The OM analysis apparatus

The O M analysis apparatus consists of a gas extraction unit, a gas dilution unit, the NDIR, an operating controller, and a computerized peak-area integrator. The schematic diagram of the apparatus is shown in Fig. 1. The gas extraction unit consists of an impulse furnace, a power supply, a refrigerator and a compressor. The impulse furnace consists of the upper and lower electrodes and the electrode driving cylinder. The heating conditions of the sample were controlled using the operating...

Taejon Republic of Korea

Korea Plutonium

Neulronic feasibility of a PWR core with mixed oxide (MOX) fuels has been investigated as part of the feasibility study for recycling spent fuels in Korea. A typical 3-loop PWR with 900 MWe capacity is selected as reference plant to develop equilibrium core designs with low-leakage fuel management scheme, while incorporating various MOX loading. The fuel management analyses and limited safety analyses show that, safely stated, MOX recycling with 1 3 reload fraction can be accommodated for both...

Karlsruhe Germany

We investigate a novel scheme for burning weapons grade plutonium (W-Pu) in conventional light water reactors with a view to optimising the destruction rate of plutonium and increasing the proliferation resistance of the resulting spent fuel. The main feature of this scheme is the use of a fuel based on W-Pu and weapons grade uranium (W-U) in an inert matrix. The extended irradiation ( 2000 days) of this fuel leads to a high destruction rate (95 ) of the Pu. Proliferation resistance of the...

Abstract

The paper reviews the status of MOX fuel fabrication for Light Water Reactors (LWRs) at the BELGONUCLEAIRE Plant at Dessel (Belgium), as well as the irradiation experience accumulated so far. Since 1986, about 240 tons of MOX fuel rods have been fabricated and loaded in commercial reactors in France, Switzerland, Germany and from 1995 on, in Belgium. Their excellent in-reactor performance up to 50 GWd tHM has been demonstrated through surveillance programmes as well as specific experimental...

Average burnup GWdtHM

BWR 8x8 Fusion Gas Release of MIMAS Fuel Nr of fuel E-I 1 1 10 designs Evolution of the MIMAS Production Field of Experience Evolution of the MIMAS Production Field of Experience FIG. 7. Prospects ofMOX Fabrication at BELGONUCLEAIRE Beyond 2005, the MOX market and thus BN's position in such market shall depend on the future reprocessing commitments in Europe. If required, future prospects of the plant can also lay in the transformation into MOX fuel of plutonium originating from nuclear weapons...

B

PWR 17x17 Fission Gas Release of MIMAS Fuel * Data on 8x8 MIMAS fuel segments at high power Fig. 5 6 compares FGR results on MIMAS and U02 fuel segments irradiated at powers in the range 30-40 kW m up to about 60 GWd tHM. No difference between the two types of fuel can be found, if one takes into account that the U02 fuel power levels are 5 to 10 lower than in the The mechanical resistance of MIMAS fuel rods is good, as has been proven by power ramps performed in fee BR2 (MTR -Mol,...

British Nuclear Fuels pic Sellafield United Kingdom

The main business drivers for the next generation of reprocessing and fabrication plants will be cost reduction and diversion resistance. Integration of reprocessing plant with refabrication plant provides the scope to reduce powder handling stages prior to pelleting, e.g. by utilising ammonium carbonate co-precipitation or thermal de-nitration to produce a U Pu Masterblend for pelleting. The pelleting stage must be eliminated to achieve greater cost reduction, as this will also eliminate the...

C

ISSUES ADDRESSED FOR Pu RECYCLE IN TAPS. 1. Decrease in Control System Capability 2. Decrease in delayed neutron fraction 3. Increase in negative reactivity feedback 4. Increase in long term decay heat of the spent fuel bundles 5. Thermal margin criteria (MCHFR)+ 6. Design basis accidents (e.g. control rod drop accident) 7. Operational transients (e.g generator lockout) fuel for power reactors. Table-IV gives the summary of these irradiation experiments. Several fuel characteristics which are...

Conclusion

These experimental results confirm clearly that the abrasion is the main mechanism occurring during the milling of nuclear powders and is responsible for the reduction of the size of the initial particles and of their subsequent blending the impact mechanism is never reached under these conditions. The detailed analysis of the quantitative data in terms of the homogeneity of the distribution of the minor powder (i.e. plutonium oxide) in the bulk of the main compound (i.e. uranium oxide) is...

