Geological Challenges in Radioactive Waste Isolation Third Worldwide Review

The first worldwide review of geological problems in radioactive waste isolation was published by the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) in 1991 (Witherspoon, 1991). This review was a compilation of reports that had been submitted to a workshop held in conjunction with the 28th International Geological Congress that took place July 9Ð19, 1989, in Washington, D.C. Reports from 15 countries were presented at the workshop, and four countries provided reports after the workshop, so that material from 19 different countries was included in the first review.<br><br>It was apparent from the widespread interest in the first review that the challenges of providing a permanent and reliable method of isolating radioactive waste from the biosphere for long periods of time were quite formidable. This is especially the case in connection with highlevel waste (HLW), after its removal from nuclear power plants. There is also the additional problem of isolating low- and intermediate-level waste (LILW). Significant quantities of LILW are generated from various sources, and while they are not as long lived and do not pose the same level of difficulty as HLW, they constitute another problem for the nuclear industry.<br><br>After the 1991 review, new technology was being developed to solve these waste isolation problems, and there was a need to publish the results for the benefit of the nuclear industry. Thus, it was decided to gather material on the latest developments, and Berkeley Lab published the Second Worldwide Review in September 1996 (Witherspoon, 1996). This second review contains reports from 26 countries. <br><br>By 1996, no repository for HLW had been put in operation, but some important progress had been made on the fundamental problems involved in characterizing a site for a disposal project. To decide where to locate a repository for HLW requires a lengthy and detailed process of characterizing the rock mass in which the waste will be placed. Some countries have been working on this process for a number of years, and the 1996 review describes a wide variety of technologies developed by the various countries. As more experience has been gained, the use of underground test facilities in countries such as Canada, Germany, Sweden, Switzerland, and United States has been found to provide a means of carrying out large-scale investigations on rock masses, as an important part of the characterization process. The term &quot;underground research laboratory &quot; (URL) is now used to describe such facilities.<br><br>Five years have passed since the 1996 review was published, and there are now over 30 countries where a great variety of field investigations are being carried out to locate suitable disposal sites for both HLW and LILW. Many countries have made significant progress since 1996, and therefore it was decided to gather material on the latest developments on radioactive waste isolation and publish another review.<br>