Review and comparative assessment of helium-cooled divertor concepts

Within the european power plant conceptual study (PPCS) started in 2000 it is planned to integrate a Helium cooled blanket with a divertor using the same coolant. The present work is intended to focus research on concepts that are capable of withstanding the large heat fluxes expected for the divertor. Five divertor plate concepts - two from the first phase of the PPCS, one variation, and two concepts from the literature - are assessed on the basis of consistent assumptions and operating parameter ranges. While thermohydraulic performance is judged by maximum wall temperatures and pressure drop, thermal stresses are estimated based on temperature differences across the cooling channel. The results show that thermal stress is the limiting quantity for all concepts. They confirm that (i) a large heat transfer coefficient on the fluid side; (ii) the delivery of low temperature coolant to the First Wall, i.e. a flow path transversal to the First Wall; and, (iii) the use of refractory metals are key elements of a Helium cooled divertor. (orig.)Available from TIB Hannover: ZA 5141(6597) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman