132 research outputs found
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Effects of mixed waste simulants on transportation packaging plastic components
The purpose of hazardous and radioactive materials packaging is to, enable these materials to be transported without posing a threat to the health or property of the general public. To achieve this aim, regulations have been written establishing general design requirements for such packagings. While no regulations have been written specifically for mixed waste packaging, regulations for the constituents of mixed wastes, i.e., hazardous and radioactive substances, have been codified. The design requirements for both hazardous and radioactive materials packaging specify packaging compatibility, i.e., that the materials of the packaging and any contents be chemically compatible with each other. Furthermore, Type A and Type B packaging design requirements stipulate that there be no significant chemical, galvanic, or other reaction between the materials and contents of the package. Based on these requirements, a Chemical Compatibility Testing Program was developed in the Transportation Systems Department at Sandia National Laboratories (SNL). The program, supported by the US Department of Energy`s (DOE) Transportation Management Division, EM-261 provides the means to assure any regulatory body that the issue of packaging material compatibility towards hazardous and radioactive materials has been addressed. In this paper, we describe the general elements of the testing program and the experimental results of the screening tests. The implications of the results of this testing are discussed in the general context of packaging development. Additionally, we present the results of the first phase of this experimental program. This phase involved the screening of five candidate liner and six seal materials against four simulant mixed wastes
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A testing program to evaluate the effects of simulant mixed wastes on plastic transportation packaging components
Based on regulatory requirements for Type A and B radioactive material packaging, a Testing Program was developed to evaluate the effects of mixed wastes on plastic materials which could be used as liners and seals in transportation containers. The plastics evaluated in this program were butadiene-acrylonitrile copolymer (Nitrile rubber), cross-linked polyethylene, epichlorohydrin, ethylene-propylene rubber (EPDM), fluorocarbons, high-density polyethylene (HDPE), butyl rubber, polypropylene, polytetrafluoroethylene, and styrene-butadiene rubber (SBR). These plastics were first screened in four simulant mixed wastes. The liner materials were screened using specific gravity measurements and seal materials by vapor transport rate (VTR) measurements. For the screening of liner materials, Kel-F, HDPE, and XLPE were found to offer the greatest resistance to the combination of radiation and chemicals. The tests also indicated that while all seal materials passed exposure to the aqueous simulant mixed waste, EPDM and SBR had the lowest VTRs. In the chlorinated hydrocarbon simulant mixed waste, only Viton passed the screening tests. In both the simulant scintillation fluid mixed waste and the ketone mixture waste, none of the seal materials met the screening criteria. Those materials which passed the screening tests were subjected to further comprehensive testing in each of the simulant wastes. The materials were exposed to four different radiation doses followed by exposure to a simulant mixed waste at three temperatures and four different exposure times (7, 14, 28, 180 days). Materials were tested by measuring specific gravity, dimensional, hardness, stress cracking, VTR, compression set, and tensile properties. The second phase of this Testing Program involving the comprehensive testing of plastic liner has been completed and for seal materials is currently in progress
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Comments on a paper tilted `The sea transport of vitrified high-level radioactive wastes: Unresolved safety issues`
The cited paper estimates the consequences that might occur should a purpose-built ship transporting Vitrified High Level Waste (VHLW) be involved in a severe collision that causes the VHLW canisters in one Type-B package to spill onto the floor of a major ocean fishing region. Release of radioactivity from VHLW glass logs, failure of elastomer cask seals, failure of VHLW canisters due to stress corrosion cracking (SCC), and the probabilities of the hypothesized accident scenario, of catastrophic cask failure, and of cask recovery from the sea are all discussed
Security of major pipelines in presence of terroristic threats: prognostic estimates
The purpose of the paper is to substantiate the approach to determining the required probability of detecting unauthorized attempts to contact the pipe shell to maintain a minimum level of pipeline security losses. That is also nesseccerly to assess probability trend in the near future. Based on the information obtained it is planned to propose the structure of the physical pipeline security system to neutralize terroristic attacks. Results of studies of vibroacoustic oscillations in the shell of a major pipeline during its operation are given. The mechanisms of change in parameters of a vibroacoustic pulse excited at a local point of a pipeline when it is propagated through a pipeline are expalined. Results of studies on the solution of the problem of detection and prevention of emergencies in the protected zone by seismic oscillations are considered. It is concluded that it is possible to detect precursors of emergencies by vibroacoustic and seismic vibrations of the pipe shell.
The effectiveness of the proposed approach to determine the requirements for systems of protection of objects from terroristic threats is demonstrated. The region was chosen in accordance with available published data for a relatively long period of time, necessary for setting up a computational experiment. It is interesting to receive prognostic estimates in that segment of economy for the country as a whole.
Presence of such information allow creating a policy for detecting terroristic attacks and deciding on the requirements for the physical protection system that have to be provided in the current period and short term.
Today, there is no way to effectively fight with prepared violators to achieve their goals using any of the known single-sensor systems.
It is concluded that there is a need to develop a multi-sensor system, minimum equipment of which should include interconnected seismic and vibro-acoustic subsystems. Combination of vibro-acoustic and seismoanalytical subsystems allows compensating the most significant drawbacks of each of them
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Chemical Compatibility Testing Final Report Including Test Plans and Procedures
This report provides an independent assessment of information on mixed waste streams, chemical compatibility information on polymers, and standard test methods for polymer properties. It includes a technology review of mixed low-level waste (LLW) streams and material compatibilities, validation for the plan to test the compatibility of simulated mixed wastes with potential seal and liner materials, and the test plan itself. Potential packaging materials were reviewed and evaluated for compatibility with expected hazardous wastes. The chemical and physical property measurements required for testing container materials were determined. Test methodologies for evaluating compatibility were collected and reviewed for applicability. A test plan to meet US Department of Energy and Environmental Protection Agency requirements was developed. The expected wastes were compared with the chemical resistances of polymers, the top-ranking polymers were selected for testing, and the most applicable test methods for candidate seal and liner materials were determined. Five recommended solutions to simulate mixed LLW streams are described. The test plan includes descriptions of test materials, test procedures, data collection protocols, safety and environmental considerations, and quality assurance procedures. The recommended order of testing to be conducted is specified
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