Underground research laboratories (URLs) are essential to provide the scientific and technical information and practical experience that are needed for the design and construction of nuclear waste disposal facilities, as well as for the development of the safety case that must be presented at various stages of repository development.

This report provides an overview of the purpose of URLs within repository development programmes; the range of URLs that have been developed, or are planned, in NEA Member countries to date; the various contributions that such facilities can make to repository development programmes and the development of a safety case; considerations on the timing of developing a URL within a national programme; and the opportunities and benefits of international co-operation in relation to URLs.