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Description: 8 5 F 5 ; 9 6 9 7 4 / 1 < =15% cold-worked Zircaloy-2 at 290, 345, and 400 deg C is being continued. Research to identify factors affecting irradiation-induced volume changes in graphite by means of sink- float density measurements was oontinued. The program to simulate conditions after a postulated loss-of coolant incident within the PRTR was completed. Lapsed-time motion pictures are being made through a windowed autoclave of the corrosive action of high-temperature water on defected Zircaloy2 U specimens. Progress on the development of an isotopic-exchange leak-detection systems is summarized. A program to develop a thermal-neutron-flux munitoring system for the Hanford reactors is reported. A project is being conducted to determine the temperature and approximate composition of the ternary eutectic in the Al--U--Ni alloys. A feasibility study to determine if Ca coatings can be successfully put on Ni by arc-spraying methods is reported. Work was continued on the valence effects of oxide additions (CaO and La/sub 2/O/sub 3/) to UO/sub 2/. An investigation is being made of the effects of combined high pressure and temperature on UO/sub 2/. Postirradiation data are presented on fueled specimens of ZrH/sub 1.65/--2 wt.% U. An evaluation of the effect of irradiation on the mechanical properties of AISI Type 347 stainless steel is being conducted. Hothardness data are presented for high-purity Nb, Nb-- Zr, Nb-V, Nb-Ti, Nb-Fe, Nb-Cr, Nb-V-Ti, Nb-V-Mo, Nb-V-Fe, Nb-V-Cr, Nb-V-Al, Nb-Zr-V, Nb-ZrTi, Nb-Zr-Mo, Nb-Zr-Cr, and Nb-Zr-Fe. A summary is presented of corrosion results obtained on Nb, Nb-Zr, Nb-W, Nb-Mo, Nb-V, Nb-Fe, Nb-Ti, Nb-Ti-Cr, Nb-Ti-Mo, and Nb-Ti-V alloys exposed in high-temperature water and steam. Corrosion data are given for Nb-U alloys in air, CO/sub 2/, NaK, water, and steam. Techniques are being developed for the preparation and cladding of cermets containing 60 to 90 vol.% of fuel dispersed in ...
Date: July 1, 1959
Creator: Dayton, R.W. & Tipton, C.R. Jr.
Partner: UNT Libraries Government Documents Department

Three-Dimensional Thermal-Neutron Radiography

Description: Three-dimensional radiographic methods provide a means of determining the depth of defect indications and minimizing the confusion that results from overlapping images of structures at various depths in an object. One method of obtaining and displaying three-dimensional radiographic images is multiple-film laminagraphy, i.e., a series of radiographic films taken at different orientations can be viewed superimposed to present a sharply focused image of any desired object plane. Methods that use multiple-film laminagraphy for three-dimensional thermal-neutron images will be described.
Date: October 1976
Creator: Berger, H. & Reimann, K. I.
Partner: UNT Libraries Government Documents Department


Description: The purpose of this work is to present the most pertinent parts of the body of physics knowledge which has been built up in the course of the Naval and Shippingport (PWR) Reactor Programs, with the aim of providing a background of understanding for those interested in nuclear core design. Volume 1 of this handbook was planned to bring together topics in the basic theoretical and experimental material which are of especially wide interest, including those common to both thermal and intermediate neutron energy reactor types. The physics design of light water-moderated and -cooled reactors is covered in Volume 2 (classified), and that of intermediate neutron-energy power reactors in Volume 3. The emphasis in Volume 1 is thus on light water reactor systems, and as many recent advances in reactor physics of the Naval and Shippingport Reactor Programs as possible have been included.
Date: January 1, 1964
Creator: Radkowsky, A. ed.
Partner: UNT Libraries Government Documents Department


