CLOSURE OF A CHAMBER IN THE RICHARD UNDERGROUND REPOSITORY

摘要

Underground disposal of low and intermediate level radioactive waste from nuclear research,medicine and industrial applications has been carried out at the Richard Underground Repositorynear Litomě?ice, in the Czech Republic since the mid nineteen-sixties. Currently, some 25,000waste packages, mostly 200-liter drums, are disposed of at Richard. In January 2000, theRadioactive Waste Repository Authority of the Czech Republic (RAWRA), established by theAtomic Act in 1997, took over into its possession the repository, and is now responsible for siteoperation. The atomic act requires preparing a general plan for repository closure including asafety assessment demonstrating the long-term safety of the disposal system. In compliance withthis requirement, RAWRA has developed a preliminary plan for the Richard repository closure,based on existing data and on general information on backfilling materials, as well as a SafetyAssessment of the proposed disposal system. Additionally, RAWRA has undertaken a series ofpreparatory activities, leading to closure of several disposal chambers, particularly those with“historical waste”. In 2003 RAWRA launched an international call for tenders for thedevelopment of the repository closure concept and for the detailed design of the closure of achamber in the Richard Repository. This project, financed by the European Union, will set up thebasis for the realization of the closure of a selected disposal chamber at Richard to be carried outin the next few years. The prototype chamber closure will provide a basis to demonstrate theclosure technology and will render a chamber properly instrumented in which the adequatefunctioning of the waste isolation system can be monitored for a longer period of time, inpreparation of the site's final closure