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SLURRY FLOW METERS AND DENSITY METERS FOR THE HOMOGENEOUS REACTOR

Description: Six types of instruments are being considered for the metering of flow and/or density in high temperature (300 deg C) and pressure (2000 psi) slurry flow systems. Three of these meters yield readings that depend only on the flow rate or the density, one (the Double Rotameter) yields two readings from which both the flow and the density may be determined while another (the venturi) yields a reading that depends on both the flow rate and the density and thus may be either a density-meter or a flowmeter depending on which variable is the unknown. The remaining instrument (the ultrasonic meter) may yield a signal dependent solely on the flowrate or the density depending on the physical setup. This memo briefly describes these instruments, listing their particular advantages, the difficulties that may arise in their use and the state of development of each. (auth)
Date: September 27, 1957
Creator: Wichner, R.P.
Partner: UNT Libraries Government Documents Department

Overview of experimental support for fission-product transport analyses at Oak Ridge National Laboratory

Description: The program was designed to determine fission product and aerosol release rates from irradiated fuel under accident conditions, to identify the chemical forms of the released material, and to correlate the results with experimental and specimen conditions with the data from related experiments. These tests of PWR fuel were conducted and fuel specimen and test operating data are presented. The nature and rate of fission product vapor interaction with aerosols were studied. Aerosol deposition rates and transport in the reactor vessel during LWR core-melt accidents were studied. The Nuclear Safety Pilot Plant is dedicated to developing an expanded data base on the behavior of aerosols generated during a severe accident.
Date: January 1, 1983
Creator: Wichner, R.P.
Partner: UNT Libraries Government Documents Department

DETERMINATION OF THE SIX TURBULENT REYNOLDS' STRESSES BY THE HOT WIRE METHOD FOR ARBITRARY TURBULENT INTENSITY AND GEOMETRY WITH SPECIAL APPLICATION TO AXISYMMETRIC FLOW

Description: A relationship is derived between the mean square fluctuating current of a hot wire anemometer and the six turbulent Reynolds' stresses in the stream- coordinate system without employing the usual low turbulent intensity approximation. The relatively simple result is a consequence of assuming proportionality between the wire current reading and the perpendicular velocity component instead of the nonlinear dependence required by King's law. The assumption is valid for instruments equipped with the proper linearizing circuitry. Tbe stream-coordinate Reynolds' stresses are then related to the cylindrical polar Reynolds' stresses. An error analysis on the experimental determination of ore of these stresses is indicated but cannot be evaluated without fu rther data. (auth)
Date: February 21, 1961
Creator: Wichner, R.P. & Peebles, F.N.
Partner: UNT Libraries Government Documents Department

C-CAMP, A closed cycle alkali metal power system

Description: A concept is presented for a Closed-Cycle Alkali Metal (C-CAMP) power systems which utilizes the heat of reaction of an alkali metal and halogen compound to vaporize an alkali metal turbine fluid for a Rankine cycle. Unique features of the concept are (1) direct contact (heat exchange) between the reaction products and turbine fluid, and (2) a flow-through chemical reactor/boiler. The principal feasibility issues of the concept relate to the degree of cross-mixing of product and turbine fluid streams within the reactor-boiler. If proven feasible, the concept may be adapted to a range of fuel and turbine fluids and ultimately lead to thermal efficiencies in excess of 35%.
Date: January 1, 1988
Creator: Wichner, R.P. & Hoffman, H.W.
Partner: UNT Libraries Government Documents Department

Carbon-14 production in the Peach Bottom HTGR core

Description: Carbon-14 concentrations were measured in a variety of core components during the Peach Bottom Surveillance Program. Five fuel element sleeves and spines were dissected to obtain radial concentration profiles at four axial locations. The profiles show that the major part of the /sup 14/C in these graphite components characteristically showed a flat radial distribution across the interior of the member; the balance was found in concentration peaks at each exposed surface. The source of these surface peaks is not fully understood. Concentrations were also determined in five fuel element fission product traps, one removable radial reflector block, and 12 fuel particle pairs taken from a number of axial locations in one fuel element. Estimates of whole-core inventory were made from these concentration determinations.
Date: July 1, 1980
Creator: Wichner, R.P. & Dyer, F.F.
Partner: UNT Libraries Government Documents Department

