Reliability and Availability Assessments for the Next European Torus

To achieve its targets in reasonable time, the Next European Torus (NET) must be operated with considerable reliability and availability (R&A). Therefore, failure modes, effects, and criticality analysis (FMECA) of the overall plant and of its major components is already being performed as the design evolves. The present status of the R&A work is described in four steps: First, the R&A targets envisaged for the NET operation are discussed. Then an FMECA covering the overall plant is described, and a more detailed FMECA of major components is presented concerning the toroidal field coil system; plasma heating systems; protection, instrumentation, and control system; first wall and blanket, as well as the cooling system. Finally, the R&A results are compared with the targets, and measures for improvements are given.