PuO
FIG. I. X-ray images at the interface of the U02Fu02 couple sintered at 2023Kfor 50 hours under FIG. 2. Evolution ofU02 grain sizes along the interdiffusion zone x200 . -132 -125 -95 -88 -81 kcal mol -132 -125 -95 -88 -81 kcal mol FIG. 3. Variation of the apparent interdiffusion coefficient in a UO2 PUO2 couple sintered at 2023K for 50 hours as a junction of oxygen potential. FIG. 3. Variation of the apparent interdiffusion coefficient in a UO2 PUO2 couple sintered at 2023K for 50 hours as a...
Conclusion
The experience accumulated so far at the BN plant has demonstrated the commercial viability of MOX fabrication. The MIMAS process developed is suited for commercial use considering the particularity of the MOX fabrication technology and the variability of the plutonium as received from reprocessing. The same process has therefore been choosen by COGEMA for the MELOX plant in Marcoule and for CFCa in Cadarache. The irradiation of MIMAS MOX fuel in commercial reactors as well as experimental...
References Fkv
1 An Assessment Could Weapon-grade Pu be an Asset for Managing Pu Inventories 2 Disposition of Weapons Grade Pu-Analysis of the best way MOX Fuel, A. Decressin amp E. Vanden Bernden 2nd Annual Int'1 Policy Forum Management and Disposition of Nuclear Weapons Materials, Lansdowne, VA, 21-24 March 1995 3 Pu Inventory in Western and Eastern Europe, FEX Report 9502 commercial 4 White Paper on Nuclear Energy, Atomic Energy Commission, Japan, Nov 94 5 Nuclear Power, Nuclear Fuel Cycle and Waste...
Design Features
Large Flow Area Upper Tie -Plate - Low Pressure Drop - Optimized Hot to Cold Reactivity Swing - Optimized Void Reactivity Coefficient - Simplified Enrichment Distribution - Proven Design Hydraulic Mechanism for High Precision Control of Coolant Leakage between LTP and Channel Box The spacer, upper tie-plate UTP and lower tie-plate LTP play important roles for the thermal-hydraulic performance. The ring-type spacer provides a high critical power which has been demonstrated by testing 4 , The low...
REFERENCES Ipk
1 YI Chang, Nuclear Technology, 88 1989 129. 2 MACLEOD H M and YATES G, 'Development of mixed oxide fuel manufacture in the United Kingdom and the influence of fuel characteristics on irradiation performance', Nuclear Technology, 102 1993 3. 3 STEINKOPFF H., KROMPASS R., SCHUMANN K., TSYKANOV V A., SKIBA O V and PORODNOV P T., 'Characteristics and performance of the plant for re-fabrication of vibro compacted fuel elements for the BOR 60 reactor', Kerntechnik, 55 1990 243. 4 HERBIG R., RUDOLPH...
Results And Discussion
3 .1 EFFECT OF MILLING ON POWDER CHARACTERISTICS The morphology of each unmilled powder can be seen in Figure 1 a. The IDRs and ADU powders appear similar, each consisting of small less that 1 xm rounded particles. The IDRP powder possessed a definite 'plate-like' morphology with individual particles approximately 1 im in size. Table 1 gives results of toe Coulter counter analysis results which show that the mean particle sizes for each powder are very similar prior to milling. All of them lie...
Mox Fabrication
The MIMAS for MIcronized MASter blend process was developed in the mid-eighties at BN to replace the former process used in the Dessel plant, which consisted in direct blending of U02 and Pu02 powders and was mainly used for the fabrication of the first core of the German Fast Breeder Reactor SNR-300. The main reasons for switching to the new process were the requirement to produce soluble fuel, for further reprocessing, and also the necessity to better adapt the fabrication to the specific...
Mol Belgium
Due to the temporary shortage of MOX fuel fabrication facilities, the stockpile of separated civilian grade Pu CPu is predicted to increase up to the turn of the century. An additional quantity of weapon grade Pu WPu will be progressively isolated at the same period. Both CPu and WPu surplusses require disposition as soon as feasible. Although non-proliferation concerns, established national policies, public acceptance problems and other considerations largely complicate the aspect of the use...
Experimental Method
The traditional approach to modelling the thermal homogenization of the Pu and U cations is to investigate the chemical interdiffusion for a couple of uranium oxide and mixed uranium plutonium oxide mono or polycrystals bonded together by hot-pressing 1-6 . In this experimental work, the diffusion couple is realized from a pellet of Pu02 powder placed inside a pellet of UP powder. The contact between these two green pellets is obtained thanks to the differential shrinkage during the heat...
Determination Of Oxygen To Metal Atomic Ratio In Mox By Nondispersive Infrared
The present method is based on the extraction gas analysis using nondispersive infrared spectrophotometry NDIR after inert gas fusion. The oxygen in the fused sample was quantitatively reacted with the carbon in a graphite crucible and the CO generated was determined using the NDIR. The relative standard deviation RSD was less than 0.20 , and the time required for one determination was about 10 min for all analytical operations. This method is applicable to sintered MOX fuels over a wide range...
