MSR_B4 - A New, Scale Based, Fuel Burnup and Fission Product Removal Tool for the IMSR

Abstract

During the IMSR reactor operation, the molten fuel salt constantly circulates throughout the reactor. There are natural removal mechanisms of fission products (FP), mostly noble gases (NG) and noble metals (NM) from the fuel salt, due to their limited solubility. The fuel salt continuously evolves due to fission, NG and NM removal and addition of makeup fuel salt. A Perl-based, MSR_B4, tool was developed using SCALE 6.2.4 to simulate the fuel salt evolution in the IMSR. This paper describes the tool and its use. The MSR_B4 connects the KENO-VI neutron transport module with the COUPLE module for a generation of one-energy group cross-section library. The ORIGEN code, with its capability for continuous feed of makeup fuel and removal of NM and NG, is used to deplete the fuel salt. The OPUS module generates the KENO-VI fuel compositions for the next depletion cycle. The MSR_B4 keeps track of the fuel salt inventory, as well as the inventories of the removed noble metals and gases. The tool also calculates the amount of the added makeup fuel salt and the total fuel salt volume in the reactor. Comparisons to the alternate design fuel evolution simulations based on EQL0D are shown.