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General-purpose heat source project and space nuclear safety and fuels program. Progress reportt, January 1980

Description: This formal monthly report covers the studies related to the use of /sup 238/PuO/sub 2/ in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of the Los Alamos Scientific Laboratory. The two programs involved are the general-purpose heat source development and space nuclear safety and fuels. Most of the studies discussed here are of a continuing nature. Results and conclusions described may change as the work continues. Published reference to the results cited in this report should not be made without the explicit permission of the person in charge of the work.
Date: April 1, 1980
Creator: Maraman, W.J. (comp.)
Partner: UNT Libraries Government Documents Department

History of critical experiments at Pajarito Site

Description: This account describes critical and subcritical assemblies operated remotely at the Pajarito Canyon Site at the Los Alamos National Laboratory. Earliest assemblies, directed exclusively toward the nuclear weapons program, were for safety tests. Other weapon-related assemblies provided neutronic information to check detailed weapon calculations. Topsy, the first of these critical assemblies, was followed by Lady Godiva, Jezebel, Flattop, and ultimately Big Ten. As reactor programs came to Los Alamos, design studies and mockups were tested at Pajarito Site. For example, nearly all 16 Rover reactors intended for Nevada tests were preceded by zero-power mockups and proof tests at Pajarito Site. Expanded interest and capability led to fast-pulse assemblies, culminating in Godiva IV and Skua, and to the Kinglet and Sheba solution assemblies.
Date: March 1, 1983
Creator: Paxton, H.C.
Partner: UNT Libraries Government Documents Department

Initial evaluation of molybdenum-rhenium alloy for reactor heat pipes

Description: Molybdenum-rhenium alloys containing less than 15% Re have been investigated for space-nuclear power-system applications. A ductile-brittle transition temperature of less than 135/sup 0/K has been demonstrated for recrystallized Mo-13 wt % Re alloy. Thermophysical properties have been measured over the temperature range from ambient to 1500/sup 0/K and the elastic modulus determined to be 289 GPa. Thermal conductivity of the alloy at temperature has been demonstrated as comparable to pure molybdenum. Fabricability of the material has been demonstrated and an investigation of weld characteristics initiated. Optimization of alloy composition for the planned application is continuing.
Date: January 1, 1983
Creator: Merrigan, M.A. & Lundberg, L.B.
Partner: UNT Libraries Government Documents Department

Comparison of finite-element stress analysis with experimental copper sphere impacts. [NONSAP computer code]

Description: Three copper spheres were impacted on targets of varying surface finishes at 100 m/s. Impact face friction was varied for each test and the impact was photographed with a high-speed camera. Postimpact strains and deformation were measured. A finite-element computer code, NONSAP, was used to model the impact. The best agreement between computer prediction and experiment was obtained using isoparametric elements, a graded mesh, and actual high-strain-rate copper stress-strain data. Frictional conditions at the impact face were also modeled by altering the standard NONSAP code. The most critical test of NONSAP was accurate prediction of experimental impact strains. The best agreement we could obtain had a maximum point-to-point error of 20%, although in general, the comparison was much better. Results of this research indicate that we must know more about material and impact interface friction in order to obtain reliable numerical predictions.
Date: July 1, 1980
Creator: Frantz, C.E.; Hecker, S.S.; Stout, M.G. & Browning, R.V.
Partner: UNT Libraries Government Documents Department

Nuclear power: key to man's extraterrestrial civilization

Description: The start of the Third Millennium will be highlighted by the establishment of man's extraterrestrial civilization with three technical cornerstones leading to the off-planet expansion of the human resource base. These are (1) the availability of compact energy sources for power and propulsion, (2) the creation of permanent manned habitats in space, and (3) the ability to process materials anywhere in the Solar System. In the 1990s and beyond, nuclear reactors could represent the prime source of both space power and propulsion. The manned and unmanned space missions of tomorrow will demand first kilowatt and then megawatt levels of power. Various nuclear power plant technologies will be discussed, with emphasis on derivatives from the nuclear rocket technology.
Date: January 1, 1982
Creator: Angelo, J.A. Jr. & Buden, D.
Partner: UNT Libraries Government Documents Department

