Absolute exp 239 Pu thermal fission yields are given for the stable and long-lived isotopes of krypton, rubidium, strontium, zirconium, xenon, cesium, barium, cerium, neodymium, and samarium. The principal measurement technique for the fission product iso...

Absolute exp 235 U thermal fission yields are given for the stable and long-lived isotopes of krypton, rubidium, strontium, zirconium, molybdenum, ruthenium, xenon, cesium, barium, lanthanum, cerium, neodymium, and samarium. The principal measurement tech...

A Ranger measurement of the distribution-in-range of knock-on protons from thin paraffin layers indicates the distribution-in-energy from 0.4 Mev to 7 Mev of the neutrons emitted from uranium bombarded by neutrons from the thermal column of the Argonne Heavy Water Reactor. The spectrum shows a broad maximum near 0.75 Mev and follows closely an exponential drop from 2 Mev to 7 Mev with a relaxation ...

A proton recoil counter has been used to determine the neutron spectrum, in the energy range 3.3-17 Mev, of a beam produced by irradiating 95 percent U235 (metal) in the central experimental hole of the Los Alamos Homogeneous Reactor. Most of the fissions were induced by slow neutrons. The data are combined with those obtained by D. Hill and by T. W. ...

Absolute /sup 239/Pu thermal fission yields are given for the stable and long-lived isotopes of krypton, rubidium, strontium, zirconium, xenon, cesium, barium, cerium, neodymium, and samarium. The principal measurement technique for the fission product isotopes was isotope dilution mass spectrometry. The number of fissions was ...

The delayed neutron emission rates of U-235 and Pu-239 samples were measured accurately from a thermal fission reaction. A Monte Carlo calculation using the Geant4 code was used to demonstrate the neutron energy independence of the detector used in the counting station. A set of highly purified actinide samples ...

Neutrons from the Project Gnome nuclear test were resolved in energy by time-of-flight and used to study symmetry of fission in U235 in the resonance region. Symmetry was deduced by measurement of the fission product ratio Ag111/Mo99 at resonances from 8.8 to 40 eV. The maximum decrease observed in the probability of symmetric fission as compared to the probability in thermal ...

... Accession Number : AD0626757. Title : U-235 RESONANCE CROSS SECTIONS AND GASEOUS CORE REACTOR CALCULATIONS,. ...

Neutrons in the resonance energy region from a nuclear explosion were resolved by time-of-flight and used to induce fissions in U235 attached to a revolving wheel. The symmetry of fission at individual resonances from approximately 10 to 60 ev was examined by radiochemical means. As measured by the ratio Ag111/Mo99, the probability of symmetric fission decreased at some resonances by a maximum of ...

An examination of the standard methods of determining the fission cross section shows that the principle sources of error are uncertainties in the spectrum of the incident neutrons, the energy dependence of the cross sections of the material being studied, the thickness of the fission foil, and the value of some reference cross section. A new method is described which eliminates all of ...

Attached is the interpolated uranium burnout values for .570% through 3.000% U-235. Due to increasing interest in higher U-235 values, this document was issued to replace HW-77929 which contained values to 1.519% U-235. The source data was based on the Re...

The 238U/235U isotope ratio has long been considered invariant in meteoritic materials (equal to 137.88). This assumption is a cornerstone of the high-precision lead-lead dates that define the absolute age of the solar system. Calcium-aluminum-rich inclusions (CAIs) of the Allende meteorite display variable 238U/235U ratios, ranging ...

The 238U/235U isotope ratio has long been considered invariant in meteoritic materials (equal to 137.88). This assumption is a cornerstone of the high-precision lead-lead dates that define the absolute age of the solar system. Calcium-aluminum-rich inclusions (CAIs) of the Allende meteorite display variable 238U/235U ratios, ranging ...

... Title : U-235 Gamma Radiation,. ... Abstract : Evidence for tho existence of a gamma ray accompanying the alpha decay of U-235 is presented. ...

... North Korean officials with evidence of a clandestine uranium enrichment program, the ... uranium (HEU) has 20% or more U-235 isotope; 90% U-235 ...

U-daughter (U-Pb, Pb-Pb, and U-series) geochronology and cosmochronology utilize the absolute value of the present day 238U/235U ratio to calculate and compare dates. For decades, this value has been assumed to be invariant and equal to 137.88, but recent experiments indicate that there is potential for �per mil level� variation in ...

