections. This will involve welding, ultrasonic weld inspection, helium leak testing, electrical installation and high voltage testing.

Precision

2024-03-22

With a precision of 0.05 millimetres, laser metrology has mapped the geometry of every section of the bevel affected by dimensional non-conformities. For each section the data obtained is made available to the welder, both as a printed document and as markings embossed on the component itself.

Up close with welders

2024-03-22

A team of four welders has started on the dimensional repairs of vacuum vessel sector #7. Here, a welder checks the temperature of the weld pass he has just completed. It must fall to 116 °C before he can start another pass.

Welders, seen from above

2024-03-22

Operating from protruding platforms located at different levels of the scaffolding, four welders have started the long and patient task of metal build-up on the regions of the sector 7 bevel affected by dimensional non-conformities.

Specialized tools

2024-03-22

Machining tools are programmed to follow a precise trajectory along the bevel area. Here, specialists from Metalock Engineering UK, contractor to the SIMANN consortium (SIMIC/Ansaldo Nucleare), are fine-tuning the initial positioning of the tools prior to actual machining.

Central solenoid stacking: update

2024-02-29

Two central solenoid modules are already installed on the bespoke assembly platform in the ��ϲʸ�� Assembly Hall. Bottom left, is a multi-purpose work platform used for work on top of the stack. To the right, are helium-cooled busbar lead extensions that feed 40 kA electric current to the magnets. A third module (in pink) will be installed in the coming weeks.

Current carriers

2024-02-29

Experts from the ��ϲʸ�� Magnet Project are carrying out the electrical site acceptance test of central solenoid busbar lead extensions prior to preparing them for installation in the central solenoid stack.

Disassembled, for now

2024-02-21

Once repaired, and in a few cases re-manufactured, vacuum vessel thermal shield panels will be reassembled on site with vacuum vessel sectors and toroidal field coils to form the modules that, once joined, constitute the doughnut-shaped plasma chamber.

Thermal shield repair

2024-02-21

Vacuum vessel thermal shield sets are being inspected on site (here, using endoscopy techniques) and tested for corrosion cracking. Only the panels with superficial defects are being shipped to India for repair by INOX-CVA. So far, that's five of nine sets.

"Equivalent power and much bigger torque"

2024-02-16

Identical in aspect and dimension to the diesel version, the electric power pack unit developed by Mammoet for ��ϲʸ�� can sustain two days of standard operation on site before requiring a charge.

Component transfer goes electric

2024-02-16

In February, a toroidal field coil (330 tonnes) was moved for the first time from the Assembly Hall by a modular trailer (SPMT) equipped with an electric power pack. Designed by Dutch specialist Mammoet for ��ϲʸ��, it reduces the noise and eliminates the pollution of diesel-type trailers.

Component repair

2024-02-08

Vacuum vessel bevel repair will be carried out at the ��ϲʸ�� site by a consortium called SIMANN comprising the Italian firms SIMIC S.p.A. and Ansaldo Nucleare. Operations on sectors #6 and #7 (pictured) will be performed in parallel.

First repaired elements leave Indian factory

2024-02-03

On the basis of a repair contract concluded with the ��ϲʸ�� Organization in 2023 (/newsline/-/3914), INOX-CVA India began on the repair of two vacuum vessel thermal shield sets. The first repaired elements left the factory in Vadodara this week for shipment to ��ϲʸ��.

Bevel repair

2024-02-02

Sector #7, seen from below. The bevel region of a vacuum vessel sector describes the joint region on either side that must be welded to the next sector.

Repairing the sectors

2024-01-23

Vacuum vessel sectors #6 and #7 are positioned in the Assembly Hall tooling for repair and early activities are underway. A third sector (#8) was moved from the Assembly Hall to the now-vacated Cryostat Workshop for repair in a horizontal position. Tooling will have to be adapted.

Qualifying procedures

2024-01-23

The vacuum vessel sectors have been stripped of thermal shielding and toroidal field magnets as preparation for repair. Repair operations will begin in parallel by the end of February/beginning of March when all tests and qualification procedures are complete.

The stack

2024-01-18

The second central solenoid module is now fully installed on the first and the team is preparing for the placement of the next module.

Finding infinitesimal needles in a haystack

2024-01-16

This photo, from summer 2022, shows how sections of thermal shield cooling pipe showing corrosion were removed and sent to CERN to be sliced, polished, and X-ray tomographed in a unique campaign to discover the extent of cracking. There will be an update on repair works soon in the ��ϲʸ�� Newsline.

Deliveries continue

2023-12-22

This 110-tonne central solenoid module is the fourth (of seven) to be delivered to ��ϲʸ�� by the US Domestic Agency.

Very last toroidal field coil

2023-12-15

The team celebrates as the delivery of toroidal field coil #18 from Europe marks the very end of the toroidal field procurement program. Nineteen magnets in all—each weighing approximately 330 tonnes (the weight of a large jetliner)—have been delivered to the ��ϲʸ�� site.

Holiday panettone

2023-11-28

Vacuum vessel sector #8 has been wrapped in three layers of plastic protection for storage. The shiny top layer, and the form of the component in its horizontal orientation, make it resemble a panettone, that Italian sweet bread hat is enjoyed throughout southern Europe at Christmas and New Year.

Disassembling sector module #6

2023-11-01

To prepare vacuum vessel sector #6 (foreground) for repair, teams are removing the two toroidal field coils and the thermal shield panels that created sector module #6. One coils has been removed so far.

Elements of the thermal shield

2023-10-06

Contractors are cleaning a silver-coated element of the vacuum vessel thermal shield. Under the terms of repair contracts signed this year the thermal shield panels will either be repaired or replaced. Photo: ��ϲʸ�� Organization/EJF Riche

Coils in storage

2023-09-29

In this image, we see two poloidal field coils in storage on the ��ϲʸ�� site: PF4 (foreground, ø24 metres) and PF6 (ø9 metres). Photo: ��ϲʸ�� Organization/EJF Riche

A busy hall

2023-09-27

Looking across the Assembly Hall toward the wall that hides the Tokamak pit. The central solenoid stacking area is visible at right (round yellow tool). Photo: ��ϲʸ�� Organization/EJF Riche

Waiting its turn

2023-09-27

After dimensional non-conformities were found in the bevel (field joint) region of the three vacuum vessel sectors that have been delivered to ��ϲʸ�� (#6, #7 and #8), sector #8 was removed from assembly tooling. It will be the last of the three to be repaired. Photo: ��ϲʸ�� Organization/EJF Riche

Stacking area

2023-09-27

In this clearly delimited area, the central solenoid stack is rising. Two magnet modules are in place; four others will join them. Photo: ��ϲʸ�� Organization/EJF Riche

The pit

2023-09-26

Looking straight down into the 30-metre-deep Tokamak pit, which will house the world's largest tokamak. Photo: ��ϲʸ�� Organization/EJF Riche

Workhorses

2023-09-26

The workhorses of the machine are the overhead cranes, capable of working together to respectively lift 100 tonnes (the set in the foreground) and 1,500 tonnes (the set in the background). Photo: ��ϲʸ�� Organization/EJF Riche

Sector #8 on the move

2023-09-15

After spending just about one year in vertical tooling, vacuum vessel sector #8 has been returned to a horizontal orientation for removal from the Assembly Hall and repair.

Window on the (��ϲʸ��) world

2023-09-13

This new viewpoint into the Tokamak pit is proving popular with visitors.

Protected in pink

2023-09-07

Eighteen supports for the toroidal field magnets are protected in pink plastic. Just inside the circle formed by the supports is poloidal field magnet #5.

Pin-point precision

2023-09-05

It takes a whole range of tools to position the 110-tonne component with the required precision: once cranes and ''synch hoists'' have done the heavy job, a complex system of subtle adjustment devices allows micrometric movements in pitch, roll and spin.

Small adjustments

2023-09-05

Stacking cylindrical devices and connecting their fragile electrical and cryogenics leads demands a particular attention to concentricity and straightness.

Central solenoid: now a two-module stack

2023-09-05

Lifted by a bespoke tool exercising pressure through radial compression, a second 110-tonne central solenoid module is positioned on the assembly platform above the first. (A third waits its turn on the left.)

Thermal shield repair/replacement contracts signed

2023-08-30

For vacuum vessel thermal shield sectors showing no sign of stress corrosion cracking, the panels can be repaired. The initial scope of the repair contract is for two sector sets to be disassembled at ��ϲʸ��, repaired at the contractor's premises, and returned. For thermal shield sectors already compromised by damage, complete re-fabrication is necessary.

Thermal shield: metrology underway

2023-08-30

Metrology is underway on outboard segments of thermal shield at one end of the Poloidal Field Coils Winding Facility on site.

Disassembly works

2023-08-29

Disassembly of sector module #7 is well advanced; thermal shield panels have been removed and toroidal field coils have been dissociated. In this striking view taken from under the tool, the sector's "underbelly" is clearly visible, as are the toroidal field coils on either side in the tool "wings."

Next cylindrical magnet in line

2023-08-29

This cylindrical, 110-tonne central solenoid magnet, delivered by the United States Domestic Agency, has been unwrapped to prepare for its installation on the dedicated assembly platform in the right corner of the photo.

Sector module #8

2023-08-29

Vacuum vessel sector #8, seen here in a horizontal position on the upending tool, was removed from vertical tooling when it became evident that sector #6 (already in the pit) would need to be removed and repaired alongside sector #7. Sector #8 will be repaired horizontally in the former Cryostat Workshop.

Thermal shield panels

2023-07-21

These are some of the 27 vacuum vessel thermal shield panels that must be repaired or replaced to correct stress corrosion cracking in the cooling pipes. In September, the ��ϲʸ�� Newsline will have a full report on repair strategies and contracts.

Back towards the Assembly Hall

2023-07-05

Sector module #6 follows the same path out of the assembly pit as it did 15 months ago on its way in.

Sector module #6 removed

2023-07-05

Sector module #6 (1,350 tonnes) is removed from the Tokamak pit on 5 July 2023.

Rotating

2023-07-05

The load has now passed the wall and will be rotated 90 degrees to face the sector sub-assembly tool closest to the wall.

A few centimetres

2023-07-05

At its narrowest, the clearance between the module and the central column does not exceed a few centimetres. The lift is paused at regular intervals to slow the swinging effect.

Watching the weight

2023-07-05

The load supported by each of the four crane hooks is displayed in real time on small screens, so the math is easily done: the module weighs slightly in excess of 1,350 tonnes.

Carefully now

2023-07-05

One of the most delicate passages: the toroidal field coil termination boxes (wrapped in protective pink plastic) are the most sensitive and delicate parts of the assembly. When passing the wall that separates the assembly pit from the Assembly Hall, the vertical clearance is less than 20 centimetres.

Eagle eyes

2023-07-05

Although the lift operation relied heavily on sensors and strategically positioned cameras, "spotters" played a crucial role in overall safety and precision.

Reverse operation

2023-07-05

Lessons learned during the May 2022 installation of the sector module were essential to the reverse operation. So too was the fact that the same team was on deck... (Photo Kenichi Ueno, ��ϲʸ��)

Step by step

2023-07-05

From detaching the module from its moorings in the assembly pit to lifting and transporting it to the sub-assembly tool, more than one hundred different steps had to be defined, validated and integrated into the lift procedure.

Final instrument checks

2023-07-04

"A lift-off is not exactly the reverse of a landing," says Daniel Coelho, the ��ϲʸ�� assembly engineer who will coordinate the lift operation. Procedures have had to be adapted and additional guiding systems have had to be manufactured and installed.

Planning removal

2023-07-03

The paperwork is done. Every tool and system has been checked. A "functional briefing" has reminded everyone involved of how the operation will proceed and clarified the chain of command. This week, the delicate and complex "extraction" of vacuum vessel sector module #6 from the assembly pit (in the background) will take place.

June 2023

2023-06-28

The ��ϲʸ�� machine assembly pit, in late June 2023. (At the base of the column, a worker with a blue hard hat provides a sense of scale.)

A window into the Tokamak pit

2023-06-24

On Saturday 24 June, Open Doors Day groups are taken through a port cell to the edge of the Tokamak pit. They are among the last people to see sector module #6 in place in the pit, since it is scheduled for removal (within days) for repair.

Sector tools

2023-06-24

In the background, vacuum vessel sector #7 is suspended in tooling, and its two D-shaped toroidal field coils have been removed to the wings. The second tool, further to the back of the Hall, awaits sector module #6 from the machine pit.

Extra support from below

2023-06-01

A temporary propping system is in place to support the central column tool (in the centre of the Tokamak pit) during machine assembly. These propping elements have been installed under the concrete slab of the Tokamak Complex, directly under the machine.

Preparing for repair work

2023-05-11

The same tools that were used for assembling the vacuum vessel sector modules from 1 sector, 2 toroidal field coils and thermal shield panels, is now being used for disassembly. In this photo, two toroidal field coils are temporarily held after disassembly on the wings of vertical tool SSAT-2.

Musical chairs

2023-05-08

The view inside the Assembly Hall now gives a clear indication of what will happen soon: to the left sector #7 stands in the tall assembly tool SSAT-1, ready for repairs once the outboard thermal shield panel is removed. To the right, sector #8 is solidly attached to the upending tool, waiting to be moved from vertical to horizontal and transported to another building.

An exciting stop

2023-04-01

Welcome to the Assembly Hall, where major ��ϲʸ�� components are unwrapped and prepared for installation in the machine pit.

Look up!

2023-04-01

There is lots to see in the ��ϲʸ�� Assembly Hall, including overhead! These young visitors are taking part in the ��ϲʸ�� Open Doors Day that was organized on 1 April.

2023-04-01

Fifty people climb aboard every site tour bus, but once in the Assembly Hall they are broken into four smaller groups so that everyone can hear the guide.

Wow!

2023-04-01

Push aside the plastic curtain at the end of a long corridor and .... wow! The size of the future ��ϲʸ�� machine is suddenly apparent to all the senses.

5 other modules to come

2023-01-26

At the end of the module stacking process, the central solenoid tower will be 18 metres tall. Five other modules like the one in this photo will be added one after the other.

Inside the cylinder

2023-01-26

The first of six cylindrical superconducting magnets for the central solenoid is positioned on a dedicated assembly platform at ��ϲʸ��. This picture was taken inside the cylinder, among the helium input pipes and electrical connections.

