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Asymptotic Neutron Spectra in Multiplying Media

Description: Asymptotic low energy neutron spectra have been measured for two multiplying systems. The reentrant hold spectrum (scalar flux) and the surface leakage spectrum were obtained for both assemblies using the pulsed-source chopper technique at the RPI linear accelerator.
Date: November 1963
Creator: Slovacek, R. E.; Fullwood, R. R.; Gaerttner, Erwin Rudolf, 1911- & Bach, D. R.

Automatic Exit Steam Quality Control for Boiling Water Reactors

Description: From American Nuclear Society Meeting, New York, Nov. 1963. The need for control of the flow distribution and/or steam quality in boiling reactors is discussed. A quality control device is being developed which consists of an entrance venturi and an exit venturi for measuring the flow rates into and out of the channel, means for comparing the two flow rate signals, and a value for regulating the flow rate. This device can be used either as a constant quality device or as a controlled-quality device. Results are given of air-water studies of two-phase flow in a vertical venturi.
Date: November 1963
Creator: Gall, D. A. & Doyle, E. F.

Behavior of Irradiated Metallic Fuel Elements Exposed to Nuclear Excursion in TREAT

Description: In fast reactor safety studies, it is imperative to know the effects of temperature excursions on the fuel elements. Previous controlled out-of-pile experiments on the behavior of uranium fuel elements under meltdown or near-meltdown conditions have been performed using direct electrical resistance heating or furnace heating. As a step toward obtaining more complete information on reactivity effects accompanying fuel meltdown, the behavior of irradiated EBR II and Fermi A samples under transient nuclear heating in TREAT has been studied. The experiment results obtained indicate that effects of prior irradiation can produce significant effects upon reactivity changes produced by meltdown of metallic fast reactor fuel pins.
Date: November 1963
Creator: Monaweck, J. H.; Dickerman, Charles Edward, 1932- & Sowa, E. S.

A Cladding Failure Monitor for Liquid Metal-Cooled Reactor Systems

Description: A cladding failure monitor using the principle of detection of rare gas fission products in the cover gas system of liquid metal-cooled reactors, was developed which efficiently discriminates against AR41. This discrimination is accomplished by electrostatic precipitation of the rare gas daughter nuclides; since K41, the daughter of Ar41, is not radioactive, the activity of the precipitation is chiefly due to decay of various Rb and Cs fission products. The monitor equipment is described. Results of monitor testing in EBR-1 are reported; a simulated fuel road failure experiment was made which shows that the charged-wire cover gas monitoring principle should be useful in other sodium-cooled fast reactors systems.
Date: October 1963
Creator: Smith, R. R. & Doe, B. B.

Control of the Dissolved Gases in the Moderator of the HWCTR

Description: The Heavy Water Components Test Reactor (HWCTR) is used to test prototype fuel elements for power reactors that are moderated with heavy water and fueled with natural or slightly enriched uranium. During the initial critical experiments in the HWCTR, it was observed that there were unexpected variations in nuclear reactivity. Investigations revealed that this effect was due to bubble of helium gas appearing and disappearing in the moderator. An examination of the expected operating conditions of the HWCTR and the solubility of helium in D2O showed that it was possible during normal operation for the helium content of the moderator to exceed saturation and thus for helium to appear as bubbles in the moderator. The possibility of helium bubbles appearing in the moderator because of solubility characteristics was eliminated by modifications to the process system so as to maintain the gas content of the moderator appreciably below saturation.
Date: September 20, 1963
Creator: Arnett, L. M.

[Delta]I = 1/2 Rule for Non-Leptonic Strangeness-Changing Decay Processes

Description: Gell-Mann and Pais were the first to suggest that the non-leptonic decay processes of strange particles may be subject to an isospin selection rule, allowing only those decay transitions which involve a change [delta]I = 1/2 in to total isopin of the system. At present, however, there is really no theoretical framework for the description of weak interactions into which this selection rule fits in a natural and compelling way. The report includes sections on the 91) decay processes of the [caret] hyperon, (2) decay processes, (3) [complex conjugate] decay processes, and (6) K[pi]3 decay processes. We have considered the evidence on all of the known non-leeptonic non-radiative decay modes of strange particles. All of this evidence is in good qualitative accord with the [delta]I = 1/2 selection rule.
Date: December 2, 1963
Creator: Dalitz, R. H. (Richard Henry), 1925-2006.

