Ten years of maintenance on Tore Supra actively cooled components

Tore Supra, the only superconducting Tokamak equipped of actively water coo led plasma facing components, has now completed 10 years of operation (1988 -1998). The associated primary pressurised water cooling loop (4 MPa at 150 degreesC) is able to exhaust a 20 MW convected or radiated power during lo ng pulses of 200 s. The first part of this paper is devoted to an inventory and analysis of the water leaks from the plasma facing and their consequen ces, such as the optimisation of the pressurised water loop emptying sequen ce. The experience gained during 10 years by maintenance operations has als o led to an improvement of the water leak detection procedure, in order to identify as accurately as possible the location of the leak. The second par t of the paper describes the improvements made on quality control of Plasma Facing Components during these last 10 years. Quality Control has been inc reased right through the technological developments and the manufacturing p rocess of mock-up, prototypes and series production. A specific helium tigh tness procedure dedicated to water cooled components has been established, consists mainly of several validation tests under pressure and temperature operating conditions. Hence reliability of the components has been largely increased. (C) 2000 Elsevier Science B.V. All rights reserved.