Multiphysics Simulation of Fission Gas Production and Release in Light Water Reactor Fuel

fission gas;light water reactor;nuclear fuel;modeling and simulation;MPACT;BISON;Nuclear Engineering and Radiological Sciences;Engineering;Nuclear Engineering & Radiological Sciences

Rose, MichaelManera, Annalisa ;

University of Michigan

关键词: fission gas;    light water reactor;    nuclear fuel;    modeling and simulation;    MPACT;    BISON;    Nuclear Engineering and Radiological Sciences;    Engineering;    Nuclear Engineering & Radiological Sciences;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/140807/mprose_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Along with a recent trend in nuclear engineering of coupling codes to perform high-fidelity, multiphysics simulations, the MOOSE application Redwing was developed to couple the neutron transport and core simulator MPACT and the fuel performance program BISON in order to simulate light water reactor (LWR) fuel pins. Redwing enables two-way data transfer of intrapin fields such as power density and temperature in order to improve the prediction of fission gas release and the overall accuracy of the simulation. An original algorithm was developed to enable transfer of fission gas data between MPACT and BISON, referred to as fission gas coupling. A fuel pin model based on the Watts Bar Nuclear 1 reactor was created, and several aspects of the model were studied: radial mesh and time step sensitivity, the effect of fission gas coupling on a single pin at constant power, and the effect of fission gas coupling on a fuel pin array that undergoes a shutdown. The results show that fission gas coupling has a significant effect on the solution for fuel pins at high power and high burnup, causing an approximate 9% increase in fission gas released to the plenum. It was hypothesized that changes in output quantities of interest (QOIs) were mainly due to a change in the fission gas source. So, a fissionable nuclide-dependent fission gas source was implemented in the Sifgrs module of BISON to test this; results showed some improvement in QOIs compared to standard BISON simulations. Although the fissionable nuclide-dependent source did not have the same effects as enabling fission gas coupling in Redwing, results showed that improving the fission gas source prescription for BISON can capture some effects of fission gas coupling. The fissionable nuclide-dependent source requires further study to validate it. Apart from fission gas coupling, this research illustrated a few little-discussed ways that coupling neutron transport, nuclide depletion, and fuel performance simulations can effect QOIs usually associated with fuel performance. For one, capturing the time dependence of the recoverable energy released per fission has a significant effect on several QOIs in high-burnup fuel. Another important physical quantity derived from the neutron transport solution is the fast neutron flux in the cladding, which has a large effect on cladding creep rate.