Accurate determination of the absolute ages of the oldest Solar System objects � chondrules and Ca-Al-rich inclusions (CAIs), requires knowledge of their 238U/235U ratios. This ratio was assumed to be invariant in all U-Pb dating of meteorites so far, but the recent discovery of U isotope variations in CAIs (Brennecka et al., 2010a) shows that this assumption is invalid. We ...

Absolute fission excitation functions have been measured with an ionization chamber to detect the pulse of a recoiling single fragment. In the experiment performed, the 60-in. Crocker cyclotron deuterons and alpha-particles were used with Th232, U235, and U238 targets. Thresholds of these reactions were also observed. The maximum ...

The ratio of 238U and 235U, the two primordial U isotopes, has been assumed to be constant on Earth and in the solar system. The commonly accepted value for the 238U/235U ratio, which has been used in Pb-Pb dating for the last ~ 30 years, was 137.88. Within the last few years, it has been shown that 1) there are considerable U isotope variations (~1.3�) within terrestrial material produced by ...

This patent relates to nuclear reactors of tbe type utilizing a liquid fuel and designed to convert a non-thermally fissionable isotope to a thermally fissionable isotope by neutron absorption. A tank containing a reactive composition of a thermally fissionable ...

... values of two different kinds of spent fuel pins (natural uranium (0.7% U235) and enriched uranium (7.0% U235)) by the Cs134/Cs137 activity ratio. ...

...For uranium with an enrichment in the isotope U235 of 0.01...For uranium with an enrichment in the isotope U235 below 0...parameter. Fissile isotope means: (1...uranium-235 by enrichment category,...

...purposes of this part, special nuclear material in quantities not sufficient to form a critical mass means uranium enriched in the isotope U-235 in quantities not exceeding 350 grams of contained U-235; uranium-233 in quantities not exceeding 200...

... NDA OF SPECIAL NUCLEAR MATERIALS FOR BWR AT ... DEVIATING BY 10% OR MORE FROM ... NOMINAL U-235 ENRICHMENT; TOTAL FISSILE ...

...2010-07-01 2010-07-01 false Uranium-235 (U235). 540.315 Section...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...General Definitions § 540.315 Uranium-235 (U235). The term...

...2009-07-01 2009-07-01 false Uranium-235 (U235). 540.315 Section...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...General Definitions § 540.315 Uranium-235 (U235). The term...

...to 10 percent or more in the isotope U235 ; (3) Protect...to 10 percent or more in the isotope U235 (for centrifuge enrichment facilities this requirement...to 10 percent or more in the isotope U235 ; and (9)...

The aim of this paper was the measurement of the integral beta spectrum of the fission products of exp 235 U after thermal fission. (Atomindex citation 13:713181)

Beta and gamma fission product decay heat curves are evaluated for the thermal fission of exp 235 U. Experimental data that include beta, gamma, and total measurements are combined with summation calculations based on ENDF/B in a consistent evaluation. Le...

... Accession Number : ADA156593. Title : The Development of a Neutron Evaporation Theory Code for the Thermal Fission of Uranium-235. ...

Radiochemically determined mass-yield curves are given for the fission of U/sup 235/ and U/sup 238/ by l4.7-Mev neutrons. Symmetric and to a less extent, very asymmetric modes of fission are more probable at that energy than in thermal fission. Yields of four fission products from the fission of U/sup 235/ have been measured as a function of ...

An artificial neural network (ANN) model for the prediction of measuring uncertainties in gamma-ray spectrometry was developed and optimized. A three-layer feed-forward ANN with back-propagation learning algorithm was used to model uncertainties of measurement of activity levels of eight radionuclides (226Ra, 238U, 235U, 40K, 232Th, 134Cs, 137Cs and 7Be) ...

Delayed neutrons are emitted by excited nuclei formed in beta decay of fission products called delayed neutron precursors. About 1% of the total neutrons released in fission are delayed neutrons; however, this small fraction plays an important role in nuclear reactor control. The delayed neutrons determine the time-dependent behavior of reactors, and knowledge of parameters used to predict neutron ...

The first in a series of quarterly progress reports on ERDA budgeted activities subcontracted to Allied Chemical Corporation at the Idaho National Engineering Laboratory is presented. The work is performed by the Technical Division and is divided into three subjects. Fuel cycle research and development includes fluidized-bed calcination and post treatment of commercial nuclear fuel process waste; ...

This method permits the nondestructive measurement of U-235 in uranium tetrafluoride (UF/sub 4/) using a Ge(Li) gamma spectrometer. The method was evaluated for UF/sub 4/ in the 0.20 to 1.25 wt% U-235 concentration range, but it could be easily extended to higher U-235 concentrations by using the appropriate ...

