Abstract
The Molten Salt Reactor (MSR) Multiphysics Applications technical area in the Nuclear Energy Advanced Modeling and Simulation program has supported the development of 3D Monte Carlo models of the Molten Salt Breeder Reactor (MSBR) over the last couple of years. This MSBR model was previously run with the Shift Monte Carlo code to perform radiation shielding calculations in the reactor cell area. The MSBR is a 2250 MWth (1000 MWe) liquid-fueled molten salt reactor design developed at Oak Ridge National Laboratory in the 1970s. Determining the source terms from activated primary heat exchanger (HX) components is important because delayed and prompt neutron fluxes incident on these components affect the dose rate in the primary HX maintenance areas. This information can be used in the development of remote handling procedures required during shutdown for maintenance. A methodology has been developed and is proposed in this paper to quantify the activated source term from the primary HX components as a result of the movement of the delayed neutron precursors in flowing primary fuel salt through the primary HXs in the MSBR. The goal of this research is to evaluate the gamma dose rates in the maintenance hatches above the primary HX using the activated HX source terms. The study showed that the gamma dose rates are approximately two orders of magnitudes higher when accounting for the neutron activation from the movement of delayed neutron precursors through the HXs than when flowing fuel is not considered. Thus, the movement of delayed neutron precursors must be taken into account for accurately predicting the neutron activation of primary loop components.
| Original language | English |
|---|---|
| Article number | 110276 |
| Journal | Annals of Nuclear Energy |
| Volume | 199 |
| DOIs | |
| State | Published - May 2024 |
Funding
This research was supported by the US Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Program Non-LWR Application Drivers Technical Area , which is under the direction of Dr. E. Shemon and Dr. C. Permann. This research made use of Idaho National Laboratory computing resources, which are supported by the US Department of Energy Office of Nuclear Energy and the Nuclear Science User Facilities under Contract No. DE-AC07-05ID14517 . Notice: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan)The authors would like to acknowledge Dr. F. Bostelmann and B. Hiscox at ORNL for their invaluable feedback on this work and paper. This research was supported by the US Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Program Non-LWR Application Drivers Technical Area, which is under the direction of Dr. E. Shemon and Dr. C. Permann. This research used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the US Department of Energy under Contract No. DE-AC05-00OR22725. This research made use of Idaho National Laboratory computing resources, which are supported by the US Department of Energy Office of Nuclear Energy and the Nuclear Science User Facilities under Contract No. DE-AC07-05ID14517. Notice: This manuscript has been authored by UT-Battelle , LLC , under contract DE-AC05-00OR22725 with the US Department of Energy (DOE) . The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ) This research used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the US Department of Energy under Contract No. DE-AC05-00OR22725 . The Nuclear Energy Advanced Modeling and Simulation (NEAMS) program funded by the U.S. Department of Energy Office of Nuclear Energy (DOE-NE) aims to develop advanced modeling and simulation capabilities to enable the deployment of advanced reactors and fuels. Several technical areas within NEAMS drive the development of various multiphysics capabilities to enable coupled multiphysics simulations for light water reactors and non-light water reactors. The Molten Salt Reactor (MSR) Multiphysics Applications technical area supports the testing and validation of tools developed to support multiphysics simulation of MSRs.
Keywords
- Delayed neutron precursors
- Facility dose
- Hybrid Monte Carlo/deterministic methods
- Molten Salt Breeder Reactor
- Shift