[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] 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] 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 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] 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.

No abstract available

[en] After a presentation of the context, situation and stakes of the nuclear sector, this document presents the five structuring actions which build up the strategic contract of this sector. These actions are to guarantee necessary abilities and expertise for an attractive, safe and competitive nuclear sector, to structure, by using digitalisation, the supply chain and the innovation approach within the sector, to promote a circular economy within the sector, to define tomorrow's nuclear reactors and future tools, to develop a global strategy for the sector at the international level, and to launch an approach to accelerate the transformation of the industrial tissue. For each of these actions, context, objectives, key points and State's main commitments for the sector are described, and key figures are proposed

[en] As exports of MOX by Areva towards Japan have been resumed in 2013 after having been stopped because of the Fukushima accident, this article discusses why Areva keeps on exporting MOX, and what are the commercial stakes and objectives for this plutonium-based fuel which is supposed to replace uranium. The author evokes the relationship between fuel recycling and nuclear proliferation, radioactivity problems raised by the molten MOX in Fukushima, a demonstration by ecological activists against this new transport, and de-pollution problems related to MOX. This strategy of Areva in favour of MOX could be a worrying sign of a possible come back of breeder reactors