Conclusions

The business drivers set for the next generation of fuel recycle plant require reductions in cost and improvements in resistance to diversion. This paper shows that these can be achieved by a combination of integration of fabrication and finishing routes, selection of processes suitable for remote operation, and acceptance of products with a relaxed specification. All of these lead us to consider the use of vibro fuel in thermal reactors. The fabrication and use of vibro MOX fuel has been...

Dessel

Bwr Vip Engineering

The Venus International Programme (VIP), executed at the VENUS facility, aimed at validating reactor codes in order to meet safety requirements enforced by licensing authorities. The VIP programme has validated the reactor codes DOT and WIMS (GOG and TWOTRAN) for reactivity and fission rate distribution calculations in PWR and BWR MOX configurations. The VIPO programme has been performed to cope with future developments of the nuclear fuel cycle. The tendency of going to higher burn-ups causes...

Determination Of Occluded Gas Component Analysis In Mox Using Gas Sampling Unit And Gas Chromatograp

The gases extracted from the sample at vacuum condition were injected into a gas chromatograph through an originally developed gas sampling unit (GSU). The gases were simultaneously determined using the improved gas chromatograph equipped with several separation columns and a photo-ionization detector (PID). The relative standard deviations (n 10) were 1.0, 3.4, 0.6, 1.0, 1.4, 0.8 and 0.9 for H2, 02, N2, CH*, COz, CO and QH, respectively. The gases B,, Qz, N,, Cii, CO, and CO from the MOX fuel...

Fig U isotopic masses per tonne of matrix in fresh fuel and after and cycles in a PWR cycledays

Evolution of an inert matrix containing 2.5 W-Pu+2.5 W-U in the neutron spectrum of a PWR (lcycle 879 EFPD). Densities of matrix and standard fuel are assumed equal. critical mass of this mixture is approximately 50 kg 8 , heating rates of 7.5 kwatt per device will have to be contended with Clearly, from this result the amounts of W-U present in the fresh matrix could be considerably reduced. The neutron emission rates from such chemically separated plutonium are shown in Fig. 5. After...

Fig Variation of kx with time for different fuels and mixing ratios of WPu and WU

The same as that of the U02 fuel, then approximately 50 kg of W-Pu per tonne of matrix (i.e. 5 assuming equal densities) is required for equivalent power production. The inert matrix is a material which replaces conventional U02. It should not form actinides by neutron capture, but otherwise have properties similar to or superior to those of U02. To avoid actinide formation, the atomic number of all components should be significantly less than 92. To have good reactor properties, the melting...

France

An important stage of MOX fuel pellets fabrication is the blending process of the nuclear powders which is carried out in the French plants in a ball milling and under dry conditions in order to avoid any criticality related difficulties. The milled powders must present a sufficiently intimate distribution of the UO, and Pu02 particles which is necessary to synthesize the homogeneous (UPu)02 solid solution during the subsequent reactive sintering the homogeneity of the U02 Pu02 fuels is...

Future Plans

In order to put these analysis technologies for MOX to practical use, further improvements are necessary. Particularly, the developments of automatic handling system, simultaneous determination methods for impurity and more accurate methods need to be proceed. 1 LYON, W.L. USEC Report, GEAP 4271 (1963). 2 McNEILLY, C.E. and CHIKALLA, T.D., J. Nucl. Mat. 39 (1971) 77. 3 Annual Book of ASTM Standards, Vol. 12.1 C698 (1990). 4 HIYAMA, T., SUGAYA, S., YAMAMOTO, J. and KAMIMURA, K., Journal of Nucl....

Introduction

Although the BELGONUCLEAIRE (BN) MOX plant went first in operation in 1973 already, the industrial production started in 1986, using the new fabrication process MIMAS (MIcronized MASter blend) described hereafter. The evolution of BN-Dessel as well as the various processes which were experienced earlier have been extensively described elsewhere 1 , The main achievements reached over 9 years (1986-1994) of operation of the plant are presented in the next chapter, with emphasis on the production...

Irradiation Time

Isotopic heating rates per unit mass of total Pu for fresh fuel, and after 1, 2, and 2.3 cycles in a PWR. Fresh fuel Inert Matrix + 2.5 W-F'u + 2 5 W-U Fig. 4. Isotopic heating rates per unit mass of total Pu for fresh fuel, and after 1, 2, and 2.3 cycles in a PWR. Fresh fuel Inert Matrix + 2.5 W-F'u + 2 5 W-U Fig. 5. Isotopic neutron emission rates per unit mass of total Pu for fresh fuel, and after 1, 2, and 2.3 cycles in a PWR CRITICALITY ASPECTS OF INERT MATRIX-BASED MIXED U-PU...