Up and up

2023-01-26

In one corner of the ��ϲʸ�� Assembly Hall, work has started on the central solenoid magnet tower. The first module now sits atop nine lower key blocks on a dedicated assembly platform. Five more modules will bring the tower to well over 20 metres (platform included), rivalling the height of a seven-storey residential building.

Oversight

2023-01-26

American Carl Cormany from ��ϲʸ��'s Magnet Section works closely with the contractor team as it carries out the many assembly steps required on module one.

Next in line

2023-01-26

Module 2 is protected under a pink covering in the central solenoid zone.

Squeezing through

2023-01-25

The coil now enters the narrow space between SSAT-1 and SSAT-2. Limited clearance was the main challenge of the operation.

Activity in the Assembly Hall

2023-01-25

There is activity in and around the double sector sub-assembly tools (SSATs) in the Assembly Hall, as component transfers are planned in relation to upcoming repair work.

Moving a huge component

2023-01-25

Halfway between the two sub-assembly tools, toroidal field coil TF8 is being readied for a 90-degree pivot. Operators standing next to the component give a sense of scale...

Pull!

2023-01-25

As the crane hook slowly rotates to align the component, operators use a pair of "Tirfor" devices with a relatively low but sufficient pulling capacity (800 kilograms). Precise positioning is achieved by working the two "Tirfor" units one against the other.

Pushing and pulling

2023-01-25

Measuring between 6 and 9 metres in length and weighing between 2.2 and 9 tonnes, the cryoline spools need to be perfectly aligned before welding operations can begin. Sometimes, a bit of pushing and pulling is necessary...

Close up

2023-01-25

Hanging a few centimetres above the floor, the connexion box (wrapped in pink plastic) is the most fragile part of a toroidal field coil. Note the precision of the steel machining on the larger coil case.

Tool back in action soon

2023-01-16

This specialized sector lift tool will be back in action this year as vacuum vessel sector #6 is removed from the Tokamak pit for repair. It interfaces with the radial beam that supports the D-shaped sector.

Important arrival

2023-01-13

Another toroidal field coil has arrived at ��ϲʸ��—this one from ��ϲʸ�� Japan. Only four more of these D-shaped coils are expected (out of 19).

Investigation and analysis

2023-01-09

Following months of discussion, tests and analysis, a clear picture of the repairs to be executed on the thermal shield is now emerging. The decision has been taken to remove and replace all cooling pipes (23 kilometres in total).

Questions to answer

2023-01-09

How does the removal of cooling pipes from a thermal shield panel impact the component's dimensions, rigidity and capacity to accommodate a new set of piping? This is what experts have been busy evaluating.

Pipe removal trials

2023-01-09

Under a tent in the Cryostat Workshop, contractors are stripping piping from a panel of thermal shielding as part of strategy trials. (In the photo, you see some of the pipes that have been removed.) In total, 23 kilometres of piping snake along the surface of the 27 vacuum vessel thermal shield segments and will be removed and replaced.

Deviations on the outer shell

2023-01-08

During the formation of the D-shaped sector in factory, welding deformations created deviations from nominal on the outer shell of the sectors. Schematically (very schematically...), valleys must be filled and hills must be shaved in order to restore the geometry to nominal.

Repair of the sectors

2023-01-08

The logistics are already planned for the repair of dimensional non-conformities on the three vacuum vessel sectors: sector #1(7) will stay where it is in the SSAT-1 vertical tool; sector #8 (currently in SSAT-2) will be removed and placed horizontally on a repair platform; sector #6 will be removed from the pit and installed in the SSAT-2 vertical tool.

To be removed

2023-01-08

In late May/early June, one of the twin sub-assembly tools will be ready to accommodate vacuum vessel module #6. The component will be lifted out of the Tokamak pit and placed in tooling to be stripped of its thermal shield panels and toroidal field coils in order to be ready for repair in late 2023.

This sector will remain in tooling

2023-01-06

Sector#1(7) remains in vertical tooling, where it is being disassembled in order to prepare for repairs on both the thermal shield segments and the geometry of vacuum vessel field joints. Notice the D-shaped coils that are now back on the tool wings.

From above

2022-12-06

From the rafters, with a view all the way through to the Tokamak Pit at the far end. Machine components visible in this photo include an element of the vacuum vessel thermal shield (bottom left), a D-shaped toroidal field coil (lying horizontally); the start of the central solenoid stack (middle right), and a sector of the vacuum vessel (mainly hidden in vertical tooling, middle left).

Couldn't be closer

2022-11-26

A port cell has been specially prepared to receive visitors on Saturday 26 November during ��ϲʸ��'s latest Open Doors Day. Impossible for a visitor to get any closer to the machine assembly pit.

Root cause

2022-11-21

A total of approximately 23 kilometres of piping are welded to the surface of the thermal shield panels. In three instances, stress caused by the bending and welding of the cooling fluid pipes to the thermal shield panels, compounded by a slow chemical reaction due to the presence of chlorine residues, caused "stress corrosion cracking" near the pipe welds.

Sector non-conformities

2022-11-21

Deviations during the welding process of the vacuum vessel sectors led to dimensional ''non-conformities'' on the outer shells of the three sectors that have been delivered to ��ϲʸ��, affecting the geometry of the field joints where the sectors are to be welded together. Repairs will have to be carried out.

Defects identified

2022-11-21

In November 2022, the ��ϲʸ�� Organization announces that it had identified issues in key tokamak components, the thermal shield (stress corrosion cracks in cooling pipes) and three vacuum vessel sectors (dimensional non-conformities). These defect are repairable; repair strategies are under investigation now. (In this picture, the thermal shield and its snaking cooling pipes are visible sandwiched between the magnet and the sector.)

Bottom-up assembly

2022-10-17

In the heart of the Tokamak Building, this 30-metre-deep pit is the stage for ��ϲʸ�� machine assembly. Assembly is progressing bottom to top. October 2022

Sector module: in work

2022-10-06

Vacuum vessel sector #8 is suspended in the centre of the sub-assembly tool, as thermal shield panels (protected in pink wrap) wait on the wings to be rotated and attached. Note the pillar at bottom left that supports the 440-tonne sector under its lower port stub extension.

Down under

2022-09-21

There is a whole world at the bottom of the Tokamak pit—one which we rarely enter. In this image, we can distinguish the bottommost poloidal field coil (PF6, left, with white coverings to protect openings from dust) and one kidney-shaped bottom correction coil (wrapped in pink, overhead).

"Really impressive"

2022-09-17

On 17 September, staff and contractors were able to bring their families on site and share their work environment. One of the most impressive sights of the visit: a 440-tonne vacuum vessel sector suspended in tooling.

Sector #8: Moved into tooling

2022-09-12

On 12 September, vacuum vessel sector #8, from Korea, is transferred from the upending tool (left) to the available sector sub-assembly tool on the other side of the Assembly Hall. The twin assembly tools are now both occupied, one with sector #1(7) and one with sector #8.

Out of one tool, into another

2022-09-12

The 440-tonne sector is lifted out of the upending cradle and rotated before insertion into the V-shaped opening of the SSAT tool (sector sub-assembly tool).

Coil alignment achieved

2022-09-09

The toroidal field coils that are part of the first vacuum vessel sector module have been aligned to their final position in the pit and are ready to be bolted to the toroidal field coil gravity supports.

Shining performance

2022-09-09

The shinier a thermal shield's silver coating, the better its thermal radiation performance. Here, the right-hand outboard segment for vacuum vessel sector #8 is hand polished before being moved into position on the vacuum vessel sub-assembly tool.

Early September in the Assembly Hall

2022-09-08

The long view of the ��ϲʸ�� Assembly Hall, with component pre-assembly in the foreground and the machine well in the background. On the right, vacuum vessel sector #8 from Korea is in the upending tool, ready for transfer across the hall to tooling.

Central solenoid assembly begins

2022-09-07

Six independent modules make up the 1,000-tonne, 18-metre-tall central solenoid. This summer, the first module was positioned with millimetric precision on the bespoke assembly platform (centre) in the Hall in order to assemble the extensions that will later connect to the magnet feeders. (Positioning accuracy is +/-1mm in plane.) A second module is covered in pink, at right.

Third sector to be moved

2022-09-06

For the first time in its existence, vacuum vessel sector #8 is in a vertical position. (At the factory, during D-shape assembly, and during transport, the ��ϲʸ�� vacuum vessel sectors are always horizontal.) Sector #8 is the third section of the vacuum vessel to be delivered. Six more sectors are expected, one from Korea and five from Europe. This image also features, in the background, the second central solenoid module (wrapped in pink plastic) being lifted to its assembly zone at the far end of the Assembly Hall.

Module moves

2022-07-20

A specially designed tool is used to move the first 110-tonne module to the central solenoid assembly platform in July.

Seeing with their own eyes

2022-07-06

During a management walkthrough on 6 July, magnet expert Min Liao (left) and the head of the Machine Construction Department Xavier Bravo (right) brief ��ϲʸ�� Director-General (interim) Eisuke Tada (centre) on the latest progress in the assembly of the second vacuum vessel module.

The ��ϲʸ�� assembly pit

2022-06-14

Machine assembly, June 2022.

Home at last

2022-05-13

The sector module has now been lowered to its supports, arriving "home" after a long and complex journey.

2022-05-13

Although only one-ninth of the Tokamak's torus-shaped vacuum vessel, the sector module dwarfs everything around it. Eight other similar operations, plus welding, will be necessary to close the torus.

Particularly complex rigging

2022-05-13

The complex rigging required for the lifting of the sector module is clearly visible is this view from high above: the yellow structure is the Dual Crane Heavy Lifting Beam (DCHLB) that synchronizes the four hooks of the cranes into a single lift point, enabling the rotation of the load. The grey device below is the Sector Lifting Tool. Connected to both the DCHLB and the radial beam, this tool can precisely align the load with the cranes.

The first of nine similar "sub-assemblies"

2022-05-11

The "piece" of the ��ϲʸ�� machine installed today is a modular assembly, formed from one 40° vacuum vessel sector fitted with silver-coated thermal shields, and two D-shaped vertical superconducting electromagnets called toroidal field coils. Eight other similar assemblies will form the complete chamber and surrounding toroidal field coil superstructure.

��ϲʸ�� achieves major lift

2022-05-11

On 11 May 2022, the ��ϲʸ�� Organization team achieves a major assembly milestone: lifting the first sub-section of the ��ϲʸ�� plasma chamber out of tooling and lowering it into the machine well.

Over the wall, with only 20 cm to spare

2022-05-11

The massive component—representing one-ninth of the ��ϲʸ�� plasma chamber—was extracted from its assembly tool, rotated, transferred over the bioshield wall (with only 20 cm to spare), and lowered into the Tokamak pit.

Most complex lift to date

2022-05-11

The 1,380-tonne assembly (component plus rigging) is six storeys high and weighs the equivalent of four fully loaded Boeing 747s. The lift operation achieved today was the most complex of ��ϲʸ�� machine assembly to date.

Eyes everywhere

2022-05-11

As the sector module is slowly lifted from the sub-assembly tool, an operator closely monitors the feedback from three of the seven video cameras positioned at strategic locations inside the tool.

Months of practice and preparation

2022-05-11

From one of the "command centres," looking through a port cell window out into the Tokamak pit, where the first section of the ��ϲʸ�� plasma chamber is slowly descending toward waiting supports. The DYNAMIC consortium (Ansaldo Nucleare; Endel Engie; Orys Group ORTEC; SIMIC; Ansaldo Energia; and Leading Metal Mechanic Solutions SL) is ��ϲʸ��'s TAC2 assembly contractor (for Tokamak Assembly Contractor 2), in charge of sector sub-assembly, and assembly of the main vessel and ports including welding.

Right in the axis

2022-05-11

Extracted from the sub-assembly tool, the component has rotated 90 degrees and is now heading towards the wall separating the Assembly Hall from the Tokamak pit.

Coordination

2022-05-11

The perfect coordination of a 50-person team belonging to half a dozen different companies and organizations was key to the operation's success. Lift coordinator for this operation is Daniel Coelho, ��ϲʸ�� assembly engineer.

A very slow lift-off

2022-05-11

As one of a dozen "spotters" communicates by walkie-talkie with the operators in charge of the lift, the 1,380-tonne sector module commences its journey to the assembly pit.

Seven centimetres of clearance

2022-05-11

During the descent to its mooring position, at the bottom of the Tokamak assembly pit, the distance between the vertical section of the D-shaped component and the central column never exceeded 7 centimetres.

Pre-lift: a success

2022-05-05

The pre-lift operation on Thursday 5 May was a partial rehearsal for the big lift to come, testing the tools, sequences, and coordination. For the ��ϲʸ�� Organization and DYNAMIC teams that participated, it was a success.

There they are

2022-05-05

On 5 May, in a pre-lift test, the sector module is lifted 50 centimetres above its supports. This small distance is visible below the rectangular structure illuminated by the green pointer's beam at the centre of the image.

Only 50 cm, but ...

2022-05-05

Lifting the 1,380-tonne load (module + rigging) a mere 50 centimetres required the participation of dozens of specialists from the ��ϲʸ�� Organization and the DYNAMIC SNC consortium (in charge of the TAC2 machine assembly contract covering the main vessel and ports, sector sub-assembly with toroidal field coils and vacuum vessel thermal shielding, and welding.

Wow

2022-05-05

Each of the bridge crane's four hooks can be seen to support loads of approximately 345 tonnes (two totals are visible in this image). The total weight of the sector module plus its rigging apparatus is in the range of 1,380 tonnes—the equivalent of four fully loaded Boeing 747s.

Watching the instruments

2022-05-05

Although it represented only a fraction of what the actual operation will require, the "pre-lifting" of the sector assembly on Thursday 5 May permitted the thorough testing of every instrument that will be involved in the major move to come.

Magnet storage on site

2022-05-03

Two toroidal field coils rest on their sides in storage. They will be called back into the Assembly Hall when repair is completed on the vacuum vessel sectors and thermal shield. Photo: ��ϲʸ�� Organization/EJF Riche

The golden hour

2022-05-02

Evening is upon us and the teams working to prepare sector module #6 for transfer have turned on some extra lighting ...

A second sub-assembly underway

2022-04-29

Toroidal field coil #9 (TF9) from Europe has been mounted on one of the standing tools. Through the rotary motion of the wing, the coil will be brought toward the vacuum vessel sector at the centre and attached.

