European Programme on High Temperature Reactor Nuclear Physics, Waste and Fuel Cycle Studies

This project represents a collaborative R&D programme in the field of HTR-related nuclear physics, waste and fuel cycle studies (HTR-N) and is funded by the European Commission in the HTR-N and HTR-N1 contracts of the 5th Framework Programme (FP5). The paper illustrates the nuclear physics analyses of first criticality of the Japanese High-Temperature Test Reactor (HTTR) and of the Chinese 10 MWth High-Temperature Reactor (HTR-10). Reasons for discrepancies in the predictions of critical core configuration of HTTR are explained. Further activities deal with different fuel cycles aimed at effective burning of plutonium and minor actinides. First studies, for first generation plutonium (Pu-I) from reprocessed LWR uranium fuel, show that it is possible to reduce the fissile Pu content by up to 90%. Work continues on a symbiotic fuel cycle for LWR and HTR by burning of 2nd generation plutonium (Pu-II) from reprocessed spent LWR MOX fuel in an HTR core still maintaining HTR safety features with regard to nuclear stability and self-acting decay heat removal. Both, block-type and pebble fuel are analyzed. Studies on burnable poison and on uncertainties of nuclear data are included into the HTR-N programme. R&D on waste minimization options and experiments and first results on long-term behavior of spent HTR-fuel is reported, too.