Distribution and transport of tritium in the Peach Bottom HTGR

Description: This report completes the first phase of a two-phase effort to describe and understand tritium production and movement in an operating high-temperature gas-cooled reactor (HTGR) system. The principal objective of phase 1 is to report the findings on tritium concentrations in core components acquired during the Peach Bottom Surveillance Program, which dealt with fission product migration in general, and a follow-on task devoted specifically to tritium. Administrative procedures are being developed for the second phase of the work to be performed in the Federal Republic of Germany under the auspices of the international umbrella agreement on gas-cooled reactor (GCR) development. In this effort, computer model predictions of tritium transport in the reactor system will be compared with observed concentration levels.
Date: August 1, 1979
Creator: Wichner, R.P. & Dyer, F.F.
Partner: UNT Libraries Government Documents Department

Silver transport in H-451 graphite

Description: Diffusion profiles have been measured for silver in hollow and solid cylinders in the temperature range 490 to 800/sup 0/C. The profiles show two components of diffusion. There is a high concentration, relatively immobile zone near the surface and a low concentration, rapidly moving component deeper into the sample. The rapid component is well fitted by the diffusion equation when irreversible trapping is assumed. The diffusion coefficients determined by least-square analysis of the profiles can be represented by D (m/sup 2//sec) = 17.4 exp (-22,100/T). Excessive scatter was seen in the trapping coefficients determined from the profiles. This is believed to be due to varying amounts of impurities in the different samples. A limited number of desorption measurements were performed for silver from H-451 graphite. Evidence of Elovich-type behavior was noted.
Date: January 1, 1981
Creator: Causey, R.A. & Wichner, R.P.
Partner: UNT Libraries Government Documents Department

The significance of the centripetal acceleration due to the earth's rotation on the generation of oceanic circulation

Description: This report proposes that the tangential component of the centrifugal body force due to the earth's rotation plays a significant role as a motive force for the major oceanic circulations. A comparison of its magnitude relative to the Coriolis force and wind shear, on which current circulation models are based, indicates its potential effect is significant if an appropriate mechanism can be constructed that generates a circulation force. Such a mechanism is proposed, based on the coupled effect of water-density variations with the tangential component of the centrifugal force. An order-of-magnitude model, which equates the generated circulation force with a rough estimate of the flow resistance, indicates a favorable comparison between predicted and observed current velocity. 13 refs., 4 figs.
Date: November 1, 1991
Creator: Wichner, R.P.
Partner: UNT Libraries Government Documents Department

SOME EXPERIMENTS ON THE ACCURACY OF THORIA SLURRY SAMPLES

Description: Tests were performed on a thoria slurry flowing in a pipe to determine the magnitude of the possible error involved in the sampling process. Evidence indicates that a correct sample is obtained by withdrawing the sample isokinetically (i.e., by facing the sampler into the flow and adjusting the sampler velocity to match the ambient velocity) provided that the sampler is larger than some minimura diameter that is dependent on the mean eddy length and/ or the mean particle size. (auth)
Date: April 21, 1960
Creator: Wichner, R P
Partner: UNT Libraries Government Documents Department

Program ESTU: a method for estimating estuarine temperature distributions for Harleman's closed-form, one-dimensional model

Description: A method is presented for obtaining accurate numerical results for Harleman's closed-form, one-dimensional estuary model. The model applies to the case of a single-source input, steady net flow, and tidal flow varying sinusoidally with time. Though more sophisticated estuarine computational procedures are now available, this simple, closed-form model may continue to be useful for approximations and parameter surveys. Some general characteristics of temperature distributions as a function of time within the tidal cycle in the vicinity of a warm input are discussed for a typical East Coast estuary. Temperature profiles for 15-min intervals throughout the tidal cycle are plotted revealing some interesting and not well-known features. It is shown that a tidal average maximum temperature peak occurs very close to the location of the outfall for the range of net flows and dispersion coefficients that were examined. (auth)
Date: April 1, 1974
Creator: Wichner, R. P.
Partner: UNT Libraries Government Documents Department

Review of tellurium release rates from LWR fuel elements under accident conditions

Description: Although fission product tellurium presents a potentially significant radiohazard, its release and transport in source-term experiments is frequently overlooked because it does not possess a readily measurable, gamma emission; moreover, a recent study emphasized noble gas, iodine and cesium release from LWR fuel elements because of the large data base that exists for these materials. Some new tests show that in some cases tellurium may be held up in core material to a greater degree than previously assumed - an observation that prompts a careful reappraisal of the existing tellurium-release data and its chemical foundation.
Date: January 1, 1983
Creator: Lorenz, R A; Beahm, E C & Wichner, R P
Partner: UNT Libraries Government Documents Department

