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The Diffusion Length and the Utilization of Thermal Neutrons in a Heterogeneous Pile

Description: Abstract: "An accurate calculation is given for the quantity which corresponds to the diffusion length in the theory of the pile. The procedure is to establish a relationship between the diffusion length and the change in thermal utilization from a pile with infinite sides to one with sides of a finite length. The calculation of this change in the thermal utilization is then carried through. Approximation to the answer and numerically exact calculations are given in the report. The results show that for radif very near the optimum values the exact diffusion length is slightly larger than the one obtained from the usual formula...However, over most of the range of radii the exact diffusion length is smaller than the approximate one."
Date: October 6, 1943
Creator: Plass, Gilbert N.
Partner: UNT Libraries Government Documents Department

The Effects of Internal Conversion on Critical Mass and Operating Life of a Thermal Reactor

Description: "This report was prepared for preliminary use only in the course of work under W31-109 Eng. 52, and the information contained herein may not be correct or in agreement with more recent experimental and operating data. Any values or opinions expressed in the report may only be those of the author, and the General Electric Company makes no representation or warranty (1) as to the value of this report for any purpose or (2) that any use of the report will not infringe the rights of others."
Date: July 21, 1952
Creator: Snyder, T. M.
Partner: UNT Libraries Government Documents Department

Notes on Predicted Fast Neutron Dose from Thermal Neutron Data in Water

Description: Abstract: "An appropriate method has been applied to predict fast neutron dosimeter data from thermal neutron measurements. Results are compared with actual dosimeter data and it is concluded that the method presented gives a good approximation for fast neutron dose. This is important since in many previous experiments fast neutron dosimeter data had not been taken, but thermal neutron data had been obtained."
Date: 1953
Creator: Stone, Henry E.
Partner: UNT Libraries Government Documents Department


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

Small Source Model of a Thermal Pile

Description: Report discussing the use of a small-source approximation for engineering calculation of thermal piles. Explanation for how this type of approximation is more appropriate in certain problematic situations where a homogenization approximation would be doubtful is given.
Date: April 30, 1952
Creator: Horning, W. A.
Partner: UNT Libraries Government Documents Department

Review of the Xenon Problem

Description: Report discussing studies regarding the properties and nuclear constants of xenon, an element relevant to use of high power thermal neutron reactors.
Date: March 12, 1952
Creator: Gast, P. F.
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