29 Matching Results

Search Results

Advanced search parameters have been applied.

Autoradiography as a safeguards technique

Description: Autoradiography gives a simultaneous piece count and attribute check for special nuclear material without, however, a quantitative measurement of fissile material. Applications to fuel elements containing plutonium for fast critical assemblies or uranium for LWRs are discussed. 15 figures.
Date: January 1, 1978
Creator: Brumbach, S.B.
Partner: UNT Libraries Government Documents Department

Interaction of molecular beams with solid surfaces

Description: From proceedings of the International Summer Institute in surface science; Milwaukee, Wisconsin, USA (28 Aug 1973). Molecular beam - surface scattering experiments, the nature of elastic and inelastic scattering, and the information obtained from detection of the angular distribution and kinetic energy of the scattered particles are described. The types of energy exchange that take place between a gas atom or molecule and the surface atoms and the theories that have been developed to explain some of these energy transfer processes are discussed. Finally the results of some experiments are reviewed, and directions for future research are pointed out. (JFP)
Date: August 1, 1973
Creator: Somorjai, G.A. & Brumbach, S.B.
Partner: UNT Libraries Government Documents Department

JUPITER-II Program: ANL analysis of ZPPR-13A and ZPPR-13B

Description: The ZPPR-13 experiments provide basic physics data for radial-heterogeneous LMFBR cores of approximately 700 MWe size. Assemblies ZPPR-13A, ZPPR-13B and ZPPR-13C comprised the JUPITER-II cooperative program between US-DOE and PNC of Japan. The measurements were made between August 1982 and April 1984. This report describes in detail the results of the ANL analyses of phases 13A and 13B/1 and includes preliminary results for the later assemblies of phase 13B. The data were compiled primarily for discussions at the Third Jupiter Analysis Meeting to be held at ANL-West between September 11th and 14th, 1984.
Date: August 9, 1984
Creator: Collins, P.J. & Brumbach, S.B. (comps.)
Partner: UNT Libraries Government Documents Department

Autoradiographic inventory methods

Description: Described are autoradiographic techniques which can verify the number and SNM content of plutonium- and uranium-containing fuel elements. These techniques are applied to fast critical assembly fuel and to low-enriched uranium in LWR fuel assemblies. Autoradiographic images are formed by the spontaneously emitted X and gamma rays from the fuel elements striking X-ray film in contact with the fuel elements or their containers. Autoradiography allows a large number of items to be examined in a minimum inspection time and with minimum facility impact. Results are presented for fast critical assembly fuel in a variety of storage modes as well as in fast critical assemblies themselves. Results are also presented for low-enriched uranium rods in unirradiated LWR fuel assemblies. In all cases, missing fuel elements or substitution of elements containing inert material or depleted uranium were detected. (6 figs.)
Date: January 1, 1978
Creator: Brumbach, S.B. & Perry, R.B.
Partner: UNT Libraries Government Documents Department

Experiments and analysis for an axially heterogeneous LMR assembly at ZPPR

Description: Experiments in ZPPR-17 provided physics data for a full-scale (700 MWe) axially heterogeneous LMR. Measurements and analysis are reported for control rod worths, reaction rate distributions, gamma dose distribution, sodium void worths and criticality. Agreement between measurement and calculation are generally satisfactory, but the axial heterogeneity did introduce analytical complications. Some calculational methods gave less good agreement with measurements than in previous homogeneous or radially heterogeneous assemblies. 10 refs., 7 figs., 6 tabs.
Date: January 1, 1988
Creator: Collins, P.J. & Brumbach, S. B.
Partner: UNT Libraries Government Documents Department

Autoradiography as a safeguards inspection technique for unirradiated LWR fuel assemblies

Description: A nondestructive autoradiographic method is described which can provide a verification that rods in the interior of unirradiated LWR fuel assemblies contain low-enriched uranium. Sufficient absorber must be used to reduce contributions to image density by beta radiation from /sup 238/U daughters. When appropriate absorbers are used, the density of the image of a uranium-containing fuel rod is proportional to the /sup 235/U enrichment in that rod. Exposure times as short as 1.5 hours can be achieved by using fast film and intensifying screens. Methods are discussed for reducing contributions to the image density of any single rod from radiation produced by all other rods in the assembly. The technique is useful for detecting missing rods, dummy rods, and rods containing depleted uranium. These defects can be detected by visual inspection of the autoradiographs. In its present state of development, the technique is not sensitive enough to reliably detect the difference between the various /sup 235/U enrichments encountered in current BWR fuel assemblies. Results are presented for field tests of the technique at BWR and PWR facilities.
Date: May 1, 1978
Creator: Brumbach, S.B. & Perry, R.B.
Partner: UNT Libraries Government Documents Department

