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Interaction of $sup 238$PuO$sub 2$ heat sources with terrestrial and aquatic environments

Description: Radioisotope thermoelectric generators used in space missions are designed with a great factor of safety to ensure that they will withstand reentry from orbit and impact with the earth, and safely contain the nuclear fuel until it is recovered. Existing designs, utilizing $sup 238$PuO$sub 2$ fuel, have proved more than adequately safe. More data about the interaction of this material with terrestrial and aquatic environments is continually being sought to predict the behavior of these heat sources in the extremely unlikely contact of these materials with the land or ocean. Terrestrial environments are simulated with large environmental chambers that permit control of temperature, humidity, and rainfall using different kinds of soils. Rain falling on thermally hot chunks of $sup 238$PuO$sub 2$ causes the spallation of the surface of the fuel into extremely fine particles, as small as 50 nm, that are later transported downward through the soil. Some of the plutonia particles become agglomerated with soil particles. Plutonium transport is more significant during winter than during summer because evaporation losses from the soil are less in winter. Aquatic environments are simulated with large aquaria that provide temperature and aeration control. Earlier fuel designs that employed a plutonia-molybdenum cermet showed plutonium release rates of about 10 $mu$Ci/m$sup 2$ - s, referred to the total surface area of the cermet. Present advanced fuels, employing pure plutonium oxide, show release rates of about 20 nCi/m$sup 2$ - s in seawater and about 150 nCi/m$sup 2$ - s in freshwater. The temperature of these more advanced heat sources does not seem to affect the release rate in seawater. (auth)
Date: January 1, 1975
Creator: Patterson, J.H.; Nelson, G.B.; Matlack, G.M. & Waterbury, G.R.
Partner: UNT Libraries Government Documents Department

Nuclear heat sources for cryogenic refrigerator applications

Description: Spacecraft cryogenic refrigerators require thermal inputs on the order of 1000 W. First, the characteristics of solar-electric and radioisotope heat source systems for supplying this thermal input are compared. Then the design of a $sup 238$Pu heat source for this application is described, and equipment for shipping and handling the heat source is discussed. (LCL)
Date: June 1, 1975
Creator: Raab, B.; Schock, A.; King, W.G.; Kline, T. & Russo, F.A.
Partner: UNT Libraries Government Documents Department

Design, testing, and fabrication of heat sources for underwater application

Description: The sequence of events in the design, testing and fabrication of a radioisotopic heat source using available $sup 238$PuO$sub 2$ fuel that would be amenable to a Navy 0.5-W (electrical) Radioisotopic Thermoelectric Generator for undersea application is discussed. Various designs were considered as a function of heat leak in order to adopt the most desirable capsule for a volume- constrained application. Testing considerations are discussed for capsule compliance with IAEA/ENEA Safety Series 6 and 33 and 10 CFR 71. (auth)
Date: November 1, 1975
Creator: Luthy, D.F. & Anderson, C.G.
Partner: UNT Libraries Government Documents Department

Publications of LASL research, 1974

Description: This bibliography includes Los Alamos Scientific Laboratory reports, papers released as non-Los Alamos reports, journal articles, books, chapters of books, conference papers (whether published separately or as part of conference proceedings issued as books or reports), papers published in congressional hearings, theses, and U. S. patents. Publications by LASL authors which are not records of Laboratory-sponsored work are included when the Library becomes aware of them. The entries are arranged in sections by broad subject categories; within each section they are alphabetical by title. The following subject categories are included: aerospace studies; analytical technology; astrophysics; atomic and molecular physics, equation of state, opacity; biology and medicine; chemical dynamics and kinetics; chemistry; cryogenics; crystallography; CTR and plasma studies; earth science and engineering; energy (non-nuclear); engineering and equipment; EPR, ESR, NMR studies; explosives and detonations; fission physics; health and safety; hydrodynamics and radiation transport; instruments; lasers; mathematics and computers; medium-energy physics; metallurgy and ceramics technology; neutronic and criticality studies; nuclear physics; nuclear safeguards; physics; reactor technology; solid state science; and miscellaneous (including Project Rover). Author, numerical and KWIC indexes are included. (RWR)
Date: May 1, 1975
Creator: Kerr, A.K.
Partner: UNT Libraries Government Documents Department

Improvement and verification of fast reactor safety analysis techniques. Progress report, September 1, 1975--November 31, 1975

Description: A number of improvements and refinements have been made to the VENUS-II analysis of the KIWI-TNT experiment. The final calculations for this study are now being performed. Areas of difference that appeared during the initial VENUS- II/PAD intercomparison study have been investigated and largely resolved. In particular, the treatment of the energy-of-vaporization was examined and found not to have a significant effect on the calculated temperatures. The next round of comparison calculations are currently underway. A study aimed at comparing and evaluating different methods of characterizing work-energy or damage- potential of core-disruptive accidents has been initiated.
Date: January 1, 1975
Creator: Jackson, J. F.
Partner: UNT Libraries Government Documents Department

Improvement and verification of fast reactor safety analysis techniques

Description: An initial analysis of the KIWI-TNT experiment using the VENUS-II disassembly code has been completed. The calculated fission energy release agreed with the experimental value to within about 3 percent. An initial model for analyzing the SNAPTRAN-2 core disassembly experiment was also developed along with an appropriate equation-of-state. The first phase of the VENUS-II/PAD comparison study was completed through the issuing of a preliminary report describing the results. A new technique to calculate a P-V-work curve as a function of the degree of core expansion following a disassembly excursion has been developed. The technique provides results that are consistent with the ANL oxide-fuel equation-of-state in VENUS-II. Evaluation and check-out of this new model are currently in progress. (auth)
Date: January 1, 1975
Creator: Jackson, J.F.
Partner: UNT Libraries Government Documents Department