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After Shutdown Heating in the HFIR

Description: After shutdown heating rates have been calculated for the target, control plates, and the beryllium reflector of the HFIR. Hilvety previously calculated the after shutdown heating rates in the element and his results are reported in ORNL CP-60-4-110. Decay times of 1.0 10, 10^2, 10^3, 10^4, and 10^5 seconds have been considered, and heat fluxes have been computed for all of the mentioned components. The greatest heat fluxes were found to be at the surfaces of the control plates and the permanen… more
Date: December 29, 1960
Creator: McLain, H. A.
open access

Status Report on the Pneumatic Temperature Measuring system Studies for the EGCR

Description: The pneumatic temperature probe (PIM) is a device for measuring gas temperatures by utilizing the dependency of the flow of gases through a restriction on the temperature and pressure conditions. The determination is made by measuring critical mass flow across a restrictive element such as a nozzle and by knowing the upstream pressure and other variables pertinent to the critical flow equation, computing the temperature at the entrance to the restrictive element. In practice it has been found u… more
Date: December 30, 1960
Creator: Hochreiter, H. M.
open access

Homogeneous Molten Salt Reactors

Description: Multigroup one-dimensional calculations were done recently to obtain estimates of critical masses, power density distributions and fissioning spectra for some homogeneous molten salt reactors having outer reflectors and central "islands," placed inside the currently proposed MSRE vessel. For a 5-inch-thick outer reflector and 1-ft-diamter island, both beryllium, the calculated critical mass is 108 kg; 40 percent of the fissions occur at thermal, and the maximum power density of 3.9 times the co… more
Date: December 13, 1960
Creator: Nestor, C. W., Jr
open access

Thermal-Neutron Flux at the HRE-2 Core Wall, Determined from Zircaloy-2 Induced-Activity Measurements During Runs 13, 14, 16, 17, 18, 19, 20 and 21.

Description: The thermal-neutron flux prevailing near the upper hole in the HRE-2 core wall was determined from measurements of the induced activity in a specimen cut from the edge of the hole. The specimen was removed following run 21 and was thus exposed to reactor neutrons during runs 13, 14, 16,17, 18. 19, 20, and 21. The neutron flux, calculated for an average core power level of 2 Mw, was 2.8 x10^13 neutrons/cm^2 sec. the core wall area from which the specimen was removed was located approximately 16-… more
Date: December 20, 1960
Creator: Baker, J. E.
open access

Steady-State Radial and Axial Temperature Profiles of an E. G. C. R. 5 1/2" O. D. Through Tube During 1500 KW Operation - Part II

Description: The steady-state radial and axial temperature profiles of an E. G. C. R. 5 1/2" O. D. through tube are determined for the test condition of an attemperated fuel assembly operating at 1500 KW in the loop. The profiles are determined for the case of the central control rod fully inserted and bank insertion to 62 inches (Δk = 0.025). The data are presented in the form of tables and curves.
Date: December 30, 1960
Creator: Noggle, L. W.
open access

Analog Computer Analysis of the Thermal Behavior of the EDCR Due to Reactivity Accidents

Description: The ORNL analog computer was used to examine one aspect of a safety system for the EGCR. The thermal behavior of the fuel as a result of increases in reactivity at various power levels and gas flows was examined. Safety actions initiated by wither a flux-minus-flow signal or a reactor outlet gas temperature signal were included in simulation.
Date: December 16, 1960
Creator: Pierce, R. M.
open access

Use of Convergent and Asymptotic Series for Computation of the Modified Bessel Function of the First Kind.

