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Analytical prediction and experimental verification of reactor safety system injection transient

This paper describes the computer code that was developed for thermal hydraulic transient analysis of mixed phase fluid system and the flow tests that were carried out to validate the Code. A full scale test facility was designed to duplicate the Supplementary Shutdown System (SSS) of Savannah River Production Reactors. Several steady state and dynamic flow tests were conducted simulating the actual reactor injection transients. A dynamic multiphase fluid flow code was developed and validated with experimental results and utilized for system performance predictions and development of technical specifications for reactors. 3 refs.

Date: January 1, 1991

Creator: Roy, B.N. & Nomm, E.

Partner: UNT Libraries Government Documents Department

Compact-Toroid Fusion Reactor (CTOR) based on the Field-Reversed Theta Pinch

Scoping studies of a translating Compact Torus Reactor (CTOR) have been made on the basis of a dynamic plasma model and an overall systems approach. This CTOR embodiment uses a Field-Reversed Theta Pinch as a plasma source. The field-reversed plasmoid would be formed and compressionally heated to ignition prior to injection into and translation through a linear burn chamber, thereby removing the high-technology plamoid source from the hostile reactor environment. Stabilization of the field-reversed plasmoid would be provided by a passive conducting shell located outside the high-temperature blanket but within the low-field superconducting magnets and associated radition shielding. On the basis of this batch-burn but thermally steady-state approach, a reactor concept emerges with a length below approx. 40 m that generates 300 to 400 MWe of net electrical power with a recirculating power fraction less than 0.15.

Date: January 1, 1981

Creator: Hagenson, R.L. & Krakowski, R.A.

Partner: UNT Libraries Government Documents Department

Subharmonic buncher for the Los Alamos free-electron laser oscillator experiment

A high efficiency free-electron laser oscillator experiment is being constructed at Los Alamos National Laboratory. A buncher system has been designed to deliver 30-ps, 5-nC electron bunches to a 20-MeV standing-wave linac at the 60th subharmonic of the 1300-MHz accelerator frequency. The first 108.3-MHz buncher cavity accepts a 5-ns, 5-A peak current pulse from a triode gun. Following a 120-cm drift space, a second 108.3-MHz cavity is used, primarily to enhance the bunching of the trailing half of the bunch. A 1300-MHz cavity with 20-cm drift spaces at the each end completes the beamline components. The bunching process continues into the linac's first three accelerating cells. Two thin iron-shielded lenses and several large-diameter solenoids provide axial magnetic fields for radial focusing.

Date: January 1, 1983

Creator: Fraser, J.S.

Partner: UNT Libraries Government Documents Department

Effect of phosphorus on the swelling and precipitation behavior of austenitic stainless steels during irradiation

It has been observed that increasing the volume fraction of the needle-shaped iron phosphide phase in austenitic stainless steels tends to inhibit void swelling during neutron irradiation. An earlier analysis showed that this effect could not be accounted for in terms of enhanced point defect recombination at particle-matrix interfaces. The behavior of the iron phosphide phase has been further examined using dual ion beam irradiations. It was found that the particle-matrix interface serves as a site for the nucleation of a very fine dispersion of helium bubbles. It is thought that since a high number density of cavities lowers the number of helium atoms per cavity, the irradiation time for the cavities to accumulate the critical number of gas atoms for bias-driven growth is correspondingly increased. Although the phosphide phase nucleates rapidly, it eventually undergoes dissolution if either the G or Laves phase develops with increasing dose.

Date: January 1, 1983

Creator: Lee, E.H.; Mansur, L.K. & Rowcliffe, A.F.

