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Determination of the neutron energy and spatial distributions of the neutron beam from the TSR-II in the large beam shield

Description: The TSR-II reactor of the ORNL Tower Shielding Facility has recently been relocated within a new, fixed shield. A principal feature of the new shield is a beam port of considerably larger area than that of its predecessor. The usable neutron flux has thereby been increased by a factor of approximately 200. The bare beam neutron spectrum behind the new shield has been experimentally determined over the energy range from 0.8 to 16 MeV. A high level of fission product gamma ray background prevented measurement of bare beam spectra below 0.8 MeV, however neutron spectra in the energy range from 8 keV to 1.4 MeV were obtained for two simple, calculable shielding configurations. Also measured in the present work were weighted integral flux distributions and fast neutron dose rates. (auth)
Date: January 1, 1976
Creator: Clifford, C.E. & Muckenthaler, F.J.
Partner: UNT Libraries Government Documents Department

Deep penetration integral experiment for a thorium blanket mockup

Description: An integral experiment has been performed for verification of radiation transport methods and nuclear data used for design of the radial shield for the gas-cooled fast breeder reactor (GCFR). The experiment included a thorium oxide blanket mockup and several shield configurations. The blanket measurements were needed to reduce uncertainties in the cross-section data used for calculating neutron transmission through a thorium blanket and to bound the uncertainties in calculated gamma-ray heating rates within the blanket. Measured neutron spectra and integral flux data are compared to 1D calculations of the transmitted flux. Calculations using ENDF/B-IV and ENDF/B-V data for thorium are compared and show the version V data to be superior above 1 MeV. The experiment, which is primarily sensitive to the total removal cross section, also showed V to be an improvement below 1 MeV, but still discrepant from the measurements.
Date: January 1, 1979
Creator: Ingersoll, D.T. & Muckenthaler, F.J.
Partner: UNT Libraries Government Documents Department

Shielding experimental methods

Description: Benchmark, parametric, and design-confirmation shielding measurements are made at the Tower Shielding Facility (TSF) in Oak Ridge. A powerful reactor (to 1 MW thermal) is used with spectral modifiers to provide neutron spectra close to those associated with the various parts of an LMFBR. The source strength allows measurements through shields of full reactor thickness using sensitive detectors. The detectors include spectrometers and dosimeters for both neutrons and gamma rays. A large exclusion area provides much flexibility in arranging shield assemblies to be studied.
Date: November 1, 1978
Creator: Maienschein, F.C. & Muckenthaler, F.J.
Partner: UNT Libraries Government Documents Department

The Tower Shielding Facility: Its glorious past

Description: The Tower Shielding Facility (TSF) is the only reactor facility in the US that was designed and built for radiation-shielding studies in which both the reactor source and shield samples could be raised into the air to allow measurements to be made without interference from ground scattering or other spurious effects. The TSF proved its usefulness as many different programs were successfully completed. It became active in work for the Defense Atomic Support Agency (DASA) Space Nuclear Auxiliary Power, Defense Nuclear Agency, Liquid Metal Fast Breeder Reactor Program, the Gas-Cooled and High-Temperature Gas-Cooled Reactor programs, and the Japanese-American Shielding Program of Experimental Research, just to mention a few of the more extensive ones. The history of the TSF as presented in this report describes the various experiments that were performed using the different reactors. The experiments are categorized as to the programs which they supported and placed in corresponding chapters. The experiments are described in modest detail, along with their purpose when appropriate. Discussion of the results is minimal, but references are given to more extensive topical reports.
Date: May 7, 1997
Creator: Muckenthaler, F.J.
Partner: UNT Libraries Government Documents Department

Measurements for the JASPER Program fission gas plenum experiment

Description: The Fission Gas Plenum Experiment was conducted at the Oak Ridge National Laboratory Tower Shielding Facility during FY 1987 to: provide data for verification of the assumptions and calculational methods used to determine the neutron leakage from the plenum, and provide an uncertainty evaluation associated with the calculations. The Tower Shielding Reactor source was modified to represent the neutron spectrum leaving a typical liquid-metal-cooled reactor core along its axis. The experimental configurations resulted from the insertion of either a homogeneous or homogeneous-heterogeneous gas plenum combination into the iris of a concrete slab, with the only variable being the thickness of the plenum. Integral neutron fluxes were measured behind each of the configurations at specified locations, and neutron spectra were obtained behind selected mockups. The experimental data are presented in both tabular and graphical form. This experiment is the second in a series of six experiments to be performed as part of a cooperative effort between the United States Department of Energy and the Japan Power Reactor and Nuclear Fuel Development Corporation. The research program is intended to provide support for the development of advanced sodium-cooled reactors.
Date: June 1, 1987
Creator: Muckenthaler, F.J.
Partner: UNT Libraries Government Documents Department

