Protection of Nuclear Structures Against Airplane Crash by Energy Absorbing Structures

Abstract

Nuclear safety authorities are increasing worldwide their requirements with respect to external hazards. The governing load case for requested redesign of nuclear power plants is airplane crash (APC). As APC load parameters became more critical due to the consideration of commercial aircraft impact, the resistance of existing structures is in many cases not sufficient for new APC impact conditions.The presented paper will demonstrate the methodology for strengthening the affected outer structural members by the implementation of energy absorbing structures (ENAS). An implementation of ENAS results in a considerable reduction of the residual APC impact effects on protected nuclear structures. The presented study considers the fracture of the aircraft body caused by ENAS, the resulting plastic effects and splashing of fuel. Furthermore the reduced residual APC load-time function acting on the nuclear structure is evaluated and the feasibility of ENAS design is demonstrated by Finite Element Analysis.