36 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Uranium 235"  
Results: 1 - 24 next
open access

Isotopic distributions, element ratios, and element mass fractions from enrichment-meter-type gamma-ray measurements of MOX

Description: The gamma-ray spectra from infinitely'' thick mixed oxide samples have been measured. The plutonium isotopics, the U/Pu ratio, the high-Z mass fractions (assuming only plutonium, uranium, and americium), and the low-Z mass fraction (assuming the matrix is only oxygen) can be determined by carefully analyzing the data. The results agree well with the chemical determination of these parameters. 8 refs., 3 figs., 3 tabs.
Date: January 1, 1991
Creator: Close, D. A.; Parker, J. L.; Haycock, D. L. & Dragnev, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A review of the Y-12 Plant discharge of enriched uranium to the sanitary sewer (DEUSS)

Description: The Oak Ridge Y-12 Plant is situated adjacent to the Oak Ridge city limits and is operated by the United States Department of Energy (DOE). The Y-12 Plant is located on 4,860 acres, which is collectively referred to as the Y-12 Plant site. Among the missions for which the facility is in existence are producing nuclear weapons components, supporting weapon design laboratories, and processing special nuclear materials (SNM). The Y-12 Plant is under the regulatory guidance of DOE Order 5400.5 and … more
Date: September 1, 1991
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Minimum detectable activities of contamination control survey equipment

Description: The Instrumentation External Dosimetry (I ED) Section of the Health Physics Department at the Pacific Northwest Laboratory (PNL) has performed a series of tests to determine the ability of portable survey instruments used at Hanford to detect radioactive contamination at levels required by DOE 5480.11. This semi-empirical study combines instrumental, statistical, and human factors as necessary to derive operational detection limits. These threshold detection values have been compared to existin… more
Date: August 1, 1991
Creator: Goles, R. W.; Baumann, B. L. & Johnson, M. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Innovative nuclear thermal propulsion technology evaluation: Results of the NASA/DOE Task Team study

Description: In response to findings from two NASA/DOE nuclear propulsion workshops held in the summer of 1990, six task teams were formed to continue evaluation of various nuclear propulsion concepts. The Task Team on Nuclear Thermal Propulsion (NTP) created the Innovative Concepts Subpanel to evaluate thermal propulsion concepts which did not utilize solid fuel. The Subpanel endeavored to evaluate each of the concepts on a level technological playing field,'' and to identify critical technologies, issues,… more
Date: January 1, 1991
Creator: Howe, S. (Los Alamos National Lab., NM (United States)); Borowski, S. (National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center); Motloch, C. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Helms, I. (Nuclear Utility Services, Damascus, MD (United States)); Diaz, N.; Anghaie, S. (Florida Univ., Gainesville, FL (United States)) et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The Molten Salt Reactor option for beneficial use of fissile material from dismantled weapons

Description: The Molten Salt Reactor (MSR) option for burning fissile fuel from dismantled weapons is examined. It is concluded that MSRs are very suitable for beneficial utilization of the dismantled fuel. The MSRs can utilize any fissile fuel in continuous operation with no special modifications, as demonstrated in the Molten Salt Reactor Experiment. Thus MSRs are flexible while maintaining their economy. MSRs further require a minimum of special fuel preparation and can tolerate denaturing and dilution o… more
Date: January 1, 1991
Creator: Gat, U.; Engel, J.R. (Oak Ridge National Lab., TN (USA)) & Dodds, H.L. (Tennessee Univ., Knoxville, TN (USA))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Criticality accident alarm system

Description: The American National Standard ANSI/ANS-8.3-1986, Criticality Accident Alarm System provides guidance for the establishment and maintenance of an alarm system to initiate personnel evacuation in the event of inadvertent criticality. In addition to identifying the physical features of the components of the system, the characteristics of accidents of concern are carefully delineated. Unfortunately, this ANSI Standard has led to considerable confusion in interpretation, and there is evidence that … more
Date: January 1, 1991
Creator: Malenfant, R.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Criticality reference benchmark calculations for burnup credit using spent fuel isotopics

Description: To date, criticality analyses performed in support of the certification of spent fuel casks in the United States do not take credit for the reactivity reduction that results from burnup. By taking credit for the fuel burnup, commonly referred to as burnup credit,'' the fuel loading capacity of these casks can be increased. One of the difficulties in implementing burnup credit in criticality analyses is that there have been no critical experiments performed with spent fuel which can be used for … more
Date: April 1, 1991
Creator: Bowman, S.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Comparison of the Savannah River Site billet active well coincidence counter and two Californium Shufflers

