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SNS source term evaluation program

Description: Plutonium-238 is currently used in the form of a pure refractory oxide as a power source on a number of space vehicles that have already been or will be launched during the next few years. Results are reported on aerosol experimental studies, that concern interactions between soils and $sup 238$PuO$sub 2$ aerosols which might be created in a space launch abort environment; marine animal studies, which concern support activities for the SNS underwater experiments; ultrafilterability studies, concerns in vitro solubility tests of $sup 238$PuO$sub 2$ as a function of time, temperature, suspension concentration, and molality of solvent; and mathematical modeling, which concerns support of the SNS safety effort to standardize analytical techniques for system risk analysis, including the modeling or biological data obtained from inhalation exposure of rodents and dogs to $sup 238$PuO$sub 2$ aerosols and comparison of the models to that developed for $sup 239$PuO$sub 2$. (CH)
Date: January 1, 1976
Creator: Craig, D.K.; Cannon, W.C.; Filipy, R.E.; Powers, G.J. & Dionne, P.J.
Partner: UNT Libraries Government Documents Department

Plutonium Isotopic Measurements by Gamma-Ray Spectroscopy

Description: The nondestructive assay of plutonium is important as a safeguard tool in accounting for stategic nuclear material. Several nondestructive assay techniques, e.g., calorimetry and spontaneous fission assay detectors, require a knowledge of plutonium and americium isotopic ratios to convert their raw data to total grams of plutonium. This paper describes a nondestructive technique for calculating plutonium-238, plutonium-240, plutonium-241 and americium-241 relative to plutonium-239 from measured peak areas in the high resolution gamma-ray spectra of solid plutonium samples. Gamma-ray attenuation effects have been minimized by selecting sets of neighboring peaks in the spectrum whose components are due to the different isotopes. Since the detector efficiencies are approximately the same for adjacent peaks, the accuracy of the isotopic ratios are dependent on the half-lives, branching intensities and measured peak areas. The data presented describes the results obtained by analyzing gamma-ray spectra in the energy region from 120 to 700 keV. The majority of the data analyzed was obtained from plutonium material containing 6% plutonium-240. Sample weights varied from 0.25 g to approximately 1.2 kg. The methods have also been applied to plutonium samples containing up to 23% plutonium-240 with weights of 0.25 to 200g. Results obtained by gamma-ray spectroscopy are compared to chemical analyses of aliquots taken from the bulk samples.
Date: May 1, 1976
Creator: Haas, Francis X. & Lemming, John F.
Partner: UNT Libraries Government Documents Department

Isotope Heat Source for Dynamic Power Systems

Description: A design is described for automatically limiting the temperature excursion of an isotope heat source following loss of cooling in dynamic space power systems. Its purpose is to keep the resultant temperature rise small enough and brief enough to prevent fuel capsule degradation: i.e., not merely to avoid meltdown, but also to retain adequate capsule ductility to ensure fuel retention in case of subsequent reentry and earth impact. Applications of the concept in designs of heat source assemblies for Brayton, Rankine, and Stirling cycle power systems are illustrated.
Date: September 1, 1976
Creator: Schock, Alfred
Partner: UNT Libraries Government Documents Department

Nuclear Heat Source for Cryogenic Refrigerators in Space

Description: To supply the heat input required by space-borne cryogenic refrigerators, a possible design for a reliable Pu-238 radioisotope heat source, based on state-of-the-art technology, is described. The isotope heat source, which makes use of existing fuel elements, would replace electrical heaters powered by solar panels and batteries, without requiring redesign of the refrigerators. The heat source contains all necessary safety features, and also a simple thermal control system to permit refrigerator shut-down for indefinite duration. A system for thermal interfacing with the spacecraft, the booster, and ground support is also described. The isotope heaters are compared with solar-electric heaters for the same application, and found to result in very significant weight and size savings.
Date: January 1, 1976
Creator: Raab, B.; Schock, Alfred & King, W. G.
Partner: UNT Libraries Government Documents Department

Warm hydroforming of iridium + 0.3 wt % tungsten hemishells

Description: A technique for the production of iridium alloy hemispherical shells to be used for the primary encapsulation of plutonium-238 oxide spheres is described. The encapsulated spheres, 24 per heat source, provide the thermal heat used to drive thermoelectric converters which supply power for the Department of Defense's LES 8/9 satellites. The technique used a standard production type Hydroform machine converted for hot tooling. The iridium alloy discs were canned in stainless steel waster sheets of a larger size than the iridium discs and separated from the latter by tantalum foil barrier discs. The stainless steel was electron beam welded around the edge to form an envelope. The iridium disc assembly was heated to approximately 900$sup 0$C and the tooling to approximately 500$sup 0$C. After forming, the iridium shell was cut to length while in the waster sheet; and the latter was removed by dissolving in hot aqua regia. After removal of the waster sheets, the hemishells were cleaned and heat treated. Production efficiency reached a level of better than 95 percent and was maintained to produce some 600-odd hemishells.
Date: March 1, 1976
Creator: Wyder, W.C.
Partner: UNT Libraries Government Documents Department

