05 Nuclear fuels (scientific, technical)

97101939 Structural transformations in phenol-formaide- hyde-pitch dispersions in the course of their curing and coking Bahaevskii, P. G. and Siplyvyi, I. V. Vy.sokomol. Soedin., Ser. A Ser. B, 1996, 38, (6), 94.5-949. (In Russian) A dynamic mechanical method was used to study the parameters of curing kinetics. The relaxation transitions during the cure and in the cured state of a phenol-formaldehyde-coal tar pitch (PF-CTP) dispersion was also studied by the same method. This was obtained by dispersing a quinoline-soluble fraction of a coal-tar pitch in melted phenol, followed by condensation with formaldehyde. Electron microscopy and X-ray diffraction showed a heterophase structure of the PF-CTP dispersion. This structure provides the formation, upon thermolysis, of the dispersion of ordered graphitized coke in a less ordered non-graphitized medium.

97101940 Study of the effect of autoxidation processes on aikanes from coal lithotypes Markova, K. 1. et al. Oxid. Commun. 1996, 19. (3). 419-425. A study of quantitative changes and distribution of n-alkanes in lithotypes from Bulgarian brown coals during their autoxidation at 150 and 200 “C. The reaction mechanism involves radical-chain reactions, similar to that of low rank coal lithotypes. The differences registered for separate petro- grahical ingredients were related to a degree of coalification and structural peculiarities.

97101941 Testing of the Westinghouse hot gas filter at Ahistrom Pyropower Corporation. Lippert, T. er al. Proc. Int. Conf. Fluid. Bed Comhust.. 1995, 13, (I), 25 l- 2hl. A single cluster Westinghouse hot gas filter has been tested. This filter system houses 128 ceramic candles in three plenums. Two candle types, an alumina/mullite candle manufactured by Coors Ceramics and a clay bonded Sic candle manufactured by Refractron Corporation were evaluated over a range of filtration face velocities, dust loadings, coal types and tempera- tures. The results of the study are discussed.

97101942 Transport and plant uptake of soil-applied dry flue gas desuifurization by-products Stehouwer, R. C. et al. Soil Sci., 1996, 161, (9), 562-574. Clean air legislation has resulted in increased production of flue gas desulfurization (FGD) by-products by coal-fired boilers. Use of FGD hy- products as substitutes for agricultural limestone represents a potential beneficial use alternative to landfill disposal of these materials. To determine the efficacy and potential for environmental impact of such use, an H-month greenhouse study was conducted in which three dry FGD by-products were mixed with Wooster silt loam at rates of 0, 3.5, 7, 14, and 28 g kg-‘. Dry FGD by-products appear to be effective substitutes for agricultural limestone with little potential for adverse environmental impacts.

97101943 Use of low-rank vitrinites of Kuzbass coal field in byproduct coke industry Eremin, I. V. and Bronovets, T. M. Khim. Tverd. Topl. (Moscow), 199h, (3), X1-87. (In Russian) The effect of thermal plasticization and caking on a (5O:SO) mixture of two coals of different rank [vitrinite 1G (Oktyahr’skaya mine, Kuzhass coal field) and coal concentration 2K (Neryungrinskoe coal field, Southern Yakutiya)] was studied. According to the tests carried out in four integrated iron and steel works of Russia and Kazakhstan, the vitrinite 1G was recommended as an additive to the coke batch for increasing coke strength.

97101944 Use of tar in Denmark Petersen, H. J. S. Dan. Kemi, 1993, 74, (9) 18-20. (In Danish) The use and exploitation of coal tar and its components in Denmark, from the early part of the twentieth century until the present, is explored with historical data.

05 NUCLEAR FUELS

Scientific, Technical

97101945 Calculation of the systematic error and correction factors in gamma waste assay system Dung, T. Q. Ann. Nucl. Energy. 1997, 24, (I), 33-47. The measurement system of a segmented gamma scanner was simulated to give a model for the calculation of systematic errors and correction factors. The calculation values exhibited good agreement with experimental values. Through a simple code the results are used for estimating the range of measured uncertainty, and for giving the correction terms to improve accuracy.

