Safety Case Considerations for Deep Borehole Disposal of Cs/Sr Capsules - 16294

Conference · Fri Jul 01 04:00:00 EDT 2016

OSTI ID:22838141

Freeze, Geoff; Brady, Patrick; Hardin, Ernest; MacKinnon, Robert; Stein, Emily; Hadgu, Teklu ^[1]

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1. Sandia National Laboratories (United States)

The U.S. Department of Energy Office of Nuclear Energy (DOE-NE) performed an assessment of disposal options that recommended the consideration of deep borehole disposal of smaller DOE-managed waste forms, such as cesium (Cs) and strontium (Sr) capsules. To assess the feasibility of the deep borehole disposal concept for Cs/Sr capsules, safety case considerations are identified and examined. A safety case includes quantitative (e.g., safety assessments) and qualitative information related to both pre-closure (operational) and post-closure safety. For deep borehole disposal of Cs/Sr capsules, pre-closure safety considers potential hazards associated with waste package surface handling and downhole emplacement activities; post-closure safety considers scenarios for long-term radionuclide transport to the biosphere. A preliminary list of qualitative indicators of pre-closure and post-closure safety is presented. Research, development, and demonstration (RD and D) activities that can provide a quantitative basis for these indicators are discussed. In particular, DOE-NE has initiated a Deep Borehole Field Test, using surrogate test packages without radioactive waste, to further investigate various aspects of site characterization, deep drilling, and waste package handling and emplacement that would be needed for a full-scale disposal facility for Cs/Sr capsules or other DOE-managed waste forms. Finally, preliminary results from pre-closure hazard analyses and post-closure performance assessment (PA) calculations are presented as examples of supporting information for the quantitative safety case considerations. These preliminary results suggest that a favorable safety case can be developed for deep borehole disposal of Cs/Sr capsules. (authors)

• Research Organization: WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
• OSTI ID: 22838141
• Report Number(s): INIS-US--19-WM-16294
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
BOREHOLES
CAPSULES
CESIUM
CLOSURES
DRILLING
FIELD TESTS
HAZARDS
RADIOISOTOPES
RADIONUCLIDE MIGRATION
RISK ASSESSMENT
SITE CHARACTERIZATION
STRONTIUM
TRANSPORT
US DOE
WASTE FORMS