Research situation of claystone as hosting rock for high level radioactive waste geological disposal

Many countries have studied the possible hosting rocks of the geological repository in detail and found that granite, claystone and rock salt are suitable to the geological repository. Moreover, claystone is considered to have many incomparable advantages due to its self sealing ability and low permeability, more and more attention has been paid to the study of claystone as the hosting rock of geological repository for high level radioactive wastes. At the same time, this paper introduces the research results in some countries, such as Switzerland, France and Belgium, which has performed a great quantity of study on claystone, and all believes that claystone is safety for disposal of high level radioactive waste and spent nuclear fuel. The conception and design of claystone geological repository, the study on the hosting rock of claystone geological repository in underground laboratory and the importance of claystone study as the hosting rock of geological repository in China are summarized in this paper. (authors)