... Abstract : The half lives and yields of the photoneutrons created in heavy water by U(235) fission product gamma rays have been measured. ...

... weapons-grade and weapons useable nuclear materials, highly enriched uranium ... Uranium 233 (U-233), Uranium 235 (U-235), and Plutonium- ...

and actinium decay series such as 234 U, 235 U, and 238 U and their immediate decay progeny 234 Th, 234m Pa

... was to evaluate the gamma ray dose rate from an infinite homogeneous ground plane source of fission products from U-235, U-238, and Pu-239. ...

... A separative work unit (SWU) is a measure of the ef- fort required to separate U235 and U238 isotopes during enrichment. Production of 1 kg of ...

... the effort required to separate U235 and U238 isotopes during enrich ... of $190 million, the proliferator uses aerodynamic enrichment to complete his ...

... Efj = the macroscopic fission cross section of U235 for neutrons in group i EJ. ... u T u T u T where Gfu = the microscopic fission cross section of U 235 ...

Search Criteria: Search Field: All > Results : All > Search Term: (Thermal Fission Factor) [x]. Sort results by: NASA Center | Date Added to NTRS ...

More than 80% of the uranium leaving uranium enrichment plants is depleted to a residual content of about 0,25% U 235. Due to the present uneconomical further depletion to the technically possible residual content of 0,1% U 235, the so-called 'tails' are ...

This paper summarizes the conversion status of US research and test reactors and estimates uranium densities needed to convert reactors with power levels 21 MW from HEU ({ge} 20% U-235) to LEU (<20% U-235) fuels. Detailed conversion studies for each reactor need to be completed in order to establish the ...

This report describes the POTS Gaseous Diffusion Transient Analysis Code and how it was used to calculate the times that would be required to get production uranium-235 (U-235) gradients in the cascades at the Oak Ridge and Paducah Gaseous Diffusion Plant...

A method for the separation of uranium isotopes, particularly U235 is disclosed. The method employs a frequency selective laser irradiation of an adiabatically cooled beam of UF6 molecules, followed by the 'chemionization' i.e., SbF5 + UF6 SbF6(-) + UF5(+) of the selectively irradiated UF6 molecules, and finally separates the favored ...

This paper explores the possibility of manufacturing very small reactors from U-235, U-233 and Cm-245. Pin type reactor systems fueled with uranium or curium metal zirconium hydride (UZrH or CmZrH) are compared with similar designs using U-235. Criticalit...

Diode-laser excited optogalvanic spectroscopy (OGS) of a glow discharge has been utilized to measure U-235/U-235 + U-238 isotope ratios. This ''optical mass spectrometric'' measurement has been demonstrated for a number of samples including uranium oxide,...

Selected neutron-cross-section data for use in Monte Carlo determinations of neutron slowing down moments are presented. Data for hydrogen (H-l), carbon (C-12), oxygen (0-16), fluorine (F-19), Zirconium (Zr-90), uranium (U-235), and uranium (U-235) are included. (W.L.H.)

A rapid, comparison-type determination for wt% U-236 is performed on all depleted (0.20 wt% U-235) product ingots. A composite sample representing up to 30 ingots is prepared and fluorinated to UF(sub 6) for the analysis. The U-236/(U-235 + U-235 + U-238)...

This manual provides a list of the quantities of plutonium and plutonium isotope formation. Other isotopes whose concentrations are important and included in this report are U-236 buildup, U-235 burnout, U burnout, Np-237 build-up, GVR (the Gas Volume Ratio) in coproduct target elements and equivalent gram of plutonium. These conversion tables have been ...

A body is presented for use in a thermal fission reactor comprising a sintered compressed mass of a substance of the group consisting of uranium, thorium, and oxides and carbides of uranium and thorium, enclosed in an envelope of a sintered, compacted, heat-conductive material of the group consisting of beryllium, zirconium, and oxides and carbides ...

An empirical formula has been suggested to describe the dependence of known exponential (n,p) reaction cross sections averaged over (sup 235)U thermal fission neutron spectrum on the asymmetry parameter (N-Z)/A of the target nucleus. 9 refs.; 1 fig.; 1 ta...

In order to study the influence of fluctuations on various phenomena linked to heavy ion collisions, a Langevin equation has been derived from a microscopic model. Parameters entering this equation are completely determined from microscopic quantities characterizing nuclear matter. This equation has been applied to various phenomena at intermediate energies. This paper focuses on large amplitude ...

