[2B01-04] Geological disposal

9:30 AM - 9:45 AM JST(12:30 AM - 12:45 AM UTC)

[2B01] Concept of the Performance Assurance System for Geological Disposal (1)Considerations on Directions for Performance Confirmation Based on Overseas Examples

*Takahiro Yoshida¹, Masahiro Kawakubo¹, Kinji Yoshimoto¹ (1. RWMC)

Keywords:

Geological Disposal,Performance Assurance,Performance Confirmation,Periodical Safety Review,Monitoring

In geological disposal, periodic safety reviews may be required to confirm that underground components, such as engineered barriers, perform according to design specifications or that there is a reasonable expectation of such performance. This study investigates international performance confirmation strategies. In France, which established its disposal concept based on a policy of reversibility, and the USA, characterized by an unsaturated geological environment, direct monitoring of engineered barriers is considered under their non-backfilled disposal concepts. Conversely, Finland and Switzerland, which utilize bentonite buffers like Japan, avoid direct monitoring to prevent impacting long-term safety. Instead, they adopt methods to indirectly confirm performance based on full-scale tests and geosphere monitoring. These findings suggest that monitoring strategies depend on geological environments and disposal concepts.