核容器焊接质量疲劳可靠性评估的试验研究

AN EXPERIMENTAL STUDY OF ASSESSMENT OF WELD QUALITY ON FATIGUE RELIABILITY ANALYSIS OF A NUCLEAR PRESSURE VESSEL

秦山30万千瓦核电设备中的蒸汽发生器,是国产关键设备之一。对该蒸汽发生器焊接质量进行疲劳可靠性评估的试验研究,旨在根据国产核容器用钢S-271的疲劳性能测试结果,通过对该容器底封头模拟装置试验数据分析,为国家核安全局进行质量审评提供参考依据,并作为秦山核电工程概率安全评价的补充。按照美国机械工程师学会《锅炉及压力容器规范》第三分篇有关条款的要求进行了模拟试验,提出了两种方法进行可靠性定量求解。

The steam generator in PWR primary coolant system is one of the equipment made by our own country in Qinshan Nuclear Power Plant of China. It is a crucial unit belonging to the category of nuclear pressure vessel. The purpose of this research work is to make an examination of the weld quality of the steam generator under fatigue loading and to assess its reliability by using the experimental results of fatigue test of material of nuclear pressure vessel steel S-271 (Chinese Standard) and of qualified tests of welded seams of a simulated prototype of bottom closure head of the steam generator. A guarantee of weld quality is proposed as a subsequent verification for China National Nuclear Safety Supervision Bureau. The results of reliability analysis reported in this work can be taken as a supplementary material of Probabilistic Safety Assessment (PSA) of Quinshan Nuclear Power Plant. According to the requirement of Provision Ⅱ-1500 cyclic testing, ASME Boiler and Pressure Vessel Code, Section Ⅲ, Rules for Construction of Nuclear Power Plant Components, a simulated prototype of the bottom closure head of the steam generator was made in this work for qualified tests. To find the quantified results of reliaability assessment by using the testing data, two proposals are presented in this paper.