Technical Basis for Regulatory Guidance on Design-Basis Hurricane-Borne Missile Speeds for Nuclear Power Plants

摘要

The report documents the approach to and results of the calculation of hurricane-borne missile speeds for the design of nuclear power plants. The missile spectrum, the assumptions on which the calculations are based, and the range of wind speeds being considered, were based on discussions between the authors and NRC staff. Four types of missiles were considered in Regulatory Guide 1.76 (RG 1.76), Revision 1, entitled 'Design-Basis Tornado and Tornado Missiles for Nuclear Power Plants'. In order to provide an adequate coverage, Three more types of missiles (one plate-like missile and two plank-like missiles) were included in the missile spectrum. Such missiles arise from dislodged metallic siding attached to Non-Seismic Category buildings during a tornado event. It is a safety concern that those wind-borne siding missiles may compromise structural integrity of the neighboring nuclear island Seismic Category I structures.