安全注入系统逆止阀密封性试验影响因素分析与改进

Analysis and Improvement of Influencing Factors of Sealing Test of Check Valve in Safety Injection System

安全注入系统(RIS)逆止阀密封性试验是核电厂换料大修主线上一项必不可少的工作,且逆止阀的密封性直接影响机组的核安全。若大修机组启动期间出现逆止阀密封性试验不满足验收准则的情况,逆止阀解体检查需将机组状态大幅后撤,造成大修关键路径大幅延误。本文通过深入分析RIS系统逆止阀密封性的试验原理及影响因素,完善大修逆止阀密封性试验预案,并规范试验方法,优化了试验步骤的逻辑顺序,在面临由于试验边界阀密封不严而导致试验结果不满足验收准则时,采用估算的方法对阀门的实际泄漏率进行核算和评估,避免对试验结果误判,对提高试验的可靠性具有重要参考价值。

The sealing test of the safety injection system(RIS)check valve is an indispensable work on the main line of the refueling overhaul of the nuclear power plant,and the sealing of the check valve directly affects the nuclear safety of the unit.If the sealing test of the check valve does not meet the acceptance criteria during the start-up of the overhaul unit,the disassembly inspection of the check valve needs to greatly withdraw the state of the unit,resulting in a significant delay in the critical path of the overhaul.In this paper,through in-depth analysis of the test principle and influencing factors of the sealing performance of the check valve of the RIS system,the test plan for the sealing performance of the overhaul check valve is improved,and the test method is standardized,and the logical sequence of the test steps is optimized.When the test results do not meet the acceptance criteria due to the lax sealing of the test boundary valve,the actual leakage rate of the valve is calculated and evaluated by the estimation method to avoid misjudgment of the test results,which has important reference value for improving the reliability of the test.