Lessons From ITER Magnet Experience on the Need for an Improved Nuclear Quality Approach for Magnets in Future Fusion Reactors

Now that ITER magnets are nearing procurement completion, with many of them on site and being installed, there is growing interest in the next step to a tokamak fusion reactor. A big question in this next step will be the safety and reliability of the magnet system. Even before operation we have many lessons to be applied in the next step. ITER magnets are not largely safety-important components and have been produced without the appointment of an Authorised Notified Body(ANB), by the Safety Regulator. In future fusion reactors, reliability and reparability will have a higher importance than pure functionality, and construction cannot be approached with an R&D mentality. Methods and techniques for implementing quality assurance in ITER superconducting magnets started with design control, then extended to manufacturing quality control in procurement including control verification and methods for acceptance tests. Use of on-line tools such as a manufacturing database to provide the quality traceability during procurement control and non-conformities database applied to ensure conformity to fulfil the requirements over the ITER international suppliers. As a staged project, currently ITER is facing the installation process control including component identification and tracing, tool proofing, qualification of installation, inspection and test. Next will be the control of commissioning activities and verification functions until the hand over of superconducting magnets for operation. There has been remarkable progress from the ITER programme on developing and applying quality assurance, with many lessons learned. However, the examples given by incidents such as occurred in LHC, JT60-SA and ITER CS module test would not be acceptable for a nuclear reactor. We need now to review our approach to give a firm footing for DEMO QA/QC.