Diffusion of uranium in H-451 graphite at 900 to 1400/sup 0/C

Description: In this study, the diffusion of uranium (as a stand-in for plutonium) was investigated under conditions approximating those of the primary coolant loop in a High Temperature Gas-Cooled Reactor (HTGR). Profiles were obtained for uranium penetration in H-451 graphite (from the Great Lakes Carbon Company) at temperatures ranging from 900 to 1400/sup 0/C. Diffusion coefficients are established for UO/sub 2/ and UC/sub 2/.
Date: March 1, 1983
Creator: Tallent, O.K.; Wichner, R.P. & Towns, R.L.
Partner: UNT Libraries Government Documents Department

Fission-product release from irradiated LWR fuel

Description: An experimental investigation of fission product release from commercial LWR fuel under accident conditions is being conducted at Oak Ridge National Laboratory (ORNL). This work, which is sponsored by the US Nuclear Regulatory Commission (NRC), is an extension of earlier experiments up to 1600/sup 0/C and is designed to obtain the experimental data needed to reliably assess the consequences of accidents for fuel temperatures up to melting. The objectives of this program are (1) to determine fission product release rates from fully-irradiated commercial LWR fuel in high-temperature steam; (2) to collect and characterize the aerosol released; (3) to identify the chemical forms of the released material; (4) to correlate the results with related experimental data and develop a consistent source term model; and (5) to aid in the interpretation of tests using simulated LWR fuel.
Date: January 1, 1982
Creator: Osborne, M.F.; Lorenz, R.A. & Wichner, R.P.
Partner: UNT Libraries Government Documents Department

Sorption of iodine on low-chromium-alloy steel. [HTGR]

Description: The sorption behavior of iodine on the surfaces of 2 1/4% Cr-1% Mo steel was investigated as a part of the High Tmeperature Gas-Cooled Reactor (HTGR) Chemistry Program at Oak Ridge National Laboratory (ORNL). The primary objective of these tests was to determine the equilibrium sorptive capacity of this alloy, which comprises most of the cooler regions of HTGR coolant circuit, under representative conditions. The data will be used to improve the capability for predicting, with computer programs, iodine deposition as functions of temperature and location in the primary circuit.
Date: January 1, 1981
Creator: Osborne, M.F.; Briggs, R.B. & Wichner, R.P.
Partner: UNT Libraries Government Documents Department

Fission product release from fuel under LWR accident conditions

Description: Three tests have provided additional data on fission product release under LWR accident conditions in a temperature range (1400 to 2000/sup 0/C). In the release rate data are compared with curves from a recent NRC-sponsored review of available fission product release data. Although the iodine release in test HI-3 was inexplicably low, the other data points for Kr, I, and Cs fall reasonably close to the corresponding curve, thereby tending to verify the NRC review. The limited data for antimony and silver release fall below the curves. Results of spark source mass spectrometric analyses were in agreement with the gamma spectrometric results. Nonradioactive fission products such as Rb and Br appeared to behave like their chemical analogs Cs and I. Results suggest that Te, Ag, Sn, and Sb are released from the fuel in elemental form. Analysis of the cesium and iodine profiles in the thermal gradient tube indicates that iodine was deposited as CsT along with some other less volatile cesium compound. The cesium profiles and chemical reactivity indicate the presence of more than one cesium species.
Date: January 1, 1983
Creator: Osborne, M.F.; Lorenz, R.A.; Norwood, K.S.; Collins, J.L. & Wichner, R.P.
Partner: UNT Libraries Government Documents Department