Thermal fission of (sup 239) Pu was used to produce (sup 68,69) Co and (sup 68) Fe isotopes, the lightest ones ever observed in thermal fission, at the ILL high-flux reactor, in Grenoble. Separated with the Lohengrin recoil spectrometer, then identified b...

Fragments of mass A=68 and 69 are identified for the first time in thermal fission. Their chain production yields and isotopic percentages are evaluated on (sup 239)Pu. The (beta)-decay half-lives of the very neutron-rich isotopes (sup 69)Co, (sup 68)Co a...

The patented means is described for controlling a nuclear reactor which comprises a tank containing a dispersion of a thermally fissionable material in a liquid moderator and a material convertible to a thermally fissionable material in a container disposed about the tank. The control means comprises a ...

The half-lives of very neutron rich isotopes of Ni and Cu have been measured. The isotopes are produced in very asymmetric thermal fission of (sup 235)U and (sup 239)Pu at the I.L.L. high flux reactor. They are separated by means of the Lohengrin spectrom...

Several new sets of synthetic isotope reference materials for mass spectrometer calibration have been developed at IRMM based on proven methods of purifying and mixing highly enriched oxides. In the first stage a set of 10 mixtures of 233U, 235U and 238U was made in which the 235U:238U ratios were kept at 1:1 and the 233U/235U ratios varied from 1.0 to ...

Resonance-parameter covariance matrix (RPCM) evaluations in the resolved resonance region were done for 232Th, 233U, 235U, 238U, and 239Pu using the computer code SAMMY. The retroactive approach of the code SAMMY was used to generate the RPCMs for 233U, 235U. RPCMs for 232Th, 238U and 239Pu were generated together ...

We have observed isotopically selective diode laser-excited optogalvanic effects in uranium at 778.42 and 776.19 nm. The samples were natural abundance uranium oxide, as well as depleted (0.3% U-235), natural (0.7% U-235) and enriched (9.75% U-235) uranium metal or powders. ...

The U-238/U-235 ratios for nine bulk chondritic meteorites and a terrestrial basalt were measured. The total range in U-238/U-235 determined for both total meteorites and for acid leaches was from 137.2 terrestrial U. The typical errors in a single determination are plus or minus 6 per thousand (2 sigma m) for a 2 ng U sample from a chondrite. Taking the extreme values of delta ...

Results are presented on the fluidized-bed calcination of simulated radioactive waste from the reprocessing of spent commercial nuclear fuel and on the removal of actinide elements from the waste prior to calcination. Other programs include the development of storage technology for /sup 85/Kr waste; and the behavior of volatile radionuclides during the combustion of HTGR graphite-based fuel. The ...

Fuel Cycle Research and Development: Results are presented on the fluidized-bed calcination of simulated waste from the reprocessing of spent commercial nuclear fuel, on the post-treatment of the resultant calcine, and on the use of bidentate extractants for the separation of actinide elements from the high-level waste prior to calcination. In addition, the development of storage technology for ...

Fuel cycle research and development: results are presented on fluidized-bed calcination and on post-treatment of commercial wastes; study was done on the use of microwave energy in processing wastes and on the use of bidentate compounds for separation of actinides from commercial power reactor reprocessing waste. Work on the krypton-85 storage development program, including the results of rubidium ...

Fuel Cycle Research and Development: Results are presented on the fluidized-bed calcination of high-level radioactive waste from reprocessing on the post treatment of the calcine, and on the removal of actinide elements from the waste prior to calcination. Other projects include the development of storage technology for /sup 85/Kr waste; a study of the hydrogen mordenite catalyzed reaction between ...

Tags canada, education, nai iptai team, south africa, workbook. Comments 1. Tags .planetary dynamics 3d simulations 16srrna 17p 26al 79 ceti 85p 238u/235u ...

Tags banded iron formations, bifs, early earth, iron isotopes. Comments 1. Tags .planetary dynamics 3d simulations 16srrna 17p 26al 79 ceti 85p 238u/235u ...

Uranium 235 consumption is comparatively evaluated with thorium cycle for a PWR type reactor. Modifications are only made in fuels components. U-235 consumption is pratically unchanged in both cycles. Some good results are promised to the mixed U-238/Th-2...

This article is a brief overview of the uranium industry in the Ukraine. A historical aspect is provided, as is a review of nuclear projects with the country. These include power projects and fuels projects such as uranium mining and ore-processing.

The Analytical Development Section of Savannah River Technology Center (SRTC) was requested by the Facilities Decommissioning Division (FDD) to determine the holdup of enriched uranium in the 321-M facility as part of an overall deactivation project of th...