Partner: UNT Libraries Government Documents Department

Constructing a bit string universe. Progress report

We present a case for discrete, constructive physics that generates four scale constants, a connection to laboratory events and scattering theory that ties these to the dimensional constants c, h, m/sub p/, and G, and a tentative quantum number assignment consistent with standard model for leptons and quarks with three generations. Current first approximations from the theory are dirac constant c/e/sup 2/ = 137 +- O(1/137), dirac constant c/Gm/sup 2//sub p/ - 2/sup 127/ + 136 approx. = 1.7 x 10/sup 38/(1 +- 0(1/137)), and m/sub p//m/sub e/ = 1836.151497... +-. Our understanding of wave-particle dualism and observational cosmology creates no more experimental paradoxes than currently accepted views - perhaps fewer. 19 references.

Date: February 1, 1984

Creator: Noyes, H.P.; Manthey, M.J. & Gefwert, C.

Partner: UNT Libraries Government Documents Department

X-ray characterization of oxidized tantalum nitride

Sputter deposited non-stoichiometric tantalum nitride films are oxidized in air between 200 and 500{degrees}C to form a passive film. The oxidized films have been studied with x-ray absorption near edge spectroscopy (XANES) and extended x-ray absorption near edge spectroscopy (EXAFS). Films exposed to KOH formed a non-protective surface layer identified in low angle XANES and EXAFS as KTaO{sub 3}. Auger electron and x-ray photoelectron spectroscopies were also used to characterize these films.

Date: January 1, 1991

Creator: MaSaitis, R.L.; Opila, R.L. (AT and T Bell Labs., Murray Hill, NJ (United States)); Ibidunni, A.O. (AT and T Bell Labs., North Andover, MA (United States)); Davenport, A.J. & Isaacs, H.S. (Brookhaven National Lab., Upton, NY (United States))

Partner: UNT Libraries Government Documents Department

Radioactive Fallout From the Chernobyl Nuclear Reactor Accident

This report describes the detection of fallout in the United States from the Chernobyl nuclear reactor accident. As part of its environmental surveillance program, Lawrence Livermore National Laboratory maintained detectors for gamma-emitting radionuclides. Following the reactor accident, additional air filters were set out. Several uncommon isotopes were detected at the time the plume passed into the US. (TEM)

Date: August 1, 1987

Creator: Beiriger, J. M.; Failor, R. A.; Marsh, K. V. & Shaw, G. E.

Partner: UNT Libraries Government Documents Department

The ALS -- A high-brightness XUV synchrotron radiation source

The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory is scheduled to be operational in the spring of 1993 as a US Department of Energy national user facility. The ALS will be a next-generation source of soft x-ray and ultraviolet (XUV) synchrotron radiation. Undulators will provide high-brightness radiation oat photon energies from below 10 eV to above 2 keV; wiggler and bend-magnet radiation will extend the spectral coverage with high fluxes approaching 20 keV. The ALS will support an extensive research program in which XUV radiation is used to study matter in all its varied gaseous, liquid, and solid forms. the high brightness will open new areas of research from the materials sciences, such as spatially resolved spectroscopy, to the life sciences, such as x-ray microscopy with element-specific sensitivity. Experimental facilities (insertion devices, beamlines, and end stations) will be developed and operated by participating research teams working with the ALS staff. 6 refs., 2 figs., 2 tabs.

Date: May 1, 1991

Creator: Robinson, A.L. & Schlachter, A.S.

Partner: UNT Libraries Government Documents Department

Bias factors for radiation creep, growth and swelling

Central to the present concepts of the origin of the radiation-induced creep, growth and swelling phenomena is the relative interaction of interstitials and vacancies with various sinks. Radiation-induced climb of dislocations, which figures in many theories of radiation creep and growth, requires the absorption of an excess of either vacancies or interstitials. On the other hand, radiation swelling requires the absorption of an excess of vacancies to affect void growth. These relative preferences are normally expressed in theoretical models by certain bias factors, or capture efficiencies, usually assumed to be constant. Several attempts have been made to estimate their magnitude theoretically but all are seen to involve errors or physically unrealistic assumptions. We present here a unified treatment in which these various bias factors are estimated in a self-consistent model which incorporates, for the first time, all the essential physics, i.e., defect production, interactions of both vacancies and interstitials with sinks and the presence of two types of sinks. We present quantitative evaluations for the SIPA creep model and for radiation swelling, and compare with previous estimates of these phenomena.

