Review of Transient Analysis and Accident Simulation Codes for Nuclear Reactor

Abstract In the background of global carbon emission reduction, nuclear energy plays an important role in mitigating global warming. Safety is the cornerstone of nuclear energy development. Nuclear reactor transient analysis and accident simulation codes can be used for safety assessment to evaluate the design and operation of reactors, thus reducing the occurrence of nuclear accidents. Efficient nuclear reactor transient analysis and accident simulation codes can also help operators make decisions in emergencies. In this paper, we review the past nuclear reactor transient analysis and accident simulation codes for LWR and some advanced reactors. We summarize and classify different codes. We find that the system analysis codes mainly include thermo-hydraulic models, reactor dynamic models, and control models. Overall the code size is huge and the computational cost is high. Local transient analysis codes are less computationally intensive and more accurate for, for example, the simulation of transients introduced by reactivity. The integrated transient analysis code combines the advantages of each code, but it requires data transfer between different codes, resulting in high computational costs. The accident process simulation code focuses on the presentation of the accident evolution trend. This paper also describes the future direction of transient analysis and accident simulation codes. Both the transient analysis code and the accident simulation code will need to become more specialized and more generalized in the future. Accurate physical models and computational efficiency are important for transient analysis codes. Speediness and lightweight are important for accident simulation codes. Finally, the role of AI in code model design is presented.