DEVELOPMENT OF THE EU WATER-COOLED PB-17LI BLANKET

The reference concept of the EU water-cooled Pb-17Li DEMO blanket is e ssentially formed by a directly-cooled steel box having the function o f Pb-17Li container and by a double-wall U-tube bundle, immersed in th e liquid metal, in which the pressurised water-coolant flows. The stru ctural material is martensitic steel. All blanket performances satisfy DEMO requirements, such as tritium breeding self-sufficiency, capabil ity of the box-structures to withstand water-coolant pressure under fa ulted conditions, limitation of the Pb-17Li/steel interface temperatur e to 480 degrees C, power conversion efficiency of about 35%, and acce ptable increase of temperature in case of out-of-vessel LOCA. A prelim inary design of the test module and of the associated circuit componen ts to be tested in ITER has been performed taking into account ITER sp ecifications for test ports and ITER pulsed working conditions. Test-m odule DEMO-relevance has been one of the leading criteria for the modu le design. Preliminary module manufacturing sequences have been define d. The paper recalls the associated R and D activities which have to b e finalised prior to the ITER testing and mainly involve tritium perme ation barrier development, tritium extraction from Pb-17Li, advanced m anufacturing techniques, definition of water/Pb-17Li interaction count er-measures, and Li-concentration control techniques. (C) 1998 Elsevie r Science S.A. All rights reserved.