Fast reactor fuel preparation

Thermal reactor fuel preparation 65.2.3.4 Fast reactor fuel preparation... 

Pnictides. Plutonium nitride, PuN, has been studied as a possible fast-reactor fuel. It can be prepared by reaction of PuH with NH at 600—650°C or N2 above 230°C. The pnictides ate also interesting for their soHd-state magnetic and electrical properties. For the latter reason they also have been prepared as single crystals (165). 

The JRC/rru prepared oxide fuels containing minor actinides for irradiation tests in the fast reactor PHENIX in France (SUPERFACT experiment). The analysis of the irradiated fuels enabled to determine the transmutation rate of minor actinides and the incurred occupational dose during handling of this material. Another experiment, SUPERFACT2, of transmutation of U and Pu oxide with 2% minor actinides is planned in PHENIX. 

The Instituto de Estudos Avanfados is coordinating a project which aims to establish a basic know-how for an eventual utilization of fast reactors in Brazil. In spite of the many limitations due to reduced funds, we firmly believe that activities in this field should be maintained if we wish to keep fast reactors as an option for future use. A reference design for a 60 MWt experimental reactor has been prepared, based on some parameters and general description of fast reactors built or being designed in other countries. Also, research activities in areas such as metallic fuel, materials, etc. have been started. 

A method for determining the reactivity of highly sub-critical systems of fissile material, u ng neutron-noise power spectral densities in conjunction with a %f source, had previously been tested in two fast reactor critical assemblies (a mockup of the Fast Flux Test Facility reactor and unreflected enriched uranium metal assemblies ) and one thermal reactor (a light water moderated and reflected lattice of Oak Ridge Research Reactor ftiel elements. The last-mentkmed test demonstrated the effectiveness of the method in watermoderated systems and thereby prompted the prexnt study, of its application to facilities for fuel preparation, reprocessing, and storage. 

In January of 1994, the Department of Energy mandated the termination of the Integral Fast Reactor (IFR) Programme, effective as of 1 October 1994. To comply with this decision, Argonne National Laboratory-West (ANL-W) prepared a plan providing detailed requirements to place the EBR-II in a radiologically and industrially safe condition, including removal of all irradiated fuel assemblies from the reactor plant, and removal and stabilization of the primary and secondary sodium used to transfer heat within the reactor plant. 

I was initially appointed as a junior engineer in the operations department, looking after final preparation of new fuel before loading to the reactor. A first impression was that all the staff seemed old. When I started work at Dounreay I was 24, and most of the rest of the staff at PFR seaned to be over 40. PFR had been operating since 1974, and its construction had begun in me late 1960s. In addition, many of the staff had been transferred to PFR when me old Dounreay Fast Reactor had closed. Hence most of me staff had been at Dounreay for a long time and mere had not been many recent new recruits. 

Switzerland Within the framework of the CAPRA project, the fuel option for amplified plutonium consumption is being studied. In the area of materials for actinide transmutation, the following tasks has been completed in 1994 (1) preparatory experiments and solubility tests for (Ui, PUJ O2 (0.25 < x < 0.65 and for (Uj., PU,J N (0.25 < x< 0.75), as possible materials for the efficient fission of plutonium in a fast neutron flux (2) fabrication of pure PuN-microspheres for ceramic-metal fuel (3) design calculations for sphere-pac segments, based on the idea of a ceramic-metal fiiel (4) material preparation of (U, Zr) N and pelletization tests of TiN and (U, Zr)N for the irradiation experiment in the reactor PHENIX (5) experimental preparations of (Ce,U) O2, (Ce,U,Pu)02 and (Ce, PU)02 for the CAPRA core with lower Pu content, and (6) cleaning of americium from waste streams of the plutonium separation equipment (extraction chromatography). 

Abstract The chapter is devoted to the practical application of the fission process, mainly in nuclear reactors. After a historical discussion covering the natural reactors at Oklo and the first attempts to build artificial reactors, the fimdamental principles of chain reactions are discussed. In this context chain reactions with fast and thermal neutrons are covered as well as the process of neutron moderation. Criticality concepts (fission factor 77, criticality factor k) are discussed as well as reactor kinetics and the role of delayed neutrons. Examples of specific nuclear reactor types are presented briefly research reactors (TRIGA and ILL High Flux Reactor), and some reactor types used to drive nuclear power stations (pressurized water reactor [PWR], boiling water reactor [BWR], Reaktor Bolshoi Moshchnosti Kanalny [RBMK], fast breeder reactor [FBR]). The new concept of the accelerator-driven systems (ADS) is presented. The principle of fission weapons is outlined. Finally, the nuclear fuel cycle is briefly covered from mining, chemical isolation of the fuel and preparation of the fuel elements to reprocessing the spent fuel and conditioning for deposit in a final repository. 

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