Martin Alan Molecke

SPENT FUEL SABOTAGE TESTING: DEPLETED URANIUM OXIDE AEROSOL RESULTS.

Abstract This paper summarises a multinational, four phase, spent fuel sabotage test programme that quantifies aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets (∼20 cm long rods) that contain pellets of either surrogate materials or actual spent fuel. This programme provides source term data that are relevant to plausible sabotage attack scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. Details and significant results are presented from three phase 3 tests performed using depleted UO2 (DUO2) pellets plus non-radioactive fission product dopants in surrogate spent fuel test rodlets. Measured aerosol results include: respirable fractions produced; particle size distributions; measurements of volatile fission product species enhanced sorption: enrichment factors onto respirable particles; and status on determination of the spent fuel ratio (SFR), needed for scaling studies. The DUO2 aerosol particle results are compared directly with similar phase 2 results from cerium oxide ceramic pellet and fission product dopant surrogate test rodlets. A status update is provided on preparations for the final phase 4 tests using rodlets containing actual PWR spent fuel. The source term data and programme design have been tailored to support and guide follow-on computer modelling of aerosol dispersal hazards and radiological consequence assessments. This spent fuel sabotage test programme was performed primarily at Sandia National Laboratories, with support provided by both the US Department of Energy and the Nuclear Regulatory Commission. This programme is strongly supported and coordinated by US and international programme participants in Germany and France, as part of the International Working Group for Sabotage Concerns of Transport and Storage Casks (WGSTSC).

Spent Fuel Sabotage Aerosol Test Program: FY 2005-06 Testing and Aerosol Data Summary

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 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{sub 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.

International Working Group for Sabotage Concerns of Transport and Storage Casks

Abstract The International Working Group for Sabotage Concerns of Transport and Storage Casks (IWGSTSC), gathers multiple organisations from different countries (for US party Department of Energy, Nuclear Regulatory Commission, and Sandia National Laboratories; for German party Gesellschaft für Anlagen- und Reaktorsicherheit and Fraunhofer Institut; for the French party Institut de Radioprotection et de Sûreté Nucléaire). The goal of the IWGSTSC is to continue cooperation to improve the analytic capabilities, through information sharing and collaborative research and development plus modelling, to understand the potential adverse public health effects and environmental impacts of radiological sabotage directed at or associated with the transport and storage of civilian nuclear material or other civilian radioactive materials. The Parties may also undertake collaborative research and development in other areas of the physical protection of civilian nuclear materials or other radioactive materials. Since 2000, the IWGSTSC has conducted an extensive test programme for the assessment of the aerosol source term produced in the case of spent fuel transport sabotage by a high energy density device, after having examined several scenarios. The major goal of this programme is to produce an accurate estimate of the so called spent fuel ratio in the domain of respirable, aerosol particles produced. All the reports prepared by Sandia National Laboratories have precisely emphasised the important efforts they have made from the beginning and the amount of work already accomplished. In parallel, the International Atomic Energy Agency (IAEA), assisted by technical experts from different countries, has provided a draft document promised to become guidance for the security of radioactive or nuclear materials during transport. The IAEA document contains general guidance addressed to anyone who intends to implement or improve the security of material transports, but the text is, as of today, limited to rather general recommendations. Based on all the knowledge accumulated from past experiments and also based on the work carried out in Vienna at the IAEA, the IWGSTSC members have decided to work on the development of a method for the evaluation of the vulnerability and the source term. So for doing that, joint projects for the research, development, testing and evaluation of the consequences of the malevolent actions during transport are being pursued and are described in this paper.