MST-5 high rate mechanical testing facility

Description: Selected aspects of five gun systems in the MST-5 High Rate Mechanical Testing Facility are described. 238 plutonium sources heated by a projectile furnace are impacted in a 7 in. gun system which provides impact containment. Failure strains in sheet metals are determined by a biaxial punch test and a tensile test using a 2 in. bore gun. A similar gun has its target chamber in a glove box for testing radioactive materials. High temperatures (less than or equal to1000/sup 0/C) compression stress-strain curves are obtained by a Hopkinson bar where wave dispersion in the bars is corrected in the data reduction. A 40 mm gun is being set up in a glove box train for determining the shock response of hazardous materials using both instrumental and recovery tests.
Date: January 1, 1985
Creator: Frantz, C.E.
Partner: UNT Libraries Government Documents Department

Space nuclear safety and fuels program, November 1981

Description: This technical monthly report covers studies related to the use of /sup 238/PuO/sub 2/ in radioisotope power systems carried out for the Office of Coordination and Special Projects of the US Department of Energy by Los Alamos National Laboratory. Most of the studies discussed here are ongoing. Results and conclusions described may change as the work continues. Published reference of the results cited in this report should not be made without the explicit permission of the person in charge of the work.
Date: April 1, 1982
Creator: Bronisz, S.E. (comp.)
Partner: UNT Libraries Government Documents Department

Space nuclear safety and fuels program. Progress report, April 1981

Description: The studies related to the use of /sup 238/PuO/sub 2/ in radioisotope power systems carried out for the Office of Coordination and Special Projects of the US Department of Energy by the Los Alamos National Laboratory in April 1981 are reported. Impact testing, module handling procedures, and non-destructive test data for encapsulated pellets are reported. (WHK)
Date: July 1, 1981
Creator: Bronisz, S.E.
Partner: UNT Libraries Government Documents Department

Space nuclear-power reactor design based on combined neutronic and thermal-fluid analyses

Description: The design and performance analysis of a space nuclear-power system requires sophisticated analytical capabilities such as those developed during the nuclear rocket propulsion (Rover) program. In particular, optimizing the size of a space nuclear reactor for a given power level requires satisfying the conflicting requirements of nuclear criticality and heat removal. The optimization involves the determination of the coolant void (volume) fraction for which the reactor diameter is a minimum and temperature and structural limits are satisfied. A minimum exists because the critical diameter increases with increasing void fraction, whereas the reactor diameter needed to remove a specified power decreases with void fraction. The purpose of this presentation is to describe and demonstrate our analytical capability for the determination of minimum reactor size. The analysis is based on combining neutronic criticality calculations with OPTION-code thermal-fluid calculations.
Date: January 1, 1985
Creator: Koenig, D.R.; Gido, R.G. & Brandon, D.I.
Partner: UNT Libraries Government Documents Department

Space nuclear safety and fuels program. Progress report

Description: This technical monthly report covers studies related to the use of /sup 238/PuO/sub 2/ in radioisotope power systems. These studies are conducted by Los Alamos National Laboratory for the Office of Coordination and Special Projects of the US Department of Energy. Because most of the studies discussed here are ongoing, results and conclusions may change as the work continues. Published reference of the results cited in this report should not be made without explicit permission from the person in charge of the work.
Date: January 1, 1982
Creator: Bronisz, S.E. (comp.)
Partner: UNT Libraries Government Documents Department

Space nuclear safety and fuels program. Progress report, July 1981

Description: This technical monthly report covers studies related to the use of /sup 238/PuO/sub 2/ in radioisotope power systems carried out for the Office of Coordination and Special Projects of the US Department of Energy by Los Alamos National Laboratory. Most of the studies discussed here are ongoing. Results and conclusions described may change as the work continues. Published reference of the results cited in this report should not be made without the explicit permission of the person in charge of the work.
Date: July 1, 1981
Creator: Bronisz, S.E. (comp.)
Partner: UNT Libraries Government Documents Department

Space nuclear safety and fuels program, December 1981

Description: This technical monthly report covers studies related to the use of /sup 238/PuO/sub 2/ in radioisotope power systems carried out for the Office of Coordination and Special Projects of the US Department of Energy by Los Alamos National Laboratory. Most of the studies discussed here are ongoing. Results and conclusions described may change as the work continues. Published reference of the results cited in this report should not be made without the explicit permission of the person in charge of the work.
Date: April 1, 1982
Creator: Bronisz, S.E. (comp.)
Partner: UNT Libraries Government Documents Department

Reentry thermal testing of light-weight radioisotope heater units

Description: Two Light-Weight Radioisotope Heater Units (LWRHU) were exposed to thermal ramps simulating atmospheric reentry. The helium release rates were measured during each test and modeled after simple diffusion theory. The reentry pulses did not result in swelling of the claddings or degradation of fuel pellets.
Date: March 1, 1982
Creator: Peterson, D.E. & Starzynski, J.S.
Partner: UNT Libraries Government Documents Department

