Demonstration of the Structural Performance of Ensa’s ENUN 24P in Impact Scenarios in Storage and Transportation

The ENsa UNiversal ENUN 24P is a dual purpose metal cask developed by Ensa for dry storage and transportation of up to 24 PWR non-damaged, high burnup, spent fuel assemblies.The ENUN 24P cask design meets the principal international storage and transportation regulations for high radioactive material from the IAEA (SSG-15 and SSR-6), as well as those standards required for the licensing in Spain by the Spanish Safety Council (CSN). In addition, it has been also designed to comply with regulations from the US Code of Federal Regulations (10 CFR 71 and 10 CFR 72) and recommendations from the US Nuclear Regulatory Commission. The ENUN 24P cask is currently under licensing process for transportation in Spain and China.Structural performance of the ENUN 24P cask in the tipover accident scenario of storage, 0.381m drops accident scenario of storage, 1m drop onto a punch accident scenario of transport, as well as penetration impacts in normal condition of storage and transport, have been simulated by state-of-theart explicit transient finite element methods and evaluated against the design requirements of Section III, Division 1 and Division 3 the ASME Boiler and Pressure Vessel Code.For the analyses of the accident impact scenarios, the finite element models consisted of the complete package modelled in detail and in three dimensions, to take into account the details in the geometry and the complex interaction between the components.This paper presents the analysis methodology and modelling technique as well as the brief discussions on the behaviour of the cask in the base down drop as an example.