Subcompartment Pressurization Analysis Following Feedwater Line Break Accident using Realistic Evaluation Model

Abstract

Currently, a high energy line break in the Main Feedwater Piping Area of Kori Unit 1 Nuclear Power Plant would be not vented through the room doors and ventilation dampers. Therefore, modifications to the wall design should be done to demonstrate that the Main Feedwater Piping Area walls are structurally sound during the feedwater line break event. The modifications to the wall design are minimized through the Realistic Evaluation Methodology. The purpose of this paper is to present the pressurization analysis of the Main Feedwater Piping Area in the event of feed water line breaks using the Realistic Evaluation Methodology, which consists of simulation of the response of the Nuclear Steam Supply System using RETRAN-3D code and generation of the realistic conservative Mass and Energy release rates through the break using the enveloping pressure curve to bound the RETRAN-3D calculated break pressure, and calculation of the optimized differential pressure of the Main Feedwater Piping Area using COMPARE/MOD1A code. Based on the Realistic Evaluation Methodology, a blowout panel with vent flow area of at least 14 m2 will be designed and installed to help control the room pressurization and to meet the wall structural design criteria of 0.02Mpa.