표준형 원전 2차계통 수격현상 분석 및 방지방안 연구

Abstract

ABSTRACT

Analysis and Study on Water Hammer Prevention Measures in KSNP Secondary System

By Cho, Dong Ki Adviser : Prof. Lee, Goung Jin, Ph. D. Department of Nuclear Engineering, Graduate School of Chosun University

Water hammer in nuclear power plant has occurred for a variety of reasons, mainly in the secondary system. Although water hammer is not threaten directly the safety of nuclear reactor, in the long term, water hammer can disturb the plant operation and cause damage to the equipment, such as piping, piping supports and welded joint. Water hammer, which is one of the thermal-hydraulic instability can occur at any time and requires close attention because it can be a factor to inhibit the safety and reliability of the equipment of a nuclear power plant. Water hammer occurred in KSNP has been mostly occurred during start-up, shut-down operation, it occurred in a two-phase fluid flow environment due to the condensation of steam, such as HP HTRs connection pipe, SGBD connection pipe, deaerator connection pipe. In this study, we analyzed the physical phenomena and processes occur, root cause for each mechanisms that water hammer most often characteristic equipment and systems to a common occurrence in KSNP secondary system. In addition, we analyzed the causes based on the operating conditions of the water hammer occurs, and established and applied water hammer prevention measures. This report could be applied to similar industries suffering water hammer. It could be referred for further studies to analyze and retrofit equipments related to water hammer in NPP.