Radioactivity and decay heat analysis of the MNSR with HEU and LEU fuels using the GETERA code

摘要

The knowledge of the decay heat of nuclear fuel is necessary for performing the reactor safety analysis. In this study, analysis of the radioactivity, decay heat and the isotopic mass variation with time post the shutdown of the Miniature Neutron Source Reactor (MNSR) for the potential LEU fuels (U_3Si_2-Al, U_3Si-Al, U_9Mo-Al, 19.75% enriched and UO_2, 12.6% enriched) and the existing HEU fuel (UA1_4-A1, 90% enriched) have been performed using the GETERA code. The results showed that the total radioactivities were 2.13E05, 2.58E05, 2.59E05, 2.13E05 and 2.57E05 Ci, and the total decay heats were 1379.9, 1677.0, 1677.2, 1380.6 and 1672.6 W instantly after the reactor shutdown for the LEU and HEU-UA1_4 cores respectively. Finally, good agreements were noticed between the analytical, ORIGEN-2 and GETERA results.