Fuel Assembly Design for High Seismic Sites

摘要

Fuel assembly spacer grids must maintain the fuel rods in a coolable array during and following an earthquake whenrnthey will be subject to impact loads. This can be a challenging requirement at a high seismic site. If a preliminary corernseismic analysis indicates that the spacer grid impact loads exceed the strength of the spacer grids, design modification ofrnthe fuel assembly may be necessary. Modifying the fuel assembly design requires an understanding of the effects ofrnindividual design parameters on the dynamic behavior of the fuel assembly. With this understanding, the necessary designrnmodifications can be determined. In this study, dominant parameters affecting the integrity of a fuel assembly have beenrnexamined to determine appropriate design parameters for application to a fuel assembly subject to high seismic loads.rnBased on these parametric studies, guidelines for fuel assembly design under high seismic loads are provided.