Methods Of Cost Reduction

2.1 INTEGRATION OF FINISHING AND FABRICATION Integration of finishing into fabrication, eg by producing a mixed U Pu stream directly by a thermal de-nitration route, would have the potential to reduce combined finishing and fabrication costs due to elimination of some of the milling and conditioning stages and associated equipment. Additional reductions in cost could be obtained by eliminating conventional pellet pressing, eg by adopting vibro compacted granules as pin fill for thermal MOX...

O

MIMAS Commercial Irradiation Experience 3.3. TYPICAL RESULTS OF THE MIMAS IRRADIATION BEHAVIOUR Out of all the MIMAS fuel irradiated in commercial reactors in France (EDF NPPs), Switzerland (BEZNAU) or Germany (PHILIPPSBURG, BROKDORF, UNTERWESER, GRAFENRHEINFELD) or under experimental conditions in The Netherlands (DODEWAARD) or Belgium (BR3), no foiled MOX assembly could be detected, except one in the BEZNAU-1 core two failed rods were identified in this assembly and the investigations...

O o

10000 20000 30000 40000 Rod Average Burnup (MWd t) More Helium is produced in MOX fuel through a-decay. This Helium production and release from pellet increase fuel rod internal pressure. This is modelled in the fuel design code. Based on these considerations, the fuel design code can fairly predict fuel rod internal pressure and fuel temperature as illustrated in Fig. 7 and Fig. 8, and both of them show good agreement. Nuclear characteristics of MOX fuel is slightly different from that of U02....

Pg Boczar

Atomic Energy of Canada Ltd, Chalk River, Ontario, Canada J.R. HOPKINS Atomic Energy of Canada Ltd, Mississauga, Ontario, Canada H. FEINROTH Gamma Engineering Corp., Rockville, Maryland, United States of America J.C. LUXAT Ontario Hydro, Toronto, Ontario, Canada Recently, die U.S. Department of Energy (DOE) sponsored Atomic Energy of Canada Limited (AECL) to evaluate salient technical, strategic, schedule, and cost-related parameters of using CANDU1 reactors for dispositioning of weapons-grade...

Plant Outline

The basic plant requirements as defined by the client were A design throughput of 120 t year Heavy Metal. The plant must be capable of handling any plutonium dioxide material likely to arise from reprocessing operations at Sellafield site, together with the ability to receive plutonium dioxide from overseas reprocessors. Thus there is a wide variation in the composition of plutonium dioxide that the plant can receive. Initially the plant will utilise depleted or natural uranium dioxide as its...

Procedure

The sample was placed into a degassed graphite crucible, weighed to an accuracy of 0.1 mg and the metal flux was added. The crucible was placed in the impulse furnace, and it was heated up to 2700 C for 30 sec under a helium atmosphere. Gases released from the sample were carried to the pre-cut system by the helium carrier gas. N2 was determined by the TCD, and the chromatogram peak-area of N2 was integrated by the computerized peak area integrator. The concentration of N2 in the iron powder...

PufPuU

Histogram representing the homogeneity ofSBR MOX pellets measured by EPMA LESSONS LEARNT DURING THE EARLY STAGES OF OPERATING MDF Although the fabrication plant and processes used by BNFL are now becoming well established the need to produce good quality product to a closely defined schedule proved demanding on occasions for both the customer and the supplier. During plant commissioning and qualification a number of valuable lessons were learnt before BNFL could ensure that the plant...

PuUPu

Variation of the apparent interdiffusion coefficient in a U02 Pu02 couple sintered for 50 hours under N2-5 H2 (pHJPHfi 20) as a Junction of Pu content for different sintering times. Investigation of the U and Pu interdiffusion coefficients obtained from compacted uranium and plutonium oxide powders enables determination of the diffusion mechanisms involved, taking into account the additional diffusion effect of densification and grain growth. This work has shown that, whatever the...

References

1 KILGOUR, W H et al, Capabilities and Validation of the ENIGMA Fuel Performance Code, Paper to the International Topical Meeting on LWR Fuel Performance, Avignon, France, April 2 HESKETH, K W et al, Elimination of the Homogenisation Step in the Manufacture of Mixed Oxide Assemblies for Light Water Reactors by Means of a Reactivity Equivalence Formulation, Paper presented to Jahrestagung Kerntechnik '92, May 1992.

