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LMFBR (LIQUID METAL FAST BREEDER REACTOR) READTION RATE AND DOSIMETRY 3RD QUARTERLY PROGRESS REPORT DECEMBER 1971 JANUARY FEBRUARY 1972

Description: This report was compiled at the Hanford Engineering Development Laboratory operated by Westinghouse Hanford Company, a subsidiary of Westinghouse Electric Corporation, for the United States Atomic Energy Commission, Division of Reactor Development and Technology, under Contract No. AT (45-1) 2170. It describes technical progress made in the Interlaboratory LMFBR Reaction Rate Program during the reporting period. The Interlaboratory LMFBR Reaction Rate (ILRR) program has been established by USAEC/RDT to develop a capability to accurately measure neutron-induced reaction rates for LMFBR fuels and materials development programs. The initial goal for the principal fission reactions, {sup 235}U, {sup 238}U, and {sup 239}Pu, is an accuracy to within {+-}5 at the 95% confidence level. Accurate measurement of other fission and non-fission reactions will be required, but to a lesser accuracy, between {+-}5 to 10% at the 95% confidence level. A secondary program objective is improvement in knowledge of the nuclear parameters involved in fuels and materials dosimetry measurements of neutron flux, spectra, fluence, and burnup. These accuracy goals for the ILRR program are severe; measurements of fast-neutron-induced reaction rates have not been rapidly moving toward this level of precision. Using a number of techniques in well established neutron environments of current interest for fast reactor development and critically evaluating the results will help establish existing levels of accuracy and indicate the scale of effort required for improvement. To accomplish the objectives of this program, reliable and documented experimental values of reaction rates and ratios will be determined for various well established and permanent neutron fields. The Coupled Fast Reactivity Measurement Facility (CFRMF) at Aerojet Nuclear Company (ANC) is the first neutron field being studied because of the similarity of its spectrum to that of a fast reactor and the range and reproducibility of flux levels available for track etch, fission chamber, radiochemistry, and ...
Date: March 1, 1972
Creator: WN, MCELROY
Partner: UNT Libraries Government Documents Department

Characterization of an energy source for modeling hypothetical core disruptive accidents in nuclear reactors. First interim report. [LMFBR]

Description: The expansion characteristics of the detonation products of a high-explosive energy source used to simulate the pressure-volume change relationships for sodium-vapor expansions during hypothetical core disruptive accidents in a Fast Test Reactor were determined experimentally. Rigid cylinder-piston experiments performed at two scales (ratio 1:3) were undertaken to determine a pressure-volume relationship as a function of source mass and expansion environment. Some of these measurements were compared with code calculations for the source.
Date: October 1, 1972
Creator: Cagliostro, D J & Florence, A L
Partner: UNT Libraries Government Documents Department

Pu, U redistribution in (U,Pu)O/sub 2/ fuels by temperature gradients

Description: A predictive model of the time-dependent evolution of radial Pu/U + Pu gradients in operating nonmolten mixed oxide fuels is being developed. This model is based on preferential evaporation-condensation and vapor transport of metal-bearing species either along cracks and porosity channels within the fuel or inside closed pores migrating up the temperature gradient; equilibrium thermodynamics are applied to calculate the continually changing vapor composition over the hot fuel. Predictions of the model are used in combination with recent in-pile experimental data (from nonmolten mixed oxide fuel pins irradiated in EBR-II from 0.2 to about 11 at. % burnup at varying powers) to delineate the key parameters in radial actinide redistribution. A correlation between fuel stoichiometry (O-to-Pu ratio) and the degree of redistribution (described by an enrichment factor ..gamma../sub Pu/) identified, however, the degree of restructuring of the fuel - as determined by the peak linear power rating, time at this power, and the initial fuel density - also has a strong influence on the final value of ..gamma../sub Pu/. Certain kinetic features of the process and intended modifications to the present model are discussed, and evidence for axial actinide vapor transport in an irradiated annular fuel is also presented.
Date: August 1, 1972
Creator: Adamson, M.G. & Aitken, E.A.
Partner: UNT Libraries Government Documents Department

Acoustic emission weld monitoring of nuclear components

Description: Acoustic emission monitoring augments other nondestructive testing methods and is sometimes applicable when other tests cannot be applied. This is, in part, due to the high sensitivity of acoustic emission monitoring. Acoustic emission monitoring is only sensitive to active flaw-growth, however, and will not detect a flaw in equilibrium. This paper describes the application of acoustic emission monitoring to nuclear reactor fuel pin end closure welds and other weldments of the reactor piping.
Date: January 25, 1972
Creator: Romrell, D.M.
Partner: UNT Libraries Government Documents Department

Length changes in FTR prototypic cladding irradiated in EBR-II to 1 x 10/sup 22/ N/CM/sup 2/, E > 0. 1 MeV (PIN B-65)(RM-24)

Description: Swelling in prototypic FTR cladding and duct specimens is being determined from a series of three irradiations designed to cover a range of temperatures approximately 800 to 1500/sup 0/F and peak fluences of approximately 1 x 10/sup 22/, 6 x 10/sup 22/, and 1 x 10/sup 23/ n/cm/sup 2/. The length change measurements for the low fluence irradiation have been completed and are summarized in this report. No swelling, only shrinkage, was found in the 20 percent cold worked Type 316 stainless steel cladding specimens. This shrinkage is of the same magnitude and has the same temperature dependency as unirradiated, control samples. Annealed specimens did swell slightly. Details of the experiment and analysis are given.
Date: July 1, 1972
Creator: Straalsund, J.L.; Guthrie, G.L. & Larson, T.J.
Partner: UNT Libraries Government Documents Department