Structure and capabilities of the VVER simulator developed for use in performing independent expert calculations in the framework of the expert reviews of design-basis justifications for BDBA and SAMG procedures are descripted.
The VVER simulator is intended for simulation of beyond-design-basis accidents, including severe accidents, in accelerated mode, as well as in real time, both without taking into account, and taking into account the operations personnel actions on accident management. The simulator allows performing a through calculation of beyond design basis accidents from the initial state to fuel severe damage, including the in-vessel and out-of-vessel stages of accident. This simulator can be adapted for each of NPP units with VVER-1000, VVER-1200 and VVER-TOI.
The VVER simulator mathematical model includes models of a reactor facility (based on certified CMS code), and a model of the in-vessel and out-of-vessel stages of a severe accident. Such set of computational models corresponds to the scope of modeling implemented in the accident analysis in the safety analysis report.
Use of VVER simulator in supporting expert reports is relevant, since the performance of independent calculation analysis allows either confirming the Applicant's conclusions or substantiating the Experts' comments, which increases the expert review quality. In addition, the simulator can be used for the educational process, as well as in Rostechnadzor the crisis center, as a tool for performing quick estimates and predictive calculations. As it is further developed, the scope of verification of its computational models will accumulate.
Keywords: simulator, independent expert calculations, design-basis justifications for BDBA and SAMG procedures.
Article language: Russian. Pp. 14–27. DOI: 10.26277/SECNRS.2021.99.1.002.