Sector assembly line

2022-04-25

Thermal shield panels have been pivoted to the vacuum vessel sector in the foreground and attached. A toroidal field coil from Europe is already held vertically in tooling, ready to be transferred across and installed on one of the tool's wings.

Bustling

2022-04-25

The busy ��ϲʸ�� Assembly Hall. Only 97 metres long and 60 metres wide ... and a lot of pre-assembly activities to house.

A, B then C

2022-04-25

The purpose-built central solenoid module lift tool (bottom left) is ready to exert a radial force on the first 110-tonne magnet module (top left) in order to lift it to the central solenoid assembly platform (top right). This operation is planned before the end of April 2022.

Toroidal field coil #9 goes vertical

2022-04-25

In the ��ϲʸ�� Assembly Hall, the overhead bridge cranes are used to raise a 330-tonne toroidal field coil, tightly lashed inside the upending frame, to vertical. The coil will be moved across the Hall to join vacuum vessel sector #1(7).

"The beam" is in place

2022-04-25

A new scaffolding element called "the beam" has been installed above the Tokamak pit (to the right). This 28-metre-long structure will allow for the installation of the cable trays and ventilation ducts.

At the centre of it all

2022-04-22

Two workers stand in the central Tokamak pit, a 30-metre-tall x 30-metre-wide space where the assembly of the ��ϲʸ�� machine is proceeding from bottom up.

All it takes

2022-04-08

A vacuum vessel sector, two toroidal field coils, thermal shield segments... that's all it takes to assemble a 1,250-tonne "sector module." In the Assembly Hall, barely visible in the background, sector module #6 is ready to be installed in the Tokamak pit; in the foreground, sector module #1(7) has entered the pre-assembly process.

Central solenoid "corner"

2022-04-08

Delivered in September 2021, the first of the six modules required for the central solenoid magnet sits between the lifting fixture (holding an orange mockup) and the assembly platform (grey). The six modules will be stacked one atop the other in order to form the 18-metre tall, 1,000-tonne magnet.

Sector #8 uncovered

2022-04-08

Sector #8, recently delivered by the Korean Domestic Agency, has been removed from its transport housing and placed on temporary supports.

Third time around

2022-04-07

Like sectors #6 and #1(7), this vacuum vessel sector (#8) will be first be inspected, then equipped with fasteners, instrumentation and diagnostics before moving on to a vertical position in sub-assembly tooling. With repetition, these operations are carried out with ever more efficiency.

Before the double doors open

2022-04-01

Before the double doors into the Assembly Hall open to admit vacuum vessel sector #8, from Korea, the transport container is cleaned with high-power washers.

Start of shift

2022-04-01

It is a bit after 1:00 p.m. in the vast ��ϲʸ�� Cleaning Facility and second-shift workers from the CNPE consortium are assembled for their daily briefing. As they stand to attention, a foreman in a green helmet, bullhorn in hand, communicates the objectives of the day, describes the co-activity they will encounter, and emphasizes the importance of strictly observing safety rules. The CNPE consortium is one of two ��ϲʸ�� machine assembly contractors.

Sector #8 enters the stage

2022-04-01

Vacuum vessel sector #8, recently arrived from Korea, is the third sector to enter the ��ϲʸ�� assembly buildings (pictured: the Cleaning Facility). The project is expecting six more sectors (one from Korea and five from Europe).

Taking care of scaffolding

2022-03-15

A dedicated team on site takes care of the assembly and disassembly of all scaffolding. For scaffolding operations in the Tokamak pit, such as this assembly around the central column of the in-pit column tool, a carbon-free kit is necessary. The team now has almost 100 tonnes of carbon-free material on hand after developing and procuring it especially for ��ϲʸ��'s needs.

Scaffolding: always changing

2022-03-15

Scaffolding. Imagine you have a massive Lego kit with 1,600 different types of references and you need to build hundreds of one-of-a-kind structures while facing challenging deadlines ...

Demand for scaffolding is increasing

2022-03-15

As construction and assembly accelerate at ��ϲʸ��, the demand for scaffolding is increasing. There are currently about 800 scaffolds in use on the site and every month there are more than 300 new scaffolding jobs that need to be done, without considering the modification and dismantling tasks.

Central column

2022-03-15

Inside of the Tokamak pit, where the central column tool is ready to receive the first 1,200-tonne section of the vacuum vessel. The beam connected to the top of the section will brace between the central column and the surrounding wall.

Custom designed for the SSAT1 tool

2022-03-15

This scaffolding was specifically designed to give contractors access to all parts of the sector sub-assembly tool SSAT1 in the Assembly Hall. The ��ϲʸ�� construction team works with Construction Management-as-Agent contractor MOMENTUM and scaffolding contractor Entrepose Echafaudages to design and build these specialized projects.

"The beam"

2022-03-15

This 28-metre-long scaffolding structure known as ''the beam'' will be installed above the Tokamak pit to allow for the completion of cable trays and ventilation ducts.

300 specialized joints

2022-03-01

Approximately 300 superconducting feeder joints need to be created as part of assembling the magnet feeders on site at ��ϲʸ��. These highly critical joints require special qualification and training to carry out.

In one corner of the Assembly Hall

2022-02-28

This is the first ��ϲʸ�� central solenoid module to enter the assembly process. As the yellow lifting tools and devices are progressively removed from the module on the left, the platform to the right is being equipped for the first assembly steps.

Another bottom coil

2022-02-15

A small superconducting magnet, a bottom correction coil, is inserted into the space at the bottom of the Tokamak pit between ring coil PF6 (hidden under staging at left) and PF5 (right).

Careful preparation

2022-02-10

The team spent more than one hour preparing the load for the lift. It was essential to avoid any contact between the rigging and the electrical connections on the central solenoid module.

Travelling

2022-02-10

Once six modules are stacked and assembled, the ��ϲʸ�� central solenoid will be placed at the very centre of the Tokamak pit where the central column (a temporary assembly tool) presently stands.

Tasks in the Assembly Hall

2022-02-10

The two main machine assembly contractors (CNPE and DYNAMIC) have learned to share tooling and common services in an efficient manner as they execute work packages under the oversight of ��ϲʸ�� Organization and MOMENTUM (Construction Management-as-Agent) teams.

A simple table

2022-02-10

Equipment and tests will be performed on this simple ''table'' before the module is moved over to the assembly platform, visible on the right side of the image.

Sector alley

2022-02-10

Against the backdrop of vacuum vessel sector assembly, CNPE* consortium members are preparing to move a 100-tonne central solenoid module. (China Nuclear Power Engineering = China Nuclear Industry 23 Construction Company Ltd.; Southwestern Institute of Physics; Institute of Plasma Physics, Chinese Academy of Sciences ASIPP; and Framatome).

First central solenoid module aloft

2022-02-10

A 110-tonne central solenoid module is moved to the far end of the Assembly Hall for tests on its instrumentation, sensors and superconducting joints.

Powerful ducts

2022-02-10

Against the backdrop of the travelling module are ducts belonging to the Assembly Hall's powerful HVAC system. The Assembly Building will be operated as a clean space for the duration of machine assembly.

Careful adjustment

2022-02-10

The workers in the cherry picker will adjust strap lengths, millimetre by millimetre, so that the 110-tonne central solenoid module will be perfectly balanced and the lift perfectly vertical.

Calling down

2022-02-03

Work is underway on the second vacuum vessel sub-assembly, with technicians at every level.

Working on a 2nd sub-assembly

2022-01-19

The teams are working on the second vacuum vessel sub-assembly. In this tool we see sector #1(which will be placed next to sector #6 in the pit in position 7) and an outboard thermal shield panel on the left. The thermal shield will be rotated toward the vacuum vessel sector and attached in place.

Pieces all aligned

2022-01-17

Like Erector set or Meccano parts, components and tools for ��ϲʸ�� machine assembly cover the floor of the vast hall that serves as an antechamber to the Tokamak pit.

2 sectors of 9

2022-01-03

One sub-assembly is ready (far end), another is in the early stages. A third vacuum vessel sector sub-assembly will be built around Korean sector #8, which will leave Hyundai Heavy Industries later this month. Nine sectors in all will form the ��ϲʸ�� machine torus (4 from Korea and 5 from Europe).

Second sector assembly underway

2022-01-03

A second 440-tonne vacuum vessel sector, #1(7), is positioned vertically in the tooling for sub-assembly with other major components (a pair of vertical coils and thermal shield panels). Far to the right, the first completed sub-assembly (around sector #6) waits for transfer this month into the Tokamak pit.

Assembly row

2021-12-21

TWO vacuum vessels sectors are docked in Assembly Hall tooling. One has completed the pre-assembly sequence (far end); the other is at the start. Two identical sub-assembly tools were planned to keep this critical stage of machine assembly moving.

Pit is ready

2021-12-20

The 30-metre-deep Tokamak pit is ready to receive its first 40-degree vacuum vessel section. As the sections begin to fill up the space the hollow central column, equipped with ladders and access ports, will be used to reach different levels of the emerging torus.

Transfer day

2021-12-20

On 20 December 2021, the second vacuum vessel sector to arrive from Korea (called #1(7)) is lifted out of the upending tool and into the standing assembly tooling.

Second sector docked

2021-12-20

Sector #1(7) has been docked in the sub-assembly tool SSAT1. Work begins now to pair the sector with approximately 880 tonnes of additional components (two magnet coils and thermal shielding), creating a perfect 40-degree section of the ��ϲʸ�� torus.

Strong back

2021-12-20

The standing sub-assembly tool will support the weight of the 440-tonne component for several months, as thermal shielding and two toroidal field coils are attached.

Lower slowly

2021-12-08

Once vertical, the upending tool and its load are returned to the shop floor. The tool has been specifically designed to upend 9 vacuum vessel sectors and 18 toroidal field coils, or 27 lifts in all. This is number four.

One week later

2021-12-08

One week later, the crane rigging is altered to bring the upending tool to vertical.

Mid-air ballet

2021-12-08

It's an industrial ballet in mid-air.

Up close

2021-12-08

The sector is 11 metres tall ; the tool is even taller.

Next?

2021-12-08

Next up: the sector will be lifted out of the tool, rotated, and installed on the assembly tool we see at left.

Hefty

2021-12-08

The tool weighs 250 tonnes itself. Adding the vacuum vessel sector and rigging, that's nearly 700 tonnes under the cranes.

Hold tight

2021-12-08

The component is lashed tightly so that it doesn't budge an inch during the upending operation.

Second sector on the move

2021-12-02

Vacuum vessel sector #1(7) is on the move. On Thursday 2 December it was lifted into the upending tool. See the full story in the ��ϲʸ�� Newsline on 6 December.

Fine tuning

2021-12-02

The vacuum vessel sector is now inside the upending tool. Fine-tuning of the lifting system was performed by four hydraulic ''sync hoists'' attached to a pair of load-balancing beams suspended to the crane hooks.

Coming down

2021-12-02

The D-shaped toroidal field coil (TF13) has been removed from sector module #6 and placed in the "upending" tool (photo). The tool will return the coil to the horizontal position it was delivered in, so it can be removed from the Assembly Hall and placed in storage.

Into its cradle

2021-12-02

The 440-tonne sector, securely strapped to its staging platform, is lowered into the upending tool. Next week, it will be raised to vertical.

Sector #1(7): prep work underway

2021-11-19

In order to support the instrumentation that monitors the main electromagnetic parameters of the plasma, several hundred welded attachments (i.e., bosses or clips) need to be precisely fitted to every vacuum vessel sector. (Pictured: Korean sector #1(7))

Faster the second time around

2021-11-19

Experience and lessons learned brought the total duration of preparation works on the second vacuum vessel sector down from 36 weeks to an expected 15 to 17 weeks.

Second sector in the wings

2021-11-19

Another imminent operation at ��ϲʸ��: the lifting of the second Korean sector, #1(7), into the assembly tooling. The teams were able to prep this sector for lifting in half the time as the first.

Only six more "steps"

2021-11-18

The path to lowering the first vacuum vessel sub-assembly into the Tokamak pit was set out in 27 distinct construction work packages, and 21 of these have now been achieved. The transfer of the sub-assembly into the Tokamak pit will be a major project milestone.

Next lift into pit: 1,250 tonnes

2021-11-15

��ϲʸ��'s first vacuum vessel sub-assembly is nearly ready for transfer into the Tokamak pit. Together, the sub-assembly components weigh 1,250 tonnes.

Awesome

2021-11-15

Workers look small when they stand at the foot of this unique and spectacular D-shaped structure.

One-ninth of the chamber revealed

2021-11-12

Part of the scaffolding around the first vacuum vessel sub-assembly has been removed, revealing one-ninth of the ��ϲʸ�� vacuum chamber. Follow the arrows to make out the three parts of the 1,200-tonne assembly: the vacuum vessel sector (yellow), one of two toroidal field coils (red), and the thermal shield for sector #6 (blue).

Dizzying

2021-10-29

A drone hovers over the ��ϲʸ�� Tokamak pit and captures a dizzying array of components, tools, staging platforms and equipment. This view of the lower machine will be impossible in a few weeks, when the first vacuum vessel sub-assembly is inserted. © Les Nouveaux Médias/SNC ENGAGE

Central solenoid assembly to begin in January 2022

2021-10-21

Delivered to ��ϲʸ�� in September, the first central solenoid module is undergoing a battery of tests and verifications—metrology, sensors, electrical insulation inspection, etc. Assembly of the 18-metre tall, 1,000-tonne central solenoid is set to begin in January 2022.

First correction coil lifted

2021-10-21

The lift operation for correction coil BCC/4 gets off to a start at 10:30 a.m. on 21 October. The total load under the crane is 5.3 tonnes including lift accessories.

2021-10-21

Correction coils are manufactured in unusual shapes to fit into the space between the poloidal and toroidal field magnets. At the bottom and the top of the machine, the coils are rectangles that curve inward to espouse the torus shape of the vacuum vessel.

Success

2021-10-21

The lowering of the BCC/4 coil onto its temporary supports goes smoothly, thanks to detailed preparation that included metrology, reverse engineering and accurate positioning. In the final machine geometry, the correction coils will be attached to the toroidal field coil superstructure.

