Probabilistic seismic design considerations for a high-level nuclear waste repository

Earthquakes in the vicinity of an underground high-level waste (HLW) repository have potential effects that must be estimated during the design of the facility. The production facilities above ground will be in operation for several decades, and standard probabilistic techniques can be used to select design ground motions consistent with target acceptable risk levels for earthquakes. For the permanent underground facilities, consideration must be given to shearing of waste containers by fault movement, and to strong shaking that might fail the air gap around containers. The geometry of container emplacement in boreholes or drifts will determine the ultimate impact of earthquakes on waste material. For any design a probabilistic format can be used to calculate the probability of strong shaking or fault displacement, but for design decisions the effects on waste transport to the accessible environment must be included in the analysis