Design Review and Safety Analysis of Experiments in ORNL Research Reactors

Description: Since 1943 when the oak Ridge Graphite Reactor was put into operation, literally thousands of individual irradiation have been performed in this reactor and in other ORNL research reactors. Over the years there have been many minor incidents caused by experiments. Such incidents have provided a basis cor continued improvement in experiment design review and safety-analysis procedures. The reports lists the Design Review and Safety Analysis (1) objectives, (2) principles and rules of design, and (3) limits of application of the review process. The report includes a review of 19 incidents at ORNL research reactors.
Date: October 1963
Creator: Stanford, L. E. & Costner, R. A., Jr.

Detection and Identification of a Ruptured Fuel Element at the SM-1 (APR-1) Nuclear Power Plant

Description: Summary. In October 1960, increases in the fission product activity of the primary coolant of the SM-1 power plant indicated that a fuel element failure had occurred. Low power tests were run first to determine the nature and magnitude of the defect. Flux tilting experiments were then performed to determine the general location of the failed element. Finally, the primary coolant flowing through each of the fuel elements was sampled at low reactor power for relative iodine activity to determine the exact location of the defective element.. The element was found and replaced. Upon return to power, the fission product activity dropped back to its normal full power value.
Date: 1961
Creator: Misenheimer, Leo J.; Purple, Robert A. & Brown, Paul S.

The Determination of k∞ From Measurements on a Small Test Sample in a Critical Assembly

Description: Abstract. The determination of the infinite multiplication factor, k∞ , from measurement son a small test sample was investigated by both theoretical and experimental techniques. Theoretical relations were developed to calculate the error in the measurement due to a mismatch between the flux ratios in the critical assembly and those of the test sample. Experiments were carried out at the Hanford Laboratory of the General Electric Company with the PCTR, to obtain values of the multiplication factor for comparison with the theoretical results. Calculations with two-group theory gave results that agreed with the experimental results when the test sample, with natural uranium fuel, was surrounded by a buffer region of the same material. When this buffer region was loaded with highly enriched fuel, the errors in the measured values were not predicted by the two-group theory. Three-group theory relations were derived which gave calculated values in agreement with the experimental values and indicated that a mismatch of the epithermal neutron group leads to the measured differences in the value of k∞ for the two buffer types.
Date: November 1963
Creator: Lanning, David Dayton

The Diffusion of Fast Neutrons

Description: From American Nuclear Society Meeting, New York, Nov. 1963. The use of the asymptotic solution to the one-velocity transport equation is considered. The angular distribution for fast neutron elastic scattering by heavy elements is discussed. An exponential angular distribution on is assumed to simplify the decay length calculation. The diffusion length of 1 to 15 Mev neutrons in iron is calculated, as well as the vector flux angular dependence. The asymptotic solution for an arbitrary angular distribution of a plane delta -function source is also found. An isotropic source is investigated, and some applications of the model are examined.
Date: November 1963
Creator: Francis, N. C.; Brooks, E. J. & Watson, R. A.

Diffusion Parameters of Water for Various Scattering Kernels

Description: Abstract. Some diffusion parameters of water are computed with various thermal-neutron scattering laws. It is found that the diffusion cooling coefficient, in particular, is reasonably sensitive to the scattering law, but that the diffusion cooling coefficients predicted by the Radkowsky and Nelkin kernels are in fortuitious agreement. The coefficients computed for the Nelkin kernel, when treated in a manner consistent with the way in which experimental data are treated, are in reasonable agreement with the results of a recent experiment.
Date: August 16, 1963
Creator: Calame, Gerald P.

The Education, Experience, Training, and Certification of Reactor Operators at AEC-Owned Reactors

Description: Results of a questionnaire survey are presented on reactor supervisor and operator education, experience, and training, and on certification procedures by reactor category. The questionnaires were obtained from 362 supervisors, 393 operators, 44 supervisor trainees, and 139 operator trainees.
Date: October 31, 1964
Creator: Wilgus, Walter S.; McCool, Whittie J. & Biles, Martin B.

Effect of Eddy Diffusion on Temperatures in a Fixed Bed, Particulate-Fueled Nuclear Reactor

Description: Abstract: To assess diffusion's importance, the temperature distribution in a cylindrical reactor is derived for a coolant with uniform properties and velocity, taking into account both radial and axial diffusion, for a cosine-J0 power distribution. The fractional temperature rise of the coolant is found to be [chemical formula] where E(z) = [sin(z) + sin(Z)]/2 sin(Z), z= π x/2′, x is the axial distance from the core center, -H and ′ are the core half-height and extrapolated half-height, -H≤x≤H; Fn = 1/J0(Pn)·[(Pn/2.405P)2-10, J1(Pn) = 0, P= R/R′ = core radius/extrapolated radius, ρ = r/R, r = radial distance from axis, 0≤r≤R; an = = βnH/Z, 2 Aβn + 1 =[1 + 4αβ(Pn/R)2]½, A = axial diffusivity /u, B = radial diffusivity /u, u = coolant axial velocity, and [chemical formula]. The expression is evaluated for a variety of values for all the parameters, and the results are discussed analytically and presented in tables and graphs. The effect is dependent upon the relative size of the diffusion eddies in comparison with the dimensions of the reactor. The eddy diffusivity is proportional to the size of the particles in the bed and is about ten times larger axially than radially. A small core with large fuel particles will be affected by eddy diffusion, thereby reducing hot spots, but a large core with small particles will not. For a core 8 ft in diameter cooled by sodium flowing at 2 ft/sec, the effect is perceptible with 2-in. particles, but not with 0.2-in. particles.
Date: November 1963
Creator: Barker, James J. & Benenati, Robert F.