Description: In the Communications of the ACM of April, 1960, p. 240, there appeared two Algol algorithms for the computation of In, the modified Bessel function of the first kind. One of these algorithms uses a convergent series and the other an asymptotic series. Their author, Dorothea S. Clarke, did not give any information with regard to which algorithm is more appropriate in a given situation (a given situation meaning the computation of In (x) for a definite pair of numbers n and x). Such information … more
Date: December 12, 1960
Creator: Bumgarner, L. L.
open access

Analysis of Uranium Fuel-Element Wafers from Atomics International for Uranium, Plutonium and Samarium

Description: Five irradiated and five unirradiated wafers were analyzed. Each wafer was analyzed for samarium by emission spectrography. The unirradiated wafers were analyzed for uranium by coulometric and potentiometric methods and for uranium isotopes by mass spectrometry. The irradiated wafers were analyzed for uranium and plutonium by coulometric methods, for plutonium isotopes by the 256-channel alpha pulse analyzer, and for the isotopes of uranium and of plutonium by mass spectrometry. The methods of … more
Date: December 27, 1960
Creator: Gaitanis, M. J.
open access

A Statistical Model of Nuclear Level Spacings

Description: A generalization of Wigner's simple model for the distribution of nuclear level spacings is studied. It is based on a stochastic process which reproduces the correct joing probability distribution of N enerfy levels for small spacings. The case N=3, which includes the effect of the correlation between adjacent spacings, is discussed in detail. The resulting distribution and the correlation coefficient are compared with experimental data. No definite conclusion can be drawn except to say that th… more
Date: December 4, 1960
Creator: Dresner, L. & Inönü, E.
open access

A Transport Calculation of the HFIR Beam Hole Currents

Description: An estimate was made of the beam hole currents to be expected from both the radial and tangential beam holes in the present HFIR design. The angular fluxes required for these calculation were determined by an 18-group, S8 transport calculation (SNG reactor code). Both type beam holes produced thermal neutron currents of 7.5 x 10^10 neutrons/cm^2 sec. at a power level of 100 Mw. The nonthermal component of the beam current was 7.0 x 10^10 and 4.5 x 10^10 neutrons/cm^2 -sec for the radial and tan… more
Date: December 5, 1960
Creator: Claiborne, H. C. & Rakavy, G.
open access

Fission Product Release from UO2 and by High Temperature Diffusion and Melting in Helium and Air.

Description: The experimental demonstration of fission product release from over heated reactor fuel is necessarily subject in many respects to the arbitrary conditions imposed by the experimenter. Since an almost infinite latitude exists in the choice of materials, atmospheres, gas, velocities, temperatures etc., some allowance for an extrapolation to alternate conditions is definitely in order. The conditions imposed in this study are best described as those most likely to maximize fission product release… more
Date: February 8, 1961
Creator: Parker, G. W.; Creek, G. E. & Martin, W. J.
open access

Design Study of a Pebble-Bed Reactor Power Plant

Description: Sanderson & Porter have carried out a series of studies over the last four years which indicate that the pebble-bed reactor way be an attractive way to obtain low-cost power. At the request of the Atomic Energy Commission, two design studies have been carried out on this concept at the Oak Ridge National Laboratory. The first of these a preliminary design of a 10-Mw(t) reactor experiment, the PRRE, was initiated September 10, and a report on the study was issued November 1960. The second phase … more
Date: May 11, 1961
Creator: Fraas, A. P.; Carlsmith, R. S.; Corum, J. M. & Foster, J.
open access

Chemical Development Section C Progress Report for October-November 1960

Description: Studies are being made on the recovery of thorium (and uranium) from granitic rock, since this source represents a very large potential thorium reserve for the nuclear power industry. In preliminary leaching studies on 16 granite samples (containing 8-95 ppm thorium and 1.5-16 ppm uranium), maximum recoveries of thorium and uranium ranged 30-85% and 15-65% respectively, and sulfuric acid consumption was high (30-120 lbs H2SO4 per ton of granite). A relatively high acidity was needed to obtain r… more
Date: March 3, 1961
Creator: Brown, K. B.
open access

Radioactivation Analysis

Description: The development of nuclear reactors and other sources of nuclear particles has provided the analyst with a new method which has been successfully applied to the determination of microgram and even submicrogram quantities of many elements. In this method, known as "radioactivation analysis," the element to be determined is "activated" through some type of nuclear reaction which produces a radioactive isotope of the element. Since the radioisotope produced decays with its own characteristic radia… more
Date: September 22, 1961
Creator: Leddicotte, G. W.
open access

