DESIGN & APPROVAL TESTING OF THE DN3705 TYPE-B & DN3726 TYPE-A \"NESTED\" CONTAINERS

This paper summarises the design and approval testing of a new family ofTypeA and Type-B medium-size container. It also discusses some of their operational features Following a review of its packaging operations in the mid-1990s. AEA Technology decided to replace the small-to medium size ON 0399 Type-A design of \"nested\" containers (Figure I) which had served the industry for many years This was to maintain consistency with the latest IAEA regulations for Type-A packagings which require safe operation down to temperatures of- 40\"C. The opportunity was also taken to upgrade the containers in other ways to make them more versatile units For example. an adaptation of the ne\"' Type-A design includes a drain feature on each container to facilitate drying when used in ponds The Type-A family has the generic design number D. ·3726 To capitalise on this initiative two designs of Type-B ··overpack\" were also introduced . one to permit operation of the Type-As with gamma-emitting radioactive contents. and the second to permit neutron-source materials to be carried. The Type-B arrangement is designated the DN3705 These containers entered service progressively throughout 1997