GCFR radial blanket and shield experiment: objectives, preanalysis, and specifications

Description: An integral experiment has been designed for the verification of radiation transport methods and nuclear data used for the design of the radial shield for the proposed 300 MW(e) gas-cooled fast breeder reactor (GCFR). The scope of the experiment was chosen to include a thorium oxide radial blanket mockup as well as several shield configurations in order to reduce the uncertainties in the calculated source terms for the radial shield, and to reduce the uncertainties in the calculated radiation damage to the prestressed concrete reactor vessel (PCRV). Additionally, the measurements are intended to bound the uncertainties in calculated gamma-ray heating rates within the blanket and shield. Although designed specifically for the GCFR, the experiment will provide generic data regarding deep penetration in ThO/sub 2/ and common shield materials, which should also benefit LMFBR designers.
Date: September 1, 1979
Creator: Ingersoll, D.T.; Bartine, D.E. & Muckenthaler, F.J.
Partner: UNT Libraries Government Documents Department

Final report on a benchmark experiment for neutron transport in thick sodium

Description: An experiment concerning deep neutron penetration in sodium is described, and experimental results are presented which provide a basis for verification of the accuracy of sodium cross sections to be used in transport calculations. The experiment was performed at the Tower Shielding Facility of ORNL and included measurements of both the neutron fluence and neutron spectra through a large diameter sample of sodium up to 15 ft thick. Ca1culated resu1ts for the experiment are presented for comparison with the experimental measurements. These results were obtained using the multigroup Monte Carlo code, MORSE, and a twodimensional discrete ordinates code, DOT III. One-hundred group data sets were developed from both a preliminary and the final version of the ENDF/III set (MAT = 1156) for sodium for use in the calculations. Comparisons of the calculations with experiment indicate that the preliminary version is slightly superior to the flnal version and that using the preliminary set the total neutron leakage above thermal energies penetrating up through 15 ft of sodium can be calculated to within approximates 15% and the absolute spectra penetrating up through 12.5 ft of sodium can be calculated to within 20%. Using the final set, the corresponding comparisons are 30% and 60%. (20 references) (auth)
Date: January 1, 1974
Creator: Maerker, R.E.; Muckenthaler, F.J.; Childs, R.L. & Gritzner, M.L.
Partner: UNT Libraries Government Documents Department

Review of ORNL-TSF shielding experiments for the gas-cooled Fast Breeder Reactor Program

Description: During the period between 1975 and 1980 a series of experiments was performed at the ORNL Tower Shielding Facility in support of the shield design for a 300-MW(e) Gas Cooled Fast Breeder Demonstration Plant. This report reviews the experiments and calculations, which included studies of: (1) neutron streaming in the helium coolant passageways in the GCFR core; (2) the effectiveness of the shield designed to protect the reactor grid plate from radiation damage; (3) the adequacy of the radial shield in protecting the PCRV (prestressed concrete reactor vessel) from radiation damage; (4) neutron streaming between abutting sections of the radial shield; and (5) the effectiveness of the exit shield in reducing the neutron fluxes in the upper plenum region of the reactor.
Date: January 1, 1982
Creator: Abbott, L.S.; Ingersoll, D.T.; Muckenthaler, F.J. & Slater, C.O.
Partner: UNT Libraries Government Documents Department

Analysis of the TORT validation experiment

Description: The radiation flux in a concrete block building with windows exposed to irradiation at the ORNL Tower Shielding Facility was measured directly with Bonner balls and the measured flux compared with calculations performed with Oak Ridge's 3-D discrete ordinates code TORT. 6 refs., 2 figs. (ACR)
Date: January 1, 1985
Creator: Rhoades, W.A.; Childs, R.L.; Ingersoll, D.T. & Muckenthaler, F.J.
Partner: UNT Libraries Government Documents Department