Date: January 1, 1979

Creator: Nichols, F.A.

Partner: UNT Libraries Government Documents Department

Negative-hydrogen-ion sources

There are two main areas of negative hydrogen ion applications: injection into high energy accelerators and production of beams of energetic hydrogen atoms for fusion devices. In both cases, the ease with which the charge state of negative ions can be changed by either single or double electron stripping is the reason that made their application attractive. In tandem accelerators, the final energy of H/sup +/ ions is twice as high as it would correspond to the terminal voltage, in circular accelerators (synchrotrons, storage rings) injection of H/sup +/ ions by full stripping of H/sup -/ ions in a foil inside the ring is not limited by the Liouville's theorem and results in a higher phase space density than achieved by direct H/sup +/ injection. Finally, beams of hydrogen atoms at energies above 100 keV, which will be required for plasma heating and current drive in future fusion devices, can efficiently be produced only by acceleration of negative ions and their subsequent neutralization.

Date: January 1, 1983

Creator: Prelec, K.

Partner: UNT Libraries Government Documents Department

Friction in nuclear dynamics

The problem of dissipation in nuclear dynamics is related to the breaking down of nuclear symmetries and the transition from ordered to chaotic nucleonic motions. In the two extreme idealizations of the perfectly Ordered Regime and the fully Chaotic Regime, the nucleus should behave as an elastic solid or an overdamped fluid, respectively. In the intermediate regime a complicated visco-elastic behaviour is expected. The discussion is illustrated by a simple estimate of the frequency of the giant quadrupole resonance in the Ordered Regime and by applications of the wall and window dissipation formulae in the Chaotic Regime. 51 refs.

Date: March 1, 1985

Creator: Swiatecki, W.J.

Partner: UNT Libraries Government Documents Department

Ion confinement and radiation losses in the Advanced Toroidal Facility

Collapses of stored energy are typically observed in low-density ({anti n}{sub e} {approx} 10{sup 13} cm{sup {minus}3}) extensively gettered ATF plasmas when the electron density rises to the ECH cutoff point, and the central heating is supplied only by neutral- beam-injection (NBI). However, the decline of stored energy can be avoided if the density is raised rapidly to about 5 {times} 10{sup 13} cm{sup {minus}3}. Three mechanisms have been proposed to explain the collapses: (1) impurity radiation, (2) excitation of an electron instability driven by the neutral beams, or (3) poor coupling of the beam ions to the thermal plasmas. Detailed spectroscopic studies of plasma cleanliness as a function of the gettering procedure have shown that radiation is an unlikely candidate for initiating collapses, although it may become an important loss mechanism once the electron temperature has fallen to a low level. No specific electron instability has yet been identified with injection, but recent experimental and computational work indicates that losses by shinethrough and charge exchange strongly influence the evolution of low-density plasmas. This report discusses the beam particle losses, thermal ions, and the evolution of radiation profiles.

Date: January 1, 1991

Creator: Isler, R. C.; Colchin, R. J.; Wade, M. R.; Lyon, J. F.; Fowler, R. H.; Rome, J. A. et al.

Partner: UNT Libraries Government Documents Department

TMX-Upgrade neutral-beam injection system

The TMX experiment proved that axial confinement of central-cell ions is improved ninefold by the electrostatic potential of end-cell plasmas. The TMX Upgrade task is to improve this confinement further. This paper discusses the injector system aspects of the TMX Upgrade.

Date: October 5, 1981

Creator: Felker, B.; Kane, R. J.; Wong, R. L.; Calderon, M. O. & Moore, T. L.