Metal burning in graphite-moderated reactors

Description: Pinto beans, sweet corn, and zucchini squash (Cucurbita pepo var. black beauty) were grown in a randomized complete-block field/pot experiment at a site that contained the highest observed levels of surface gross gamma radioactivity within Los Alamos Canyon (LAC) at Los Alamos National Laboratory. Soils as well as washed edible and nonedible crop tissues were analyzed for various radionuclides and heavy metals. Most radionuclides, with the exception of {sup 3}H and {sup tot}U, in soil from LAC were detected in significantly higher concentrations (p <0.01) than in soil collected from regional background (RBG) locations. Similarly, most radionuclides in edible crop portions of beans, squash, and corn were detected in significantly higher (p <0.01 and 0.05) concentrations than RBG. Most soil-to-plant concentration ratios for radionuclides in edible and nonedible crop tissues from LAC were within the default values given by the Nuclear Regulatory Commission and Environmental Protection Agency. All heavy metals in soils, as well as edible and nonedible crop tissues grown in soils from LAC, were within RBG concentrations. Overall, the total maximum net positive committed effective dose equivalent (CEDE)--the CEDE plus two sigma for each radioisotope minus background and then all positive doses summed--to a hypothetical 50-year resident that ingested 160 kg of beans, corn, and squash in equal proportions, was 74 mrem y{sup -1}. This dose was below the International Commission on Radiological Protection permissible dose limit (PDL) of 100 mrem y{sup -1} from all pathways; however, the addition of other internal and external exposure route factors may increase the overall dose over the PDL. Also, the risk of an excess cancer fatality, based on 74 mrem y{sup -1}, was 3.7 x 10{sup -5} (37 in a million), which is above the Environmental Protection Agency`s (acceptable) guideline of one in a million. 25 refs.
Date: May 1, 1997
Creator: Wichner, R.P.; Ball, S.J.; Daw, C.S. & Thomas, J.F.
Partner: UNT Libraries Government Documents Department

Analysis of iodine and cesium chemical forms evolved from graphite surfaces at temperatures from 425 to 1400{sup 0}C

Description: Information has been obtained to aid in the identification of the chemical forms of fission product cesium and iodine which are evolved from graphite surfaces heated to temperatures up to 1400{sup 0}C. Iodine and cesium were initially added to the graphite as adsorbed CsI; subsequently, more cesium was added as Cs{sub 2}0 to allow variations of the initial cesium/iodine mol ratio from 1 to 10. The identifications were determined, in part, by inference from the locations of cesium and iodine deposits on a graphite thermal gradient tube, the measured mol ratios of the deposits, and the results of electron surface chemical analyses. Cesium iodide was the most abundant of the chemical forms found; however, significant quantities of cesium-rich oxygen-bearing deposits (probably cesium oxide) and of iodine-rich deposits (mostly molecular I{sub 2}) were also present. The iodine species, CsI and I{sub 2}, were found to move downstream with time and/or gas flow from the hotter to the colder regions of the system. 3 refs., 8 figs., 5 tabs.
Date: August 1, 1985
Creator: Tallent, O. K.; Wichner, R. P.; Towns, R. L. & Godsey, T. T.
Partner: UNT Libraries Government Documents Department

Characterization and chemistry of fission products released from LWR fuel under accident conditions

Description: Segments from commercial LWR fuel rods have been tested at temperatures between 1400 and 2000/sup 0/C in a flowing steam-helium atmosphere to simulate severe accident conditions. The primary goals of the tests were to determine the rate of fission product release and to characterize the chemical behavior. This paper is concerned primarily with the identification and chemical behavior of the released fission products with emphasis on antimony, cesium, iodine, and silver. The iodine appeared to behave primarily as cesium iodide and the antimony and silver as elements, while cesium behavior was much more complex. 17 refs., 7 figs., 1 tab.
Date: January 1, 1984
Creator: Norwood, K.S.; Collins, J.L.; Osborne, M.F.; Lorenz, R.A. & Wichner, R.P.
Partner: UNT Libraries Government Documents Department

Iodine sorption/desorption from low-alloy steel and graphite. Draft

Description: Tests have been performed at Oak Ridge National Laboratory on the sorptive behavior of iodine on two prominent HTGR primary circuit materials - type H-451 graphite, which is the selected core graphite, and a low-alloy steel (T-22), a type which is employed in the lower temperature regions of the primary system. The main emphasis of the work is the determination of equilibrium sorptive capacities for very low iodine partial pressures. Toward this goal, the test procedures allow on-line determination of sorptive capacity down to iodine partial pressures of approx. 10/sup -11/ bar in helium at a total pressure of 1 atm. The apparatus employed is of the helium flow-through type. Detectors monitor the degree of sorption on specimens and traps, which, together with the helium flowrate and source vapor pressure, yield a continuous determination of iodine mass transport.
Date: January 1, 1980
Creator: Wichner, R.P.; Osborne, M.F.; Lorenz, R.A. & Briggs, R.B.
Partner: UNT Libraries Government Documents Department