Performance of a personal neutron dosemeter based on direct ion storage at workplace fields in the nuclear industry

In the framework of the EVIDOS project, funded by the EC, measurements were carried out using dosemeters, based on ionisation chambers with direct ion storage (DIS-N), at several workplace fields, namely, at a fuel processing plant, a boiling and a pressurised water reactor, and near transport and storage casks. The measurements and results obtained with the DIS-N in these workplaces, which are representative for the nuclear industry, are described in this study. Different dosemeter configurations of converter and shielding materials were considered. The results are compared with values for personal dose equivalent which were assessed within the EVIDOS project by other partners. The advantages and limitations of the DIS-N dosemeter are discusse

Surrogate/spent fuel sabotage : aerosol ratio test program and Phase 2 test results.

A multinational test program is in progress to quantify the aerosol particulates produced when a high energy density device, HEDD, impacts surrogate material and actual spent fuel test rodlets. This program provides needed 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 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 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 crucial for predicting radiological impacts. This document includes a thorough description of the test program, including the current, detailed test plan, concept and design, plus a description of all test components, and requirements for future components and related nuclear facility needs. It also serves as a program status report as of the end of FY 2003. All available test results, observations, and analyses - primarily for surrogate material Phase 2 tests using cerium oxide sintered ceramic pellets are included. 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 Nuclear Regulatory Commission

Spent fuel sabotage aerosol ratio program : FY 2004 test and 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 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

Spent fuel sabotage test program, characterization of aerosol dispersal : interim final report.

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)

PVP2006-ICPVT11-93393 FEM SIMULATION OF EXTREME THERMAL AND MECHANICAL ACCIDENT LOADS ON SCREWED SPENT FUEL CASK LID STRUCTURES

ABSTRACT The complex analysis of screwed spent fuel cask lid structures under extreme thermal and mechanical loads is very important for the evaluation of cask integrity and leak tightness under such conditions. The interest of such problems has been increasing since the terrorist attacks from September 11, 2001. Due to extension experiences of BAM in calculation and experimental testing of transport and storage casks for radioactive materials, BAM in this context has developed new methods to estimate the safety margins of transport and storage spent fuel and high-level waste casks under extreme thermal and mechanical loads resulting from aircraft crashes. In case of thermal loads, a thermal heat transfer analysis has to be made, which gives the time-dependent temperature distribution of the casks. But this is not enough, while the extreme kerosene fire scenario creates a strong transient heating of the cask body and its lid system. This causes elastic and plastic deformation of the cask body, the decrease of screw forces and especially great relative displacements between the seals and its contacting flanges. This results in an elevated leak rate. To cover this case so-called thermo-mechanical analyses had been carried out. One of the most critical mechanical loads on the cask is a central impact onto the lid-seal-system. This can be caused by direct aircraft crash or its engine as well as by a following impact of building structures of a nuclear facility like a storage hall. In this situation dynamical analyses had been carried out. Although it is currently not possible to calculate the leakage rates from deformation analysis directly, for the present it is possible to estimate the behaviour of the seal based on the calculated relative displacements at its place and the behaviour of the lid bolts under the thermal and mechanical impact loads respectively, in combination with experiments where the leakage rate of the seals had been measured after radial and axial shifting of the flanges. Except of the lid bolts, the geometry of the cask and the thermal/mechanical loads are axial-symmetric, which simplified the analysis considerably by using two dimensional finite element models and parameter studies are possible. The lid bolts had been "smeared" with a special technique as twodimensional plane-stress bolt model, which has been verified with three dimensional bolt calculations. Experiments and calculation studies show that the German transport and storage casks for radioactive material have sufficient safety margins even by extreme thermal/mechanical loads. This paper will present the methodologies developed for the studies. Some of the calculation results will be presented

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

Problems of creating scientific and methodological bases of spent nuclear fuel dry cask storage thermal safety in Ukraine

An analytical review of modern researches into spent nuclear fuel (SNF) dry cask storage, or dry storage thermal processes is presented and problems of creating scientific and methodological foundations for SNF dry storage thermal safety are discussed.Подано аналітичний огляд сучасних досліджень теплових процесів за сухого зберігання відпрацьованого ядерного палива (ВЯП) та висвітлено проблеми створення науково-методологічних основ теплової безпеки сухих сховищ відпрацьованого ядерного палива.Представлен аналитический обзор современных исследований тепловых процессов при сухом хранении отработавшего ядерного топлива (ОЯТ) и освещены проблемы создания научно-методологических основ тепловой безопасности сухих хранилищ отработавшего ядерного топлива