Partner: UNT Libraries Government Documents Department

Martensitic phase transformation in shape-memory alloys

Isothermal studies are described of the shape-recovery phenomenon, stress-strain behavior, electrical resistivity and thermo-electric power associated with the martensite-parent phase reaction in the Ni-Ti shape-memory alloys. The energy-balance equation that links the reaction kinetics with the strain energy change during the cooling-deforming and heating cycle is analyzed. The strain range in which the Clausius-Clapeyron equation satisfactorily describes this reaction is determined. A large change in the Young's modulus of the specimen is found to be associated with the M ..-->.. P reaction. A hysteresis loop in the resistivity-temperature plot is found and related to the anomaly in the athermal resistivity changes during cyclic M ..-->.. P ..-->.. M transformation. An explanation for the resistivity anomaly is offered. The M structure is found to be electrically negative relative to the P structure. A thermal emf of greater than or equal to 0.12 mV is found at the M-P interface.

Date: January 1, 1979

Creator: Golestaneh, A A

Partner: UNT Libraries Government Documents Department

Spatial dependence of flux and damage in the FMIT test cell

Experimental Li(d,n) thick target yields have been combined with nuclear models to determine the microscopic Li(d,n) cross section as a function of incoming deuteron energy (E/sub d/ < 40 MeV), of outgoing neutron energy (0 less than or equal to E/sub n/ less than or equal to 50 MeV), and of outgoing neutron angle (0 less than or equal to theta less than or equal to 180/sup 0/). A generalized least squares adjustment procedure using all the experimental data for 14 less than or equal to E/sub d/ less than or equal to 50 provided the overall normalization and the angular distribution, while the Serber stripping model and the evaporation model provided the neutron energy dependence. The cross sections are applied to the conditions appropriate to the FMIT (Fusion Materials Irradiation Testing) facility to determine flux and damage parameter levels inside the test cell.

Date: January 1, 1979

Creator: Mann, F. M.; Schmitroth, F.; Carter, L. L. & Schiffgens, J. O.

Partner: UNT Libraries Government Documents Department

Report of the working group on data taking with bunched beams

The purpose of this working group was to consider the problems created for experimenters under the bunched beam running conditions of ISABELLE Phase I. Some indication is given of the nature of the problem, the kinds of experiments that will have difficulties are identified, and some of the possibilities for dealing with them are considered.

Date: January 1, 1981

Creator: Blumenfeld, B.; Fernow, R. C.; Herrera, J. C.; Kabe, S.; Marx, M.; Nappi, A. et al.

Partner: UNT Libraries Government Documents Department

Discussion session: nucleon- and antinucleon-nucleus inelastic scattering and charge exchange

This short article summarizes one part of the discussion session concerning nucleon- and antinucleon-nucleus inelastic scattering and charge exchange. Assigned an unconstrained role somewhere between that of rapporteur and ''rioteur'' I've decided to use a few highlights of the conference to stage a number of personal opinions regarding our current status in this game and where we might be going. 20 refs.

Date: January 1, 1985

Creator: Carey, T.A.

Partner: UNT Libraries Government Documents Department

Radiation damage in optical fibers

While plastic-clad-silica (PCS) fiber shows the greatest radiation resistance, PCS fiber has been difficult to reliably connectorize for routine field operations. For this reason, all-glass fibers have been studied as an alternative to PCS. Based on available literature and some preliminary tests at Los Alamos, we have concentrated on fluorosilicate clad, step index, pure silica core fibers. This paper reviews recent laboratory data for these fibers relative to the PCS fibers. This paper also discusses use of a fiber (or any optical medium) on a Cerenkov radiation-to-light transducer. Since the radiation induces attenuation in the medium, the light output is not proportional to the radiation input. The nonlinearity introduced by this attenuation is calculated.

Date: January 1, 1983

Creator: Lyons, P. B.; Looney, L. D. & Ogle, J. W.

