Optimization of protection against large commercial aircraft crash of HPR1000

Protection against large commercial aircraft crash is a new design requirement for international advanced nuclear power plants, and gradually becomes one of important advance characteristics. The HPR1000 demonstration NPP adopts redundant features physical isolation + Anti-Plane Crash (APC) shell as protection measure, which covers reactor building, fuel building and electrical building. However, the conservative thick double-shell is a challenge for site conditions with insufficient bearing capacity of foundation which may results in subsidence problem. In the optimized measure, balanced safety and economy to fulfill the safety acceptance criteria, the fuel building and electrical building get rid of double-shell and all the outer shells are thinner than demonstration NPP. Beside the overall analysis on the impact effects of global structure, local structure, the vibration effect is carefully evaluated by transferring acceleration vs. equipment median fragility since the vibration transfer route is much nearer of single outer shell, and the new rule sets and analysis method are adopted in fuel effect evaluation to comply with the design of duration/pressure of fire resistance of safety fire zoning. This outcome of the study enhances the safety and capability against external extreme hazards of HPR1000, and strengthens the public confidence on nuclear safety and anti-terrorism. (author)