900-755 degradation model for an RTG with a silicon-germanium thermopile. [DEGRA computer code]

Description: This report describes the RTG degradation mechanisms which have been identified as occurring in thermoelectric power generating systems that use the alloy of silicon germanium as the thermoelectric material and that incorporate a multifoil thermal insulation system. The synergetic effects of all of the identified degradation mechanisms are determined by a computer code, DEGRA, which calculates the available generator output power as a function of generator operating time.
Date: September 1, 1976
Creator: Stapfer, G.
Partner: UNT Libraries Government Documents Department

Decontamination of HEPA filters. Quarterly report, October, November, December 1976

Description: Mound Laboratory, in its many years of plutonium processing experience, has recovered over 150 kilograms of plutonium-238. Much of this material has been recovered from HEPA filters and other secondary wastes such as sludge, slag, etc. The basic recovery nitric acid leach process at Mound for the decontamination of HEPA filters will be improved and modified i this project for processing filters from the Nuclear Fuel Cycle. Efforts this past quarter were directed toward determining the dissolution parameters of plutonium in HNO{sub 3} which included a study of the optimum acid concentration and optimum dissolution temperature.
Date: December 31, 1976
Partner: UNT Libraries Government Documents Department

Tentative method for the determination of plutonium-239 and plutonium-238 in water (by a coprecipitation anion exchange technique)

Description: A procedure for the determination of plutonium 238 and plutonium 239 in water is described. The procedure consists of a coprecipitation, an anion exchange separation and electrodeposition, followed by alpha pulse height analysis. More specifically, the sample is acidified with nitric acid and plutonium-242 is added as a tracer before any chemical separations are performed. Iron is added to the water as iron (III) and the plutonium is coprecipitated with the iron as ferric hydroxide by adding ammonium hydroxide. After decantation and centrifugation, the ferric hydroxide precipitate containing the coprecipitated plutonium is dissolved and the solution is adjusted to 8M in HNO{sub 3} for anion exchange separation. When the sample fails to dissolve because of the presence of insoluble residue, the residue is treated by a rigorous acid dissolution using concentrated nitric acid and hydrofluoric acids. The sample is poured over an anion exchange column. The iron and most other elements that might be present pass through the column. Thorium is removed from the column with 12 M hydrochloric acid and then the plutonium is eluted by reducing it to plutonium (III) with the iodide ion. The plutonium is electrodeposited onto a stainless steel slide for counting by alpha pulse height analysis using a silicon surface barrier detector. From the recovery of the plutonium-242 tracer, the absolute amounts of plutonium-238 and plutonium-239 can be calculated, and from the volume of sample analyzed the concentrations of these two isotopes in the water sample can be calculated.
Date: September 17, 1976
Creator: Bishop, C. T.; Brown, R.; Glosby, A. A.; Phillips, C. A. & Robinson, B.
Partner: UNT Libraries Government Documents Department

Annual highlights report for 1975

Description: Mound`s work through the year centered on development, production, and surveillance of weapon components; development and assembly of plutonium-238 heat sources; production and sales of stable isotopes; separation of special radioisotopes; development of Safeguards procedures for nuclear materials control; and development of improved techniques for effluent control and waste management. Reductions in funding for certain programs led to reductions in the work force during the last half of the year. Year end employment was 1542, down 157 from January 1. Application of the Zero-Base Budgeting concept, particularly in the overhead areas, enabled the Laboratory to manage the funding reductions with minimal impact on vital services.
Date: March 1, 1976
Creator: Flitcraft, R. K. & McClain, J. R.
Partner: UNT Libraries Government Documents Department

Parameter study of dual-mode space nuclear fission solid core power and propulsion systems, NUROC3A. AMS report No. 1239c

Description: The three-volume report describes a dual-mode nuclear space power and propulsion system concept that employs an advanced solid-core nuclear fission reactor coupled via heat pipes to one of several electric power conversion systems. The NUROC3A systems analysis code was designed to provide the user with performance characteristics of the dual-mode system. Volume 3 describes utilization of the NUROC3A code to produce a detailed parameter study of the system.
Date: September 13, 1976
Creator: Smith, W.W. & Layton, J.P.
Partner: UNT Libraries Government Documents Department

