Mitigation and Treatment of Accidents in HPR1000 SGTR

HPR1000 provides mitigation measures for accidents in SGTR in the design. It can prevent SG overfill and mitigate SGTR accident by many means, such as decreasing the shutoff head of the safety injection pump and providing functions of fast cooling, automatic isolation and automatic control of auxiliary feedwater, and post-accident discharge of the blowdown system. The origin and mitigation measures for HPR1000 SGTR accidents are analyzed, and the process of accident treatment is described. Effectiveness of the mitigation measures to prevent SG overfill is verified, to satisfy the acceptance criteria for the radiological consequence of HPR1000.