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[en] In France the complete closure of the fuel cycle can be reached in 3 steps. The first step relies on the improvement of the present fuel cycle by implementing the use of reprocessed uranium (URT) and by enlarging the use of MOX fuel from 900 MW to 1300 MW PWR. The first loading of URT fuel is planned in 2023. The second step will be the multi-recycling of plutonium. The loading of a test fuel assembly with multi-recycled Pu in a PWR core could be made in 2025-2028 and the industrial deployment may be made in 2040 at the soonest. The third step implies the development of a fleet of fast reactors that will allow a limitless recycling of spent fuels and no necessity of using enriched natural uranium. (A.C.)
[en] The development of advanced thorium-based nuclear system raises new requirements on nuclear data. The multi-group data file of critical nuclides in the thorium-uranium recycle is the foundation of physical design, analysis and calculation of the reactor core. Based on authoritative nuclear data processing code NJOY, this paper obtains a WIMS format multi-group cross section data files through processing the ENDF/B-VII.1 evaluation nuclear data file, uses the specific update maintenance procedure WILLIE to get a WIMS format data file, and conducts a series of critical benchmarks on the data file using the multi-group reactor core calculation code WIMSD5B. The results show that the computed results of the WIMS file based on the processing of ENDF/B-VII.1 are basically the same as those of the latest WIMS-D file published on the websites of the 'WIMS-D' library updating project (WLUP) with higher accuracy and reliability than those of the shipped WIMS-D file of the WIMSD5B code. Furthermore, the average deviation of the new WIMS file performing in the validation of 16 thorium-uranium cycle benchmarks is 0.225 3% smaller than that of the old WIMS file. (authors)
[en] At the Plutonium Conversion Development Facility (PCDF) in the Nuclear Fuel Cycle Engineering Laboratories, the co-conversion technologies to purify the mixed plutonium and uranium nitrate solution discharged from a reprocessing plant have been developed. The probability of a criticality accident in PCDF is extremely low. However, the criticality accident alarm system (CAAS) has been in place since 1982 to reduce the radiation dose to workers in case of such a rare criticality accident. The CAAS contains criticality accident detector units (CADs), one unit consisting of three plastic scintillation detectors, and using the 2 out of 3 voting system for the purpose of high reliability. Currently, eight CADs are installed in PCDF evaluating the dose using a simple equation allowing for a safety margin. The purpose of this study is to show the determination procedures for the adequate relocation of the CADs which adequately ensures safety in PCDF. (author)
[en] The International Atomic Energy Agency (IAEA) supports free information exchange and international collaboration by its statute. Out of several possibilities the mechanism of Coordinated Research Projects (CRP) is described, which can bring together scientists and research groups from developing and developed countries to form teams on projects of mutual interest. Examples of successfully CRP's in the nuclear data field are described, which include the production of the reference input parameter library for nuclear model codes, photonuclear data library, an updated processed WIMS-D library for reactor lattice calculations and evaluated nuclear data files for the thorium-uranium fuel cycle. (author)
[en] The waste management strategy of partitioning and transmutation is currently the cutting edge development of nuclear technologies, which has been intensively researched over the last several decades, as it is highlighted in the following two excerpts on the history of partitioning and transmutation given below.
[en] The technique of evaluation of the multiplication factors and reactivity characteristics of fast reactors operating in the mode of multiple refueling is presented. We describe and apply the calculation method. The results demonstrate that fuel composition comes into equilibrium concentration in the multiple refueling reactor operation mode. If initial loads were based on plutonium from spent fuel of thermal and fast power reactors, equilibrium was achieved with twice repeated refueling. For initial fuel loads based on highly enriched uranium nitride or uranium-plutonium nitride fuel with high enrichment of 239Pu, equilibrium is reached after 4-5 refuelings
[en] The paper deals with the evaluation of fuel handling in fast reactors in the closed nuclear fuel cycle. To solve these problems, the REPRORYV program code has been developed. It simulates the nuclide streams in out-of-reactor stages of the closed fuel cycle. Existed verified code JARFR is used for the calculation of neutron-physical characteristics of the core. Various options for nuclide streams are considered with a representative full-scale model of a fast reactor with sodium-cooled high-power. The changes of multiplication factor and mass of plutonium in the closed nuclear fuel cycle for a Russian BN-type fast reactor with use of the REPRORYV code are evaluated. Different scenarios of fuel reprocessing assuming the removing or retaining of actinides, taking into account various plutonium losses on reprocessing steps were considered. The questions of influence of the initial content of plutonium in nitride fuel (Pu-U-N) and the impact of the initial parameters to the possibility of fuel self-sufficient mode of the reactor during the whole period of its operation are studied
[en] This paper summarises the work done in India in the field of physics and economics of plutonium utilization. Plutonium recycle was considered in Tarapur Atomic Power Project and Rajasthan Atomic Power Project and the results obtained are presented in this paper. A short description of the plutonium laboratory being constructed in India i s also presented. (author)
[en] The French fleet of reactors is made up of 58 pressurized water reactors (PWR). Before being loaded in the core of a reactor, the nuclear fuel comes from a long process, beginning in the mine and going through enrichment and the manufacturing of fuel assemblies. After a 4-year long irradiation in reactor, used fuels are unloaded, separated and packaged for final disposal. Separation allows the recovery of plutonium and uranium and their re-use as nuclear fuel in reactors. This article details every stage of nuclear fuel from mining to disposal via reprocessing. A graph shows how in 2013, the recovery of plutonium allowed the fabrication of 100 tonnes of mixed uranium and plutonium oxides fuel (MOX) and the recovery of uranium allowed the fabrication of 70 tonnes of re-enriched fuel (URE). The total amount of nuclear fuel required to feed 58 reactors is 1000 tonnes a year. (A.C.)
[en] The Plutonium Utilization Program (PUP) of the USAEC is being carried out by the Pacific Northwest Laboratory of Battelle Memorial Institute. The basic mission of the program has been to develop the- base technology necessary for the implementation of plutonium recycle in commercial power reactors. Hie program scope has been quite broad in the past, including plutonium fuels development, chemical reprocessing studies, physics of plutonium-enriched systems, and technical and economic optimization studies of plutonium-enriched reactors. More recently, the major efforts have been directed toward solving the immediate problems of utilizing plutonium as enrichment in refueling cycles in the present generation of H2O moderated and cooled power reactors. This report summarizes the current and planned program activities. Another report prepared for the panel meeting ''Results from USAEC Plutonium Utilization Program Conducted by Battelle-Northwest'' presents detailed results and conclusions from the programs and therefore these will not be presented here. The major emphasis of the program are on physics and fuels developments.