Neutron yields from (sup 19)F((alpha),n)(sup 22)Na reaction of uranium neutron interaction with uranium-bass materials, and the characteristics of shielded neutron assay probe have been studied. On the basis of the above examination, U-235 enrichment in U...

A target for the reduction of fission product Mo-99 is prepared from uranium of low U-235 enrichment by coating a structural support member with a preparatory coating of a substantially oxide-free substrate metal. Uranium metal is electrodeposited from a ...

The intent of this document is to combine data from salt samples and historical process information to bound the uranium (U-235) enrichment which could be expected in the upper portion of the salt in Tank 41H. This bounding enrichment will be used in anot...

An analytical method of determining the effective reactivity coefficient from fundamental cross sections using the four factor formula is presented. Values of the coefficient obtained by this method compare well with experiment. (A.C.)

Irradiated uranium aluminide fuel plates of 40% U-235 enrichment were heated for the determination of fission products released under flowing helium gas at temperatures up to and higher than the melting point of fuel-cladding material. The release of fiss...

Depleted uranium is produced from the UF6 tailings of the uranium enrichment process for nuclear power reactors and contains about 99.8 percent U238 and 0.2 percent U235. This report presents properties, processing, and fabrication information for deplete...

A study of relative plutonium and orallay values is being made by representatives of the production sites under direction of AEC Headquarters, Division of Production. (Oralloy is uranium enriched to 93-15 percent U-235.) Under study assumptions that will ...

The two main research objectives of the contract were to demonstrate high power nuclear lasering (of the order of a kWatt), and demonstrate nuclear pumping with fission fragments from (U-235)F6. The progress made towards these objectives is discussed.

... PU240, W, PB, NI, CR, C, LI6, LI7 ... Abstract : Neutron cross-section sets have been prepared for ... The cross sections tabulated include the total, elastic ...

An experiment of the nondestructive measurement of uranium content in the fuel compact has been made by gamma-ray spectrometry. Uranium content was determined by comparing gamma-ray emissions at the 185 kev U-235 photopeak between a sample and a counting ...

GAMSCAN is a computer program designed for the INEL CDC 76/173 operating system to check the accuracy of the supplier assigned U-235 values to fuel plates used in elements of the Advanced Test Reactor (ATR).

An analysis of alternative options for the recycle of discharged makeup U-235 (''residual'' makeup) in HTGRs shows that the three-particle system which has been the reference plan remains optimal. This result considers both the resource utilization and th...

FY08 annual report for project the "Nuclear Resonance Fluorescence Imaging" project. Reviews accomplishments of last 3 years, including U-235 signature search, comparison of different photon sources, and examination of NRF measurements using monochromatic photon source.

A study of various modes of handling spent U-235 fissile particles in either a commercial or demonstration recycle plant has been performed under the Thorium Utilization Program. A detailed engineering study and cost estimate were available for a commerci...

... Accession Number : AD0195155. Title : ENRICHMENT TESTER FOR 0.15 TO 3.0 WEIGHT PERCENT U235 URANIUM FUEL. Corporate Author : ...

This report, prepared for INFCE, gives data for an extrapolated 1000 MW(e) CANDU-PHW design operating on various thorium cycles. In the reference cycle, the requirements for externally supplied fissile material are met using U-235, with the feed adjusted ...

This manual provides a list of the quantities of plutonium and plutonium isotope formation. Other isotopes whose concentrations are important and included in this report are U-236 buildup, U-235 burnout, U burnout, Np-237 build-up, GVR (the Gas Volume Rat...

Cobalt-60 (Co-60) Iodine-131 (I-131) Iridium-192 (Ir-192) Plutonium Polonium 210 Strontium-90 (Sr-90) Uranium-235 (U-235) & Uranium-238 (U-238) Email Print Share Add this to......

Minimum critical fissile concentrations are calculated for U-233, U-235, Pu-239, and Am-242m mixed homogeneously with hydrogen at temperatures to 15,000K. Minimum critical masses of the same mixtures in a 1000 liter sphere are also calculated. It is shown...

The capacity of critically safe cylindrical pulse columns limits the size of nuclear fuel solvent extraction plants because of the limited cross-sectional area of plutonium, U-235, or U-233 processing columns. Thus, there is a need to increase the cross-s...

