Deep Boreholes Attributes and Performance Requirements

Abstract

This is a progress report covering work through mid-May 2010 under a Sandia-MIT contract dealing with design and siting/licensing criteria for deep borehole disposal of spent nuclear fuel or its separated constituents. It consists of additional short technical notes which scope out the performance-related requirements of a deep borehole repository. The most important changes since our last report are reversion to a single-branch vertical borehole (as recommended in the March 15 Workshop), and the consequential recommended adoption of a cast iron canister to alleviate the resulting bottom canister crushing threat. The case is also made that post closure nuclear criticality is not a credible scenario, with a very large margin of safety, even under very conservative assumptions.