In-cell reaction rate distributions and cell-average reaction rates in fast critical assemblies

Description: Measurements are described for determining average values of fission rates in /sup 235/U, /sup 238/U and /sup 239/Pu and capture rates in /sup 238/U for heterogeneous cells used to construct fast critical assemblies. The measurements are based on irradiations of foils of /sup 238/U, /sup 235/U and /sup 239/Pu with counting of fission and capture products using gamma-ray spectroscopy. Both plate and pin cells are considered. Procedures are described for inferring cell-average reaction rate values from a single foil location based on a cell using a quantity called a cell factor. Cell factors are determined from special measurements in which several foils are irradiated within a cell. Comparisons are presented between cell factors determined by measurements and by Monte Carlo calculations which lend credibility to the measurement procedures.
Date: August 1, 1985
Creator: Brumbach, S.B. & Gasidlo, J.M.
Partner: UNT Libraries Government Documents Department

In-situ verification techniques for fast critical assembly cores

Description: Active and passive autoradiographic techniques were used to obtain piece counts of fuel plates in fast critical assembly drawers and to verify the assembly loading pattern. Active autoradiography using prompt-fission and fission-product radiation was more successful with uranium fuel while passive autoradiography was more successful with plutonium fuel. A source multiplication technique was used to measure changes in reactivity when small quantities (2-2.5 kg) of fissile material were removed from a subcritical reference core of the Zero Power Plutonium Reactor. Efforts to compensate for unsuccessful. Some compensation was achieved by replacing U-238 with polyethylene. The sensitivity for detection of partially compensated fuel removed from minimum worth regions was approximately 2.5 kg (fissile) for a core containing 2600 kg (fissile). Substitution of polyethylene was detected with a spectral index which was the ratio of the rate of the In-115 (n,..gamma..) reaction to the rate of the In-115 (n,n') reaction. This spectral index was sensitive to the presence of an 0.64-cm-thick, 5.08-cm-high polyethylene column 10-15 cm away from the indium foil. The reactivity worth of Pu-239 was also obtained as a function of location in the reactor core with the use of an inverse kinetics technique. Reactivity worths for Pu-239 varied from a maximum of 58.67 Ih/kg near the core center to a minimum of 14.86 Ih/kg at the core edge.
Date: January 1, 1979
Creator: Brumbach, S.B.; Amundson, P.I. & Roche, C.T.
Partner: UNT Libraries Government Documents Department

Studies of spatial decoupling in heterogeneous LMFBR critical assemblies

Description: Recent measurements at the Zero Power Plutonium Reactor have studied the spatial decoupling in large, heterogeneous assemblies. These assemblies exhibited a significantly greater degree of decoupling than previous homogeneous assemblies of similar size. The flux distributions in these heterogeneous assemblies were very sensitive reactivity perturbations, and perturbed flux distributions were achieved relatively slowly. Decoupling was investigated using rod-drop, boron-oscillator and noise-coherence techniques which emphasized different times following the perturbations. Reactivity changes could be measured by analyzing the power history from a single detector using inverse kinetics methods with the assumption of an instantaneous efficiency change for the detector. For assemblies more decoupled than ZPPR-13, the instantaneous efficiency change assumption begins to be invalid.
Date: January 1, 1984
Creator: Brumbach, S.B.; Goin, R.W. & Carpenter, S.G.
Partner: UNT Libraries Government Documents Department

Measurements and analysis of control rod worths in large heterogeneous LMFBR cores

Description: The ZPPR-13 program provides basic physics data for heterogeneous LMFBR cores of 700 MW(e) size. A number of internal blanket variations were studied and measurements of control rod worths were made in each configuration. The cores are sensitive to asymmetric perturbations and have strong interaction effects between control rods. Calculations with ENDF/B-IV data are within about 5% of experimental values but show systematic variations in accuracy of prediction with location in the core.
Date: January 1, 1984
Creator: Collins, P.J.; Brumbach, S.B. & Carpenter, S.G.
Partner: UNT Libraries Government Documents Department