Effect of Fluoride Ions on the Aqueous Corrosion of Zirconium Alloys

Description: Abstract. A review has been made of the effects of fluoride ions on the corrosion behavior of zirconium alloys in high-temperature water. Corrosion was found to occur as the result of contamination of the water or the zirconium surface. A major source of fluorides is undue delay in rinsing the HF-HNO3 pickling solution during surface preparation. The oxide on corrosion-resistant material has been found to contain up to 7600 ppm fluoride from this source. The threshold concentration of fluoride in the oxide film which produces poor corrosion resistance ranges from 8500 to 17,000 ppm. Accelerated corrosion from fluorides in water at 300 to 360 C occurs at about 100 ppm, although increased corrosion has been reported at 10 ppm fluoride in water at 300 C. Fluorocarbon plastics degrade and contribute fluorides to the high-temperature water or to the alloy surface when in direct contact with zirconium. Chlorides (1 to 10,000 ppm) and iodides (1270 ppm) do not adversely affect the corrosion behavior of zirconium alloys in water at 360 C. The mechanism of corrosion is not well understood but apparently is related to the formation of insoluble zirconium oxyfluorides during pickling and during exposure to fluoride-contaminated water.
Date: November 1963
Creator: Berry, Warren E., 1922-

Effect of Radiation on Mechanical Properties of CVTR Pressure Tube Material

Description: An essential part of establishing the acceptability of warm extruded Zircaloy-4 for the CVTR pressure tube application was the determination of irradiation effects on mechanical properties of the alloy. Representative specimens were irradiated in low temperature process water in the WTR for simulated two, three and five year exposure. The effects of this irradiation were then evaluated in terms of changes in tensile, impact and creep properties. The experiment results concluded that the irradiation-induced changes in mechanical proprieties will not introduce any operational hazard to the CVTR pressure tube under anticipated operating conditions.
Date: November 1963
Creator: Smalley, W. R.

An Electrochemical pH-STAT

Description: An apparatus has been developed which controls automatically the acidity of unbuffered solutions in the region from pH 4 to 10. A potentiostat is used to control the potential of an inert electrode on which the hydrogen gas-hydrogen ion reaction occurs in a solution saturated with hydrogen gas. The inert electrode acts as both a sensing element and a regulating electrode for the control of acidity. Current from the potentiostat passes through the inert electrode and an auxiliary polarizing electrode in an external compartment separated from the main cell by a salt bridge or porous plate. Transients which occur during the regulating action are presented and analyzed. The electrochemical pH-stat may be used to measure corrosion rates. Limitations of the device are discussed and a modification is proposed which makes use of a differential amplifier instead of a potentiostat.
Date: October 1963
Creator: Posey, F. A. (Franz Adrian), 1930-; Morozumi, T. & Kelly, E. J.

Energy Deposition by Fast Neutrons. [Part] II, Yield of the Fricke Dosimeter at 14.6 Mev

Description: A measurement of the yield of the aerated, ferrous sulfate-sulfuric acid (Fricke) dosimeter for 14.6-Mev neutrons gave a value of GF /sub Fe/sup +5/= 11.5 plus or minus 1.8. G/sub Fe/ number of ferric ions produced per 100 ev deposited. The determination combined an analysis of the energy deposit by scattering and charged particle reactions with a determination of the neutron flux by two independent means: (1) a "long counter" method and (2) an activation technique. The result is in reasonable agreement with a prediction for G/sub Fe// sup plus or minus 5/ based on measured yields of the dosimeter to irradiations by monoenergetic charged particles.
Date: November 1963
Creator: Axtmann, Robert C. & Licari, Joseph A.

