核电厂反应堆功率运行工况下安全壳隔离阀泄漏对安全壳密封性影响的评价方法研究

Evaluation Method of the Influence of Containment Isolation Valve Leakage on Containment Seal under Reactor Power Operation in Nuclear Power Plant

核电机组安全壳内、外侧机械隔离阀的密封性直接影响到反应堆第三道屏障的完整性,测量或评估安全壳隔离阀的密封性是核电厂安全监督的一项十分重要的工作。一般情况下都会在机组停堆检修期间,用仪器设备直接对其进行有计划的系统性的测量,但在反应堆功率运行工况下,由于不具备直接测量的条件,如何准确评估安全壳隔离阀的密封性变得十分棘手。文章提出了一种在反应堆功率运行工况下对安全壳隔离阀泄漏率进行测量的方法,进而分析其对安全壳完整性影响,并以核取样系统(REN)安全壳隔离阀REN121/131VP为例说明该方法的具体应用,为今后处理类似问题提供了一种思路。

The sealing of the inner and outer mechanical isolation valves of the containment of nuclear power units directly affects the integrity of the third barrier of the reactor, and measuring or evaluating the sealing of the containment isolation valves is a very important work in the safety supervision of nuclear power plants. In general, during the shutdown and maintenance of the unit, a planned and systematic measurement will be carried out directly with the instrument and equipment, but under the operating condition of the reactor power, due to the lack of direct measurement conditions, how to accurately evaluate the sealing of containment isolation valves becomes very difficult. In this paper, a method of measuring the leakage rate of containment isolation valve under reactor power operating condition is presented, and its influence on containment integrity is analyzed. Taking the nuclear sampling system(REN) containment isolation valve REN121/131VP as an example, the concrete application of this method is illustrated, which provides an idea for dealing with similar problems in the future.