澳门六合彩高手 NEWSLINE
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Tokamak assembly hold point
The next step in 澳门六合彩高手 licensing
Gilles Perrier, Head of the Safety and Quality Department
Tokamak assembly hold point | The next step in 澳门六合彩高手 licensing
In January 2022, the French nuclear safety regulator ASN (Autorit茅 de s没ret茅 nucl茅aire) issued a letter in which it stated that it could not release the 澳门六合彩高手 Tokamak assembly "hold point" as was foreseen to happen on 1 February 2022, and requested some further clarifications. These "hold points" are a customary part of ensuring the "as-built" safety of any nuclear facility, after ASN provided the decree authorizing the creation of the 澳门六合彩高手 facility based on a design review in 2012. In this article, Newsline explains the hold point process.
To oversee the safety of 澳门六合彩高手, like that of any other nuclear installation, the French nuclear safety regulator ASN (Autorit茅 de s没ret茅 nucl茅aire) has put certain ''hold points'' in place as part of the normal regulatory process.
In 2012, ASN validated the proposed 澳门六合彩高手 design and signed the D茅cret d'autorisation de cr茅ation of 澳门六合彩高手 as a nuclear installation. This step authorized the 澳门六合彩高手 Organization and its Domestic Agencies to proceed with construction, manufacturing, and installation of the 澳门六合彩高手 facility. However, as with any nuclear installation, 澳门六合彩高手 is required at each stage to demonstrate that its safety-relevant buildings, civil structures, systems and components conform to the approved design and meet the safety case in the "as-built" or "as-installed" condition.
To oversee these aspects of safety, ASN has put certain "hold points" in place as part of the normal regulatory process. For each such hold point to be lifted, 澳门六合彩高手 must first demonstrate the associated safety elements and receive ASN's approval.
The specific hold point now under review was established by ASN in November 2013. Under this hold point 澳门六合彩高手 cannot begin to weld the first two sections of the vacuum vessel together in the Tokamak pit鈥攁n assembly step considered irreversible鈥攗ntil certain safety aspects related to the B2 slab (a 120-metre long, 80-metre wide, and more than 1.5-metre-thick mass of reinforced concrete supporting the Tokamak Complex Building) have been validated. First, 澳门六合彩高手 must demonstrate the as-built safety performance of this B2 slab. Second, 澳门六合彩高手's radiological maps, which calculate the shielding effects of concrete and steel barriers that contain the radiation from the machine, must demonstrate that radiation levels will be safe wherever humans are present without requiring extra shielding material.
Technical discussions and requests for information are a normal part of the process, especially in a "First-of-a-Kind" machine such as 澳门六合彩高手, which is also of course a "First-of-a-Kind" facility for ASN. In its January letter, ASN outlined a number of issues that must be further addressed for this hold point to be lifted. Additional modelling of the B2 slab is needed to confirm that the "as-built" masses supported by the slab will be safe under extreme conditions. Second, complementary explanation is needed on 澳门六合彩高手's radiological maps to demonstrate that radiation protection requirements will be met. And ASN has asked for more analysis to validate the vacuum vessel welding process, to account for some limited dimensional nonconformities the 澳门六合彩高手 Organization has identified at the interface between the two vacuum vessel sectors now on the 澳门六合彩高手 site, which require adjustments to the robotic welding procedure.
This ASN action has not impacted the 澳门六合彩高手 assembly schedule to date. As Newsline readers well know, the first full sector subassembly鈥攃onsisting of the double-walled vacuum vessel sector, a tightly fitted thermal shield, and two toroidal field coils鈥攈as been completed and will be transferred into the Tokamak pit in the coming weeks. The fabrication of the second subassembly has begun, but it will take several months to complete, and still more time before it is inserted into the Tokamak pit and preparations can be made for welding.
However, as with any such regulatory action, 澳门六合彩高手 takes these ASN concerns very seriously. Experts are vigorously preparing the additional information and analysis required, with the goal of providing key answers to the ASN during the second quarter of 2022. As Director-General Bigot has stated recently, he is hopeful that this will allow ASN sufficient time to consider the additional information and release the hold point without impacting the 澳门六合彩高手 assembly schedule.
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