Results of measurements of the properties of a pulsed neutron source are presented. The source consists of a slightly sub-prompt-critical fast reactor of uranium metal (93% U-235) shpere struck by a pulsed 29 MeV electron beam from a linear accelerator. T...

of depleted uranium rather than the normally used U-235. The. The nuclear fuel in the core closely approximated ...... U. S. Naval Civil Engineering Laboratory (Library) ... Commander , TC/DASA, Sandia Base (TCTG5 , Library) ...

The reactor, including the reflector, is 0.355 meter in diame- ...... Some further variation on the cylindrical barrel radiator array, ..... If uranium-235 nitride (U235N) is used as the fuel (with the same volume fraction as ...

...2010-07-01 false Uranium enrichment. 540.316 Section 540...Definitions § 540.316 Uranium enrichment. The term uranium enrichment means the process of increasing the concentration of the isotope U235 relative to that of...

...2009-07-01 false Uranium enrichment. 540.316 Section 540...Definitions § 540.316 Uranium enrichment. The term uranium enrichment means the process of increasing the concentration of the isotope U235 relative to that of...

...critical mass means uranium enriched in the isotope U-235 in quantities not exceeding...special nuclear material, determine the ratio between the quantity of that special...special nuclear material. The sum of such ratios for all kinds of special nuclear...

...terabequerels or TBq for byproduct material) and its chemical and physical form. (2) For enriched uranium, the maximum weight percentage of enrichment and maximum weight of contained U-235. (3) For nuclear equipment, total dollar...

At the request of the Department of Energy, the RERTR Program has summarized the conversion status of research and test reactors in the United States and has made estimates of the uranium densities that would be needed to convert the reactors with power levels greater than or equal to 1 MW from Highly Enriched Uranium (HEU) (greater than or equal to 20% ...

The laser induced fluorescence method using atomic beam combined with Doppler-free two-photon absorption technique was applied for the measurement of isotope shifts and hyperfine structures of atomic uranium including ^{234}U, ^{235}U, ^{236}U and ^{238}U isotopes. The isotope shifts between ^{238}U ^{234}U, ^{238}U ...

This method is designed to automatically measure the U-235 concentration of various uranium-containing matrices (e.g., UO/sub 3/, UF/sub 4/, U/sub 3/O/sub 8/, sump samples, UNH, residues, etc.). Analyses are performed using a computer controlled sample changer. The technique is applicable to samples ranging from 0.20 to 20.0 wt% U-235. A complete gamma ...

The BETA and gamma activities and emission powers of the total fission products of U/sup 235/ have been plotted against times of irradiation and decay in the range 1 to 1000 days. (auth)

Deeper insight into the features of a reactor as a source of antineutrinos is required for making further advances in studying the fundamental properties of the neutrino. The relationship between the thermal power of a reactor and the rate of the chain fission reaction in its core is analyzed.

hide Your Search Criteria. Search All: (Thermal Fission Factor) � Remove All. Records; Concept Cloud. Matching Records: 2672. 1 2 3 4 5 6 7 8 9 10 Next >> ...

A least squares analysis of fission neutron standard fields has been performed using the latest dosimetry cross sections. Discrepant nuclear data are identified and adjusted spectra for {sup 252}Cf spontaneous fission and {sup 235}U thermal fission fields are presented.

Because 235U has a very large thermal fission cross-section, the deposit must be highly depleted. Before using the counter to detect fast n6utrons from the ...

S>The average power emitted as gamma or beta radiation from U/sup 235/ thermal fission products is calculated as a function of time after fission. Previous work on the subject is surveyed and compared with the present results. (W.D.M.)

A multigroup theory developed in connection with an investigation of inelastic scattering of fission neutrons was adapted for use in calculations of fast effect in solid iael rods. Theoretical values of both EPSILON and sigma were calculated on this basis and compared with experimental values determined at Hanford and Argorne. (auth)

Calculations of anisotropy of angular distribution of oriented sup 235 U nuclei thermal fission neutrons have been carried out. The neutrons were assumed to evaporate isotropically by completely accelerated fragements in the fragment system with only its ...

A method and a system for detecting the presence of special nuclear materials in a suspect container. The system and its method include irradiating the suspect container with a beam of neutrons, so as to induce a thermal fission in a portion of the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the ...

A method and a system for detecting the presence of special nuclear materials in a suspect container. The system and its method include irradiating the suspect container with a beam of neutrons, so as to induce a thermal fission in a portion of the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the ...

A method and a system for detecting the presence of special nuclear materials in a suspect container. The system and its method include irradiating the suspect container with a beam of neutrons, so as to induce a thermal fission in a portion of the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the ...