Reentry thermal testing of a general purpose heat source fueled clad

Description: A General Purpose Heat Source (GPHS) module was exposed to heat treatments simulating an isothermal prelaunch condition, followed by thermal pulses corresponding to atmospheric reentry. Helium release rates were determined during each heating and modeled after simple diffusion theory. Following the tests, the module was examined metallurgically with no evidence of swelling of the cladding nor degradation of the fuel.
Date: March 1, 1982
Creator: Peterson, D.E. & Frantz, C.E.
Partner: UNT Libraries Government Documents Department

Transient performance investigation of a space power system heat pipe

Description: Start-up, shut-down, and peak power tests have been conducted with a molybdenum-lithium heat pipe at temperatures to 1500 K. The heat pipe was radiation coupled to a water cooled calorimeter for the tests with rf induction heating used for the input to the evaporator region. Maximum power throughput in the tests was 36.8 kw corresponding to a power density of 23 kw/cm/sup 2/ for the 1.4 cm diameter vapor space of the annular wick heat pipe. The corresponding evaporator flux density was approximately 150 w/cm/sup 2/ over an evaporator length of 40 cm at peak power. Condenser length for the tests was approximately 3.0 m. A variable geometry radiation shield was used to vary the load on the heat pipe during the tests. Results of the tests showed that liquid depletion in the evaporator region of the heat pipe could occur in shut-down and prevent restart of the heat pipe. Changes in surface emissivity of the heat pipe condenser surface were shown to affect the shut-down and re-start limits. 12 figs.
Date: January 1, 1986
Creator: Merrigan, M.A.; Keddy, E.S. & Sena, J.T.
Partner: UNT Libraries Government Documents Department

Thirty-five years at Pajarito Canyon Site

Description: A history of the research activities performed at the Pajarito Canyon Site from 1946 to 1981 is presented. Critical assemblies described include: the Topsy assembly; Lady Godiva; Godiva 2; Jezebel; Flattop; the Honeycomb assembly for Rover studies; Kiwi-TNT; PARKA reactor; Big Ten; and Plasma Cavity Assembly.
Date: May 1, 1981
Creator: Paxton, H.C.
Partner: UNT Libraries Government Documents Department

Potential applicability of the Los Alamos Antiproton Research Program to advanced propulsion

Description: The Los Alamos National Laboratory currently has a research program in antimatter interactions. The immediate objective of the program is to develop the low energy antiproton production capabilities at LEAR and the technology to store antiprotons. The initial experimental goal is to measure the gravitational mass of antiprotons. The technology required for the experiment, however, may allow high-density storage concepts to be experimentally investigated. Analysis of antiproton production over the last 30 years indicates that milligram quantities of antiprotons could conceivably be produced early in the next century. Thus, antiproton propulsion concepts may begin to be feasible. Some results of preliminary calculations pertinent to antiproton powered rocket engines will be presented.
Date: January 1, 1986
Creator: Howe, S.D.; Hynes, M.V.; Prael, R.E. & Stewart, J.D.
Partner: UNT Libraries Government Documents Department

Performance demonstration of a high-power space-reactor heat-pipe design

Description: Performance of a 15.9-mm diam, 2-m long, artery heat pipe has been demonstrated at power levels to 22.6 kW and temperatures to 1500/sup 0/K. The heat pipe employed lithium as a working fluid with distribution wicks and arteries fabricated from 400 mesh Mo-41 wt % Re screen. Molybdenum alloy (TZM) was used for the container. Peak axial power density attained in the testing was 19 kW/cm/sup 2/ at 1465/sup 0/K. The corresponding radial flux density in the evaporator region of the heat pipe was 150 W/cm/sup 2/. The extrapolated limit for the heat pipe at its 1500/sup 0/K design point is 30 kW, corresponding to an axial flux density of 25 kW/cm/sup 2/. Sonic and capillary limits for the design were investigated in the 1100 to 1500/sup 0/K temperature range. Excellent agreement of measured and predicted temperature and power levels was observed.
Date: January 1, 1983
Creator: Merrigan, M.A.; Martinez, E.H.; Keddy, E.S.; Runyan, J. & Kemme, J.E.
Partner: UNT Libraries Government Documents Department

