Consideration of the “Dual Purpose Cask Concept” in the IAEA Transport Regulations

The joint TRANSSC/WASSC Working Group (JWG) was established in April 2011, and has developed a technical document “Methodology for a Safety Case of a Dual Purpose Cask for Storage and Transport of Spent Fuel” (TECDOC-DPCSC, to be published). To follow the Terms of Reference, the WG has also recommended TRANSSC to incorporate a concept of dual purpose cask (DPC) into the IAEA Transport Regulations, SSR-6. Proposals to incorporate DPC concept to SSR-6 were first submitted to the 2013 initiated review cycle, and have been improved through discussions at the WGs in TRANSSC meetings, the consultancy meeting and the corresponding group led by Japan. In the 2015 initiated review cycle, the proposals were further elaborated and approved as one of major changes important to safety to initiate the revision cycle.SSR-6 text changes comprise the introduction of “shipment after storage” to the scope of the Regulations. A few technical and administrative requirements on packages to be used for shipment after storage have been added in order to assure transportability after storage as follows.The design of such packages shall take into account ageing mechanisms.For such packages, maintenance of package performance to comply with applicable Regulations and certificates of approval during storage shall be ensured before the shipment after storage.In an application for approval of such package designs, an Ageing Management Programme (AMP) and a Gap Analysis Programme (GAP) shall be submitted by the applicant.Guidance (SSG-26) text changes consider explanations of shipment after storage and more details of ageing consideration in package designs, additional explanations on AMP (the IAEA Coordinated Research Programme on AMP will be commenced in 2016), GAP and a countermeasure to certification lost in the country of origin of the design are included.The draft of SSR-6 with changes incorporated was provided in February 2016, and have subjected to Member States 120-day review at present. Revision process of SSG-26 is proceeding a half year later than that of SSR-6. Those revised documents are expected to be published as the 2018 Editions.