Testing of packages with LSA materials in very severe mechanical impact conditions with measurement of airborne release

Abstract

To assess the risks associated with transport accidents involving solid LSA-II and LSA III materials a comprehensive experimental programme was conducted to quantify and characterise airborne release of radioactive particulate matter in transport and handling accidents with mechanical impact of varying severities and to determine the dependency from influencing parameters such as LSA material and packaging properties and size. The experimental approach combined well-controlled and very reproducible impact experiments with small scale specimens and drop tests of larger scale specimens from different heights up to 27m. In both cases the associated airborne release of particulate matter is determined by measuring the amount and aerodynamic particle size characteristics of released dust. The small scale tests revealed fundamental results on airborne release and size distribution which helped to design the test matrix of the large scale experiments, especially with brittle material. In the large scale tests, volumes of specimens were varied systematically up to 200L and the LSA material was contained either within packaging or without protective packaging in order to determine the influence of the packaging on the airborne release and to be able to extrapolate other configurations of package sizes and impact severities. The LSA surrogate materials were either concrete, used to immobilize radioactive wastes as representative brittle material, or appropriately chosen powders representing dispersible materials. Based on the experimental results it can be concluded that the requirements of the current IAEA Transport Regulations sufficiently limit potential radiological consequences from transport accidents with mechanical impact involving packages with LSA-II or LSA-III materials.     

Plans for the future for the Packaging,Transport, Storage and Security of Radioactive Material Journal

Abstract

The regulatory driven design of radioactive material transportation packages leads package vendors to perform analyses that demonstrate the ability of packages to meet the regulatory requirements. For risk assessment and communication, the analysis of package response to thermal environments that are more severe than those described in the regulations is required. In general, experimental and analytical assessments of casks exposed to thermal insults other than the regulatory environment are performed in the USA by the Department of Energy national laboratories. This paper provides a brief summary of some recent thermal analyses of spent fuel transportation packages exposed to thermal environments different from regulatory standards. The analyses were performed by Sandia National Laboratories under several different projects for multiple customers. These analyses examined the response of spent fuel packages exposed to severe thermal environments different from the regulatory hypothetical accident condition. One assessment determined the response of four generic casks to very long duration engulfing fires. The results from these analyses included fire durations necessary to reach critical temperatures of the fuel and seals. In another assessment, two certified spent fuel casks were analysed for exposure to 1 h pool fires. The height of the cask above the pool was varied to study the effect of the vapour dome on the heating of the casks. Another assessment investigated the effect of offset long duration fires on rail cask performance, which showed that casks can withstand offset fires of much longer duration than the regulatory fire. Other assessments examined the response of packages to thermal environments resulting from propane fires and realistic liquid hydrocarbon fires that included various positions of the transportation rail car in the simulation.     

Low-Temperature Partitioning of Plutonium with High U(VI)-Loading for Fuel Reprocessing

Measurement of the distribution ratios of Pu(IV), U(VI) and HNO₃ at low temperatures and its treatment with DIST code revealed that a high U (VI)-loading of 30% TBP in n-dodecane splits Pu(IV) down to the aqueous phase more strongly than do at 25°C. Based on these findings, flowsheet conditions to separate Pu(IV) from U(VI) were investigated with EXTRA.M code including the distribution equations obtained above. And tentative flowsheets for non-reductive Pu-splitting process at a temperature of 5°C were proposed for fuel reprocessing mainly based on the effects of U (VI)-loading in the solvent and temperature on distribution ratios of Pu(IV) and U(VI). Distribution ratios of the fission products, Zr, Nb, Ru and Ce were also measured to assess their decontamination from U or Pu products in the above process. Finally behavior of Np, in the proposed partitioning process was discussed by analysis with EXTRA. M code and a redox reaction model.     

Overview of five decades of testing and evaluation of packages to environments beyond regulatory requirements

Abstract

For decades, questions have frequently been asked whether the material and package test standards set forth in the IAEA Transport Regulations – the latest edition of which was issued in 2009 (IAEA, 2009) – are sufficient to provide a high level of protection to workers, the public and the environment. This paper assembles in a single location a summary of an extensive body of data and information that has been developed and published in the international journal Packaging, Transport, Storage & Security of Radioactive Material to address such questions. It provides guidance to interested parties on how to access further details on these studies in the Journal.     

Versioning and configuration management in an object-oriented data model

Many database applications require the storage and manipulation of different versions of data objects. To satisfy the diverse needs of these applications, current database systems support versioning at a very low level. This article demonstrates that application-independent versioning can be supported at a significantly higher level. In particular, we extend the EXTRA data model and EXCESS query language so that configurations can be specified conceptually and non-procedurally. We also show how version sets can be viewed multidimensionally, thereby allowing configurations to be expressed at a higher level of abstraction. The resulting model integrates and generalizes ideas, in CAD systems, CASE systems, and temporal databases.