Proliferation resistant

Pu. The Pu has seen appHcation as a long-Hved isotopic heat source. Plutonium-238 is most usehil in space programs, but is also of interest as part of a proliferation-resistant fuel cycle (2). 

Tumor cells may become resistant when genetic changes occur during cell proliferation. Resistant cancer cells with the mdr-1 gene may possess a membrane-associated protein, p-glycoprotein, that facilitates efflux of chemotherapy agents out of the cells. Numerous attempts at blocking this efflux pump have been unsuccessful. 

JamesTape,Los Alamos National Laboratory Commercial Nuclear Power and Proliferation What is Proliferation Resistance ... 

Three of these awards were for proliferation resistant reactors. By exploring advanced concepts such as modular reactors with long-life cores and thorium-based firel cycles, we may be able to find solutions to the greatest challenges facing the nuclear energy industry. 

R.A. Krakowski, L. Bennett, and E. Bertel, Nuclear Fission For Safe, Globally Sustainable, Proliferation-Resistant, and Cost-Effective Energy, Proceedings of the International Conference on Preparing the Ground for Renewal of Nuclear Power, held October 22-23,1998, edited by B.N. Kursunoglu, et al., Kluwer Academic / Plenum Publishers, 1999. 

If nonproliferation considerations have not led to official opposition to nuclear power, their effect on fuel cycle policy has been profound. Although, its rhetoric and many of its implementating actions have been more restrained, the Clinton Administration has, in principle, adopted the Carter policy of opposition to reprocessing and plutonium recycle, hr at least one important area, however, it has inexplicably out-Cartered earlier policy by terminating work on proliferation-resistant firel cycles that involve recycle of still highly radioactive plutonium. 

While the goal of bringing plutonium production and consumption into balance is a long term one, research and development on proliferation-resistant fuel cycles should be taking place at present. International cooperation ofthe appropriate countries in this R D is also essential. Failure to pursue a suitable R D effort and international cooperation is virtually certain to result in the adoption ofthe most proliferation-prone fuel cycle when the plutonium breeder is deployed in the next century. 

The bacterium Staphylococcus aureus, which is a major cause of infection in the developed countries, is now resistant to most antibiotics. It is usually present on the skin, where it causes no problems, but it can invade the body through cuts and wounds, including those caused by surgery. These bacteria are now prevalent in many hospitals, so that infection is a major problem for the medical staff in hospitals. The resistant bacterium is known as methicillin-resistant Staphylococcus aureus (MRSA). It is also known in the mass media as the super bug . Penicillin kiUs bacteria because the P-lactam group in the antibiotic inhibits a reaction that is essential for bacterial ceU wall production. Consequently, the bacteria cannot proliferate. Resistance to penicillin in many bacteria is due to production of an enzyme, p-lactamase, that degrades P-lactams. The antibiotic methicillin is one of a group of semisynthetic penicillins in which the P-lactam group is not... 

Schenkel, R., Magill, J. Glatz, J.-P. Mayer, K. Partitioning and Transmutation - Technical Feasibility, Proliferation Resistance, and Safe guar dability. 2-21-2003. Ref Type Electronic Citation. 

Further improve proliferation resistance (PR) and safety. The essential elements to enhance nonproliferation of nuclear weapons or to suppress harmful usage of nuclear power are to (i) decrease the global inventory of separated fissile nuclides, including the existing warheads (ii) make the... 

Tachimori, S., Yaita, T., Suzuki, S., Rais, J. 2008. Development of CHON- extractants and proliferation resistant advanced reprocessing ARTIST, in Japan. Proc DAE-BRNS Biennial Symp on Emerging Trends in Separation Science and Technology, SESTEC-2008, University of Delhi, March 12-14, pp. 18-24. 

Kang, J., von Hippel, F. 2005. Limited proliferation-resistance benefits from recycling unseparated transuranics and lanthanides from light-water reactor spent fuel. Science and Global Security 13 169-181. 

Future nuclear reactors are expected to be further progressed in terms of safety and reliability, proliferation resistance and physical protection, economics, sustainability (GIF, 2002). One of the most promising nuclear reactor concepts of the next generation (Gen-IV) is the VHTR. Characteristic features are a helium-cooled, graphite-moderated thermal neutron spectrum reactor core with a reference thermal power production of 400-600 MW. Coolant outlet temperatures of 900-1 000°C or higher are ideally suited for a wide spectrum of high temperature process heat applications. 

