Dr. Ningbo Lei, Senior Engineer, China Nuclear Power Engineering Co., Ltd, Beijing, China.

Speech Title: Overview of methods for vessel integrity maintenance under severe accident in PWR

Abstract: The PWR vessel contains the whole core and almost all the radioactive products. After severe accident, core will be molten due to loss of cooling and relocate to the lower head of vessel finally. In this situation if the integrity of vessel could be maintained by various methods, mass fraction of radioactive products will be retained in the vessel and the accident consequence will be mitigated. After Fukushima accident, Chinese government raises the “practically elimination” request to the NPP in plan, and it is a meaningful approach to meet this request by maintaining the integrity of vessel after severe accident. In this paper, the methods of maintaining integrity of vessel implemented in mainstream advanced PWR are classified and introduced by the decay heat removal approach.