文中对过一台反应器爆炸事故进行现场勘察、分析了爆炸原因,用断裂力学观点解释了事故发生的原因,指出开裂性质是低应力脆断。并采用应力强度因子法评定与验证,结论为缺陷是不可接受的,必产生爆炸。针对事故原因,从设计、制造、使用诸方面提出预防事故发生措施,避免此类事故再次发生。 In this paper, a reactor explosion was investigated on site, the cause of the explosion was analyzed, the reason of the accident was explained by the view of fracture mechanics, and it was pointed out that the nature of cracking was low stress brittle fracture. And the use of stress intensity factor assessment and verification method, the conclusion is not acceptable defects, will produce an explosion. In view of the cause of the accident, measures should be taken to prevent accidents from being designed, manufactured and used so as to prevent such accidents from happening again.