Teamwork

2021-10-21

��ϲʸ�� Organization teams are working with the Tokamak Assembly Contract (TAC1) consortium CNPE for the correction coil lift operations. See more on assembly contractors here: /construction/TokamakAssembly

Just a sliver of space

2021-10-21

Final touch down is the most critical part of the lift. The "sliver" of space between poloidal field coil #5, poloidal field coil #6, lower magnet feeders, and staging platforms does not exceed 25 mm for BCC/4 (pictured) and 15 mm for BCC/5.

Second tool enters action

2021-10-20

On the sector sub-assembly tool #2 (SSAT2), we are counting down the days until the first sub-assembly (built around vacuum vessel sector #6) is transferred to the Tokamak pit. Meanwhile, on SSAT1, assembly contractors have mounted the inboard segment of the thermal shield. On this tall tool, a sub-assembly unit will be built around vacuum vessel sector #7.

First correction coils

2021-10-07

Two out of six bottom correction coils have completed site acceptance tests are are in line for pit insertion. The Chinese Domestic Agency is supplying 18 correction coils in all (six bottom, six side and six top).

Assembly precision

2021-10-05

The elements of the first vacuum vessel sub-assembly are positioned precisely relative to one another. To the right, the bottom of one of the toroidal field coils (TF13); in the centre, the much thinner silver-plated thermal shield; and to the left, the opening of the vacuum vessel sector lower port stub extension.

Sub-assembly #1: final alignment achieved

2021-10-05

Final alignment has been achieved for the first building block of the ��ϲʸ�� plasma chamber—four major components, totalling 1,250 tonnes, have been aligned to within 1 mm of tolerance in the radial, toroidal and vertical directions. (Picture taken inside of the sub-assembly group.)

New thermal shield set

2021-10-01

Contractors have unpacked the three thermal shield panels that will be mounted onto vacuum vessel sector #1(7)—the second sector to be equipped. (Pictured: the inboard sector.) All nine sets of vacuum vessel thermal shielding are on site. © Christian Luenig

Hidden corridor

2021-09-29

To exit the ground floor of the Tokamak pit, you have to pass under poloidal field coil #5. © Christian Luenig

Ring coil PF5 is in place

2021-09-16

The coil has now reached its "parking position," where it will remain for a few years. When all vacuum vessel sectors are in place, it will be raised approximately 1.5 metres to its permanent position.

Another major magnet installed

2021-09-15

Right on time, the assembly teams lower poloidal field coil #5 into the Tokamak pit. This magnet, which is captive under the machine, needed to be in place before the first vacuum vessel sub-assembly is lowered late next month.

A pause for metrology

2021-09-15

Part of the way down, the load is paused in order for metrologists to take measurements. It must be positionned at the bottom within a few millimetres of tolerance.

Early morning briefing

2021-09-15

Approximately 20 workers from the machine assembly consortium CNPE, two crane operators and four ��ϲʸ�� Organization supervisors were involved in the operation.

Created on site by Europe

2021-09-15

Poloidal field coil #5 is the first magnet to exit the Poloidal Field Coils Winding Facility, a production facility created on site by the European Domestic Agency for the realization of four of the five ring-shaped magnets under its responsibility. (The fifth, poloidal field coil #6) was produced at the Chinese institute ASIPP under an agreement with Europe.)

Altitude 35 metres

2021-09-15

The coil is now approximately 35 metres above its final position. Its diameter is just a few centimetres smaller than the lower cryostat thermal shield that is visible (wrapped in protective pink plastic) at the bottom of the pit.

Planarity check

2021-09-15

Poloidal field coil #5: Lifting and positioning a 17-metre-in-diameter steel coil demands a perfect balancing of the lifting hooks and a constant check for planarity.

Using the column for access

2021-09-08

At the base of the central column tool, the first work platform has been installed. Platforms will be installed at three other levels, with access possible through the hollow interior of the column (equipped with ladders).

Unpacked

2021-09-07

The latest vacuum vessel sector to arrive at ��ϲʸ��—sector #1(7)—has been positioned in the Assembly Hall and unwrapped.

The antechamber of the tokamak

2021-09-07

Before being assembled in the Tokamak pit, all large components are brought through this space: the ��ϲʸ�� Assembly Hall. Their sojourn in this space can be long or short, depending on the number of pre-assembly activities required to prepare the components for lifting.

A spaceship?

2021-09-07

The shape of an in-pit radial beam is strongly evocative of slim spaceship—the bow turned toward its destination, an upper deck gangway, and openings in its hull like rocket exhausts.

Good fit

2021-09-07

The test operation demonstrated that the docking and bolting of the test beam fell within the required tolerances.

First sub-assembly underway

2021-09-07

The assembly teams are creating the first vacuum vessel sub-assembly in one of the tall tools in the Assembly Hall. Vacuum vessel sector #6, seen from below covered by its shiny thermal shield, will be paired with toroidal field coils TF11 (left) and TF12 (right). The completely integrated unit, weighing 1,200 tonnes, will be lowered into the Tokamak pit in late October.

Preparing for a big lift next month

2021-09-07

The first vacuum vessel sector should be ready for transfer to the pit late October, fully assembled with its thermal shielding and two toroidal field coils. It will travel into place under a radial beam that will brace its its weight between the column and the wall. In early September, this docking operation was tested without load.

From the upper galleries

2021-09-01

At 55 metres above the floor, the gangway offers a spectacular view of the Assembly Hall's ever-changing landscape. In this 6,000-square-metre building, components are unloaded, received, equipped, and handled prior to being lifted into the Tokamak assembly pit.

Revealed

2021-08-30

The metal housing is lifted and ... voilà! ... the 440-tonne sector is revealed.

Inspection underway

2021-08-30

Delivered on Friday 27 August, sector #1(7) was unpacked the next day. In this image, members of the vacuum vessel team are carrying out a first visual inspection prior to removing the component's protective plastic wrapping.

Rotation is next step

2021-08-30

For now, this D-shaped magnet coil (left) is supported from below. Once it is rotated to the vacuum vessel sector (right) and attached, the load can be transferred.

Second vacuum vessel sector received

2021-08-27

Vacuum vessel sector #1(7) from Korea enters the Cleaning Facility. It is just a few hundred metres from its final destination.

Assembling a puzzle

2021-08-24

A vacuum vessel sector sub-assembly tool is photographed from an overhead crane. All the pieces are in place to assemble the first section of the ��ϲʸ�� vacuum vessel.

Shiny surfaces

2021-08-24

If you look closely into this V-shaped tool, you'll see the components that must be associated: the triangular form of the vacuum vessel sector (centre, shiny) already covered in panels of thermal shielding, and toroidal field coils on wings to either side. At the top of the image, poloidal field coil #5 stands ready for installation in the pit.

Second vertical coil delivered to tool

2021-08-12

To the right of the image, the newly installed toroidal field coil. To the left, vacuum vessel sector #6. (A second vertical coil is out of sight to the left.)

Ready for coil number 2

2021-08-12

Two days after the transfer of coil TF12 to the standing tool, its twin—TF13—was raised to vertical and delivered to the opposite wing. Vacuum vessel sector #6 now has a toroidal field coil on each side.

Vertical coil moved into place

2021-08-10

Toroidal field coil #12 (supplied by Japan) is moved out of temporary storage on one standing assembly tool and into the other, where all the action is ready to begin. To form a sub-assembly ready for installation in the machine pit, a vacuum vessel sector must be pre-assembled with two toroidal field coils and panels of thermal shielding.

Vertical ballet

2021-08-10

Toroidal field coil #12 (TF12) is rotated in mid-air to approach its final destination on the wind of the standing tool in the proper position.

Horizontal coil PF5 ready for positioning

2021-08-10

A major lift operation will take place in mid-September, as the second poloidal field coil (PF5, pictured) is installed in the Tokamak pit.

From one tool to the other

2021-08-10

Since 15 June, this toroidal field coil had been stored vertically on one of the wings of SSAT1 (the first vacuum vessel sector sub-assembly tool to be erected in the Assembly Hall). On 10 August, it was moved by overhead crane to the SSAT2 tool, where teams are preparing to create the first vacuum vessel sub-assembly.

Second ring coil in line for installation

2021-07-26

Manufactured on site by Europe, poloidal field coil #5 left the production line in April. The component was three and a half years in the making. On 26 July 2021, it was brought into the Assembly Hall, to be prepped for installation in the Tokamak pit.

Next major component to be installed

2021-07-26

A lead actor enters the stage: poloidal field coil #5, 17 metres in diameter, is one the six ring-shaped coils required for the machine.

A quick swap

2021-07-12

The overhead cranes of the Assembly Hall were required to move this toroidal field coil (TF3, from Europe) from its transport frame to a storage frame.

Tight space

2021-07-08

The set of three spare pre-compression rings was installed in the tight space between the bottom cylinder of the central column tool and the recently installed poloidal field coil #6.

First pre-compression rings installed

2021-07-08

A set of three spare pre-compression rings made of glass fibre/epoxy composite are installed in the Tokamak pit on Thursday 8 July. Two other sets of three rings will tightly hold the toroidal field coils at top and bottom with a radial force of 7,000 tonnes per coil to push back against expansion forces during operation.

Creating a "sub-assembly"

2021-07-02

This coil, TF13, will join TF12 on the sector sub-assembly tooling to be matched with vacuum vessel sector #6 and thermal shielding. Both coils were supplied by Japan.

Reverse lift imminent

2021-07-02

Late June, technicians were busy preparing sector module #6 for removal from the pit.

The pit, early July

2021-07-02

Sixteen of the eighteen toroidal field coil gravity supports are in place in a circle on the cryostat base. Next to be installed? A set of three pre-compression rings around the central column.

Sub-assembly progressing

2021-07-02

In the Assembly Hall, the first vacuum vessel sector sub-assembly operation is underway. On the left tool, a vacuum vessel sector has been paired with thermal shielding. On the right, one D-shaped toroidal field coil waits to be transferred over. (Another is ready for vertical upending and installation.) A sub-assembly marries one sector, inboard and outboard thermal shield panels, and two toroidal field coils.

Preserving all installed components

2021-06-28

Preservation activities are defined for each component that needs to be maintained in good condition prior to entering service. In this photo, a worker performs a "white cloth test" to check for moisture on a cryostat support bearing during a preservation inspection.

Rotated inward

2021-06-26

The outboard thermal shield sections have been rotated in by the tooling, and they match perfectly. (Photo courtesy of Chang Hyun Noh.)

Seen from the back

2021-06-23

A 40-degree sector of the ��ϲʸ�� vacuum vessel is photographed in the sub-assembly tool from behind. Two outboard panels of thermal shielding are ready to be rotated inward and affixed, perfectly matching the shape and openings of the sector. (Courtesy of Chang Hyun Noh.)

Thermal shield installed

2021-06-21

You have to look twice to see it: the inboard thermal shield section has been clamped to vacuum vessel sector #6. Only its colour, shiny silver, permits us to distinguish it from the background grey of the vacuum vessel.

Specialized tool required

2021-06-21

The thermal shield is designed to fit like a glove. Little by little, the tool introduces the inboard panel behind the vacuum vessel.

From below

2021-06-21

Seen from under the sector. The right and left outboard sectors are already attached on the wings of the tool; they will be rotated inward to meet and match perfectly, leaving no part of the vacuum vessel visible.

Smooth

2021-06-15

The operation went smoothly, with no show-stopper, no physical mismatching, and no major adjustments required. It was an important rehearsal for the identical sequences to follow. In only two weeks, TF13 (also from Japan) will follow the same path.

Ready to remove

2021-06-15

Time to lift the 320-tonne vertical coil from its upending frame and transfer it over to one of the sector sub-assembly tools on the opposite side of the Hall.

A guest from inside the house!

2021-06-15

��ϲʸ�� Director-General Pietro Barabaschi (far right) takes part in one of the early bus tours of the day ... as a visitor, not a guide!

First toroidal field coil in tooling

2021-06-15

In a series of operations that started on Wednesday 9 June and concluded six days later, TF12 was successfully attached to the left wing of one the twin sector sub-assembly tools (SSAT-1). The 320-tonne coil will be moved to SSAT-2 in about a month for the start of pre-assembly operations with vacuum vessel sector #6 (visible to the far right).

The team in charge

2021-06-15

Responsible for the operation today is the DYNAMIC SNC consortium (Ansaldo Nucleare; Endel Engie; Orys Group ORTEC; SIMIC; Ansaldo Energia; and Leading Metal Mechanic Solutions SL). As TAC-2 contractor (for Tokamak Assembly Contract 2) for the ��ϲʸ�� Organization, DYNAMIC is in charge of the assembly of the main vessel and ports, sector sub-assembly with toroidal field coils and vacuum vessel thermal shielding, and welding.

Crossing the Hall

2021-06-15

Toroidal field coil #12 (supplied by Japan) crosses the Hall to be installed on the left wing of the first sector sub-assembly tool (SSAT-1). The component will remain in this temporary location for about a month, before it is moved to the other sector sub-assembly tool (SSAT-2) for the actual pre-assembly operations.

For the first vacuum vessel sub-assembly

2021-06-09

Seventeen metres tall and 9 metres wide, this D-shaped coil (TF12, procured by Japan) is one of two that will be matched with a 40-degree sector of the ��ϲʸ�� vacuum vessel. Sector #6 is already in the SSAT assembly tooling; TF12 will be transferred to the tooling next week.

Near ready

2021-06-09

This correction coil feeder element is already in the lift frame that will be used for its transfer into the pit.

Satisfaction

2021-06-09

The team can be satisfied with work well done. The next step is to "detach" toroidal field coil #12 from the upending tool and perform the balancing of the load under the cranes, before it is moved to the sector sub-assembly tooling.

Ready to go

2021-06-09

The teams are ready to perform the first "upending" of a D-shaped toroidal field coil (TF12). The upending tool (light grey) can handle both vacuum vessel sectors and vertical coils.

Points d'attache

2021-06-09

Technicians attach crane hooks to the transport frame in order to lift the component and free the modular transporter.

Temporary rest area

2021-06-09

The newly arrived load is transferred to a temporary laydown area. Later, in the order determined by assembly sequences, it will be transferred to the Tokamak pit.

First of 18

2021-06-09

Eighteen "D"-shaped toroidal field magnets placed around the vacuum vessel produce a magnetic field whose primary function is to confine the plasma particles.

A vast hall

2021-06-09

The upending tool is located in the middle of the Assembly Hall, not far from the sector sub-assembly tools.

