38 Matching Results

Search Results

Advanced search parameters have been applied.

HERMETIC SEALING PROBLEMS IN A SMALL BOILING WATER REACTOR

Description: The results of an extensive survey of the literature and of the subsequent analysis permit the prediction of the rate of radiolytic decomposition of the water coolant. Due to the difficulty in assessing the rate of the back reactions, fundamental data from water radiation chemistry could not be applied in a straightforward manner. It proved more expedient to employ the actually observed decomposition rate data from other boiling water reactors and to extrapolate to the operating conditions of SNAP 4. By this approach, the water decomposition rate was estimated to be 5 lbs/day. To assure adequate capacity under all conditions, the catalyst bed was sized to handle twice this rate. Based on the design method of Garber and Peebles, a catalyst bed 3 inches in diameter by 12 inches long, consisting of platinum-coated alumina pellets, appears ample. Operation of the recombiner in a closed recirculatory system was analyzed. It appears that an excess of hydrogen will result as oxygen is preferentially consumed in the initial corrosion process (metal oxidation). Once a stable oxide film is established on the stainless steel surfaces and the excess hydrogen is drawn from the system, the recombiner can thereafter handle the radiolytic gases satisfactorily. (auth)
Date: March 12, 1964
Creator: Haroldsen, G.O.
Partner: UNT Libraries Government Documents Department

FURTHER DEVELOPMENT OF MODIFIED MONOSODIUM TITANATE, AN IMPROVED SORBENT FOR PRETREATMENT OF HIGH LEVEL NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

Description: High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove Cs-137, Sr-90, and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include caustic side solvent extraction, for Cs-137 removal, and sorption of Sr-90 and alpha-emitting radionuclides onto monosodium titanate (MST). The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes Pu-238, Pu-239, and Pu-240. This paper describes recent results from the development of an improved titanate material that exhibits increased removal kinetics and effective capacity for Sr-90 and alpha-emitting radionuclides compared to the baseline MST material.
Date: January 12, 2011
Creator: Taylor-Pashow, K.; Hobbs, D.; Fondeur, F. & Fink, S.
Partner: UNT Libraries Government Documents Department

Compact thermoelectric converter. Quarterly progress report, July 1, 1968- -September 30, 1968. Phase II-C

Description: Declassified 30 Aug 1973. An initial analysis of experimental heatup data was compiled to determine the success of module experiments designed to triple the voltage power ratio of standard TEM-9 modules. Accomplishment of this design improvement is extremely significant in the development of tabular module systems having lower power applications. With the increased voltage to power ratio, power conditioning devices will not be required to step up the module output voltage to a more usable level. Heatup data from TEM9AE S/N-1, employing 0.030-inch lead telluride washers and 0.0015-inch mica insulators, correlate very closely with performance calculations. A study was initiated to determine an optimum design for a module to be internally fueled using cobalt60. In addition, alterations to the calculation model TEMOD were made to handle the effects of gamma heating within the lead telluride washers. An experimental test program was defined which would verify the validity of the mathematical model. Additional analytical work was accomplished to correlate predicted axial heat transport rates of heat pipes with experimental data. A study of sodium heat pipe performance data revealed that a sonic vapor velocity can occur in the region between evaporator and condensor sections of the heat pipe to produce a limit to the axial heat transfer rate. Evaluation of niobium contacts show them to be considerably more compatible with p-type lead telluride than iron contacts. However, the niobium does not yield absolute electrical stability and, as a result, no further work beyond the present analysis is contemplated. Six modules containing solid tungsten conductors were placed on test at elevated temperatures. Although degradation rates measured were the lowest yet recorded for modules employing TEGS-2P material, for temperatures above 1100 deg F the most stable operation is achieved through the substitution of TEGS-3P.material for TEGS-2P material. (auth)
Date: October 12, 1968
Partner: UNT Libraries Government Documents Department

NRX/EST Test Prediction Report (U)

Description: The objectives of this test are to demonstrate the ability of a NERVA-type engine system to bootstrap from a tank pressure of 45 PSIA to full power, to study the stability of the control systems, to obtain high power mapping data and to demonstrate the stability of the core at high power. System response measurements will be conducted at both low and high power points to study the control systems. The operation of the engine at 4000{sup o}R chamber temperature will be mapped from design pressure down to the pressure at which the tie rod temperature limit is reached.
Date: January 12, 1966
Partner: UNT Libraries Government Documents Department