Report of working group MHD for the Blanket Concept Selection Exercise (BCSE)

The Blanket Concept Selection Exercise (BCSE) was performed between 1994 and 1995 with the objective to select two out of four of the most promising European DEMO blanket concepts for further development and testing in ITER. In this framework 14 working groups have been created each treating one particular technical aspect of the blankets. This report represents the result of the Working Group MHD on the magnetohydrodynamic issues of the two blanket concepts using liquid Pb-17Li, the Dual Coolant Blanket (DCB) and the Water-Cooled Blanket (WCB). Two design versions of both blanket types were considered: the reference designs use an electrically insulating direct coating either on the total surface of the structural material (DCB) or on a part of the surface (WCB). In the back-up designs the liquid metal is in contact with metal walls (MANET structure in case of the WCB and Flow Channel Inserts (FCI) for the DCB). The following issues have been identified and analysed in detail: pressure drop, heat transport, tritium transport, corrosion product generation and transport. As a separate issue, the degradation of insulation is included which comprises the effects on pressure drop and transfer processes. Weighting factors between 1 and 10 were attributed to each criterion and scores for the evaluation of the individual issues were given ranging between '0' (not relevant) and '-2'(considerable problems or not suitable). For the DCB, the critical issue is the degradation of insulation (for FCI's this issue might be less severe). Pressure drop (for intact insulation) is of medium importance and requires future R and D work. The other issues are of minor importance. For the WCB, all issues are evaluated to be of minor importance which, however, still necessitates R and D work in order to optimize the design. One topic to be mentioned is free convection flow within the blanket box. (orig.)SIGLEAvailable from TIB Hannover: ZA 5141(5652) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman