Development and Presentation of the Drigg Post-Closure Safety Case

Drigg is an operational facility for the near-surface disposal of solid low level radioactive waste (LLW). The disposal facility is located in Cumbria, north-west England, near the Sellafield nuclear site, and is owned and operated by British Nuclear Fuels plc (BNFL). Disposals at Drigg are carried out under the terms of an authorisation granted by the UK Environment Agency. Periodically the Drigg authorisation is subject to formal regulatory review. The current regulatory guidance, 'Disposal Facilities on Land for Low and Intermediate Level Radioactive Wastes: Guidance on Requirements for Authorisation' (the GRA) was published in 1997 and contains guidance on the principles and requirements against which the Environment Agency will consider applications for disposal authorisation. BNFL has undertaken to produce an updated Drigg postclosure safety case (PCSC) in September 2002 to support the next authorisation review. In preparation for this, BNFL published a 'Status Report on the Development of the 2002 Drigg PCSC' in March 2000. This paper discusses the main components of the Drigg PCSC and how they relate to each other. Central to the safety case will be a systematic, post-closure radiological safety assessment (PCRSA). However the main focus of this paper is on the other main components of the PCSC which are presented in conjunction with the PCRSA to make a complete and integrated safety case. In addition other confidence building activities which are key to developing and presenting the safety case are discussed, in particular communications with the stakeholders