Description: A Scrap Californium Shuffler at the Savannah River Site (SRS) was calibrated to assay the U-Al cores of billets (an intermediate step in the SRS reactor fuel fabrication cycle.) The precision of the Scrap Shuffler over several years has been approximately 0.50%. A typical total uncertainty for the assay of a core on the Scrap Shuffler is approximately 0.33% for a twelve minute assay. The precision over several months and a typical total uncertainty for the Billet Active Well (neutron) Coinciden… more
Date: January 1, 1991
Creator: Sadowski, E.T.; Griffin, J.C. (Westinghouse Savannah River Co., Aiken, SC (United States)) & Rinard, P.M. (Los Alamos National Lab., NM (United States))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Average values of sup 235 U resonance parameters up to 500 eV

Description: An R-matrix analysis of {sup 235}U neutron cross sections was recently completed. The analysis was performed with the multilevel-multichannel Reich-Moore computer code SAMMY and extended the resolved resonance region up to 500 eV. Several high resolution measurements namely, transmission, fission and capture data as well as spin separated fission data were analyzed in a consistent manner and a very accurate parametrization up to 500 eV of these data were obtained. The aim of this paper is to pr… more
Date: January 1, 1991
Creator: Leal, L.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Radon suppression in storage silos at the United States Department of Energy Feed Material Production Center, Fernald, Ohio

Description: Two silos at the Department of Energy Feed Material Production Facility in Fernald, Ohio, contain an estimated 8800 metric tons of high-grade pitchblende ore residue solids, which contain approximately 3,300 curies (Ci) of radium and 1810 Ci of thorium. These silos are the subject of an on-going CERCLA RI/F Program. Fugitive radon emissions from the silos exceed EPA limits. In addition, structural analyses have revealed that the silos have little credible remaining design life. While pursuing f… more
Date: January 1, 1991
Creator: Land, R.R. (Bechtel National, Inc. (USA)); Biancheria, A. (Westinghouse Materials Co., Fernald, OH (USA)) & Craig, J.R. (USDOE, Washington, DC (USA))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The file of evaluated decay data in ENDF/B

Description: One important application of nuclear decay data is the Evaluated Nuclear Data File/B, the base of evaluated nuclear data used in reactor research and technology activities within the US. This report discusses the decay data file.
Date: January 1, 1991
Creator: Reich, C.W. (Idaho National Engineering Lab., Idaho Falls, ID (USA)) & England, T.R. (Los Alamos National Lab., NM (USA))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Active Well Coincidence Counter measurements of enriched uranium fuel assemblies in scanning and stationary modes

Description: Enriched uranium fuel assemblies were measured with an Active Well Coincidence Counter (AWCC) at the Beloyarskaya Nuclear Power Plant. Special AWCC inserts, electronics, and software were used. Stationary and scanning measurements were performed to establish calibrations and performance specifications for the assay of {sup 235}U and {sub 235}U/cm for BN600 fuel. 6 refs., 7 figs., 2 tabs.
Date: January 1, 1991
Creator: Krick, M.S.; Cowder, L. (Los Alamos National Lab., NM (United States)); Maltsev, V.; Chernikov, A.; Mokeenko, P.; D'yadkov, K. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Loss of shutdown margin during PWR refueling

Description: A study has been carried out of the frequency and consequences of misloading fresh fuel assemblies during the reloading of a pressurized water reactor. The consequences were in terms of losing the required shutdown margin and inadvertent criticality. The calculations used a model of a Combustion Engineering reactor and considered different patterns of fresh fuel clustered together which would be the result of multiple operator errors. The fresh fuel had a high U-235 enrichment and was assumed t… more
Date: January 1, 1991
Creator: Diamond, D. J. & Hsu, Chia-Jung.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Energy Production Using Fission Fragment Rockets

Description: Fission fragment rockets are nuclear reactors with a core consisting of thin fibers in a vacuum, and which use magnetic fields to extract the fission fragments from the reactor core. As an alternative to ordinary nuclear reactors, fission fragment rockets would have the following advantages: Approximately twice as efficient if one can directly convert the fission fragment energy into electricity; by reducing the buildup of a fission fragment inventory in the reactor one could avoid a Chernobyl … more
Date: August 1, 1991
Creator: Chapline, George & Matsuda, Yoshiyuki
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Fission cross sections in the intermediate energy region

Description: Until recently there has been very little cross section data for neutron-induced fission in the intermediate energy region, primarily because no suitable neutron source has existed. At Los Alamos, the WNR target-4 facility provides a high-intensity source of neutrons nearly ideal for fission measurements extending from a fraction of a MeV to several hundred MeV. This paper summarizes the status of fission cross section data in the intermediate energy range (En > 30 MeV) and presents our fission… more
Date: January 1, 1991
Creator: Lisowski, P. W.; Gavron, A.; Parker, W. E.; Ullmann, J. L.; Balestrini, S. J.; Carlson, A. D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Active neutron multiplicity counting of bulk uranium