Outline Of Pwr Mox Fuel Assembly
All fuel rods within a PWR MOX fuel assembly are made of MOX, with the distribution of Pu content of fuel rod to reduce local power peaking at the periphery of the assembly. An example of 17 x 17 type fuel is shown in Fig. 1. The average Pu fissile content of MOX fuel assembly is designed so that the reactivity of MOX fuel is equivalent to that of current standard U02 fuel for Japanese PWR's whose enrichment is 4. lwt . Typical plutonium fissile and total content as a function of fissile...
Kansai Electric Power Company Inc Tokyo Japan
A programme of physical properties measurements has been carried out on MOX fuel manufactured using the Short Binderless Route SBR by BNFL and on MOX fuel manufactured using the MIMAS process by Belgonucleaire. The programme includes the following work - Determination of the melting point of MOX fuel. - The measurement of the thermal expansion of MOX fuel. - Determination of the thermal diffusivity of MOX fuel. This paper will describe the programme of measurements and summarise the results...
Fig Pu isotopic masses per tonne of matrix in fresh fuel and after and cycles
Also from Table V, approximately 94 of the total plutonium has been destroyed over 2.3 cycles. What remains is mostly the isotope Pu which from Table III has a critical mass of 100 kg with approximately 28 Pu. If the spent fuel were to be reprocessed to separate out the plutonium, very high heating rates in excess of 150 Watt kg of Pu metal are to be expected as can be seen in Fig. 4. Since the
Plutonium Recycling And The Melox Fabrication Plant
W. FOURNIER MELOX, Bagnols-sur-Ceze, France The French decision to turn to industrial plutonium recycling through MOX fuel was taken relatively recently, by he mid-1980s, when recycling of valuable materials emerged as a satisfactory back-end solution for the fuel cycle. The French strategy currently relies on an industrial structure comprising the COGEMA reprocessing plants at La Hague with a total capacity of over 1600 tHM, the existing MOX fabrication facilities at Dessel BELGONUCLEAERE PO...
France Bvy
The French programme aiming at recycling plutonium in pressurized water reactors PWRs was initiated in 1985 by Electricite de France EDF in close cooperation with the Commission for atomic energy CEA , Cogema and Fragema. At the request of the French safety authority DSIN , the programme proposed by EDF was submitted in 1986 to a preliminary safety examination, concerning the different stages of the plutonium and uranium mixed oxides MOX fuel cycle manufacturing, transport, use in reactors,...
Comparisons Between Measured and Calculated Values of Core Parameters Fuel
GG Gray Groups Overlapping EDF, by its position, belongs to the small circle of utilities who keep a long term vision as far as nuclear fuel is concerned, this latter represents several decades . The reprocessing - recycling technology has attained maturity in Europe, from plutonium separation to irradiated MOX fuel reprocessing. Used fuel reprocessing and fissile material uranium and plutonium whose energetic value is unquestionable recycling is the fundamental option of the back end of the...
Belgonucleaire Mimas Mox Fuel Irradiation Experience
3.1. RELATIONSHIP BETWEEN FABRICATION PROCESS AND EXPECTED IRRADIATION BEHAVIOUR The MIMAS process produces a MOX pellet made of master blend of typically 30 Pu02 distributed in the U02 matrix in agglomerates of a size which is typically 30 to 100 micron homogeneously dispersed in the pellet. The MIMAS MOX fuel can thus not be considered as a new compound as if it were a complete solid solution of U02 and PuQ. Its behaviour is very close to that of UO , regarding thermal and mechanical aspects....
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instrumentation guide tube 0 RCC guide tube 3.9wt Puf and 2.8wt Puf are commonly used with the BWR MOX fuel FIG. 7 PWR MOX Fuel Enrichment Design The advanced 9x9 BWR MOX fuel design concept that uses 2 Pu enrichment levels and allows a simple process in the MOX fuel fabrication was proposed. A core analysis has shown that the advanced BWR MOX fuel has a large operating margin of LHGR over the fuel lifetime. Based on the proposed BWR MOX fuel design, the effects of the MOX fabrication costs and...
FIG MIMAS Process
Thanks to this double blending, the MIMAS process can lead to excellent isotopic homogeneity of the Pu in the product, even with Pu of various origins LWRs, GCRs , various forms Pu02 powder as produced by European reprocessors or, if required, U02-Pu02 mixture produced in Japan and various batch sizes. It should be noted that the U02 powders used up to now are free-flowing, either of the AUC type or of the ADU type developed by COGEMA and recently qualified at the BN-Dessel plant 2 . The...