Open sesame

2021-06-09

The massive doors of the Assembly Hall open to admit a semi-circular feeder component on its self-propelled modular transporter.

Let's go

2021-06-09

By coordinating the cables of the four lift points, the overhead crane operators first lift the load and then start to tilt it.

Up it goes

2021-06-09

The new feeder element (wrapped in silver) and its transport frame are lifted off the transporter. In the foreground, another (unwrapped) feeder component awaits its turn in the assembly pit.

Stacking rings

2021-06-08

Assembly contractors are preparing for the lift of two sets of three pre-compression rings. © Les Nouveaux Médias/SNC ENGAGE

Managing a wide temperature gradient

2021-06-04

Gravity supports create the bridge between the toroidal field coils operating at 4 K (minus 269 °C) and the cryostat base at room temperature (approximate). This makes for a huge temperature gradient that must be smoothly distributed throughout the 2.65-metre-tall, 20-tonne component.

A unique place

2021-06-04

Nothing in the world remotely resembles the ��ϲʸ�� "assembly pit." What we see here are the first steps of a prodigious undertaking: the construction, from the bottom up, of the most complex machine ever designed.

Bottom to top

2021-06-04

��ϲʸ�� machine assembly is proceeding from bottom to top. After the 1,250-tonne cryostat base comes: the lower cryostat components; nine large, 40° vacuum vessel sectors (pre-assembled with thermal shield panels and a pair of toroidal field coils); components at the top of the machine; and finally the cryostat lid.

Limited space

2021-06-04

The ��ϲʸ�� Tokamak pit is alive with activity as workers, tools and components compete for limited space. Coordination is paramount.

It's happening in the pit

2021-06-04

The structure to the left of this image is one of the six temporary supports for the 17-metre-in-diameter poloidal field coil #5 (PF5), which is scheduled for installation in late July/early August. To the right, the side correction coil feeder rests in a temporary position; later, it will be lifted several metres to its final location.

Looking like microwave ovens

2021-06-04

Two "front full" support thermal shield panels are in place in front of the toroidal field coil gravity supports. A "front open" panel will be precisely fitted between them. The system is designed to shield the magnets at cryogenic temperature from the warmth coming from the cryostat base and transmitted by the gravity supports.

Thermal insulation

2021-06-04

Thermal insulation between the different components of the ��ϲʸ�� Tokamak is paramount. Here, workers prepare one of the 18 "support thermal shield" panels that will be fitted tightly to the massive toroidal field coil gravity supports. Each silver-plated panel measures approximately 1.6 m by 3.3 m and weighs 730 kg.

One to another

2021-05-21

At the entrance of the Assembly Hall, a "swap" is performed: toroidal field coil #8, from Japan, is transferred from its travel frame (right) to a temporary support frame (left) for storage.

Coil meets frame

2021-05-21

The operation goes smoothly, as the 360-tonne magnet coil is positioned on its support frame.

Preparing the transfer

2021-05-21

The teams meet ahead of the transfer operation, which is carried out by one of the two 750-tonne overhead cranes in the Assembly Hall.

17 metres

2021-05-21

When raised to vertical, the 360-tonne toroidal field coils will stand 17 metres tall.

Knocking at the door

2021-05-21

Toroidal field coil #13 (from Japan) has been unwrapped in the Cleaning Facility. It will be the second coil mounted on the sector sub-assembly tooling, joining vacuum vessel sector #6 and pairing with toroidal field coil #12.

Upending tool in action again

2021-05-18

This time, the upending tool will secure and raise to vertical one of the D-shaped toroidal field coils--TF12 from Japan. Once vertical, the coil will be installed on a giant sector sub-assembly tool in the Assembly Hall, to be paired with the first vacuum vessel sector.

How to create a sector sub-assembly

2021-05-18

Two toroidal field coils as well as panels of thermal shielding must be associated with each vacuum vessel sector before the new unit, call a sector sub-assembly, can be transferred to the Tokamak pit. (In the background, we can see sector #6, from Korea, already in the sector sub-assembly (SSA) tooling.)

Semi-circular feeder

2021-05-15

On 15 May 2021, this 10-tonne circular feeder was inserted in the assembly pit. This in-pit component will connect to a cryostat feedthrough in order to deliver electrical power to the six side correction coils located at the mid section of the machine.

Teams prepare ��ϲʸ�� games?

2021-04-26

Arranged unexpectedly in a configuration that can only remind us of the Olympic Games, six pre-compression rings in the ��ϲʸ�� Assembly Hall are being prepped for installation.

Just passing through

2021-04-21

On its way to the assembly pit the poloidal field coil passes vacuum vessel sector #6, safely docked in one of the sector sub-assembly tools.

First ��ϲʸ�� magnet lowered into pit

2021-04-21

This 400-tonne component—poloidal field coil #6 (PF6)—is the first superconducting magnet to enter the Tokamak pit. It will rest on temporary supports until the vacuum vessel is assembled and welded; at that point PF6 can be adjusted into its final position.

Lifting off

2021-04-21

Lift-off begins. One day earlier, pre-lift trials had been run to assess the risk of not compensating the slight imbalance in the component's centre of gravity caused by a one-tonne feeder on one side. The slight tilting of the coil did not exceed one degree and remained within tolerance.

4 mm of tolerance

2021-04-21

The rotating mechanism of the dual crane heavy lifting beam (in yellow) is clearly visible in this image of the PF6 coil arriving at the bottom of the assembly pit. The coil is installed to within 4 mm of tolerance.

25 metres overhead

2021-04-21

Ring magnet PF6 travels at a cruising altitude of 25 metres. Eight hours are required for the installation operation on 21 April 2021.

Nearly there

2021-04-21

PF6 slowly arrives at its destination. The coil will remain on temporary supports until the vacuum vessel has been assembled and welded; then, it will be anchored to the toroidal field coil superstructure.

Last check

2021-04-21

The journey is not complete yet. Operators check the coil's position as it hovers 10 centimetres above the temporary supports.

Lifting attachment

2021-04-20

Used in January for the installation of the lower cryostat thermal shield (/newsline/-/3547), this ring-shaped lifting attachment will serve next for the installation of ring-shaped in-cryostat feeders. For the moment it is stored in the Assembly Hall.

Europe completes poloidal field coil #5

2021-04-16

On Friday 16 April, the first ��ϲʸ�� ring magnet to be manufactured by European Domestic Agency contractors on site—poloidal field coil #5 (PF5)—has been moved into temporary storage to await assembly.

State of play in the pit (mid-April 2021)

2021-04-15

This diagram identifies the components that are visible on the floor of the Tokamak pit in mid-April 2021.

Transferred to SSAT tool #1

2021-04-06

The first 440-tonne vacuum vessel sector (#6 from Korea) has been transferred to sector sub-assembly tool (SSAT) #1, closest to the Tokamak pit. Two identical tools stand side by side in the Assembly Hall to double the speed at which vacuum vessel sub-assemblies can be created.

Without a hitch

2021-04-06

The upending, transfer and tool installation sequence performed on vacuum vessel sector #6 will be repeated eight other times. The first operation was prepared carefully, and went off without a hitch.

Cleaning the surface

2021-04-06

A worker in protective gear cleans the surface of an outboard thermal shield panel that has had its cooling pipes removed; soon a new set of pipes will be attached. With a different steel formulation, lower-energy welding techniques, and a slightly different welding wire the new process will avoid the risk of "stress corrosion cracking."

Mammoth

2021-04-06

The double-walled, D-shaped sector is 13.8 metres tall, 6.6 metres deep, and 7.8 metres wide.

To the end of the building

2021-04-06

On Tuesday 6 April, sector #6 was removed from the upending tool and carried by overhead crane to the end of the Assembly Hall and sector sub-assembly tool #2. Several bespoke attachments interfaced between the crane and the component.

Final position

2021-04-06

Seen from below, the component is in its final position, supported from above by a radial beam (soon to be detached from the crane) and from below by a pillar under the lower port stub extension.

Hollow, but reinforced

2021-03-27

The central column is hollow (although heavily reinforced with ribbing). Cat ladders and port holes will allow access to different levels of the vacuum vessel during assembly.

A strong base for a heavy task

2021-03-27

On 27 March, the teams installed the bottom cylinder of the in-pit assembly tool. With a central column and radiating beams braced against the pit walls, the in-pit column tool will support all nine sectors of the vacuum vessel as they are welded together.

Success!

2021-03-26

The first "upending" operation is successfully performed on sector #6 on 26 March 2021. The vacuum vessel sector, now vertical, will soon be mounted on specialized tooling in the Assembly Hall.

Ring magnet PF6 enters Assembly Hall

2021-03-26

Poloidal field coil #6 (PF6) is the second smallest of the ��ϲʸ�� ring magnets in terms of diameter (10 metres) but the first in the assembly sequence of the ��ϲʸ�� Tokamak. It will be lowered onto temporary supports at the bottom of the Tokamak pit in April.

2021-03-26

The tilt operation took place mid-air. At one point, the component was nine metres overhead.

Vertical

2021-03-26

For the first time of its existence, the 440-tonne component is in a vertical position ... and the observer can truly measure the size of the ��ϲʸ�� plasma chamber.

Waiting in line

2021-03-26

Two massive machine components are waiting to enter the Assembly Hall. Left: a 360-tonne vertical coil, TF12; right: a 440-tonne ring magnet, PF6.

It takes a team

2021-03-26

Personnel from the Dynamic consortium (machine assembly), crane operators from Foselev, security experts from APAVE, and ��ϲʸ�� construction team members were all involved in the successful upending operation for sector #6.

The very centre

2021-03-25

Workers stand in the very centre of the Tokamak pit, where the central solenoid magnet will be installed late in Assembly Phase 1. Before then, though, a tall column tool will brace the vacuum vessel sectors as they are installed and welded. © Christian Luenig

Assembly well

2021-03-25

��ϲʸ�� will be the first tokamak completely integrated into the surrounding building. The 23,000-tonne machine will be assembled here, in the 30-metre-deep Tokamak pit. © Christian Luenig

Strong hands

2021-03-25

A huge hook has just disengaged from a load deposited in the Tokamak pit. The back-and-forth ballet of the overhead cranes is accelerating. © Christian Luenig (www.arbeitsblende.de)

Machine assembly partners

2021-03-24

The ��ϲʸ�� Organization is collaborating with two consortia for the assembly of the core machine: the CNPE Consortium (China Nuclear Power Engineering; China Nuclear Industry 23 Construction Company Ltd.; Southwestern Institute of Physics; Institute of Plasma Physics, Chinese Academy of Sciences ASIPP; and Framatome) and the DYNAMIC SNC consortium (Ansaldo Nucleare; Endel Engie; Orys Group ORTEC; SIMIC; Ansaldo Energia; and Leading Metal Mechanic Solutions SL).

Bird's eye view

2021-03-22

A bird's eye view of the assembly and installation projects running in parallel in the ��ϲʸ�� Assembly Hall. Top right: vacuum vessel sector #6, lashed to its frame, has been positioned in the upending tool; bottom right: pre-compression rings await their turn in the assembly pit; bottom left: the base cylinder of the in-pit assembly tool, ready for lifting; top left: on a red stand, the radial beam that will attach to the top of the vacuum vessel sector once it is lifted to its vertical orientation.

Big lift to come

2021-03-22

The assembly teams are preparing the overhead cranes, and all their interfacing parts, for the next big lift: bringing the first 440-tonne vacuum vessel sector from horizontal to vertical.

Coil enters assembly antechamber

2021-03-22

This 360 magnet coil—toroidal field coil #12, from Japan—is leaving a temporary storage facility and entering the Cleaning Facility.

Upending operation

2021-03-21

This specialized upending frame will be used to raise two types of large components—vacuum vessel sectors (440 tonnes) and toroidal field coils (360 tonnes)—from their horizontal delivery configuration to vertical for subsequent installation on the sector sub-assembly tools. The "tilt" operation is carried out in coordination with the overhead cranes.

Shear keys

2021-03-10

At the bottom of the pit, the assembly teams are preparing for the installation of a tall central column, part of the in-pit assembly tool that will support the vacuum vessel during welding. The first segment of the column, the lower cylinder, will be anchored to the concrete basemat through these four shear keys.

First element of the central column

2021-03-10

Close to 6 metres tall and weighing approximately 70 tonnes, this is the first segment of the in-pit column tool, the bottom cylinder. Hollow inside, it will permit access to different levels of the vacuum vessel during in-pit welding operations. Four other segments will follow to build the full column.

Little "bosses"

2021-03-10

Approximately 700 ''bosses'' have been welded to the outer skin of vacuum vessel sector #6 in precise locations, for the attachment of instrumentation, instrumentation cables, and cable trays. Over the workers' heads are some of the magnetic sensor cases, attached with four ''bosses'' each; elsewhere, we see the routing of cables and instrumentation wires.

Concentric circles of support

2021-03-10

Half of the toroidal field magnet supports (covered in yellow) have been installed in the pit. Anchored in a circle to the cryostat base, they will support the outer edge of each toroidal field coil.

Prepping the toroidal field coils

2021-03-06

A pair of toroidal field coils supplied by Japan is being prepped for pre-assembly. The process adds approximately 10 tonnes of equipment, some of it temporary, to their already considerable mass.

Sort and connect

2021-03-06

The ��ϲʸ�� Tokamak is an experimental machine whose parameters will be closely monitored by a vast array of diagnostics devices. Sorting and connecting the low-voltage cables that transport data from sensors on the toroidal field coils is a delicate operation that is performed during the assembly prep works.

440 tonnes

2021-03-02

Planned for mid-March, the first upending operation will be quite spectacular. Once raised to vertical, this 440-tonne vacuum vessel sector will stand just over 11 metres tall.

Keeping clean

2021-03-02

A close-up of the lower cryostat work area. A strict cleanliness protocol is in effect, to keep dust and sub-microscopic particles off of the components.

Preparing for lift off

2021-03-02

Strong orange lashing lines will help to keep vacuum vessel sector #6 securely attached to its lifting frame during the 90-degree upending procedure.

Pre-compression rings: preparing to install six

2021-02-26

Metrology operations are underway on the first of six pre-compression rings to be positioned in the assembly pit at the end of the month. The rings have an inner diameter of 5 metres.

Perfect alignment

2021-02-26

Perfect alignment between two vacuum vessel thermal shield outboard panels was achieved during recent alignment tests.