Description: This paper describes a new nondestructive assay technique being developed to assay bulk uranium containing kilogram quantities of {sup 235}U. The new technique uses neutron multiplicity analysis of data collected with a coincidence counter outfitted with AmLi neutron sources. We have calculated the expected neutron multiplicity count rate and assay precision for this technique and will report on its expected performance as a function of detector design characteristics, {sup 235 }U sample mass, … more
Date: January 1, 1991
Creator: Ensslin, N.; Krick, M. S.; Langner, D. G. & Miller, M. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Derivation of uranium residual radioactive material guidelines for the Elza Gate Site

Description: Residual radioactive material guidelines for uranium were derived for a large, homogeneously contaminated area at the Elza Gate Site in Oak Ridge, Tennessee. The derivation of the single-nuclide and total uranium guidelines was based on the requirement that the 50-year committed effective dose equivalent to hypothetical individual who lives or works in the immediate vicinity of the Elza Gate Site should not exceed a dose of 100 mrem/yr following decontamination. The DOE residual radioactive gui… more
Date: February 1, 1991
Creator: Cheng, J. J.; Yu, C. & Devgun, J. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Derivation of uranium residual radioactive material guidelines for the Shpack site

Description: Residual radioactive material guidelines for uranium were derived for the Shpack site in Norton, Massachusetts. This site has been identified for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the US Department of Energy (DOE). The uranium guidelines were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the Shpack site should not exceed … more
Date: August 1, 1991
Creator: Cheng, J. J.; Yu, C.; Monette, F. & Jones, L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Preliminary Radiation Dose Assessment for the Palmerton Ore Storage Site, Palmerton, Pennsylvania

Description: Potential maximum radiation doses rates were calculated for the Palmerton ore storage site in Palmerton, Pennsylvania. The RESRAD computer code, which implements the methodology described in the US Department of Energy's manual for establishing residual radioactive material guidelines, was used in this evaluation. Four potential scenarios were considered for the Palmerton ore storage site. Two scenarios were developed on the basis of industrial use of the site, and two were developed on the bas… more
Date: February 1, 1991
Creator: Nimmagadda, M. & Yu, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Theoretical analyses of (n,xn) reactions on sup 235 U, sup 238 U, sup 237 Np, and sup 239 Pu for ENDF/B-VI

Description: Theoretical analyses were performed of neutron-induced reactions on {sup 235}U, {sup 238}U, {sup 237}Np, and {sup 239}Pu between 0.01 and 20 MeV in order to calculate neutron emission cross sections and spectra for ENDF/B-VI evaluations. Coupled-channel optical model potentials were obtained for each target nucleus by fitting total, elastic, and inelastic scattering cross section data, as well as low-energy average resonance data. The resulting deformed optical model potentials were used to cal… more
Date: January 1, 1991
Creator: Young, P. G. & Arthur, E. D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Quantities of uranium-235 buried in disposal boxes, 1985--1991

Description: IWT was asked by J. R. Schornhorst of NPSR to determine the distribution of the quantity of enriched uranium per disposal box (B-25) of the years 1985--1991 to provide input to an uptake of the E Area Safety Analysis. This information was considered important since the issue of criticality is an important concern in safety analyses. Information found in the COBRA data base shows no disposal containers exceeded 100 grams of U-235. The COBRA data base was queried in a two-step process. First a sh… more
Date: December 13, 1991
Creator: Cook, J. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Evaluation and validation of criticality codes for fuel dissolver calculations

Description: During the past ten years an OECD/NEA Criticality Working Group has examined the validity of criticality safety computational methods. International calculation tools which were shown to be valid in systems for which experimental data existed were demonstrated to be inadequate when extrapolated to fuel dissolver media. The spread of the results in the international calculation amounted to {plus minus} 12,000 pcm in the realistic fuel dissolver exercise n{degrees} 19 proposed by BNFL, and to {pl… more
Date: January 1, 1991
Creator: Santamarina, A.; Smith, H.J. (CEA Centre d'Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France)) & Whitesides, G.E. (Oak Ridge National Lab., TN (United States))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Analysis of benchmark critical experiments with ENDF/B-VI data sets

Description: Several clean critical experiments were analyzed with ENDF/B-VI data to assess the adequacy of the data for U{sup 235}, U{sup 238} and oxygen. These experiments were (1) a set of homogeneous U{sup 235}-H{sub 2}O assemblies spanning a wide range of hydrogen/uranium ratio, and (2) TRX-1, a simple, H{sub 2}O-moderated Bettis lattice of slightly-enriched uranium metal rods. The analyses used the Monte Carlo program RCP01, with explicit three-dimensional geometry and detailed representation of cross… more
Date: December 31, 1991
Creator: Hardy, J. Jr. & Kahler, A. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen