Precursor Based PTS Screening Methodology of the EOP Operator Actions for PWR Plant

Abstract

The reactor pressure vessel integrity must be preserved throughout the plant operation as well as in the postulated accidental conditions. Operator actions undertaken to mitigate consequences of the accidents should not increase the probability of Pressurized Thermal Shock transients (PTS), transients with high pressure in reactor coolant system and interaction of cold safety injection water and hot vessel wall, which can damage reactor pressure vessel. In order to provide bounding analysis for the development of the Emergency Operating Procedures (EOP) background analysis, precursor based PTS screening methodology was used, according to determined criteria, to select the most severe PTS scenarios for two loop Pressurized Water Reactor (PWR) Nuclear Power Plant (NPP). In order to bound asymmetrical behavior of the two loop plant, selected transients were further analyzed with vertically split reactor vessel model and precursor based analysis was made for the results of the split reactor vessel analysis. The results of these analyses have been used as boundary conditions for the two-dimensional FEM reactor vessel integrity analysis.Copyright © 2011 by ASME