Publications

Almquist, Keith J.; Gregson, Michael W.; Young, Sharissa G.; Schlavin, Paul H.

Abstract not provided.

Transactions of the American Nuclear Society

Gregson, Michael W.; Prinja, Anil K.

Abstract not provided.

Miller, David R.; Molecke, Martin A.; Gregson, Michael W.; Brockmann, John E.; Steyskal, Michele S.

Abstract not provided.

Brockmann, John E.; Gregson, Michael W.; Steyskal, Michele S.; Klennert, Lindsay A.

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 provides source-term data that are relevant to plausible sabotage scenarios in relation to spent fuel transport and storage casks and associated risk assessments. We present details and significant results obtained from this program from 2001 through 2007. Measured aerosol results include: respirable fractions produced; amounts, nuclide content, and produced particle size distributions and morphology; 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. Emphasis is provided on recent Phase 3 tests using depleted uranium oxide pellets plus non-radioactive fission product dopants in surrogate spent fuel test rodlets, plus the latest surrogate cerium oxide results and aerosol laboratory supporting calibration work. The DUO{sub 2}, CeO{sub 2}, plus fission product dopant aerosol particle results are compared with available historical data. We also provide a status review on continuing preparations for the final Phase 4 in this program, tests using individual short rodlets containing actual spent fuel from U.S. PWR reactors, with both high- and lower-burnup fuel. The source-term data, aerosol results, and program design have been tailored to support and guide follow-on computer modeling of aerosol dispersal hazards and radiological consequence assessments. This spent fuel sabotage, aerosol test program was performed primarily at Sandia National Laboratories, with support provided by both the U.S. Department of Energy and the Nuclear Regulatory Commission. This program has significant input from, and is cooperatively supported and coordinated by both the U.S. and international program participants in Germany, France, and others, as part of the International Working Group for Sabotage Concerns of Transport and Storage Casks (WGSTSC).

Brockmann, John E.; Klennert, Lindsay A.; Steyskal, Michele S.; Gregson, Michael W.

Abstract not provided.

Brockmann, John E.; Lucero, Daniel A.; Steyskal, Michele S.; Gregson, Michael W.

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.

2005 NCSD Topical Meeting (American Nuclear Society Nuclear Criticality Safety Division)

Knief, Ronald A.; Schwers, Norman F.; Dorsey, Daniel J.; Gregson, Michael W.

Sandia National Laboratories (SNL) has limited inventories of, and activities with, fissile-material. Personnel who perform nuclear criticality safety (NCS) assignments do so on a part-time basis. Sandia's "tailored approach" to training and qualification of these personnel can serve as a model for others with "small" NCS programs. SNL uses a single set of qualification cards for qualifying nuclear criticality safety engineers (NCSE). Provision is made for: (1) training and mentoring of new NCSE with testing or other verification of their skills and knowledge and (2) "qualification by documentation" for staff who historically have been performing NCSE-like duties. Key areas for evaluation include previous formal education and training; demonstrated success in writing Criticality Safety Assessments (CSA) and related documents; interaction with the SNL criticality safety committees; and overall knowledge (e.g., as judged against the objectives in DOE-STD-1135). Gaps of knowledge are filled through self-study, training, or mentoring. Candidate mastery of topics is confirmed primarily by evaluation of work products and interviews. Completion is approved by the Criticality Safety Officer (CSO) - the closest SNL comes to having an NCS manager - and then management. In applying the tailored approach, NCSE candidates are not required to be subject-matter experts for all NCS-related facilities and activities at SNL at the time of qualification. Familiarity with each of the facilities and activities is expected, along with the ability to "self-train" when needed (e.g., analogous just-in-time [JIT] procurement). The latter is supported by identification of applicable SNL-wide fissile-material facilities and activities along with resource organizations and personnel in NCS, safety analysis, accountability, etc. The capstone is a discussion with the CSO, or other experienced NCSE, demonstrating the ability to explain in some detail how a specific NCS assignment would be tackled (e.g., options for gaining facility/activity knowledge, performing analyses, using resource personnel, and traversing the required peer- and committee-review processes).

Gregson, Michael W.

Abstract not provided.

Brockmann, John E.; Lucero, Daniel A.; Borek, Theodore T.; Gregson, Michael W.

Abstract not provided.

Sorenson, Ken B.; Borek, Theodore T.; Dickey, Roy R.; Brockmann, John E.; Lucero, Daniel A.; Gregson, Michael W.; Coats, Richard L.

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 data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. The program also provides significant technical and political benefits in international cooperation. We are quantifying the Spent Fuel Ratio (SFR), the ratio of the aerosol particles released from HEDD-impacted actual spent fuel to the aerosol particles produced from surrogate materials, measured under closely matched test conditions, in a contained test chamber. In addition, we are measuring the amounts, nuclide content, size distribution of the released aerosol materials, and enhanced sorption of volatile fission product nuclides onto specific aerosol particle size fractions. These data are the input for follow-on modeling studies to quantify respirable hazards, associated radiological risk assessments, vulnerability assessments, and potential cask physical protection design modifications. This document includes an updated description of the test program and test components for all work and plans made, or revised, during FY 2004. It also serves as a program status report as of the end of FY 2004. All available test results, observations, and aerosol analyses plus interpretations--primarily for surrogate material Phase 2 tests, series 2/5A through 2/9B, using cerium oxide sintered ceramic pellets are included. Advanced plans and progress are described for upcoming tests with unirradiated, depleted uranium oxide and actual spent fuel test rodlets. This spent fuel sabotage--aerosol test program is coordinated with the international Working Group for Sabotage Concerns of Transport and Storage Casks (WGSTSC) and supported by both the U.S. Department of Energy and the Nuclear Regulatory Commission.

Brockmann, John E.; Lucero, Daniel A.; Dickey, Roy R.; Gregson, Michael W.; Gregson, Michael W.

Abstract not provided.

Proposed for publication in Packaging, Transport, Storage and Security of Radioactive Material (Ramtrans Publishing).

Gregson, Michael W.; Sorenson, Ken B.

The authors provide a detailed overview of an on-going, multinational test program that is developing aerosol data for some spent fuel sabotage scenarios on spent fuel transport and storage casks. Experiments are being performed to quantify the aerosolized materials plus volatilized fission products generated from actual spent fuel and surrogate material test rods, due to impact by a high-energy-density device. The program participants in the United States plus Germany, France and the United Kingdom, part of the international Working Group for Sabotage Concerns of Transport and Storage Casks (WGSTSC) have strongly supported and coordinated this research program. Sandia National Laboratories has the lead role for conducting this research program; test program support is provided by both the US Department of Energy and the US Nuclear Regulatory Commission. The authors provide a summary of the overall, multiphase test design and a description of all explosive containment and aerosol collection test components used. They focus on the recently initiated tests on 'surrogate' spent fuel, unirradiated depleted uranium oxide and forthcoming actual spent fuel tests, and briefly summarize similar results from completed surrogate tests that used non-radioactive, sintered cerium oxide ceramic pellets in test rods.

Gregson, Michael W.; Sorenson, Ken B.

Abstract not provided.

Molecke, Martin A.; Sorenson, Ken B.; Gregson, Michael W.

Abstract not provided.