Fig
1. MOX fuel rod rating - 82w cm2 2. Peak Assembly burn-up - 25,000 MWd Te 3. Local peaking factor - 1.172 4. Axial peaking factor - 1.273 5. Peak pellet burn-up - 37,200 MWd Te EXPERIMENTAL IRRADIATIONS OF MOX FUEL BWR TYPE CLUSTERS IN CIRUS Sr. Designation Max.linear Rating Burn-up No. W cm MWD Te Limited burn-up planned. Design variables studied include fuel clad gap, annular pellets, LTS, grain size and Pu cluster size. A manufacturing plant for MOX fuel was planned and constructed at...
Measurement C
Comparison of Fuel Centre Temperature 4.2 CHARACTERISTICS OF MOX FUELED CORES With the increase of MOX fuel fraction, some core physics parameters change from U02 fueled core. Typical variation of these parameters are shown in Fig. 9. The reactivity effect of control rod and boron in the coolant decrease with MOX fuel fraction. To 1 3 MOX fuel fraction, degradation of control rod worth can be mitigated by loading MOX fuel avoiding the control rod position. To increase MOX fuel fraction more...
Initial Fissle Isotope Fraction in Pu wtX
Typical Pu Content vs Fissile Isotope Fraction high as at present, it is planned that all components except for MOX pellets will be supplied by domestic vendors to overseas manufactures, who will fabricate MOX fuels for certain time period. The basic description of PWR MOX fuel is shown in TABLE 1. 3. FUEL MECHANICAL DESIGN OF MOX FUEL 3.1 MOX CHARACTERISTICS AND DESIGN CONSIDERATIONS Pu02 and U02 form solid solution, and material properties of MOX are very similar to those of U02 to...
References 1
1 HAAS D. amp al., Mixed-Oxide Fuel Fabrication Technology and Experience at the BELGONUCLEAIRE and CFCa Plants and Further Developments for the MELOX Plant, Nuclear Technology, Vol. 106, April 1994. 2 VAN VLIET J. amp al., Industrial Qualification of TU2 Powder use for MOX Fuel Fabrication, Nuclear Europe Worldscan, 11-12, 1994. 3 VANDERGHEYNST A. amp DEBAUCHE M Key Issues of MOX Fuel Plant Engineering, ICONE 3, Kyoto Japan , 23-27 April 1995. 4 DERAMAIX P. amp HAAS D., In-Pile Performance of...
Cycle Exposure GWdt Axo
Prompt neutron life time of MOX core is smaller than that of U02 core. But it is known that a prompt neutron life time dose not practically affect a transient and accident behavior. 3.4 MOX Fuel and Core Specific Considerations a Influences of Pu isotopic composition It is expected that an increase of Pu inventory in fuel and core has more influences upon a core characteristics due to a fluctuation of Pu isotopic composition 'Pu vector' . Two Typical MOX fuels with different Pu vector from the...
The gas components analysis apparatus
The gas components analysis apparatus consists of a gas extraction unit, a gas collection and a volumetric measurement unit, the GSU, the gas chromatograph and a computerized integrator. Except for the GSU and the gas chromatograph, this apparatus has been widely used for the volumetric analysis of total gas in nuclear fuel pellets by the high temperature vacuum extraction method 5 . The schematic diagram of the apparatus is shown in Fig.3. The GSU consists of special three-way and four-way...
Fig Typical microstructures of the BNMOX and PNCMOX pellets irradiated to about
Fig. 11 Fully automated MOX bundle assembling apparatus before the repair can begin. Therefore item c is essential to the automated apparatus. In fabrication tests using dummy MOX fuel rods, the apparatus demonstrated satisfactory performance 14 . In its nuclear energy policy the Japanese government is promoting systematic utilization of MOX fuel in LWRs, we have joined in the development of MOX fuel technology to allow future full scale utilization. In this paper, we selected three subject...
Fig Loading Patterns of MOX Equilibrium Cores for Annual and Month Cycles
Status of Nuclear Power Plants in Korea will be Korean Standard Type. will be Korean Standard Type. Table II. Fuel Cycle Characteristics of U02 and MOX Cores 4.2. Neutronic Characteristics of MOX Core The power distributions of MOX cores were not significantly different from those of uranium cores. The axial power distributions of MOX cores at HFP at several burnup stages, however, are slightly bottom skewed from those of uranium cores, which resulted from more negative moderator temperature...
Introduction Overview Of Plutonium Dispositions In Candu
The U.S. Government is currently considering about a dozen options for dispositioning of weapons plutonium. The U.S. National Academy of Sciences, in its 1994 January report, Management and Disposition of Excess Weapons Plutonium, urged the U.S. and Russian Governments to act expeditiously to demilitarize excess fissile material from dismantled nuclear weapons, calling the continued availability of such materials, even when placed in safe storage, a clear and present danger. As part of this...
Experimental
Three uranium dioxide powders, which were derived from powder processes used by BNFL Fuel Division at the Springfields site, were studied. The first two materials were prepared by the Integrated Dry Route IDR using different kiln conditions to provide one powder of plate like particle morphology IDRp and one of sphere like particle morphology IDI . The third powder was prepared via the Ammonium Diuranate route ADU in the BNFL Springfields Enriched Uranium Residues Recovery Plant EURRP . Each...