Manufacturing and Handling Techniques of the Monolithic Buffer Material for HLW Disposal

Small and large scale tests were performed to evaluate technical feasibility of the monolithic buffer material, defined as a large block of bentonite formed by the cold isostatic pressing, for geological disposal of high-level radioactive waste. Trial manufacturing tests up to approximately 70 [%]-scale of a Japanese disposal concept were carried out and emplacement tests were carried out by vacuum lifting and forklift-type methods for vertical and horizontal emplacement concepts, respectively. Based on the large engineering-scale tests, technical feasibility of the monolithic buffer was demonstrated.