This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program has been underway for several years. This program provides source-term data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated

more »

... risk assessments. This document focuses on an updated description of the test program and test components for all work and plans made, or revised, primarily during FY 2005 and about the first two-thirds of FY 2006. It also serves as a program status report as of the end of May 2006. We provide details on the significant findings on aerosol results and observations from the recently completed Phase 2 surrogate material tests using cerium oxide ceramic pellets in test rodlets plus non-radioactive fission product dopants. Results include: respirable fractions produced; amounts, nuclide content, and produced particle size distributions and morphology; status on determination of the spent fuel ratio, SFR (the ratio of respirable particles from real spent fuel/respirables from surrogate spent fuel, measured under closely matched test conditions, in a contained test chamber); and, measurements of enhanced volatile fission product species sorption onto respirable particles. We discuss progress and results for the first three, recently performed Phase 3 tests using depleted uranium oxide, DUO 2 , test rodlets. We will also review the status of preparations and the final Phase 4 tests in this program, using short rodlets containing actual spent fuel from U.S. PWR reactors, with both high-and lower-burnup fuel. These data plus testing results and design are tailored to support and guide, follow-on computer modeling of aerosol dispersal hazards and radiological consequence assessments. This spent fuel sabotage -aerosol test program, performed primarily at Sandia National Laboratories, with support provided by both the U.S. Department of Energy and the Nuclear Regulatory Commission, had significant inputs from, and is strongly supported and coordinated 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. Sabotage Concerns of Transport and Storage Casks are responsible for the continuing successes of this program. Most of the same people have also provided major technical inputs to the writing of this report, analyses of the data within, plus designs and fabrication for many of the test components. We also recognize Sandia National Laboratories personnel from the Explosives Components Facility: Marc Hagan, explosives technician; Roy Dickey, explosives engineer and components designer, plus Lloyd Bonzon, explosive projects department manager, both retired at the end of 2005; and, Manny Vigil, retired, consultant, for providing significant guidance on the science of the explosive components and processes, and for providing excellent test program support. Mai Luu and Traci Durbin, Aerosol Sciences, Sandia Department 1517, also provided very valuable aerosol and testing support. Kevin Ewsuk and Denise Bencoe, Ceramic Processing and Inorganic Materials Department 1815, provided key support on cerium oxide pellet and fission productdoped pellet fabrication, as well as technical support and guidance. Lorraine Herrera, Department 6146, provided key support in shipping test samples to the analytical chemistry laboratory, coordinating the analyses and results, and converting data received into the required formats and figures required for our full interpretations. A.2.10D Test 2/10D Analyses and Results Particulates from test 2/10D, the replicate for test 2/10C, were sampled using four independent Large Particle Separator and Marple impactor systems. In addition, multiple separate impact particle debris samples were collected by a HEPA vacuum system and a newly installed preseparator paper liner (collection bag). The impact particle debris was subsequently mechanically sieved and chemically analyzed by ICP-MS. Surface deposited particle samples were also obtained from the exterior and interior of each of the four internal chamber sampling tubes. Gravimetric and Debris Analyses: Graphs of gravimetric particle size distributions from the four 2/10D Marple impactors, plus the mass concentrations, are presented in Figures A2.10D .58 to Figure A2 .10C.62. The weight distribution of the sieved particle impact debris is presented in Table A2 .10C.49. Table A2 .10D.50 contains the measured impact debris elemental analysis, in weight percent, for the particles from 90 to < 25 µm (geometric) size, or 234 to <65 µm AED for CeO 2 pellets. The weight percent distribution of metals on the impact debris sieved fractions is plotted in Figure A2 .10D.63 and Figure A2 .10D.64 provides the similar impact debris weight percent distribution of fission product dopants. Marple and LPS Particle Element Analyses: Chemical analyses were performed on three of the Marple and LPS particle collection systems, the fourth Marple and LPS samples were held in reserve. Each Large Particle Sampler fiberglass substrate was cut into four separate pieces prior to chemical dissolution and elemental analysis by ICP-MS. These LPS segments cover the nominal particle size range of: Segment #1 is ~82-100 μm AED, Segment #2 is ~65-82 μm AED, Segment #3 is ~48-65 μm AED, and Segment #4 is ~30-48 μm AED.