Radioactivation Analysis

Description: The development of nuclear reactors and other nuclear particle sources has given the analyst a new analysis method which can be successfully applied to the determination of microgram and submicrogram quantities of many elements. Known as "radioactivation analysis", this method is one in which an "activation" by some type of nuclear reaction is used to produce a radioactive isotope of the element to be determined. Since this radioisotope decays with its own characteristic radiations and half-lif… more
Date: November 30, 1960
Creator: Leddicotte, G. W.
open access

Analog Stimulation of HRP In-Pile Slurry Loop Facility in the LITR

Description: An analog simulation is made of the HRP in-pile slurry loop in the LITR. The radiolytic gas pressure in the pressurizer is determined. This pressure is a result of the generation of radiolytic gas in the loop core. A graphical result is obtained showing the effect of catalyst activity and pressurizer flow rate on the pressure rise from radiolytic gas. The thermal behavior of the system is studied, and the response to various controller settings is predicted. Controller settings very near optimu… more
Date: November 28, 1960
Creator: Hinton, D. B.
open access

Specifications for Fuel Assemblies for Core I of the Experimental Gas-Cooled Reactor

Description: These specifications for the fuel assemblies for Core I of the Experimental Gas-Cooled Reactor (EGCR) have been developed for use in procuring the first core loading. A fuel assembly for EGCR consists of a cluster of seven cylindrical fuel elements spaced and supported within a graphite sleeve. Each fuel element consists of a stainless steel tube containing a column of hollow UO2 pellets and having a spacer brazed at the midsection to control the spacing between fuel elements in a cluster. A ma… more
Date: December 9, 1960
Creator: Coobs, J. H.; Wick, E. A. & Evans, R. M.
open access

Design and Development of a High-Temperature High-Pressure Spectrophotometer System: Status Report

Description: On 3/14/60 the Applied Physics Corporation was awarded a subcontract for the design and development of a high-temperature high-pressure spectrophotometer system based on the Cary Model 14pm Spectrophotometer insofar as possible, and consistent with our specifications, No. CTD-2, December 16, 1959.
Date: November 12, 1960
Creator: Biggers, R. E. & Wymer, R. G.
open access

Experimental Determination of an Adequate Fission Chamber Location in the ORR Pool

Description: An experiment was performed at the ORR in order to find a good fission chamber location. Two locations on the pool side of the reactor tank were explored with a one inch diameter fission chamber. The thermal neutron flux attention was found to vary nearly exponentially with distance, and no shadowing effect could be seen during a reactor startup. The fission products high gamma flux could be discriminated without difficulties. Both positions seem to be adequate to locate a reactor control fissi… more
Date: November 4, 1960
Creator: Roux, D. P. & Colomb, A. L.
open access

Equipoise-2: A Two-Dimensional, Two-Group, Neutron-Diffusion Code for the IBM-7090 Computer

Description: Equipoise-2, a two-dimensional, two-group neutron-diffusion code in R-Z geometry, has been programmed for the IBM-7090 computer. This code was designed to permit the running of large numbers of cases without requiring excessive machine time. Typical running times are of the order of one to three minutes per case for a 1000-point problems. The maximum number of mesh points that can be used is 1444.
Date: November 21, 1960
Creator: Fowler, T. B. & Tobias, Melvin
open access

Plasma Accumulation in a Device Fed by Energetic Ion Trapping

Description: Simon (1960) has given a general steady state theory of plasma accumulation (without energy losses) in an OGRA device. Such a device is fed by injection of energetic molecular ions which dissociate to produce trapped protons. Initial trapping is achieved by dissociation in the background gas. Such a device is usually characterized by a critical input current of critical plasma density (a function of input current) above which plasma density builds up to a value limited by Coulomb-scattering los… more
Date: November 10, 1960
Creator: Mackin, R. J., Jr.
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