U235 nuclear spin-lattice (T1?1) and spin-spin (T2?1) relaxation rates in the itinerant antiferromagnet USb2 are reported as a function of temperature in zero field. The heating effect from the intense rf pulses that are necessary for the U235 NMR results in unusual complex thermal recovery of the nuclear magnetization which does not allow ...

Material accountancy procedures for uranium under a whole nuclear fuel cycle were studied by taking into consideration the material accountancy capability associated with realistic measurement uncertainties. The significant quantity used by the International Atomic Energy Agency (IAEA) for low-enriched uranium is 75 kg U-235 contained. A loss of U-235 ...

The need for breeding does not appear to be highly cost for a moderately optimistic expanding nuclear power economy between 1960 and 2000. Since the expansion rate of the US nuclear economy is assumed to be high at least 2/3 of the U-235 recovered from natural uranium is used to supply reactor inventory. It is the remaining 1/3 of the available ...

The uranium and transuranic content of site soils and building rubble can be accurately measured using a NaI(Tl) well counter, without significant soil preparation. Accurate measurements of total uranium in uranium-transuranic mixtures can be made, despite a wide range (0.3% to 97%) of uranium enrichment, sample mass, and activity concentrations. The appropriate uranium scaling factors needed to ...

New safe interaction criteria for containers of fissionable materials handled at the Oak Ridge Gaseous Diffusion Plant have been developed on the basis of an interaction theory using the basic concepts of a safe solid angle subtended by interacting containers, and the multiplication factor as determined by two-group theory for an individually safe containers The calculated results agree ...

Resonance-parameter covariance matrix (RPCM) evaluations in the resolved resonance region were done for 232Th, 233U, 235U, 238U, and 239Pu using the computer code SAMMY. The retroactive approach of the code SAMMY was used to generate the RPCMs for 233U and 235U. RPCMs for 232Th, 238U and 239Pu were generated together with the resonance parameter ...

The AEC has indicated a need for plutonium with a high concentration of the Pu-240 isotope. Concentrations up to 25 W/o Pu-240 have been requested with a firm commitment given for 25 kilograms of plutonium with at least 18 W/o Pu-240. To meet this production demand, irradiation of depleted uranium, 0.22 W/o U-235, will be undertaken. This test authorizes ...

At this present time, fuel elements of two basic lengths are used in the IPD reactors --a ``six-inch`` enriched uranium element (0.947 w/o U-235) and an ``eight-inch`` natural uranium element. Although fuel element diameters vary fro model to model, the length of the uranium cores is reasonably constant. An evaluation of fuel element lengths has bee made ...

X-ray fluorescence determines the amount of total uranium present in gaseous UF6 inside cascade header pipes of a uranium centrifuge enrichment facility. A highly collimated source, highly collimated detctor, and a very rigid, reproducible geometry are required. Two measurements of the 185.7 keV gamma ray from U-235 using two collimators determine the ...

On the basis of Manhattan Engineer District documents, a little known Naval Research Laboratory report of 1946, and other sources, I construct a more complete history of the liquid-thermal-diffusion method of uranium enrichment during World War II than is presented in official histories of the Manhattan Project. This method was developed by Philip Abelson (1913-2004) and put into operation at the ...

Rensselaer Polytechnic Institute (RPI) - LINAC produced interrogation neutrons, from 3 eV to 3 keV, which were used to determine the relative sensitivity of a spent LWR fuel assembly assay system. The fuel assay system used for this measurement consists of three threshold fission ionization chambers installed in the Rensselaer Intense Neutron Spectrometer (RINS), a 70-ton lead slowing down ...

Diode-laser excited optogalvanic spectroscopy (OGS) of a glow discharge has been utilized to measure U-235/U-235 + U-238 isotope ratios. This ``optical mass spectrometric`` measurement has been demonstrated for a number of samples including uranium oxide, fluoride, and metal. Various diode-laser accessible atomic ...

New results are presented concerning the BETA plus or minus gamma residual power following the /sup 235/U thermal fission for cooling times going from 70 to 7 x 10/sup 4/ sec. A brief description is given of the experimental technique and of the methods used to obtain the residual power from the measurements. The different sources of errors ...

Experiments were performed to determine the existence and nuclear properties of an antimony isotope with a 30 day half life. In the antimony fraction obtained from thermal fission 30 days from the end of the irradiation, only the half lives of Sb/sup 127/ and Sb/sup 125/ were observed. In fission induc ed by 28 Mev deuteron, all the isotopes with ...

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Independent yields for 133Xe and 135Xe and cumulative yields for 133I and 135I in fission of 233U, 235U, 238U, and 232Th with protons of energies 20-85 MeV were measured. Values of Zp, the most probable charge, were obtained by two different methods. The ...

