SNAP PROGRAMS. Quarterly Progress Report No. 1 for October 22-December 31, 1959
An analysis was made of the SNAP III generator to determine the cause of failure, and the test specifications were revised in line with the findings. During calibration and demonstration runs with the SNAP III-A generator, a leak developed in the valving mechanism of the variable heatdump system. An examination disclosed that the valve was not satisfactory, so the generator was returned to the manufacturer for repair. A description is given of the generator, along with a performance evaluation program. A discussion is given of the work performed in advancing the technology of thermionic converters, specifically to increase efficiency by developing better emitter and collector materials and by reducing heat losses. Investigations were made in the areas of cesium diodes, effects of cesium on materials, electrical heaters, diffusion of gases through metals, and work function tests. Work done on the development of low-power thermionic generators included prototype development, heat-transfer studies and tests, vacuum tests in prototype shells, cathode and sapphire creep tests, metals, and work function tests. Work done on the development of low- power thermionic generators included prototype development, heat-transfer studies and tests, vacuum tests in prototype shells, cathode and sapphire creep tests, a parametric study, the development of molybdenum fuel capsules, heliarc welding of molybdenum fuel capsules, hazards studies on Ce/sup 144/ thermionic units, iabrication of a containment cask for Ce/sup 144/ units, and tueling molybdenum capsules with Ce/sup 144/ pellets. Investigations were made of the operational capabilities of SNAP-III type generators through tests simulating the anticipated environments to obtain information for conceptual designs to produce 2 to 5 watts of electrical power. Accomplishments in the development of a 1-watt nuclear power supply include the establishment of the over-all generator configuration, the sizing and arrangement of the Pu/sup 238/ fuel, the analysis for helium pressure build-up within the fuel capsule, the selection and sizing of thermoelectric elements, a radiator design, the insulation arrangement, and the thermal analysis of the configuration. Work penformed on the conceptual design of a 100-watt thermoelectric generator was devoted to heattransfer analysis, isotope requirements, basic configuration design studies, selection and optimization of thermoelectric generator parameters, radiation shield design, evaluation of fuel containment problems under conditions of helium evolution, and the measurement of thermoelectric materials data. Analyses of heat-transfer and radiation shielding and studies of generator and component designs resulted in an optimum configuration for a 13-watt generator of the radiative-cylindrical type. The weight of the generator, exclusive of voltage regulation equipment, is -8.6 lb; the over-all efficiency is 6.2%. Fuel-technology development studies were directed toward a parametric study of radioisotopes suitable for isotopic power, the feasibility of processing the selected isotopes, and the selection of purification procedures. (B.O.G.)
- Research Organization:
- Martin Co. Nuclear Div., Baltimore
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AT(30-3)-217
- NSA Number:
- NSA-15-012652
- OSTI ID:
- 4079689
- Report Number(s):
- MND-P-3009-1
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-61
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALUMINUM OXIDES
CATHODES
CERIUM 144
CESIUM
CONVERSION
CREEP
DIFFUSION
DIODES
ELECTRIC ARCS
ELECTRICITY
ELECTRON TUBES
ELECTRONICS
FAILURES
FUELS
GASES
GENERATORS
HEAT EXCHANGERS
HEAT TRANSFER
HELIUM
LEAKS
LOSSES
METALS
MOLYBDENUM
PELLETS
PLANNING
PLUTONIUM 238
PRESSURE
RADIOISOTOPES
REFINING
SAFETY
SAPPHIRE
SHIELDING
SNAP SYSTEMS
SPACE VEHICLES
TESTING
THERMAL INSULATION
THERMIONICS
THERMODYNAMICS
THERMOELECTRICITY
VACUUM
VALVES
VESSELS
WELDING
WORK FUNCTIONS
NESDPS Office of Nuclear Energy Space and Defense Power Systems