97101946 The design rationale of the IFR Wade, D. C. and Hill, R. N. Progress in Nuclear Energy, 1997, 3 I, (l/2), 13- 42. Beyond the traditional advanced reactor objectives of increased safety, improved economy and more efficient fuel utilization, the IFR is designed to simplify waste disposal and increase resistance to proliferation. Only a fast reactor with an efficient recycle technology can provide for total consumption of actinides. In a fast reactor, not all fission products need to be removed from the recycled fuel, and there is no need to produce pure plutonium. Recovery, recycle, and ultimate consumption of all actinides resolves several waste-disposal concerns. The IFR can he configured to achieve safe passive response to any of the traditional postulated reactor accident initiators, and can be configured for a variety of power output levels. An IFR can he designed to consume excess fissile material, to produce a surplus, or to maintain inventory. It appears that commercial designs should he economically competitive with other available alternatives.

97101947 Detection of subcooled boiling in a PWR using noise analysis and calculation of the steam void fraction Laggiard, E. and Runkel, J. Ann. Nucl. Energy, 1997. 24, (I), 49-54. The analysis of temperature fluctuations of thermocouples situated above the core in a 1300 Mw pressurized water reactor (PWR) was undertaken. The neutron noise of self power neutron detectors (SPNDs) located in the upper part of the core were also analysed and suhcooled boiling was detected. The changes observed in the noise functions due to the presence of bubbles were compared to the behaviour of the same functions measured by other authors during boiling simulated experiments. The cross-sectional average volumetric void fraction was calculated following a profile-fit model of suhcooled boiling and used to interpret the temperature and neutron fluctuations measured in the PWR.

97101948 The IFR fuel cycle demonstration McFarlane, H. F. and Lineberry, M. J. Progress in Nucleur Enq~. 1997, 31, (l/2), 155-173. An old ho-cell facility, the Fuel Cycle Facility (FC‘F). attached to the Experimental Breeder Reactor (EBR-II) reactor in Idaho has been refurbished hy theArgonne National Lahoratory (ANL). The refurbishment was undertaken with the intention of setting up an engineering-scale demonstration of the Integral Fast Reactor (IFR) pyroprocess fuel cycle. Only nine pieces of equipment are required to completely recycle spent fuel for return to EBR-II. Three major pieces accomplish the key steps of the recycle technology: Electrorefining to extract the uranium, plutonium and other actinides from the dissolved fuel; cathode processing to produce metal ingots from the electrorefiner products; and injection casting to fabricate new fuel pins. These three pieces of equipment are scheduled to process hatches typical of full-scale commercial operation. The fuel cycle demonstration is the final technical element needed to evaluate the technical and economic feasibility of the IFR.

97l91949 The integral fast reactor-an overview Till, C, E. et al. Progrecs in Nuclear Energy, lY97, 31, (l/2), 3-l I. This paper presents an overview of the Integral Fast Reactor (IFR). It is a system that consists of a fast-spectrum nuclear reactor that uses metallic fuel and liquid-metal (sodium) cooling. coupled with technology for high- temperature electrochemical recycling, and with processes for preparing wastes for disposition. It has four essential, distinguishing features: efficient use of natural resources, inherent safety characteristics, reduced burdens of nuclear waste, and unique proliferation resistance. These fundamental characteristics offer benefits in economics and environmental protection. Initiated in 1984 in response to proliferation concerns identified in the International Nuclear Fuel Cycle Evaluation (INFCE, 1980) the project has made substantial technical progress, with new potential applications coming to light as nuclear weapons stockpiles are reduced and concerns about waste disposal increase.

97lO1950 Metallic fast reactor fuels Hofman, G. L. el al. Progress in Nuclear Energy, 1997. 3 I, ( Ii?), X3- I IO. Metallic fuels produce an extremely hard neutron spectrum which makes them neutronically ideal for fast reactors. By incorporating space for swelling, very high burnups are now routinely achieved. Uranium- plutonium alloys with 10% zirconium to raise the melting point have been shown to he extremely reliable. Extensive studies into fuel swelling, mechanical and chemical interactions with various cladding materials. performance during transients, failure mechanisms, and hehaviour follow- ing both benign and complete failure of fuel pins have been carried out.

97101951 Monitoring of the temperature reactivity coefficient at the PWR nuclear power plant Kostic, L. Ann. Nucl. Energy, 1997, 24, (I ), 55-64. A method for monitoring the temperature coefficient of the reactivity of pressurized water reactors, based on the correlation of fluctuations in signals of in-core neutron detectors, core-exit thermocouples and neural network paradigm was used. It showed that the moderator temperature coefficient of reactivity can he predicted with the aid of the back- propagation neural network technique by measuring the frequencv response function between the in-core neutron flux and the core-exct coolant temperature.

158 Fuel and Energy Abstracts May 1997