Filling up

2021-02-26

The lower part of the assembly pit is getting more crowded by the day. On the rim of the cryostat base (the "pedestal"), five toroidal gravity supports are now installed. At the bottom level, six temporary supports for poloidal field coil #6 are arranged in a perfect circle. In the middle, drilling is underway to prepare for the bolting of the 600-tonne "central column" on to a massive circular embedded plate.

A busy month

2021-02-26

March will be a busy month in the assembly theatre. In every corner of the vast Assembly Hall, teams are preparing for the upcoming operations (the upending of the first vacuum vessel sector, the installation of part of the in-pit column tool, the installation of the first pre-compression rings...).

Lashed tightly

2021-02-26

Vacuum vessel sector #6 is tightly lashed to its support frame. It will lifted and placed inside the upending tool on its frame, and then lifted to vertical. © Les Nouveaux Médias/SNC ENGAGE

Inside sector #6

2021-02-26

Stub keys and flexible support housings dot the inner surface of vacuum vessel sector #6. Flexible support cartridges will lock into these housings and act as bolts securing the blanket modules to the vacuum vessel. This massive component is now ready to be upended and positioned on one of the twin giant sector sub-assembly tools.

Ring game

2021-02-26

Seen on the shop floor: six pre-compression rings as well as their lift tool and a seventh test coil.

Not so small

2021-02-23

The man in the middle of the image helps us to put the size of the temporary supports for poloidal field coil #6 into perspective. They are quite large ... and strong enough to support 400 tonnes.

Practising a major operation

2021-02-18

Dummy loads have been transferred from the upending tool to one of the sector sub-assembly tools. The assembly contractors are preparing and practicing for the upending of vacuum vessel #6 next month.

Temporary magnet supports

2021-02-15

A new circle is being formed by temporary supports being installed for poloidal field coil #6. In April, the 400-tonne magnet will be lowered onto these supports, where it will remain until the completion of vacuum vessel assembly. The wider circle, in pink, is the lower cryostat thermal shield, which was installed in January 2021. See: /newsline/-/3547.

Electrical connections to complete

2021-02-13

The central solenoid team is working with assembly contractors to complete the superconducting electrical connections of module 1. This involves welding, ultrasonic weld inspection, helium leak testing, electrical installation and high voltage testing.

Group visit

2021-02-12

A group of senior managers makes a tour of the pre-assembly activities underway in the Assembly Hall.

SSAT tool #2 in action

2021-02-12

Thermal shield fitting tests are being carried out on sector sub-assembly tool (SSAT) #2. The outboard panels of vacuum vessel thermal shielding were first mounted on the wings of the tool; then, the wings rotated slowly inward to test the alignment of the panels. Metrology is underway.

Before rotation

2021-02-11

The outboard thermal shield sectors have been mounted on the tools and a last metrology session is underway before the components rotated inward.

PF6 enters an ��ϲʸ�� storage facility

2021-01-27

The coil was transferred from the European coil winding facility on site to an ��ϲʸ�� storage facility to be prepared for assembly.

First poloidal field coil handed over

2021-01-27

On 27 January 2021, the first of six poloidal field coils is handed over to the ��ϲʸ�� Organization by the European Domestic Agency, Fusion for Energy. Poloidal field coil #6 (PF6) is a 400-tonne magnet that will be the first to be assembled into the ��ϲʸ�� machine pit.

Out in the galleries

2021-01-26

The coil terminal box is the part of the magnet feeder that sits farthest from the machine core. Nine metres in length, shaped like a shipping container, the box houses warm-to-cold electrical transition equipment, remote control helium supply valves, and sensors for coil instrumentation.

Magnet feeder segment installed in Tritium Building

2021-01-26

On 26 January 2021, the coil terminal box serving toroidal field coils #12 and #13 is lifted and moved inside the basement of the Tokamak Building. Each magnet feeder comprises three elements: a coil terminal box, a cryostat feedthrough (segment passing through the bioshield and cryostat) and an in-cryostat feeder (segment connecting to the magnets).

Roll it in

2021-01-26

This backend feeder component has been lowered to B2 basement level in the Tritium Building and will now move on rollers to its final position.

Heading in

2021-01-26

The load is seen here as it approaches an opening on the Tritium Building side of the Tokamak Building. Twenty-one feeders will be situated at the bottom of the machine, and another 10 at the top.

Another shiny element

2021-01-20

Another element of thermal shielding—this time the inboard shielding element for vacuum vessel sector #6—is being prepped in a laydown area in the Assembly Hall.

Intricate

2021-01-20

Delicate cooling pipes snake along the outer surface of the inboard sector of vacuum vessel thermal shielding.

Like a glove

2021-01-20

The lower cryostat thermal shield, partially draped in pink cloth, fits the depression of the cryostat base like a glove.

Gravity supports: first unit

2021-01-15

The first toroidal field coil gravity support is installed on the pedestal of the cryostat base. It stands 2.65 metres tall.

2021-01-14

The component's trajectory brings it to within a few metres of the vacuum vessel sector assembly tools (at left). A team member is stationed at the top of one tool to keep a watchful eye.

Realignment needed

2021-01-14

The lower cryostat thermal shield is now well engaged in the assembly pit. A slight rotation has been identified and re-alignment will be necessary before the component engages its final descent.

One hook, 18 attachment interfaces

2021-01-14

Attached to the overhead crane by a single hook, the "strong back" is connected to the thin component (10 millimetres) by way of 18 attachment interfaces equally distributed around its circumference. This type of rigging is designed to provide both rigidity and stability.

Well done

2021-01-14

As the load is transferred from the crane to an array of hydraulic jacks, a full-day operation comes to an end. A few more adjustments ... then final metrology ... and the day can be declared a success.

Travelling 100 metres

2021-01-14

The 50-tonne lower cryostat thermal shield travelled approximately 100 metres to the Tokamak pit at a cruising altitude of 23 metres.

Ready for lowering

2021-01-14

The component has travelled the length of the assembly theatre and is now positioned right above the pit. Two alignment tools, visible at the bottom of the large circular opening, will guide its final trajectory.

Corrected!

2021-01-14

After a bit of rope pulling to realign the load, the final descent can begin. The temporary rails (in grey against the silvery backdrop of the component) are now ready to slide into the tower-like alignment tools all the way to the bottom of the pit. The protruding bolts of the gravity support (left) were passed without incident.

Attached to a "strong back"

2021-01-14

Attached to its ''strong back,'' the 50-tonne lower cryostat thermal shield has reached cruising speed (2 metres/minute). Its silvery surface reflects the colours, lights and distorted shapes of the environment.

New tests

2021-01-13

A new series of tests is underway on the upending tool.

Tall gravity supports: in line for installation

2021-01-12

Eighteen of these toroidal field coil gravity supports must be positioned on the cryostat base. This one is about to be transferred into the Tokamak pit.

Practicing

2021-01-11

By overhead crane, the teams are transferring two dummy loads (representing approximately 700 tonnes) to the tool in its upright position, practicing for when the upending tool will handle some of ��ϲʸ��'s heaviest components: toroidal field coils or vacuum vessel sectors.

Two segments of the thermal shield are mounted

2021-01-08

With two outboard thermal shield panels now mounted on one of the giant pre-assembly tools, thermal shield assembly trials can begin.

One for the road ...

2020-12-16

The last 2020 photo of the ��ϲʸ�� Tokamak pit.

Soon: installation of the lower cryostat thermal shield

2020-12-15

Inside of the Tokamak pit, three tower-like alignment tools have been installed for the installation of the lower cylinder thermal shield.

Cable stretching

2020-12-12

New cables on the 750-tonne overhead cranes are prepared for use through some "stretching" exercises.

Advancing carefully

2020-12-12

The Larsen & Toubro/MAN Energy Solution teams continue to weld the cryostat base and lower cylinder together in the Tokamak pit. It is a precise and careful job, which is carried out by highly qualified technicians.

Cooling manifold installation

2020-12-07

On the inner surface of the lower cryostat thermal shield, workers have begun installing cooling manifold pipes.

Radial beams

2020-12-04

One of the nine radial beams that will support the vacuum vessel sectors are they are loaded onto the assembly tooling, and support the full vacuum vessel assemblies as they are transferred and installed in the pit.

Lift frame goes along

2020-11-25

A specially designed frame accompanied the thermal shield panel during the lift. Both thermal shield and lifting frames are supplied to the ��ϲʸ�� Project by Korea.

A protective "shell"

2020-11-25

The vacuum vessel thermal shield is like a shell that encloses the vacuum vessel and protects the magnetic system from thermal radiation. At the pre-assembly stage, each vacuum vessel sector will be fitted with the three panels of thermal shield: two outboard (left and right) and one inboard.

Seen from the top

2020-11-25

This picture is taken from the top of the tool, as the thermal shield panel and its structure are "docked."

Up in the rafters

2020-11-23

Taken from a height of approximately 55 metres, this photo captures the crane hall of the Tokamak Building and the deep machine assembly well.

By zone

2020-11-23

From above, we have a clear view of the different work zones of the Assembly Hall. The component the furthest from the Tokamak pit (the lower cylinder thermal shield, top) will be the next one installed.

Fearless photographer

2020-11-23

The ��ϲʸ�� photographer climbed the equivalent of 20 stories to get this comprehensive shot of pre-assembly activities underway.

Inside and outside

2020-11-23

All kinds of activity is underway to prepare the first vacuum vessel sector for pre-assembly.

Lying in wait

2020-11-17

The two toroidal field coils received from Japan will be needed next year in the first vacuum vessel sub-assembly to be mounted on the giant standing tools in the Assembly Hall. Until then there is plenty to do: leak testing the welds in the helium piping and adding handling and pre-assembly equipment.

Chunky accessories

2020-11-17

A huge crane requires huge accessories. These are some of the attachments of the ��ϲʸ�� bridge cranes.

Tall supports

2020-11-13

Some of the gravity supports for the toroidal field coils are stored in the Assembly Hall. They will be installed one by one on the pedestal of the cryostat base.

720 tonnes

2020-11-13

Two 360-tonne dummy loads have now been loaded onto the upending tool for trials that are preparing for the first component lifts.

How to lift

2020-11-11

These lifting lugs were pre-installed on toroidal field coil #12. For now, the coil is in a preparatory area not far from the Assembly Hall.

Practicing every step

2020-11-09

Behind vacuum vessel sector #6, operators are practicing the lift operation that will bring the sector from horizontal to vertical. The crane is about to raise the upending frame (seen here loaded with dummy weights).

Pre-compression rings

2020-11-03

Two sets of pre-compression rings and dedicated lifting equipment are stored on site. The bottom set will be called for installation quite early in the machine assembly process.

Heat barrier

2020-10-30

This lower cryostat thermal shield will be positioned inside of the soup-dish-shaped depression of the cryostat base to form a heat barrier.

Advancing cautiously

2020-10-30

The progress of the welding machine (8 centimetres per minute) is closely scrutinized by a technician from MAN Energy Solutions (contractor to Larsen & Toubro, the cryostat manufacturer).

Lower cryostat thermal shield

2020-10-30

In the ��ϲʸ�� Assembly Hall, contractors are joining eighteen 20° segments of thermal shield into a silver circle.

Into tool

2020-10-30

The last leg of the reverse operation for sector module #6: after removal from the Tokamak pit, the component is lowered into one of the twin sector sub-assembly tools to be disassembled and prepared for repair.

First in-pit welding

2020-10-30

The gap between the cryostat lower cylinder and the cryostat base is 40 millimetres. It will take 1 tonne of filler material to completely weld the 90 metres of circumference.

How it will look

2020-10-22

This mockup clearly illustrates the attachment role played by the "bosses": the small rectangular frame will support a sensor; the flat hold plates are for cable looms; and another set of smaller devices provides a pathway to the "continuous flux loop," a single cable that runs along the whole circumference of the torus to measure the magnetic field.

Bumps galore

2020-10-22

The larger cylinders, bordered with white, are metrology targets. The smaller "bosses" are like clips that will hold instrumentation and diagnostics cables.

Outside and inside

2020-10-22

Approximately 800 "bosses" need to be welded to the outer surface of each vacuum vessel sector. As for those planned on the component's inner wall, they will be installed once the vacuum vessel pre-assemblies have been lowered into the Tokamak pit.

Using "laser templating" for the first time

2020-10-22

Implemented in ��ϲʸ�� for the first time, "laser templating" techniques are used to project an outline of the element to be welded at its precise pre-defined position on the component's surface with a safe, low-power laser, providing the welder with a perfect template to follow.

Barnacles?

2020-10-22

Like barnacles colonizing a whale, small cylindrical "bosses" are being welded in precise locations to the outer shell of vacuum vessel sector #6. Bosses are like studs onto which other components can be bolted or welded, for example instrumentation and diagnostics cables.

Horizontal for now

2020-10-22

Vacuum vessel sector #6 is on a platform across from the large assembly tool where it will be mounted (in a vertical position) during the first sector sub-assembly operation.

Thermal shield uncovered

2020-10-15

Like a giant's tiara. This segment of silver-coated thermal shield will on the outside of the D-shaped vacuum vessel sector #6.

Thermal shield(s)

2020-10-15

Seen from above, elements of the vacuum vessel thermal shield (foreground, centre) and the lower cryostat thermal shield (foreground right, and background). To the left, a lifting frame that will support vacuum vessel thermal shield sectors as they are lifted to vertical and installed on the large pre-assembly tools.

In the pit

2020-10-15

Standing inside the Tokamak pit, where the welding of the cryostat lower cylinder to the cryostat base has started. A metrology instrument is visible on the tall pole at left.

The shine

2020-10-15

The component's shine is due to the thin layer of silver that covers its entire surface. A "low emissivity" material, silver raises an obstacle against the thermal radiation, in the form of electromagnetic waves, that a heat source generates.

Readying an assembly tool

2020-10-15

This sector lifting tool will be positioned between the heaviest components to be lifted into the giant sector pre-assembly tools in the Assembly Hall and the hooks of the overhead cranes. A control system can be activated through controllers and electrically driven actuators to optimally balance the loads.

Like a candle

2020-10-15

In this photo, the metrology tower in the centre of the pit looks a lot like a candle. Perhaps for ��ϲʸ��'s 10 years of construction? (Building works on the platform began in August 2010.)

Two types of thermal shield

2020-10-14

Panels of cryostat thermal shielding have arrived at the Assembly Hall from Korea, alongside larger sections of vacuum vessel thermal shielding.