Partner: UNT Libraries Government Documents Department

Geothermal direct use engineering and design guidebook avialable for an expanding market

The Geothermal direct use industry potential, growth trends, needs, and how they are being met, are addressed. The high potential for industry growth, coupled with a rapidly expanding use of geothermal energy for direct use, and concerns over the greenhouse effect is the setting in which a new engineering and design guidebook is being issued to support the growth of the geothermal direct use industry. Recent investigations about the current status of the industry and the identification of technical needs of current operating district heating systems provide the basis upon which this paper and the guidebook is presented. The guidebook, prepared under the auspices of the US Department of Energy, attempts to impart a comprehensive understanding of information important to the development of geothermal direct use projects. The text is aimed toward the engineer or technical person responsible for project design and development. The practical and technical nature of the guidebook answers questions most commonly asked in a wide range of topics including geology, exploration, well drilling, reservoir engineering, mechanical engineering, cost analysis, regulations, and environmental aspects. 6 refs., 2 figs., 4 tabs.

Date: January 1, 1989

Creator: Lunis, B.C. & Lienau, P.J.

Partner: UNT Libraries Government Documents Department

Comparison of electric and magnetic quadrupole focusing for the low energy end of an induction-linac-ICF (Inertial-Confinement-Fusion) driver

This report compares two physics designs of the low energy end of an induction linac-ICF driver: one using electric quadrupole focusing of many parallel beams followed by transverse combining; the other using magnetic quadrupole focusing of fewer beams without beam combining. Because of larger head-to-tail velocity spread and a consequent rapid current amplification in a magnetic focusing channel, the overall accelerator size of the design using magnetic focusing is comparable to that using electric focusing.

Date: April 1, 1987

Creator: Kim, C.H.

Partner: UNT Libraries Government Documents Department

Dynamical models of B yields. psi. /J K sub + *

An issue of some interest in the general theory of CP violation on B meson decay is the relative admixture of even and odd final CP eigenstates in B {yields} {psi}/JK*{sub +}. For example, dominance of one sign of CP in this decay would increase the available modes for measuring the CP violation in the respective B meson decays in a beauty factory by a factor {approximately}2.5 and, hence, would decrease the luminosity requirements for such a factory from the CP violation perspective. Here, we therefore study this relative admixture in several dynamical models of the respective decay. We are encouraged by our findings. 12 refs., 3 figs.

Date: September 1, 1990

Creator: Ward, B. F. L.

Partner: UNT Libraries Government Documents Department

Closure of a mixed waste landfill: Lessons learned

Much experience has been gained during the closure of the Mixed Waste Management Facility (MWMF) at the Savannah River Site (SRS) and many lessons were learned. This knowledge was applied to other closures at SRS yielding decreased costs, schedule enhancement, and increased overall project efficiency. The next major area of experience to be gained at SRS in the field of waste site closures will be in the upkeep, maintenance, and monitoring of clay caps. Further test programs will be required to address these requirements.

Date: January 1, 1990

Creator: Phifer, M. A.

Partner: UNT Libraries Government Documents Department

Analytical modeling of core hydraulics and flow management in breeder reactors

An analytical model representing the hydraulic behavior of the primary system of fast breeder nuclear reactors is discussed. A computer code capable of detailing the core flow distribution and characterizing the flow and pressure drop in each reactor component is presented. Application of this method to the reactor core thermal-hydraulic design has allowed optimization of the flow management with consequent upgrading in performance, reduction of unnecessary conservatism and very substantial cost savings. Typical quantitative examples are presented.

Date: January 1, 1979

Creator: Carelli, M.D. & Willis, J.M.

Partner: UNT Libraries Government Documents Department

Some concluding remarks about cold moderator development

This paper is the transcription of remarks made at the conclusion of the Workshop on Cold Neutron Sources held at the Los Angeles National Laboratory, Los Alamos, New Mexico, March 5--7, 1990. Areas of interest include the following: scattering functions; cold moderator materials; radiation mixing of chemical composition; comparison of some pulsed moderator spectra; hydrogen mixtures; premoderators and shields; composite reflectors; exotic moderator materials; deuterated methanes; mixed moderator materials; and test facility availabilities. 2 refs., 4 figs., 1 tab. (MHB)

Date: January 1, 1990

Creator: Carpenter, J.M.

Partner: UNT Libraries Government Documents Department

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