SUMMARY

The next generation of nuclear reactor systems is under active development and with them the next generation of modeling and simulation (M&S) methods. As the breadth of this next generation of nuclear reactors is so large, ranging from gas-cooled fast spectrum reactors to liquid-salt fueled ones, one can benefit from employing a single, well-developed simulation tool and tailoring it to their specific needs. This approach carries with it additional considerations, however, as nearly all mature M&S suites were developed to simulate traditional light water reactor systems. Unique characteristics of novel reactor systems, such as moving fuel and on-line material removals, complicates their ability to be analyzed by contemporary M&S code, but does not preclude it entirely.
The research presented herein outlines a process for characterizing the major radiological source terms, necessary for licensing activities, one would expect in a liquid-fueled molten salt reactor. This process leverages organic simulation tools in the SCALE M&S code suite to provide an ‘off-the-shelf’ solution for shielding assessments of this reactor type. Ultimately, this source development process is applied to a generic molten salt reactor system to assess the impact of ex-core source terms in varying shielding conditions. The results of the analysis determined while the prompt core source is the major dose contributor outside the radiological shielding, specific ex-core features, such as salt sampling tanks, can have an appreciable dose impact and thus must be accounted for.