Study into the possibility of using two groups of accelerated preventive protection for VVER-1200 reactors

Considering present opportunities for modernizing accelerated preventive protection (APP) for VVER-1200 reactors, a methodology for selecting two APP groups is presented. Using the described methodology and selection criteria, two APP groups (APP1 and APP2) are selected for modes of disabled RCPSs and two electric feeding pumps during operation at a rated power level. The study represents an important stage in the modernization of the safety algorithm, i.e., accelerated preventive protection of the reactor. The results presented in the article are relevant for research and development purposes, as well as for safety analysis.