We present a preliminary Pb-Pb isochron age for a newly recovered angrite of 4561.29 � 0.78 Ma (using 238U/235U = 137.84; we are in the process of measuring the U isotope composition). This is identical to the reported age of the NWA 2999 angrite.

The Harvard University mass spectrometer with the lock-in amplifier method of peak matching has been used to measure the mass differences 235U - 206PbC2H5, 238U - 206Pb32S, 238U - 235U, and 206PbH - 207Pb. The mass differences 235U - 207Pb and 238U - 206P...

The text of the Agreement between the Government of the Republic of Chile and the Agency for the application of safeguards to nuclear material in the form of UF/sub 6/, enriched to 20% in the isotope U-235, supplied from the People's Republic of China for...

Over the past three years we have studied various surrogate reactions (d,p), (3He,t), (?,?') on several uranium isotopes 234U, 235U, 236U, and 238U. An overview of the STARS/LIBERACE surrogate research program as it pertains to the actinides is discussed. A summary of results to date will be presented along with a discussion of experimental difficulties ...

... 3 Tris (2,3-dibromopropyl)phosphate; 126-72-7 (Also a listed 0.1 hazardous waste U235) 99-4-34 Trifluralin; 1582-09-8 1 99-4-35 Paraquat, salts 1 ...

Fission-product gamma-ray and photoneutron spectra resulting from thermal and/or fast fission of 232Th, 233U, 235U, 238U, 239Pu, and 241Pu have been calculated at a number of times following fission. Reported here are spectra at 1, 10, 100, 1000, and 5000...

Differential cross sections for neutron elastic and inelastic scattering from 232Th, 233U, 235U, 238U, 239Pu, and242Pu were measured at incident energies ranging from 0.6 to 3.4 MeV. Comparison of these results with the latest available evaluations show l...

This document examines potential yields from extended irradiation of plutonium in a Hanford K reactor. The study was made using the MOFOA program on the IBM-7090 Computer. Two types of plutonium were examined -- weapons grade plutonium and plutonium from (.22 w/o U- 235) depleted uranium irradiated to an exposure of about 2000 mwd/t. Both types of ...

This environmental impact assessment concerns an exemption that would permit the unregulated sale of smelted metal contaminated with uranium enriched up to 20/percent/ U-235 providing the total uranium content in the metal does not exceed 17.5 parts per m...

The nuclear power industry in the United States is currently limited to 5-wt% U235 fuel. Increasing this enrichment limit would enable utilities to decrease the number of spent fuel assemblies, allow upgrades in reactor power, have more flexibility in fuel cycle lengths, and allow for the development of advanced fuel designs. Any increase in fuel ...

The effective cross sections in Maxwellian distributions with neutron temperatures from 20 deg to 300 deg have been measured for U-233, U-235 and Pu-239 fission, and U-238, Th-232, In-115, Lu-176 and Au-197 capture by foil activation methods. Mn-55, which...

Results of a study on the feasibility of converting the Fort St. Vrain reactor core from the present 6-year, High Enriched Uranium (HEU) fuel cycle using uranium enriched to 93% U-235 and thorium to a 6-year, Medium Enriched Uranium (MEU) fuel cycle using...

The capacity of critically safe cylindrical pulse columns limits the size of nuclear fuel solvent extraction plants because of the limited cross-sectional area of plutonium, U-235, or U-233 processing columns. Thus, there is a need to increase the cross-s...

g U/sup 235/ Outputs and Charges by Use of Ideal Cascade Theory,'' TID- 8522, was extended and updated. The topics covered are single product, multiple products, incremental productivity, cost per unit of contained U/sup 235/, cost of U/sup 235/ consumption, minimum cost of products, blending uranium of different assays, and current AEC schedule of charges for enriched ...

0 REGION I CtU235,AL P1. DATA 280. 25 0.0037 ...... COMPOSITION TITLE( REGION I CoU2359AL PI ...... P1O) NEUTRON TRANSPORT CROSS SECTIONS FOR REGION I ...

The method is designed for use on recycled uranium materials and is applicable to materials that will yield at least 100 mg of uranium. Typical analysis time is 24 to 30 hours. U-232 can be measured to a lower limit of detection of 1 ppb (U-235 basis).

This citation summarizes a one-page announcement of technology available for utilization. The feasibility of a nuclear-pumped laser, which could generate high-power visible light without using high-voltage electrical-power-supply technology, has been stud...