ANL analysis of ZPPR-13A

Description: The ZPPR-13 experiments provide basic physics data for radial heterogeneous LMFBR cores of approximately 700MWe size. Assemblies ZPPR-13A, ZPPR-13B and ZPPR-13C comprised the JUPITER-II cooperative program between the U.S. Department of Energy (US DOE) and PNC of Japan. The measurements were made between August 1982 and April 1984. The core designs and the measurements were planned jointly by the two parties with substantial input from U.S. industrial interests to ensure coverage of the design requirements. This report describes in detail the results of the Argonne National Laboratory (ANL) analyses of phase 13A.
Date: August 9, 1984
Creator: Collins, P.J. & Brumbach, S.B.
Partner: UNT Libraries Government Documents Department

ZPPR progress report: August 1987-October 1987

Description: This progress report details activities during the time period of August through October, 1987. Results are presented from the axially heterogeneous assembly ZPPR-17, a part of the Jupiter-III program. The loading of the ZPPR-17B assembly, with 25 control rod positions, is described along with operational measurements, calculation models, measurements and predictions of criticality and measured axial worth profiles for B[sub 4]C. From ZPPR-17A, calculated and measured results are given for banks of control rod positions along with revised measured values for various single, central control rods.
Date: November 16, 1987
Creator: Brumbach, S.B. & Collins, P.J.
Partner: UNT Libraries Government Documents Department

ZPPR progress report, January 1989 through April 1989

Description: Further results are presented from the large, homogeneous assembly ZPPR-18 in the JUPITER-III program. Reaction rate results are given for ZPPR-18B along with measured gamma ray dose results from ZPPR-18A and 18B. Control rod worth results from the ZPPR-18 assemblies are included. Calculation models, measured and calculated k-effective values and measured sodium worth values, are presented for the ZPPR-19 assemblies of the lo program.
Date: April 27, 1989
Creator: Collins, P.J. & Brumbach, S.B.
Partner: UNT Libraries Government Documents Department

ZPPR progress report: February 1988 through April 1988

Description: Results are presented for control rod worth experiments in the axially heterogeneous assembly ZPPR-17, a part of the JUPITER-III program. From the earlier metal-fuel ZPPR-15 program, results are given for measurements and calculations of neutron spectra and sodium voiding in several configurations.
Date: May 13, 1988
Creator: Brumbach, S.B. & Collins, P.J.
Partner: UNT Libraries Government Documents Department

JUPITER-II Program: ANL analysis of ZPPR-13A and ZPPR-13B

Description: The ZPPR-13 experiments provide basic physics data for radial heterogeneous LMFBR cores of approximately 700MWe size. Assemblies ZPPR-13A, ZPPR-13B and ZPPR-13A comprised the JUPITER-II cooperative program between the U.S. Department of Energy (US DOE) and PNC of Japan. The measurements were made between August 1982 and April 1984. The core designs and the measurements were planned jointly by the two parties with substantial input from U.S. industrial interests to ensure coverage of the design requirements. This report describes in detail the results of the Argonne National Laboratory (ANL) analyses of phases 13A and 13B/1 and includes preliminary results for the later assemblies of phase 13B..
Date: August 1, 1984
Creator: Collins, P.J. & Brumbach, S.B.
Partner: UNT Libraries Government Documents Department

ZPPR progress report: November 1987-January 1988

Description: This report details activities for the time period of November, 1987 through January, 1988. Further results are presented from the axially heterogeneous assembly ZPPR-17, a part of the JUPITER-III program. The loading of the ZPPR-17C assembly, with 13 half-inserted control rods, is described along with operational measurements, calculation models, and measurements and prediction of criticality. From ZPPR-17A, calculated and measured results are given for reaction rates and measured results for bowing, expansion and small sample worth experiments. From the earlier metal-fuel ZPPR-15 program results are given for measurements and calculations of Doppler reactivity coefficients.
Date: February 15, 1988
Creator: Collins, P.J. & Brumbach, S.B.
Partner: UNT Libraries Government Documents Department

ZPPR progress report: September 1988--December 1988

Description: Further results are presented from the JUPITER-III program. Calculation models and k-effective results are given for the three configurations of the large, homogeneous assembly ZPPR-18. Reaction rate results, including sodium activation are given for ZPPR-18A. Also included are spatial decoupling results from ZPPR-18. As a successor to JUPITER-III, the Io program investigated the effects of uranium fuel distribution in mixed uranium and plutonium fueled assemblies. The ZPPR-19A and 19B assemblies which made up the Io program are described.
Date: January 20, 1989
Creator: Brumbach, S.B. & Collins, P.J.
Partner: UNT Libraries Government Documents Department

