STRONTIUM 90 POWER PROJECT. Quarterly Progress Report III covering period April 15, 1959 through July 15, 1959

Technical Report · Wed Jul 01 00:00:00 EDT 1959

OSTI ID:4240252

As a result of information received from ORNL, early strontium titanate heat elements may contain macro quantities of stable Ca and Ba. Since these contaminants could affect the solubility of strontium titanate to the detriment of safe containment, test heat elements were prepared containing varying amounts of these elements. In addition to solubility measurements in fresh and sea water, samples are being examined to determine the physical properties of this new mixture. The ceramic investigation showed that heat elements made from pure strontium titanate would be superior to any cermet of that compound. Metal additions below 30 wt.% had no effect on thermal conductivity and did, in some cases, increase the solubility of the heat element by forming soluble complex compounds with ihe otherwise insoluble strontium titanate. The process for fabricating strontium titanate heat element increments was refined to produce uniform pellets of optimal density, homogeneity, and Sr tie up. To assure future availability of pure Sr/sup 90/ in kilocurie quantities, the separation of this waste fission product is under laboratory scale investigation by ion exchange. Data compiled on the physical and chemical propperties of strontium titamate are completed. Results indicate that this choice of heat element compound will possess those properties required for the safe utilization of a Sr/sup 90/ heat source. The thermal conductivity of this compound decreases only slightly with increased temperature, thereby assuring a generator core that will not melt on accidental temperature excursion. The solubility of strontium titanate in fresh and sea water was measured over a period of 100 days. At the end of this time there was absolutely no strontium detectable in the fresh water and only 10 ppb in the sea water. Such information indicates that unclad strontium titanate heat elements would require centuries to dissolve, during which time natural radioactive decay would have reduced kilocurie quantities of Sr/sup 90/to the millicurie level. A modified sea design with a removable biological shield will make possible the use of this power supply in marine enviromnents where weight is a critical factor. This unit will employ less Sr/sup 90/ with longer thermocouples. The operational shell will be of sufficient thickness to be resistant to deep sea pressure. During storage, it will be encased in a second nickel shield with a liquid metal film between to act as a heat transfer agent. It is anticipated that both sea application devices will operate at approximately seven percent efficiency. Hazards evaluation of the land-based application is in progress. Both structural and radiation integrity are being evaluated. Data obtained during the experimental phases have been interpreted to determine the resistance of a Sr/sup 90/ generator to natural and man-made disasters. (For preceding period see MND-SR-1673.) (auth)

• Research Organization: Martin Co. Nuclear Div., Baltimore
• DOE Contract Number: AT(30-1)-2220, TASK II
• NSA Number: NSA-14-001182
• OSTI ID: 4240252
• Report Number(s): MND-SR-1674
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-60
• Country of Publication: United States
• Language: English

Related Subjects

GENERAL AND MISCELLANEOUS
ACCIDENTS- BARIUM- - CALCIUM- CERAMICS- CERMETS- COMPLEXES- CONTAMINATION- DENSITY- ENVIRONMENT- FABRICATION- FILMS- HEATING- ION EXCHANGE- LIQUID METALS- MEASURED VALUES- METALS- NICKEL- PELLETS- PLANNING- POWER- PRESSURE- RADIATION PROTECTION- SAFETY- SEA- SHELLS- SHIELDING- SOLUBILITY- STRONTIUM OXIDES- STRONTIUM 90- TEMPERATURE- TESTING- THERMAL CONDUCTIVITY- THERMOCOUPLES- THICKNESS- TITANATES- USES- WATER- WEIGHT
ACCIDENTS- BARIUM- CALCIUM- CERAMICS- CERMETS- COMPLEXES- CONTAMINATION- DENSITY- ENVIRONMENT- FABRICATION- FILMS- HEATING- - ION EXCHANGE- LIQUID METALS- MEASURED VALUES- META