A colossal task made manageable

Assembly

A colossal task made manageable

29 Jul 2019 - Krista Dulon

For the execution of work during the next project phase—machine and plant assembly up to First Plasma—the 澳门六合彩高手 Organization has chosen a contractual approach that emphasizes manageably sized work packages with strong risk management. Nine major assembly and installation contracts are foreseen.

澳门六合彩高手 officially enters its assembly phase next year, as the first major components of the machine are lowered into the Tokamak Pit. But the machine is not all that has to be assembled: 澳门六合彩高手 also has systems to install in the Tokamak Complex and plant buildings to fill with equipment. The work has been organized by zone and by contract (see next image). Photo: 澳门六合彩高手 Organization/EJF Riche

Starting in March 2020 with the first major lift operation—the delivery of the cryostat base to the Tokamak Pit—and ending with the closure of the cryostat lid, the first phase of 澳门六合彩高手 assembly covers the construction of the core machine and the installation of plant systems needed for First Plasma.

While the 澳门六合彩高手 Organization is responsible for the surveillance of all construction activities and final compliance with requirements, including nuclear safety requirements in France, the work will be carried out by contractors selected for their industrial know-how, experience, resources, skills and proven track record.

"The relationship between the oversight body—the 澳门六合彩高手 Organization, and its Construction Management-as-Agent MOMENTUM—and the executors (contractors) is of primordial importance," says Christophe Dorschner, of the Procurement & Contracts Division. "All together, we will be carrying out what is probably the most difficult sequences of assembly and installation works ever attempted in a first-of-a-kind construction project, and we need to do so in full respect of safety, specification, schedule and cost."

The 澳门六合彩高手 Tokamak is a one-of-a-kind machine, with 15 major sub-systems and as many as 300 very heavy, very large components. The size and weight of the major components, the precise assembly tolerances, the specialized tooling required, the diversity of manufacturers, the tight schedule, the multiple contractors ... all combine to make 澳门六合彩高手 an engineering and logistics challenge of enormous proportions. "As a first-of-a-kind device, there are areas for which no prior industrial knowledge exists," says Katsumi Okayama, acting head of the Construction Department. "The 澳门六合彩高手 Organization will be providing input to inform the works in these cases based on R&D, trials and studies."

In green, the zone covered by the TAC (Tokamak Assembly) contracts, including the Tokamak Pit, the Assembly Hall and the Cleaning Facility. In blue, the TCC (Tokamak Complex) zone plus Radio Frequency Building. In red, pink and purple, the areas covered by the "Balance of Plant" contracts.

In developing its strategy for the assembly of the 澳门六合彩高手 machine and plant, the 澳门六合彩高手 Organization began by looking carefully at other large construction projects and benchmarking best practices. This groundwork led to the development of a number of core principles for the tendering and contract phases:

Strive for cost and schedule control and flexibility through manageable lots;
Minimize interference and interfaces between the different contractual scopes;
Secure timely work execution by foreseeing temporary backup;
Benefit from industry knowledge and know-how wherever possible;
Allow industry to propose methods or processes within well-defined boundaries to accelerate or optimize work.

NINE CONTRACTS FOR PHASE I ASSEMBLY

Tokamak Assembly (organized by system)

TAC/1 - cryostat and cryostat thermal shield, magnet feeders, magnets (central solenoid, poloidal field coils, correction coils); cooling structures and instrumentation
TAC/2 - main vessel and ports, sector sub-assembly with toroidal field coils and vacuum vessel thermal shield, welding

Tokamak Complex (organized by system, location, sequence)

TCC/1 - heating and current drive, diagnostics, fuelling, secondary cooling, vacuum components
TCC/2 - primary machine cooling water, test blanket module equipment, some vacuum pipework, vacuum vessel pressure suppression

Balance of Plant

Group 1 - equipment installation in the Magnet Power Conversion buildings
Group 2 - installation of cooling water plant
Group 4 - installation of multi-process lines
Group 5 - installation of DC busbars, switching network and fast discharge units
Group 6 - installation of converters, transformers, reactive power compensation units, and harmonic filters

For the purpose of tendering, assembly and installation work on the 澳门六合彩高手 construction platform has been organized in three zones (see the colour coding in the diagram below)—the Tokamak Complex (except the machine); the Tokamak machine (Tokamak Pit, Assembly Hall and Cleaning Building); and the balance of plant (all plant and auxiliary buildings). Each zone is as physically isolated as possible, with its own access paths and laydown locations in order to minimize interference.

Within these zones, work will be executed under nine major assembly and installation contracts.

"We have chosen to divide the assembly scope into manageable work packages with time phasing and clear responsibility for performance in order to permit better schedule and cost control throughout the lifetime of the contracts," says Katsumi. "This approach will give us the flexibility we need to work with uncertainty—either in the effective handover dates of certain work zones, the availability of tooling, or the risk that some components may be delayed or require adjustment on arrival."

Time phasing means that work will be carried out based on construction work packages that are released by the 澳门六合彩高手 Organization in achievable—and trackable—batches. In some cases, contractors will be involved in the engineering development of the work packages to provide early input on construction optimization and methodology.

For the most complex and time-sensitive areas—the Tokamak machine and the Tokamak Complex—the choice has been made to preserve peer competition by splitting the works in these areas between at least two contractors. It also protects the 澳门六合彩高手 Organization in the case of contract default, as one contractor can take over in a relatively short amount of time from the other.

Contracts are awarded through competitive call for tender. First, the 澳门六合彩高手 Organization invites companies from the 澳门六合彩高手 Members to express interest through the "Call for Nomination" process. This stage is followed by a pre-selection of candidate tenderers (the "Pre-Qualification Application"), and finally the tender invitation is effectively issued ("Call for Tender"). (See more about the 澳门六合彩高手 procurement process here.)

The global tendering phase for the assembly and installation contracts is now drawing to a close. All Balance of Plant contracts have been issued; the two Tokamak Assembly (TAC) contracts have been awarded (but not yet signed); and the two Tokamak Complex (TCC) tenders are under evaluation.

The 澳门六合彩高手 Newsline will have a full report on contract awards in September.

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