China has asked IAEA for consultancy in initiating and implementing a site selection procedure in order to identify clay formations that may be suitable for hosting a HLW repository. Therefore, IAEA initiated a corresponding national training course, which took place from November 27 to 30, 2017, in Nanchang (China), and asked experts from ANDRA (France), GRS gGmbH (Germany) and DBE TECHNOLOGY GmbH (Germany) to hold the course.
In 2006, the competent China Atomic Energy Authority (CAEA) decided that granite and clay be considered as candidate host rocks for HLW repositories. In 2015, CAEA approved a preliminary study for assessing the suitability of Chinese clay formations as host rocks for a HLW repository. In the course of a subsequent geological survey, the East China University of Technology (ECUT) selected rocks with a high percentage of zeolite and a small fraction of clay minerals from the Tamusu Province (Inner Mongolia) for further investigations.
The French and German experts presented their national site selection programs and their experience with the procedure. Common and different criteria in the European programs and the Chinese program were discussed. In a next step, the site characterization programs for surface and underground exploration as well as the safety and safety demonstration strategies were presented and discussed.
The European experts emphasized the necessity of an overall strategy for site selection and characterization based on an identification of the objectives and of a safety strategy, criteria for rock evaluation, and corresponding measures for safety demonstration. Important steps for site characterization are a clarification of the local boundary conditions, an analysis of the geologic history as a basis for predicting the future development, and a comprehensive analysis of the geosphere (from large scale to small scale). ECUT will take into account the recommendations of the IAEA experts in their future site selection procedure.