The use of glass reinforced plastic as a flask energy absorbing material

Irradiated fuel transport flasks are designed to survive impact and fire accidents without significant leakage of contents. The impact standards laid down by the IAEA include a drop test from a height of 9 meters, in the most damaging attitude, onto a flat unyielding target. This requirement leads to the incorporation of energy absorption features for impact protection. Such features may be integral with the flask body and/or lid, as seen on the CEGB's Magnox MkM2 and AGR MkA2 flasks. Alternatively, it may be operationally more convenient to have removable energy absorbers, as on most LWR flasks and the CEGB's AGR MkA1 flask. This paper is concerned with the design of removable energy absorbers and the materials which may be used in their construction. In order to address the design issues, a notional cylindrical flask of 10 ton mass is considered. To allow a design margin, and to cater for all future requirements and possible changes in regulations etc., the drop height considered is increased to 36 meters