An evaluation of simple iron-water radiation shields and radiation measurements within concrete-lined and -capped pits

Description: Program 3 of Operation BREN consisted in a study of the performance of biological shields composed of various arrangements of steel, water, and borated polyethylene in spherical, cubical, and parallelepipedal geometries. Studies were also made of the radiation levels within concrete-lined and -capped pits, 4 ft in dia and 8 ft deep. The principal radiation source was the ORNL Health Physics Research Reactor, an unshielded, unreflected, 90 wt % U-10 wt % Mo, cylindrical bare-metal assembly. It was supported at heights ranging from 27 to 1500 ft by a hoist car riding outside of a 1527-ft-high steel tower. A 1200-curie Co/sup 60/ gamma-ray source, similarly supported, was substituted for the reactor for some measurements. The work reported includes measurements of fast-neutron and gamma-ray dose rates and thermal-neutron fluxes in air and within the various shields, using the reactor source, measurements of gamma-ray dose rates in air from the Co/sup 60/ gamma-ray source, and measurements of gamma-ray pulse-height spectra within the pits, also employing the Co/sup 60/ source. 8 refs., 33 figs., 29 tabs.
Date: July 31, 1964
Creator: Muckenthaler, F.J.; Jung, L.; Blosser, T.V.; Freestone, R.M. Jr. & Miller, J.M.
Partner: UNT Libraries Government Documents Department

Liquid Metal Reactor Program: JASPER USDOE/PNC Shielding Research Program: Technical progress report, August 1-September 30, 1986

Description: This report details activities on the JASPER Shielding Program for the time period of August 1, 1986 through September 30, 1986. This report contains the measurements in phases VI and VII, a graphite benchmark study and an alternate loop type shield design study for the Liquid Metal Reactor (LMR), respectively. This report also includes the results of analyses for phases I, II, III, V, and VI.
Date: December 31, 1986
Creator: Ingersoll, D.T.; Engle, W.W. Jr.; Muckenthaler, F.J. & Slater, C.O.
Partner: UNT Libraries Government Documents Department

Measurements for the JASPER program Axial Shield Experiment

Description: The Axial Shield Experiment was conducted at the Oak Ridge National Laboratory (ORNL) during 1990--1991 as part of the continuing series of eight experiments planned for the Japanese-American Shielding Program for Experimental Research (JASPER) program starting in 1986. The program is intended to provide support for the development of current designs proposed for advanced liquid metal reactor (LMR) system both in Japan and the United States. As in the previous two experiments, the same spectrum modifier was used to alter the Tower Shielding Reactor source spectrum to one representing the LMR neutron spectra directly above the core in the area of the fission-gas plenum. In one of the measurements the spectrum was further modified by the fission gas plenum. In all cases the modified spectrum was followed by combinations of seven hexagon assemblies that represented different coolant flow and shielding patterns within the assemblies. The varied configuration permitted not only a study of the different designs, but also allowed a comparison to be made of the relative neutron attenuation effectiveness of boron carbide and stainless steel in such designs. This experiment was the third in a series of eight experiments to be performed as part of a cooperative effort between the United States Department of Energy (US DOE) and the Japan Power Reactor and Nuclear Fuel Development Corporation (PNC). This experiment, as was the previous Radial Shield Attenuation and Fission Gas Plenum Experiments, intended to provide support for the development of advanced sodium-cooled reactors. 5 refs.
Date: August 1991
Creator: Muckenthaler, F. J.; Spencer, R. R.; Hunter, H. T.; Shono, A. & Chatani, K.
Partner: UNT Libraries Government Documents Department

Liquid Metal Reactor Program: JASPER USDOE/PNC Shielding Research Program: Technical progress report, February 1-March 31, 1987

Description: This report details activities on the JASPER Shielding Program for the time period of February 1, 1987 through March 31, 1987. During this reporting period the measurements for the Fission Gas Plenum Experiment were completed and the results are enclosed.
Date: December 31, 1987
Creator: Ingersoll, D.T.; Engle, W.W., Jr.; Muckenthaler, F.J. & Slater, C.O.
Partner: UNT Libraries Government Documents Department