Experimental Usefulness of the Kangaroo Rat

Description: Abstract. The kangaroo rat is readily tamed and has certain characteristics that make it unique and of interest in highly specialized research programs. Studies were conducted on its ability to exist on a dried diet with only a bare minimum of water and that obtained from succulent plants. Hematological studies indicate that the kangaroo rat exhibits a different hematological distribution of cells than the mouse or rat. The lymphocyte constitutes 81.4% of the total leuokocytes. The hematocrit has a value of 46 to 48 in spite of the high degree of water conservation practiced by the animal. The response to ionizing radiation of this species does not differ from that reported for the mouse or rat. Behavior studies indicate that the digging characteristics of the kangaroo rat are similar to those of the gerbil. Furthermore, the animal shows definite psychotic tendencies under the influence of psychotomimetics like LSD-25 and psilocybin. An evaluation of the physiological responses of isolated tissues from this animal as well as its responses to anesthetics is being undertaken to evaluate its further usefulness in the laboratory.
Date: September 13, 1963
Creator: Haley, Thomas J.

Feasibility of a Liquid Phase Chemonuclear Ozone Process

Description: At the Chemonuclear Workshop held at Brookhaven National laboratory in November 1962 it was pointed out that the production of ozone from oxygen by a liquid phase fission fragment chemonuclear process appears to have reasonable economic potential. The maximum theoretical reaction yield for the formation of ozone from oxygen is a "G" value of 68 molecules for 100 ev based on heat of reaction data. The authors felt a "G" value of 15 to be reasonable for this study. the reactor system chosen has liquid oxygen as its moderator and the operating pressure and temperature were selected so as to allow boiling of the oxygen-ozone mixture. The total plant investment cost is estimated to be in the range of $100,000,000. Other system designs will be considered in the future.
Date: November 19, 1963
Creator: Cagnetta, J. P.; Goellner, D. & Steinberg, M.

Fluxes and Reaction Rates in the Presence of Interferring Resonances

Description: The effects of competition between resonances of different isotopes were investigated. Flux and reaction rate calculations on a Pu/sup 239/-- U/sup 238/ system revealed that U/sup 238/ exhibits both self-shielding and interference effects, the latter becoming noticeable at enrichment of a few per cent. Gold activation was also found to be depressed by the presence of U, but was insensitive at low enrichment values, Investigation of the Pu/sup 239/ resonance integral showed an asymmetric effect involving both interference between potential and resonant scattering and interference with resonance absorption in another isotope. The interference scattering arising in each resonance level had a notable effect on the average change in the Doppler coefficient. (D.C.W.)
Date: November 1963
Creator: Kelber, Charles N.

Fuel Failure Detection in the Heavy Water Components Test Reactor

Description: The Heavy Water Components Test Reactor (HWCTR) is a pressurized reactor, cooled and moderated with D2O, and has the capability of testing fuel assemblies under operating conditions of coolant flow, temperate, and pressure that are typical of those proposed for modern power reactors. The report contains (1) description of the four systems used for failed element detection, (2) discussion of the laboratory analyses of water samples used a as backup for the fuel failure instruments, (3) description of 3 monitors, Cyclic Air Sampling Monitor, Stack Gas Activity Monitor, Health Physics Building Monitors, (4) normal full power activity readings, (5) discussion of the experience during fuel failure.
Date: September 20, 1963
Creator: Kiger, E. O.

Gas-Phase Radiolysis of Propane

Description: Abstract. the direct and inert-gas radiolysis, as well as the vacuum ultra-violet photolysis of CD3CH2CD3, CH3CD2CH3 and C3H2+C3D3 mixtures have been investigated in the presence of radical scavengers. The major conclusions are : (a) at atmospheric pressures, neutral propane decomposition contributes to the observed products although to a lesser extent than parent ion decompositions ; (b) a variation in pressure has a pronounced effect on the fragmentation of the parent ion ; (c) the hydrogen atoms in the ethyl ion are randomized in the direct as well as in the inert-gas sensitized radiolysis ; (d) rearrangement in the parent ion is of minor importance in the radiolysis ; (e) although the formation of propylene is related to the propyl ion, it is not necessarily produced by the neutralization of this ion.
Date: May 31, 1963
Creator: Ausloos, Pierre J.; Lias, Sharon G., 1935- & Sandoval, L. B., (Mrs.)

A High Speed Readout for Multi-Channel Pulse Height Analyzers

Description: From American Nuclear Society Meeting, New York, Nov. 1963. In computer-coupled automated activation analysis such as in the Mark II system, conventional methods of data readout impose a serious restriction on the minimum handling time per sample. A data coupler for operating between the data accumulation system and the computer tape unit was developed which contributes nothing to the handling time per sample, does not distort the data, and prepares the data for direct computer entry. In addition to activation analysis, the coupler may be used to obtain successive spectra separated in time by 0.16 sec in the study of short-lived isotopes.
Date: November 1963
Creator: Wilkins, W. W.; Fite, L. E. & Wainerdi, Richard E., 1931-