Close inspection

2020-10-14

This outboard panel of thermal shielding is undergoing careful inspection.

Walking inside the machine

2020-10-09

All is silver steel at the bottom of the Tokamak pit in October 2020. © Les Nouveaux Médias/SNC ENGAGE

A big job

2020-10-07

It will take several months to weld the cryostat upper cylinder to the cryostat base. Work started in October.

Cryostat welding has begun

2020-10-07

Deep in the Tokamak pit, welders working for the Indian Domestic Agency have begun root passes in the welding of the cryostat lower cylinder to the cryostat base.

Creating a clean area

2020-10-07

The thermal shield panels must be kept as clean as possible prior to their installation on the sector sub-assembly tools. Once the clear area is established and the component uncovered, assembly workers will only approach with gowns, hair covers, shoe covers, etc.

Two-sided welding

2020-10-07

Technicians from MAN Energy Solutions (contractor to Larsen & Toubro, the enterprise chosen by the Indian Domestic Agency to manufacture the cryostat) work by pair on the in-pit welding of the cryostat.

Peeking in

2020-10-07

Looking through a penetration in the cryostat lower cylinder into the machine assembly area.

Tool in testing

2020-10-01

Soon, three types of components will be lifted into the first Sector Sub-Assembly tools in the Assembly Hall: a vacuum vessel sector, a pair of toroidal field coils, and inboard and outboard thermal shield panels. This tool, in testing now, will lift and "upend" the inboard thermal shield panel.

A smaller upending tool

2020-09-29

One massive upending tool (background, lying flat) will raise ��ϲʸ��'s vacuum vessel sectors and toroidal field coils to vertical; two others will do the same for the lighter inner and outboard sectors of vacuum vessel thermal shielding. This outboard sector upending tool has just been detached from the giant SSAT tools where it was tested.

Metrology on vacuum vessel #6

2020-09-28

The first vacuum vessel sector has passed all site acceptance tests and is now being measured from every angle by the metrology teams. (Look closely to see the metrology targets.)

Gravity supports for the toroidal field coils

2020-09-24

Eighteen of these 2.65-metre-tall gravity supports will be bolted to the cryostat base to support the outer edge of the toroidal field coils. The full gravity load of the ��ϲʸ�� magnets (10,000 tonnes) will be transferred to the cryostat through these marvels of engineering delivered by China. They are next in line for delivery to the Tokamak pit.

A new workshop

2020-09-22

This new workshop will be operated by the DYNAMIC consortium, which was formed to execute one of ��ϲʸ��'s two main machine assembly contracts, TAC2 (Tokamak Assembly Contract 2). The workshop will be a space for repairs and retrofitting, and boasts two milling machines, a large CNC (Computer Numeric Control) machine, and spaces for welding and metrology.

On the base pedestal

2020-09-17

The cryostat lower cylinder is still on hydraulic jacks as final alignment activities are carried out and the first tack welds are performed.

Shrek?

2020-09-17

With the distortions of a fisheye lens, this vacuum vessel sector reminds us of Shrek—the (all-green) cartoon character with ears that look a lot like these port extensions.

Magnet feeder elements arriving

2020-09-10

This giant semi-circular component is destined for installation under the machine. It is part of a magnet feeder—the components that deliver cryogens and electrical power to the superconducting magnets.

Joining two components in the pit

2020-09-09

The assembly teams in the Tokamak pit are preparing for the root welding of the cryostat lower cylinder to the pedestal of the cryostat base. Mechanical cleaning of the bevel has been completed; next, the cylinder will be locked to the base through bridge piece welding and the alignment tool will be removed.

Warming up

2020-09-09

This large tool—the "upending tool"—will lift some of ��ϲʸ��'s heaviest components to vertical so that they can be installed in the vacuum vessel sub-assembly tools (left). Warm-up tests are underway.

That's 1,600 tonnes of steel

2020-09-09

The two major Tokamak components already installed in the pit—the cryostat base and lower cylinder—represent 1,600 tonnes of steel. Welding operations to join the two pieces begin this week.

Concentrating

2020-09-04

Contractors prepare the metrics for another round of upending tool lift tests. © Les Nouveaux Médias/SNC ENGAGE

Sector #6 is leak tight

2020-09-02

The first ��ϲʸ�� vacuum vessel sector has passed a helium leak test on site with flying colours, confirmed to be leak tight to two orders of magnitude better than acceptance criteria.

Up and over

2020-08-31

The massive component spent more than four hours suspended from the overhead cranes as it was lifted, transferred across the Assembly Hall, and lowered. Here, it clears the tallest assembly tools by just a few inches.

Weighty

2020-08-31

On the screen in red flashes the weight under one of the four crane hooks. The total load was approximately 480 tonnes (330-tonne coil plus rigging).

Lower cylinder is aloft

2020-08-31

This 375-tonne steel cylinder is the second section of the cryostat to be installed in the Tokamak pit. The operation, which was carried out on 31 August, went off without a hitch.

Exacting tolerances

2020-08-31

Not only does the component have to clear the tight tolerances that separate it from the walls as it descends, but its many openings (called penetrations) have to line up precisely with corresponding openings in the bioshield.

Second module moved to assembly zone

2020-08-31

On 6 September, the second central solenoid module, which had been delivered in October 2021, joined the first in the dedicated assembly zone at the far end of the Assembly Hall. The remaining five modules (including one spare) are in the final stages of fabrication at General Atomics in California and expected at ��ϲʸ�� by mid-2023.

Full shop

2020-08-22

The lower cylinder is just passing through. After approximately one week of preparation, metrology measurements, and trial lift tests, the 10-metre-tall lower cylinder will be lifted up and over the crowded shop floor of the Assembly Hall and lowered into the Tokamak pit.

Cryostat lower cylinder: next up in line

2020-08-22

The lightly wrapped cryostat lower cylinder—30 metres in diameter, 375 tonnes—is seen through the open doors of the Cryostat Workshop, right before its transfer into the Assembly Hall.

Plenty of space

2020-08-22

Just in time, the vacuum vessel sector that had recently been delivered from Korea was moved to the other side of the building, and its travel platform and casing were removed.

Into the airlock

2020-08-22

The component first enters the Cleaning Facility, and the doors are shut behind it, before the rolling doors of the Assembly Hall are pulled back.

Transfer successful

2020-08-20

On Friday 20 August, 490 tonnes (sector plus frame) were successfully lifted, transferred 40 metres, and redeposited on supports on the other side of the Assembly Hall.

Leapfrog

2020-08-20

The teams in the Assembly Hall are organizing the transfer of vacuum vessel sector #6 to a location on the other side of the building, across from the sector pre-assembly tools. Room must be made for the next large component expected to enter through the large double doors—the cryostat lower cylinder.

Making room

2020-08-20

The component is now directly across from the sector sub-assembly tools (SSATs), where it will be pre-assembled with a pair of D-shaped magnet coils and thermal shield panels.

At the bottom of the assembly arena

2020-08-12

Inside of (and on) the machine base, the assembly teams are busy with all kinds of preparatory activities. Before August ends, the lower cylinder of the cryostat will join the base in the Tokamak pit in ��ϲʸ��'s second major lift operation.

Then the other

2020-08-12

This 440-tonne steel component travelled 10,000 km to reach ��ϲʸ�� after it was finalized at Hyundai Heavy Industries in Korea.

First one

2020-08-12

Operators use the cranes to lift the first protective layer off the steel component.

First of nine

2020-08-12

Each vacuum vessel sector will be paired with two toroidal field coils and thermal shielding on the giant sector sub-assembly tools in the Assembly Hall. Sector #6 (pictured) will be the first to undergo this suite of assembly operations; sector #7, also from Korea, will be the next. Today, S#7 is 94% complete at Hyundai Heavy Industries.

Lid off

2020-08-11

The travel box around vacuum vessel #6 has been removed. Next in line: two layers of protective foil.

Inside the hall

2020-08-10

A panoramic view of the Assembly Hall that shows the largest assembly tools and the newly arrived vacuum vessel sector #6. (It also, by a quirk of perspective, erases or flattens the people passing by...)

First vacuum vessel sector enters Assembly Hall

2020-08-07

Vacuum vessel sector #6 arrives from Korea on 7 August 2020. This will be the first sector mounted on the giant sector sub-assembly tools in the Assembly Hall for pairing with thermal shield panels and a pair of toroidal field coils.

Join ��ϲʸ��'s start-of-assembly ceremony!

2020-07-27

On 28 July, the ��ϲʸ�� project will be livestreaming its start-of-assembly ceremony from 10:00 a.m. local French time. To log into the livestream, see our YouTube page.

Thermal shield lift frame: tests underway

2020-07-22

In the ��ϲʸ�� Assembly Hall, another pair of assembly tools designed and procured by Korea—the thermal shield frames—are undergoing tests without load. These frames will support tall panels of thermal shielding as they are lifted to vertical for installation of the sector sub-assembly tools.

Toroidal field coil #13 arrives from Japan

2020-07-03

A second toroidal field coil, TF13 from Japan, arrives at ��ϲʸ�� on 3 July. TF13 will be paired with TF12 (also from Japan) and Korea's vacuum vessel sector #6 to form the first 1,200-tonne sub-assembly of ��ϲʸ��'s vacuum vessel.

A warehouse for coil preparation

2020-06-30

Two coils—TF9 (Europe) and TF12 (Japan)—are now on temporary stands in a coil preparatory building not far from the Assembly Hall for pre-assembly operations.

PF6 arrives!

2020-06-26

Procured by Europe and manufactured in China, the ring-shaped magnet coil PF6 will be the first to be integrated into the ��ϲʸ�� machine. The massive component arrived on site on Friday 26 June 2020 after a 10,000-kilometre voyage from its manufacturing site in Hefei, China.

Unwrapped at ��ϲʸ��

2020-06-20

This is toroidal field coil #12, from Japan, seen in an ��ϲʸ�� workshop without its transport frame.

First piece installed

2020-05-28

First piece installed The first piece of the ��ϲʸ�� Tokamak—the soup-dish-shaped base of the cryostat (1,250 tonnes)—was lowered into the Tokamak pit on 26 May. It fit perfectly. Photo: ��ϲʸ�� Organization/EJF Riche

Engineering as art 3/3

2020-05-28

An artistic adaptation of a photo of the cryostat base insertion by German photographer Christian Luenig. © Christian Luenig

Pre-assembly work on the toroidal field coils

2020-05-28

For the moment, the toroidal field coils already delivered to ��ϲʸ�� are in a staging facility, where welds in the helium piping can be leak-tested and additional handling and pre-assembly equipment can be added. In this photo, TF9 from Europe.

27 assembly-phase lifts

2020-05-27

The upending tool will enter into action 27 times during ��ϲʸ�� assembly (not counting lift tests) in order to upend 18 toroidal field coils and 9 vacuum vessel sectors.

Resting at last

2020-05-27

Hydraulic jacks will support the 1,250-tonne component until the load is transferred to the cryostat support bearings.

A bit of low tech

2020-05-26

However sophisticated the technologies involved, there comes a moment when ancient tooling and methods come in handy. Here, a plumb bob attached to the component gives a clear visual indication of verticality.

Perfectly clean

2020-05-26

Perfectly clean The machine assembly "well" is perfectly clean and ready to receive machine components. The 18 cylindrical cryostat support bearings are clearly visible, like jewels in the supporting crown.

Rolling along the rails

2020-05-26

Forty-five metres above the shop floor, the crane rails run 170 metres from the Assembly Hall to past the Tokamak pit. Photo: ��ϲʸ�� Organization/EJF Riche

A tight fit

2020-05-26

A tight fit At the mouth of the pit, the distance from the rim of the cryostat base to the wall is approximately 50 centimetres. It gets smaller as the component descends into the depths of the concrete cylinder, reducing to only 5 centimetres at the level of the crown.

Major machine assembly milestone

2020-05-26

On Tuesday 26 May, the first major machine component—the cryostat base—is lifted by overhead crane and lowered into the Tokamak assembly pit.

Countdown to liftoff

2020-05-26

Following close to one week of preparation, tests, measurements and rehearsals, the teams are now confident enough to launch the actual operation. (Photo Gérard Lesénéchal - ��ϲʸ�� Organization)

Engineering as art 2/3

2020-05-26

An artistic adaptation of a photo of the cryostat base sitting on hydraulic jacks, by German photographer Christian Luenig. © Christian Luenig

First major machine component

2020-05-26

This first machine component was procured by the Indian Domestic Agency through the industrial giant Larsen & Toubro. Steel segments fabricated in India were assembled on site in the Cryostat Workshop by teams from Larsen & Toubro and MAN Energy Solutions (welding).

All with a joystick

2020-05-26

Orders are transmitted to the crane system through a console equipped with a radio control transmitter. Communication between the French operator from the crane manufacturer and the Chinese movement coordinator from the CNPE consortium is done through an interpreter.

Watching as it passes

2020-05-26

Standing in one of the bioshield's portholes, a technician from the CNPE consortium watches in awe as the cryostat base almost brushes the inner walls of the pit.

Overhead

2020-05-26

The cryostat base travelled up and over the equipment in the Assembly Hall and into the Tokamak Building—a voyage of approximately 150 metres.

Fisheye

2020-05-26

The slow descent of the base is photographed with a fisheye lens. Photo: ��ϲʸ�� Organization/EJF Riche

Perfect fit

2020-05-26

The 1,250-tonne machine base has just the room it needs to enter the Tokamak pit.

Engineering as art 1/3

2020-05-26

From the rafters

2020-05-25

Seen by drone in the very rafters of the Assembly Hall, the cryostat base is ready to be lifted. Photo: ��ϲʸ�� Organization/EJF Riche

Penultimate test

2020-05-20

Every aspect of the lift operation has been choreographed and practiced in advance of the big day. In one critical test on 20 May, the cryostat base is lifted six metres and then set back onto its supports.

Spreading the load

2020-05-20

Between the overhead heavy lift cranes and the component are yellow "spreader beams" that share the weight of the component and eliminate any tilt.

18 cryostat bearings

2020-05-13

A set of 18 spherical bearings, evenly spaced and deeply anchored into the "crown," will bear the full weight of the machine and, acting as ball-and-socket joints, will enable the smooth transfer of horizontal and rotational forces.

