Nirex is responsible for the development of a deep geological repository for the disposal of solid intermediate-level and some low-level radioactive waste. In 1991 an area near Sellafield, West Cumbria was chosen as the focus for further investigations following preliminary investigation of two sites. The Nirex Science Programme is directed at establishing the suitability, or otherwise, of the site at Sellafield to host the deep repository. This requires, amongst other things, that an assessment be developed of the post-closure performance of a repository located there and that this assessment should be supported by information from a suitably designed research programme.
The Nirex Safety Assessment Research Programme (NSARP) is a wide ranging programme providing detailed understanding and data on the physical, chemical and biological processes that may be of relevance to repository post-closure safety together with mathematical models describing the way that these processes operate and interact. The NSARP is principally concerned with improving our knowledge of two important pathways, groundwater and gas, through which radionuclides may return to the human environment and it is supplemented by a more engineering-orientated programme of research into the Nirex Reference Vault Backfill. Current Status Reports are intended to provide an overview of the research programme and so help to document its development. They rely on detailed information contained in Nirex reports and other documents in the public domain. The Nirex reports referred to here are mostly Nirex Safety Series (NSS) reports or the Nirex Science reports that have been introduced recently. All these reports have been produced by contractors partly or fully funded by Nirex and working under Quality Assurance arrangements which are either in strict accordance with BS5750 or, particularly for some of the earlier reports, in keeping with its intent.