In-Cell Reaction Rate Distributions and Cell-Average Reaction Rates in Fast Critical Assemblies

Description: Measurements are described for determining average values of fission rates in uranium-235, uranium-238 and plutonium-239 and capture rates in uranium-238 for heterogeneous cells used to construct fast critical assemblies. The measurements are based on irradiations of foils of uranium-238, uranium-235 and plutonium-239 with counting of fission and capture products using gamma-ray spectroscopy. Both plate and pin cells are considered. Procedures are described for inferring cell-average reaction rate values from a single foil location based on a cell using a quantity called a cell factor. Cell factors are determined from special measurements in which several foils are irradiated within a cell. Comparisons are presented between cell factors determined by measurements and by Monte Carlo calculations which lend credibility to the measurement procedures.
Date: August 1985
Creator: Brumbach, S. B. & Gasidlo, J. M.
Partner: UNT Libraries Government Documents Department

Benchmark physics tests in the metallic-fuelled assembly ZPPR-15

Description: Results of the first benchmark physics tests of a metallic-fueled, demonstration-size, liquid metal reactor are reported. A simple, two-zone, cylindrical conventional assembly was built with three distinctly different compositions to represent the stages of the Integral Fast Reactor fuel cycle. Experiments included criticality, control, power distribution, reaction rate ratios, reactivity coefficients, shielding, kinetics and spectrum. Analysis was done with 3-D nodal diffusion calculations and ENDFIB-V.2 cross sections. Predictions of the ZPPR-15 reactor physics parameters agreed sufficiently well with the measured values to justify confidence in design analyses for metallic-fueled LMRs.
Date: January 1, 1987
Creator: McFarlane, H.F.; Brumbach, S.B.; Carpenter, S.G. & Collins, P.J.
Partner: UNT Libraries Government Documents Department

Experimental studies of a large heterogeneous LMFBR benchmark core, ZPPR-13A

Description: The ZPPR-13 program provides basic physics information for testing calculations of radially heterogeneous cores of about 700 MWe size. ZPPR-13 is part of the JUPITER cooperative program between Japan and the US. The results are presented of measurements and analysis for the first assembly, ZPPR-13A. These are the first data for heterogeneous cores of this size available in the US and complement results from ZPPR-9, a conventional LMFBR of similar size.
Date: May 27, 1983
Creator: Brumbach, S.B.; Collins, P.J.; Carpenter, S.G.; Suzuki, S. & Kawashima, M.
Partner: UNT Libraries Government Documents Department

Measurements and calculation of /sup 10/B(n,He) and /sup 235/U(n,f) reaction rates and a control rod mockup in ZPPR (Zero Power Plutonium Reactor)

Description: Results are reported for /sup 10/B(n,He) reaction rate measurements inside B/sub 4/C pellets in a prototypic control rod mockup in the Zero Power Plutonium Reactor. The helium accumulation fluence monitor (HAFM) technique was used, with absolute amounts of helium measured by isotope dilution mass spectrometry. Rates of /sup 235/U fission were measured in foils irradiated between B/sub 4/C pellets. Both helium production and uranium fission rates were calculated using three-dimensional nodal transport methods. Average C/E values in the control rod were 0.961 +- 0.034 for boron capture and 1.094 +- 0.008 for uranium fission based on ENDF/B version V.2 cross sections. The C/E values were nearly constant in the rod interior but changed by a few percent near the rod tip. For both reactions, the C/E values were brought closer to unity by increasing the boron capture cross sections.
Date: January 1, 1986
Creator: Brumbach, S.B.; Collins, P.J.; Grasseschi, G.L. & Oliver, B.M.
Partner: UNT Libraries Government Documents Department

Recent BeO-reflector-controlled reactor experiments in ZPPR

Description: Integral reactor physics measurements were performed on a BeO-reflected fast reactor assembly in the ZPPR facility during January and February of 1985. The measurements emphasized power distributions and reflector control worths in two different critical states. The measurements have been analyzed using three-dimensional deterministic and Monte Carlo methods and the ENDF/B-V.2 nuclear data library. Together the measurements and analyses form a modern, reliable, benchmark data set for testing calculational methods that will be used in predicting some of the design parameters for future space reactors.
Date: January 1, 1986
Creator: McFarlane, H.F.; Brumbach, S.B.; Carpenter, S.G.; Collins, P.J. & McKnight, R.D.
Partner: UNT Libraries Government Documents Department