Description: A method is presented for calculating thermal neutron fluxes in the primary shields of reactor systems which eliminates reliance on mock-up experimental data. A multigroup P/sub 1/ approach is ernployed with the spatial dependence of the neutron sttenuation adjusted through use of a point source attenuation kernel for a homogeneous hydrogenous medium. Comparison of calculation with experiment is presentad. (auth)
Date: November 1, 1959
Creator: Anderson, D.C. & Shure, K.
Partner: UNT Libraries Government Documents Department


Description: A careful determination of /sub 2200/ from results of the Macklin- deSaussure manganese-bath experiment involves corrections for (1) the weak but nonzero transmission of subcadmium neutrons through the uranium or plutonium foils and (2) the small variation of with energy in the subcadmium region. The derivation of a single general expression for applying both these corrections is presented, and two lBM 704 codes (MTC and GTC) which were written especially to facilitate the numerical evaluation of this combined correction factor are described. (auth)
Date: August 17, 1959
Creator: Halbert, E.C.; Maskewitz, B.F. & Wynn, R.L.
Partner: UNT Libraries Government Documents Department

Establishment of M1 multipolarity of a 6.5 (micro)2n resonance in 172Yb at E(gamma) = 3.3 MeV

Description: Two-step-cascade spectra in {sup 172}Yb have been measured after thermal neutron capture. they are compared to calculations based on experimental values of the level density and radiative strength function (RSF) obtained from the {sup 173}Yb(3{sup 3}He,{alpha}{gamma}){sup 172}Yb reaction. The multipolarity of a 6.5(15) {mu}{sub N}{sup 2} resonance at E{sub {gamma}} = 3.3(1) MeV in the RSF is determined to be M1 by this comparison.
Date: February 4, 2004
Creator: Schiller, A; Voinov, A; Algin, E; Becker, J A; Bernstein, L A; Garrett, P E et al.
Partner: UNT Libraries Government Documents Department

A Weighted Point Model for the Thermal Neutron Multiplicity Assay of High-Mass Plutonium Samples

Description: A weighted point model for thermal neutron multiplicity counting has been developed for the assay of impure plutonium metal samples. Weighting factors are introduced for the spontaneous fission and ({alpha},n) contributions to the doubles and triples rates to account for the variations in neutron multiplication in these samples. The weighting factors are obtained from Monte Carlo simulations using the MCNPX code, which supports the simulation of spontaneous fission sources and can tally the source and detected neutron multiplicity distributions. Systematic behavior of the weighting factors was studied as a function of sample mass and geometry. Simulations were performed to evaluate the potential accuracy of assays performed with weighted point model analysis. Comparisons with experimental data are presented. The possible use of quads rates is explored.
Date: October 1, 2005
Creator: Krick, M.S.; Geist, W.H. & Mayo, D.R.
Partner: UNT Libraries Government Documents Department

UCRLDetermination of the standard deviation on multiplication based on count distributions

Description: The multiplication M of a multiplying object can be determined by analyzing the arrival times of thermal neutrons in detectors such as helium tubes. A source emitting neutrons randomly will lead to neutron inter arrival times obeying Poisson process statistics. By observing how the inter arrival times of detected counts differ from Poisson statistics, one can assess properties of the neutron source such as the source intensity and multiplication. While the method of analyzing the inter arrival times of neutrons using count distributions to determine characteristics of the source has been used for a long time, the treatment of the errors on the determined quantities multiplication M and source strength S have not yet been adequately treated. This object of this report is to assess these errors.
Date: July 7, 2009
Creator: Verbeke, J
Partner: UNT Libraries Government Documents Department


Description: A system of six codes is described that permits the solution of a broad class of problems encountered in the study of neutron thermalization, average cross sections, and spectral models. These programs are all compatible with use on MONITOR for the IBM 7090. The Fortran listings are given. (auth)
Date: February 25, 1963
Creator: Preskitt, C.A.; Nephew, E.A. & Tsagaris, M.E.
Partner: UNT Libraries Government Documents Department