https://doi.org/10.1140/epjp/s13360-020-00628-w
Review
Coupled 3D thermal–hydraulic and neutron kinetic Relap5 model for transient analysis of a 1200-MWe nuclear PWR plant
Ansaldo Nucleare S.p.A., Genova, Italy
a
Marco.Palmero@ann.ansaldoenergia.com
Received:
21
April
2020
Accepted:
23
July
2020
Published online:
14
September
2020
This paper deals with the assessment of the fully integrated three-dimensional thermal–hydraulic and neutron kinetic modeling capability of the Relap5-3D system code. The interest in integrated system codes is growing in the field of safety analyses, where coupled three-dimensional simulations can significantly improve the level of understanding of spatial core phenomena in accident conditions. For this purpose, an asymmetric design basis accident, namely a main steam line break, has been simulated for a commercial 1200-MWe pressurized water reactor. The simulation has been performed with a one-dimensional plant model, including all the major primary, secondary and safety systems included in advanced PWR designs, upgraded with a three-dimensional thermal–hydraulic representation of the reactor vessel and a three-dimensional neutron kinetic core model. The analysis demonstrated the code capability to capture 3D core phenomena, not achievable with 1D plant model based on point kinetic.
Disclaimer: "The Westinghouse AP1000™ has been considered as reference plant, while core neutron kinetic parameters have been derived from available literature data on Three Miles Island NPP (TMI-1). It shall be clarified that the purpose of this report is limited to show 3D TH–NK coupled calculation capabilities under commercial size PWRs representative operating and design conditions, as well as under conservative assumptions made to highlight local phenomena. The results here presented shall not be considered in any way applicable or associated to the AP1000™ plant, for which the safety demonstration publicly available applies.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2020