Performance predictions and measurements for space-power-system heat pipes

Description: High temperature liquid metal heat pipes designed for space power systems have been analyzed and tested. Three wick designs are discussed and a design rationale for the heat pipe is provided. Test results on a molybdenum, annular wick heat pipe are presented. Performance limitations due to boiling and capillary limits are presented. There is evidence that the vapor flow in the adiabatic section is turbulent and that the transition Reynolds number is 4000.
Date: January 1, 1981
Creator: Prenger, F.C. Jr.
Partner: UNT Libraries Government Documents Department

Plutonium release from pressed plutonium oxide fuel pellets in aquatic environments

Description: Plutonium oxide pellets (80% /sup 238/Pu, 40 g each) were exposed to fresh water and sea water at two temperatures for 3 y in enclosed glass chambers. The concentrations of plutonium observed in the waters increased linearly with time throughout the experiment. However, the observed release rates were inversely dependent on temperature and salinity, ranging from 160 ..mu..Ci/day for cold fresh water to 1.4 ..mu..Ci/day for warm sea water. The total releases, including the chamber residues, showed similar dependencies. A major portion (typically greater than 50%) of the released plutonium passed through a 0.1-..mu..m filter, with even larger fractions (greater than 80%) for the fresh water systems.
Date: December 1, 1983
Creator: Patterson, J.H.; Steinkruger, F.J.; Matlack, G.M.; Heaton, R.C.; Coffelt, K.P. & Herrera, B.
Partner: UNT Libraries Government Documents Department

Role of nuclear reactors in future military satellites

Description: Future military capabilities will be profoundly influenced by emerging Shuttle Era space technology. Regardless of the specific direction or content of tomorrow's military space program, it is clear that advanced space transportation systems, orbital support facilities, and large-capacity power subsystems will be needed to create the generally larger, more sophisticated military space systems of the future. This paper explores the critical role that space nuclear reactors should play in America's future space program and reviews the current state of nuclear reactor power plant technology. Space nuclear reactor technologies have the potential of satisfying power requirements ranging from 10 kW/sub (e)/ to 100 MW/sub (e)/.
Date: January 1, 1982
Creator: Buden, D. & Angelo, J.A. Jr.
Partner: UNT Libraries Government Documents Department

Rotating film radiators for space applications

Description: A new class of light-weight radiators is described. This radiator consists of a thin rotating envelope that contains the working fluid. The envelope can have many shapes including redundant, foldable configurations. The working fluid, which may be a liquid or a condensable vapor, impinges on the inside surface of the radiator and is driven as a film to the periphery by centrifugal force. Heat is radiated to space by the outer surface of the envelope. Pumps located on the periphery then return the liquid to the power converter. For a 100-MW radiator operating at 800 K, specific mass approx.0.1 kg/kW and mass density approx.2 kg/m/sup 2/ may be achievable. 7 refs., 4 figs., 4 tabs.
Date: January 1, 1985
Creator: Koenig, D.R.
Partner: UNT Libraries Government Documents Department

Microstructural damage produced by helium in aged /sup 238/PuO/sub 2/ fuels

Description: Microstructural damage is produced in aged /sup 238/PuO/sub 2/ fuels used to power radioisotopic heat sources by the generation and release of the helium arising from alpha decay of the fuel. We obtained information about the nature and extent of this damage from metallographic examination of fuel pellets ranging in density from 87 to 94% with a grain size range of 6 to 30 ..mu..m that either were stored at ambient temperature for 18 months and then heated at 900, 1150, or 1360/sup 0/C or were stored at 900, 1150, or 1350/sup 0/C for 27 months. Microstructural damage was not observed in the fuel pellets stored at ambient temperature and then heated at 900/sup 0/C, but grain boundary bubble damage was observed in the pellets stored at ambient temperature and then heated at either 1150 or 1350/sup 0/C. More extensive damage occurred in those pellets heated at 1350/sup 0/C. Four of the higher density pellets (92 and 94% dense) stored at 900/sup 0/C shattered during storage and the rest appeared to be highly strained. The pellets stored at 1150/sup 0/C were damaged only slightly but were somewhat strained and appeared to have released their helium inventory only partially. All pellets stored at 1350/sup 0/C showed swelling and extensive void agglomeration. These data suggest that the best fuel operating temperature, as far as helium damage is concerned, would be approx. 1200/sup 0/C because below this temperature the fuel becomes highly strained and above this temperature the fuel swells ad becomes somewhat friable. Both these situations could adversely affect the impact behavior of the fuel from the standpoint of strength and fines generation.
Date: January 1, 1980
Creator: Land, C.C.
Partner: UNT Libraries Government Documents Department