Spent Fuel Sabotage Aerosol Ratio Program and Surrogate Material Test Results

We provide a detailed overview of an ongoing test program that is developing relevant aerosol particle data for some sabotage scenarios on spent fuel transport and storage casks, and associated risk assessments. The data being measured support quantifications of aerosolized materials produced from actual spent fuel and surrogate material test rods, resulting from an impact by an explosive, high energy density device, HEDD. The need for this technical information has been strongly supported by both the U.S. and international program participants in Germany, France, and the U.K., as part of the international Working Group for Sabotage Concerns of Transport and Storage Casks, WGSTSC. In the U.S., Sandia National Laboratories has the lead test role for conducting this program, with support provided by both the Department of Energy and the Nuclear Regulatory Commission. WGSTSC partners need this research to better understand potential impacts from sabotage of nuclear material shipment and storage casks, to better protect people and the environment against subsequent, potential radiological hazards. We provide a detailed description of the multi-phase test design, a description of all explosive containment and aerosol collection test components, and a summary of aerosol test results plus observations for the recently completed, surrogate material tests; these Phase 2 tests used non-radioactive cerium oxide sintered ceramic pellets. The data obtained include HEDD-impact-produced aerosol particle amounts, size distributions, and observed enhanced sorption of volatile fission product (surrogate) nuclides onto specific respirable particle size fractions. Advanced plans are described for upcoming tests with unirradiated, depleted uranium oxide and actual spent fuel test rodlets (both high- and low-burnup). The ratio of the aerosol and respirable particles released from HEDD-impacted actual spent fuel to the aerosol particles produced from surrogate materials (depleted uranium oxide), i.e., the spent fuel ratio, SFR, will be determined under closely matched test conditions.