SrF/sub 2/ capsule design for heat engine applications. [WESF capsule]

Description: A number of design changes were considered to improve heat transfer characteristics of the WESF capsule. This capsule was evaluated in a design concept for use as a heat source in a helium-working fluid, Stirling heat engine. Throughout the study a heat block concept was used. The helium was assumed to be at 1200/sup 0/F and 200 atm. The upper temperature limit at the fuel-metal interface was assumed to be 800/sup 0/C because of material compatibility considerations. A 0.6-in. thick outer can was considered since it may be required for impact resistance and high pressure accident environments. The modifications considered were: (1) filling all gaps with helium rather than air, (2) filling gaps with powdered metal, and (3) adding a third can to the existing capsule. Also, enhancement of emissivity on metal surfaces was considered as a possible modification.
Date: April 1, 1976
Creator: Lester, D.H.
Partner: UNT Libraries Government Documents Department

Mathematical model for the preliminary analysis of dual-mode space nuclear fission solid core power and propulsion systems, NUROC3A. AMS report No. 1239a

Description: The three-volume report describes a dual-mode nuclear space power and propulsion system concept that employs an advanced solid-core nuclear fission reactor coupled via heat pipes to one of several electric power conversion systems. Such a concept could be particularly useful for missions which require both relatively high acceleration (e.g., for planetocentric maneuvers) and high performance at low acceleration (e.g., on heliocentric trajectories or for trajectory shaping). The first volume develops the mathematical model of the system.
Date: June 30, 1976
Creator: Grey, J. & Chow, S.
Partner: UNT Libraries Government Documents Department

Specification requirements summary for the Brayton Isotope Power System (BIPS) Ground Demonstration System (GDS)

Description: This document provides a summary of the required program specifications and procedures for the ERDA Phase I Brayton Isotope Power System (BIPS) Program. Also included are document definitions, descriptions, and formats, and a listing of commonly used abbreviations. This document is intended to be used as a guide in document preparation and control.
Date: February 10, 1976
Creator: Thompson, E.E.
Partner: UNT Libraries Government Documents Department

Thermoelectric materials evaluation program. Quarterly technical task report No. 46. [Minnesota Mining and Manufacturing Company, Technical Ceramic Products Div. , St. Paul, 10/1 to 12/31/1975]

Description: This forty-sixth Technical Task Report prepared under contract E(11-1)-2331 with the U.S. AEC and U.S. ERDA covers the performance period from October 1, 1975, to December 31, 1975. Highlights include the following tasks: N-type material development (material synthesis--gadolinium selenide compositions; material analyses; material processing; element contacting; ingradient compatibility and life testing; mechanical property characterization), TPM-217 P-type characterization (material preparation and analyses; element contacting; thermodynamic stability; isothermal chemical compatibility; ingradient compatibility and ingradient life testing; performance mapping of contacted and noncontacted elements; high-temperature partitioned P-legs), couple development (design and development of TPM-217/gadolinium selenide rare earth chalcogenide couple; design and development of TPM-217/3N-PbTe couples; advanced generator concepts), module development, liaison with Jet Propulsion Laboratory and material supply, liaison with GGA, and program management. 24 figures, 27 tables. (RWR)
Date: February 1, 1976
Creator: Hampl, E.F. Jr.
Partner: UNT Libraries Government Documents Department

Proven reliability of the gas-turbine engine. BIPS Phase 1

Description: The background, capabilities and experience of the Garrett Corp. in designing, developing, manufacturing and testing gas turbines and related systems are described, and the requirements for and components of the Brayton Isotope Power System (BIPS) for space vehicles are outlined. Data on the compressor and turbine, alternator, bearings, recuperator, radiator, heat source assembly, and control systems are presented. (LCL)
Date: November 1, 1976
Partner: UNT Libraries Government Documents Department

Computer code and users' guide for the preliminary analysis of dual-mode space nuclear fission solid core power and propulsion systems, NUROC3A. AMS report No. 1239b

Description: The three-volume report describes a dual-mode nuclear space power and propulsion system concept that employs an advanced solid-core nuclear fission reactor coupled via heat pipes to one of several electric power conversion systems. The second volume describes the computer code and users' guide for the preliminary analysis of the system.
Date: June 30, 1976
Creator: Nichols, R.A. & Smith, W.W.
Partner: UNT Libraries Government Documents Department