WAGR 6m3 Boxes, Re-license as IP-2 Transport Package under IAEA SSR-6 Transitional Arrangements

In September 2017, Sellafield Ltd. successfully applied for re-licence of the Windscale Advanced Gas Reactor (WAGR) 6m3 boxes as IP-2 packages under the IAEA SSR-6 Transitional Arrangements. The transitional arrangements allow packages not requiring competent authority approval to be transported in the future, when properly maintained, based on compliance with the 1985 Edition of the regulations. As a result, packages prepared in accordance with the 1985 or 1985(As Amended 1990) Editions of the Transport Regulations may be stored for many years prior to further shipment, so long as they are prepared for transport prior to a defined date. The WAGR 6m3 boxes were designed to provide containment and shielding of the dismantled WAGR pressure vessel and core during storage, transport and disposal to a geological disposal facility. The packaging design is essentially a rectangular box with top entry, made from reinforced concrete. Internal voids are filled with grout and a reinforced concrete lid is cast. The maximum weight of the complied package is 50 tonnes. In 1994 the Atomic Energy Authority successfully applied for an IP-2 transport licence under the 1985 (As Amended 1990) edition of the IAEA regulations for the safe transport of radioactive material. In a programme spanning 12 years, the decommissioning of the reactor pressure vessel and core led to the production of 110 intermediate level waste and 75 low level waste WAGR 6m3 boxes, resulting in an overall packaged volume of approximately 2500 cubic metres containing the estimated 460 cubic metres of the reactor structure. The package design safety report was maintained by UKAEA and a licenced granted under the 2005 edition of the IAEA regulations until June 2009. As of September 2017, 106 6m3 boxes remained in storage in a dedicated facility on the Sellafield site. To increase space for storage of ILW in this facility, Sellafield Ltd. took over the design authority role in a bid to re-licence the WAGR 6m3 boxes under IAEA SSR-6 transitional arrangements. This application was successful and the first boxes were transported to LLWR in the summer of 2018.