Rolling Over large load of milling balls

FIG. 1 Theoretical Milling Mechanisms as a Function of Balls Load and Rotation Speed FIG. 2 Electron Images ofU02 Powder Milled by Abrasion (a) or by Impact (b) 3. CHARACTERIZATION OF MILLED AND BLENDED POWDERS The quality of the mixing of the U02 - Ce02 or U02 - Pu02 powders cannot be easily described by simple analytical techniques, especially at a micronic scale chemical determinations on very small samples, X-ray diffraction measurements or optical microscopy are not sufficiently sensitive...

Sintered pellet store

With both areas of development mentioned above extensive use is made of simulant materials to replicate the behaviour of MOX materials. For flowsheet development uranium dioxide has sufficiently close properties to MOX for it to be used as a representative simulant. Likewise, for engineering development, extensive use has been made of uranium pellets and other simulants, such as steel pellets, which replicate the parameters under investigation. Such simulants allow development work to be...

T

Equivalent Plutonium Content vs. UO2 Fuel Enrichment Guide Tube Cell Fig. 3. Zoning and Relative Power Distribution of MOX Assembly 18 month cycle, both annual and 18 month cycle schemes are covered, in which MOX fuels are assumed to be partly loaded. We considered three scenarios of up to 40 MOX loading in the annual operating cycle in contrast to only 1 3 MOX fraction in 18 month cycle. Loading patterns of MOX equilibrium cores for both cycle schemes are shown in Fig. 4. The...

Technical Design Considerations In The Provision Of A Commercial Mox Plant

ELLIOTT BNFL Engineering Ltd, Risley, Warrington, United Kingdom The Sellafield MOX Plant (SMP) has a design production target of 120 t year Heavy Metal of mixed uranium dioxide and plutonium dioxide (MOX) fuel. It will have the capability to produce fuel with fissile enrichments up to 10 . The feed materials are those arising from reprocessing operations on the Sellafield site, although die plant also has the capability to receive and process plutonium from overseas reprocessing plants....

United Kingdom

The Short Binderless Route (SBR) has been developed for Mixed Oxide fuel production in BNFL's MOX Demonstration Facility (MDF) and the Sellafield MOX Plant (SMP). It is a compact process which enables good homogenisation of the Pu U mixture and production of free flowing press feed material. The equipment used to achieve this consists of an attritor mill to provide homogenisation and a spheroidiser to provide press feed granules. As for other powder processes, the physical properties of the UO...

Recycling Process For Clean Mox Fuel Pellet

FIG. 2 Lattice Enrichment Design, M39 (Discharge Burnup 39.5GWd t) FIG. 3 Lattice Enrichment Design, M45 (Discharge Burnup 45. OGWd t) Table I Calculated Results of Equilibrium Core Performance Table II Examples of 17 x 17 PWR MOX Fuel Enrichment Design for Pu Enrichment Common Use with BWR MOX Fuel Common Use Pu Enrichment (cf. Fig. 2, Fig. 3) (1) Case 1 and 2 use the common Pu enrichments with the BWR design case M39 and M45, respectively, (cf. Fig.2, Fig.3) (2) Both cases are designed for...

Calender Year

Estimation of Cumulative Spent Fuels Discharged from Korean PWRs The lack of proper store place for and the increasing amount of spent nuclear fuels have made their management one of the national issues. Recycling of spent fuels can provide Korea with many attractive benefits it will help to mitigate spent fuel storage problem, and contribute to the recycling of resources and the protection of natural environment through the reduction of radioactive wastes. In this regards, two types of...

Irradiation time days Fig Variation of k and power with time for the inert matrix based fuel in a PW

One quarter of the inert matrix pins in the outer blanket of the reactor are removed these pins have been in the reactor for a period of 7 x 293 2050 days from the reactor. Such a scheme will ensure that the standard pins are in the reactor for 878 days whereas the inert matrix pins are in the reactor for the required 2050 days. It is not a requirement that the outer blanket should contain the sub-critical inert matrix based pins. Depending on the neutron distribution, this array of...

PuO

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...

Design Features

9x9 Bwr Fuel

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...

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 Spectrophotometry

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

Tantalum Thermal Conductivity

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 in a PWR cycledays

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

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...

Comparisons Between Measured and Calculated Values of Core Parameters Fuel Management U and MOX

Phwr Fuel Bundle

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

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....

Ooooooooooooo

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

Belgonucleaire Dessel

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...

Smp Plutonium Grain Size

Mox Fuel Pellet

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...

Cycle Exposure GWdt

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

Simple Schematic Diagram Nitrogen

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 GWdt

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

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...