TRANSIENT DYNAMIC ANALYSIS OF 500 MWE PRESSURIZED HEAVY WATER REACTOR NUCLEAR DOUBLE CONTAINMENT FOR AIR CRAFT IMPACT LOAD

摘要

Non-linear transient dynamic analysis of 500MWe Indian Pressurized Heavy water Reactor (PHWR) nuclear containment has been carried out for the aircraft impact of Boeing 707-320. The case studies include the analyses of outer containment wall (OCW) single model and the combined model with outer and inner containment wall (ICW) for impulsive loading due to aircraft impact. The impulsive load time history is generated based on the momentum transfer of the crushable aircrafts (soft missiles) of various categories such as Boeing and Airbus families on the containment structure. Initially the load is applied on OCW single model and subsequently the load is transferred to ICW after the local perforation of the OCW is noticed in the transient simulation. In the first stage of the analysis it is demonstrated that the OCW would suffer local perforation with a peak local deformation of ～117 mm without loss of the overall integrity. However, this first barrier (OCW) cannot absorb the full impulsive load. In the second stage of the analysis of the combined model, the ICW is subjected to lower impulse duration as the load is transferred after 0.19 sec due to the local perforation of OCW. This results in the local deformation of ～ 115 mm for ICW and together both the structures (OCW and ICW) are capable of absorbing the full impulsive load. The analysis methodology evolved in the present work would be useful for studying the behavior of double containment walls and multi barrier structural configurations for aircraft impact with higher energies. The present analysis illustrates that with the provision of double containments for Indian nuclear power plants, adequate reserve strength is available for the case of an extremely low probability event of missile impact due to commercial aircrafts operated in India.