Match exactly

2020-05-13

The pedestal of the cryostat base will be affixed to the female lugs seen here in the wall of the bioshield (steel rectangles). To meet these interfacing pieces, the base must be positioned as it is lowered with a tolerance of +/-5 mm.

30 metres deep

2020-05-06

Two sets of overhead cranes (2 x 750 tonnes and 2 x 50 tonnes) will be responsible for the ballet of activity as components ready for installation are picked up in the Assembly Hall and brought to the 30-metre deep Tokamak pit. Photo: Gérard Lesénéchal

On the pit floor

2020-05-06

Painted and cleaned, everything is nearly ready in the Tokamak pit for the first machine components. Photo: Gérard Lesénéchal

The base of the machine

2020-05-04

Two weeks remain before the first "big lift" of ��ϲʸ�� assembly. Preparatory works are underway to prepare the component for handling and the Tokamak pit for receiving.

��ϲʸ��'s assembly arena

2020-05-01

Machine components make a first stop in the Cleaning Facility (right) before entering the Assembly Hall. After pre-assembly and installation activities, the components are moved by overhead crane to the Tokamak pit. © Les Nouveaux Médias/SNC ENGAGE

TF12 delivered

2020-04-25

Toroidal field coil #12 (TF12) reaches the ��ϲʸ�� site from Japan on 25 April 2020. Gathered around the certificate of acceptance are representatives of the ��ϲʸ�� Organization and ��ϲʸ�� Japan. In the background is the upper cylinder of the ��ϲʸ�� cryostat moving out of India's on-site workshop to a storage location.

First machine component enters building

2020-04-17

First machine component enters building The cryostat base enters the Cleaning Facility on a self-propelled modular transporter that has 192 wheels. Photo: ��ϲʸ�� Organization/EJF Riche

First ��ϲʸ�� magnet arrives on site

2020-04-17

A little before 2:00 a.m. on Friday 17 April, toroidal field coil #9 arrives at the ��ϲʸ�� site. The 360-tonne component is one of ten toroidal field magnets to be delivered by Europe. (Japan will deliver another nine.)

Cryostat base enters building

2020-04-17

Cryostat base enters building Installation contractors have moved the cryostat base from its fabrication workshop on site into the Assembly Hall. (The big lift to the Tokamak Building will take place next month.) The Indian Domestic Agency has delivered the completed component in collaboration with main contractor Larsen & Toubro Heavy Engineering (manufacturing design, segment fabrication in India and assembly at ��ϲʸ��) and MAN Energy Solutions, Germany (Larsen & Toubro sub-contractor for on-site welding).

Getting ready

2020-04-02

The Tokamak pit is nearly ready for its first machine component: 18 cryostat bearings are in place on the cryostat crown, contractors are finalizing painting and cleaning, and captive components have been installed in areas that will be blocked once the cryostat base has been lowered.

Pit revealed

2020-04-02

As the last segment of the lid is raised, we have access to a spectacular view of the 30-metre-deep assembly pit.

The lid is off

2020-04-02

Standing at the end of the Tokamak Building, looking over the Tokamak pit toward the Assembly Hall. The temporary lid has been removed and installation activities are about to start.

Removing the temporay lid

2020-04-02

The temporary lid over the assembly pit is made of 11 segments ranging in weight from 10 to over 80 tonnes. They have to be removed, one by one, to make way for machine assembly.

Testing the path before the real loads

2020-03-28

Totaling approximately 1,000 tonnes, the mock loads are ready to undertake their 170-metre-long journey from the entrance of the Assembly Hall all the way to the opposite end of the newly created crane hall. Testing the load path, and carefully monitoring building inflection as the loads go by, are part of the last commissioning activities before machine assembly.

Preparing for episode one

2020-03-26

As the European Domestic Agency puts the finishing touches on work in the Tokamak pit (painting, cleaning), ��ϲʸ��'s Construction Management-as-Agent contractor MOMENTUM is preparing for the first episode of machine assembly: the lowering of the cryostat base.

Open for assembly

2020-03-26

There is no longer a barrier separating the Assembly Hall from the Tokamak Building. In the next step, the temporary lid over the machine assembly pit will be dismantled and removed.

Assembly theatre

2020-03-26

The ''assembly theatre'' is a vast space that encompasses the assembly and crane halls. In the foreground, the opening of the assembly pit; in the background (past the twin sector sub-assembly tools), the cryostat base is being groomed for the upcoming assembly operations.

Team spirit

2020-02-25

Under the supervision of the ��ϲʸ�� Organization, upending tool testing was coordinated by MOMENTUM (��ϲʸ��'s Construction Management-as-Agent). It involved Apave (security), contractors from the assembly consortium DYNAMIC, an operator, and an engineer from crane manufacturer REEL.

Pre-assembly preparations

2020-02-24

The upending tool is lifted off the floor so that metrologists can measure the planarity of its support pads.

Dancers in a vertical ballet

2020-02-19

Acrobatic workers are busy disassembling the temporary wall that separates the Assembly Hall from the Tokamak Building.

First component upended

2020-02-18

A panel of outboard thermal shield for vacuum vessel sector #6 has been installed on one of the sector sub-assembly tools. For the giant tool, it represented the first ''embrace'' of an actual machine component.

Back in service

2020-02-14

Two 360-tonne test loads are back on the main tools of the Assembly Hall. With extra weight added, they will be used to commission the overhead cranes in the new crane hall of the Tokamak Building. The temporary wall between the buildings is coming down now.

Next to test: the upending tool

2019-12-13

Tool commissioning is an important activity, during which the all specified functional requirements are demonstrated. Also, for tools sourced outside of the European Union, it is the occasion to show compliance with EU regulations.

Load tests conclusive

2019-11-27

The commissioning phase for the twin sector sub-assembly tools (SSAT) in the Assembly Hall is over. The final verification tests—with test load (photo)—demonstrated that both tools are performing to expectation.

Upending tool arrives

2019-11-14

The two halves of the upending tool (right) are headed for installation in the far right corner of the Assembly Hall, on the area of floor that has been painted.

The doors open and ...

2019-11-07

... the segments of the upending tool, delivered by Korea, enter. This large structure is designed to "upend" ��ϲʸ��'s largest components (toroidal field coils and vacuum vessel sectors) from horizontal to vertical.

Shift of weight

2019-09-30

In late September, the second 360-tonne load (at left) was transferred to SSAT tool #2 (on the right). After one month of functional tests on the second tool, the loads will be removed and stored until needed for the testing of the "upending" structure that has been shipped by Korea.

Rotated completely

2019-09-04

The wings of the first sector sub-assembly tool (SSAT1) have been fully rotated inward and the tool has performed as expected. Later this month, the mock loads will be transferred to SSAT2. Both tools will enter service in 2020.

First cryostat bearing

2019-09-04

First cryostat bearing Eighteen semi-spherical bearings anchored deep in the Tokamak support crown will act like ball-and-socket joints under the pedestal of the cryostat to allow the smooth transfer of forces generated during machine operation. The first one has been installed.

Two mounted

2019-07-23

Two mock loads were built in Scotland by Doosan Babcock and shipped to ��ϲʸ�� for assembly. They represent a combined weight of 700 tonnes, now mounted on the tool SSAT#1. Rotational tests begin late in July.

A little push by hand ...

2019-07-22

Even in the most technical of operations, there is always a need for final adjustment by hand. Seen vertically, the loads share the D-shape of the toroidal field coils they are meant to represent. They also reproduce the centre of gravity and mass distribution of the coils.

Coming in

2019-07-12

At the bottom of the Tokamak pit, different openings allow for the arrival of electricity, cryogens and instrumentation. In the picture, placeholders have been pre-positioned. © Les Nouveaux Médias/SNC ENGAGE

The pit, all aglow

2019-07-03

Raw concrete in the Tokamak assembly pit has given way to the smooth shiny surface of white paint. Teams have been working to complete the job in this 25,000 cubic-metre space since early March; now only finishing touches remain to prepare for machine assembly.

Lower galleries

2018-12-06

This opening in the 3.5-metre-thick bioshield was specially designed to house the part of the feeder that crosses through the bioshield and cryostat—the feedthrough. Thirty-one feeders in all will find their way through galleries like this to reach the ��ϲʸ�� magnets.

"As installed"

2018-12-06

At the bottom of the machine assembly pit, the first metal component has been inserted into its bay. Metrologists are recording its "as-installed" position, as this component will be assembled with two other sub-assemblies to form the full magnet feeder for poloidal field coil #4. Thirty-one feeders in all will deliver electricity, cryogens and instruments to the ��ϲʸ�� magnets.

Installed!

2018-12-06

Into the slim opening of the cryostat crown: a break in the concrete had been left by building contractors for the installation of the cryostat feedthrough for poloidal field coil #4. The operation was successfully carried out on 6 December 2018.

Lifelines

2018-11-27

Feeders will reach the magnets by either crossing through the lower level of the bioshield—passing under the machine—or through the top level, passing over.

Through the opening

2018-11-26

Through the opening The magnet feeder component passes through one of the openings of the temporary bioshield lid. This lid will remain in place until the Tokamak Building roof is completed.

Watching from below

2018-11-26

Watching as the 200-tonne upending frame and its 360-tonne load are raised to vertical.

The first one

2018-11-26

The cryostat feedthrough begins its 30-metre descent—the first metal component of the ��ϲʸ�� machine to enter this space.

First of many

2018-11-26

The feeder array for the ��ϲʸ�� magnets is composed of over 100 main components. This one was scheduled for delivery ahead of the others because of its particular shape and its installation configuration at the lower level of the Tokamak Pit.

Tests completed

2018-11-26

The first metallic component to be installed in the machine pit—a feeder component—had been delivered by China for testing to the Magnet Infrastructure Facilities for ��ϲʸ�� (MIFI), next door on the CEA site, one year ago. On 26 November 2018, it was positioned outside of the Tokamak Complex for lifting.

Diagnostic cables

2018-09-05

The plasma inside the vacuum vessel is monitored in real-time by a vast array of magnetic sensors, thermocouples and accelerometers. Data, vital for machine operation, is transmitted by cables of the type that is seen here in a temporary "bundle." Once the vacuum vessel is in place inside the pit, the cables will be pulled through trays across the cryostat feedthroughs and connected to the corresponding diagnostic systems.

Waiting on the first piece

2018-09-05

Looking straight up through the machine "well" where an opening in the temporary roof will allow the first machine component to be introduced in December. © Les Nouveaux Médias/SNC ENGAGE

Small "barnacles"

2018-09-05

Like barnacles on a stranded whale, hundreds of small cylindrical devices called "bosses," some perfectly aligned, others distributed in a seemingly haphazard fashion, pockmark the grey skin of the component. (In yellow are the attachment points for blanket modules.)

Room for the bend

2018-09-05

The first machine element to be installed in the pit is an elbow-shaped feeder component. It will be slid into place through this break in the crown. © Les Nouveaux Médias/SNC ENGAGE

23,000

tonnes

1,000,000

components

1,200

engineering packages

10

years

Assembly challenges

Alignment

Accurate alignment, particularly of the magnet system and in-vessel components, is essential to the successful operation of the machine. Dimensional control is critical to ensuring that tolerances are respected, and to recording the "as-built" status of the machine, which will be directly compared against ��ϲʸ��'s Computer-Aided-Design (CAD) models in order to correct eventual deviations in alignment before they accumulate. Positional tolerances for the largest components, including the magnet coils and the vacuum vessel, are as low as 2 mm. (For more information, see Metrology.)

Ultra-high and high vacuum

��ϲʸ�� will host one of the largest and the most complex high vacuum systems ever built. To ensure correct machine performance, all connections associated with ultra-high vacuum or high vacuum components must be 100 percent leak-tight. Vacuum lines, helium lines, pipes, valves, seals, joints, and/or flanges have all gone through pre-qualification, while some of the largest vacuum components—for example, the seals manufactured for the vacuum vessel‘s 50+ large ports—are being tested on dedicated test rigs. For in-pit assembly, only qualified welding procedures, carried out by certified professionals, are employed, and the quality of all vacuum-related welds is verified by surface and volumetric non-destructive examination. Full-scale leak testing is planned during the integrated commissioning period before the Start of Research Operations, in which the large vacuum chambers—the vacuum vessel and the cryostat—are evacuated and leak tested. In parallel, the ��ϲʸ�� Organization is developing a set of specialized tools and technologies for the localization and detection of leaks smaller than the width of a human hair divided by one million.

Logistics

The ��ϲʸ�� Organization and its assembly partners are managing a large volume of assembly activities—such as major lifting operations, handling/positioning, mechanical fixation, welding, cabling, pipe work, metrology, non-destructive examination, and leak testing—all in the extremely crowded environment of the Tokamak pit and the Tokamak Complex. Close coordination between assembly contractors and supervision teams is crucial.

Vacuum vessel welding

Welding the ��ϲʸ�� vacuum vessel and ports inside of the assembly pit will require several years, a large skilled team, and a host of customized techniques and tools. The welding tools will have to manoeuvre the complex geometry of the sectors and ports and reach areas that are not directly accessible to operators and where visibility is restricted. The robots will also be confined to welding from inside the vessel and ports, as the pre-installed vacuum vessel thermal shield makes access to the exterior surfaces impossible. Extensive trials on mockups have been performed to quantify and plan for shrinkage and deformation, and to qualify tools, processes, and inspection techniques.

French nuclear regulations

As the nuclear operator of the ��ϲʸ�� installation, the ��ϲʸ�� Organization has an obligation to ensure that safety and security standards are implemented and enforced throughout construction, manufacturing, assembly, and operation in compliance with the Host country's safety and security regulations. All activities related to a safety-important or protection-important component or system (for example ��ϲʸ��'s first confinement barrier, the vacuum vessel) must be performed correctly and documented as verified through regular surveillance and inspection.

Interfaces

Once delivered to the site, the interfacing elements for a number of large components such as the ��ϲʸ�� blanket and the divertor have to be customized to comply with precise alignment requirements. Assembly contractors will have to use dimensional control and reverse engineering to plot out this customization, and must provide the workshop space, tooling and expertise to carry out the work on short timescales.

Schedule

Throughout Assembly Phase I, the ��ϲʸ�� Organization will rely heavily on the on-time delivery of components and systems from the seven Domestic Agencies. Any delay related to fabrication or transport risks disrupting the carefully planned assembly sequences, especially for time-critical components such as the magnets or the vacuum vessel sectors.

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