Advanced Proliferation Resistant, Lower Cost, Uranium-Thorium Dioxide Fuels for Light Water Reactors, Nuclear Energy Research Initiative, Idaho National Engineering and Environmental Laboratory, Idaho Falls, ID, 2000. 

Proliferation. Nuclear-fuel-cycle operations leave open the possibility of improper access to fissile material through theft or diversion. Proliferation can be addressed through near-term measures designed to improve the proliferation-resistance of current nuclear reactor operations and through long-term research to explore proliferation-resistant designs (PC AST, 1999). 

Aqueous reprocessing methods have been developed to effect an efficient and thorough separation of fissile elements from the contaminating fission products in spent fuel( l). While these processes may be altered to yield a proliferations-resistant product by coprocessing or by the addition of radioactive material that will contaminate the clean fissile material, it still is necessary to safeguard some of the process steps to ensure that material useful in nuclear weapons will not be diverted (3). The safeguard requirements and the ease of subversion of such provisions make many versions of the conventional processes subject to unacceptable proliferation risks. 

Some of the pyrochemical processes have more potential for being proliferation resistant because of the great similarity of the chemistry of uranium, plutonium, and some of the fission products in the chosen systems. Ordinary processes are designed to maximize differences in chemical behavior in order to separate constitutents. For some of the pyrochemical processes the chemical equilibria are such that partial separations are possible but complete separations are thermodynamically limited. For example, excess uranium can be separated from plutonium by precipitation in a molten metal such as zinc only until both are present in about equal quantities in solution, but no further ( 3, 4). Likewise, the solubility of fission products is selectively limited. Only a portion of elements such as ruthenium will stay in solution and be removed 05). The majority of the ruthenium precipitates with the actinides. A complete separation is again thermodynamically limited. As a result only a modest dependence needs to be placed on process equipment and facility design for proliferation resistance. 

Process is Exportable. (a) The combination of proliferation-resistant processing, compactness of plant, and minimum need for safeguards make PDPM processing attractive for export to other countries. 

Six processes that are representative of those initially selected for evaluation in the PDPM Program are summarized below. Several of these processes are described in separate papers that are included in this Actinide Separations Symposium. A seventh process, the Zinc Distillation Process is described in greater detail. This process was selected as a reference process to meet the criteria for a proliferation-resistant exportable technology. 

Zinc Distillation Process ( 3, 4 ). A zinc distillation process was selected as a reference pyrochemical process that would have a sufficient degree of proliferation resistance that it could be used by nonweapons nations to reprocess spent fuel without significantly increasing their weapons production capability. The process has the inherent proliferation-resistant advantages of being a low decontamination process with limited plutonium enrichment in uranium-plutonium-zinc mixtures. The process chemistry flow sheet for this process is shown in Figure 1. 

The solid (U,Pu)2Zni7 intermetallic compound, containing FP-3 and selective FP-4 fission products for proliferation resistance is vacuum distilled to remove the zinc, which is recycled. The uranium/plutonium concentrate is injection cast into rods suitable as feed to the refabrication process. 

Pyrochemical processing methods may offer unique advantages over more conventional aqueous methods with respect to meeting nonproliferation goals. Some pyrochemical processes are intrinsically proliferation resistant because the process is incapable of producing a weapons-usable product without significant alterations. The product also can be sufficiently radioactive that it is physically difficult to divert. These features warrant the examination of pyrochemical and dry processing methods under current nonproliferation policies. 

The present work at Rocky Flats is an extension of the Argonne work and is directed to development of a proliferation resistant pyrochemical process for LMFBR fuels. This article describes a conceptual pyrochemical process and preliminary engineering concepts for coprocessing uranium and plutonium in spent LMFBR core-axial blanket and radial blanket fuels using the Salt Transport Process. 

The pyrochemical coprocessing of spent nuclear fuel by the Salt Transport Process appears to be a potentially viable reprocessing method, not only as an "exportable proliferation resistant technology," but as a domestic reprocessing operation. All operations are nonaqueous and waste generation is in solid form, thus requiring no conversion from aqueous solutions to solids. 

Spent fuel is generally regarded as proliferation-resistant due to the high level of radioactivity and the low concentration of fissile material in the fuel removed from a reactor. High levels of radioactivity promote proliferation resistance because special, easily monitored facilities are required to process the fuel and the high level of radioactivity makes removal of fuel without detection extremely difficult. Spent fuel is also proliferation-resistant because the concentration of fissile material is below that required to achieve a nuclear detonation. 

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