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Earth sciences waste disposal investigations, January--June 1966

Description: An evaluation is given of the ground water contamination resulting from disposal of plant effluents at Hanford. Analytical results are presented for gross beta activity in the unconfined ground water aquifer and gross beta activity at depths in the ground water. Results are given where concentrations of radionuclides are above the routine detection limit for gross beta. The average concentrations detected during the previous report period are listed for comparison. (JSR)
Date: November 1, 1966
Creator: Eliason, J R
Partner: UNT Libraries Government Documents Department

Research and development activities waste fixation program. Quarterly progress report, July--September 1975

Description: Engineering-scale in-canister melting tests were made to evaluate the use of silicon to prevent formation of water-soluble molybdate phases in melts. The tests demonstrated that silicon metal powder added to the feed stock effectively prevents formation of such phases. A test also showed that coatings of ZrO$sub 2$ or chromium carbide on stainless steel canisters prevent oxidation during the in-can melting process. Thermal analysis of canister design concepts examined effects of type of storage, use of fins, emissivity, canister size and cracks in glass. Pressurization tests show that all types of calcine can produce very high pressures within the canister unless the calcine is post-treated at temperatures greater than 850$sup 0$C. Initial studies on the effects of alpha and recoil bombardment (from $sup 244$Cm doping) on devitrification of waste- containing glass were completed. The devitrification behavior of a waste-bearing zinc orthosilicate glass is being studied using optical microscopy, electron microprobe, and x-ray diffraction examination. Fine calcine particles were agglomerated into larger particles suitable for coating via chemical vapor deposition. Thermal stability tests of nickel and Cr$sub 7$C$sub 3$ coatings on waste calcine have been conducted, and deterioration has occurred at temperatures as low as 500$sup 0$C. Waste-containing pellets were successfully coated by plasma spraying Al$sub 2$O$sub 3$ powder. Calculations indicate that plasma spraying of large pellets is feasible on a production scale. Seven scoping runs made with a disc pelletizer indicate that it can provide a simple, inexpensive process for making high-quality pellets from calcine-frit powders. Risk assessment was used to systematically identify dominant sequences for the accidental release of radionuclides during the solidification, basin storage, and rail transport activities of high-level waste management. (JGB)
Date: January 1, 1976
Creator: McElroy, J. L.
Partner: UNT Libraries Government Documents Department

Program plan for comprehensive characterization of solidified high-level wastes

Description: An experimental plan is described for in-depth characterization of canistered solidified waste forms for the storage and disposal of high-level radioactive wastes. The plan is being considered for silicate glass forms at PNL. The basic aspects of the plan have general application and can be applied to other candidate waste forms as well. The plan is designed to define the behavior of waste canisters and their contents during anticipated handling, storage, and disposal regimes. Particular emphasis is placed on long-term thermal and radiation effects. A 10-year period is projected for complete characterization of any one basic type of waste form, e.g., silicate glass cast in metal canisters. A preponderance of the laboratory effort occurs in the first 5 years. It is assumed that shortly thereafter an operating solidification plant will be available, so that much of the second 5 years can be devoted to corroborative tests made on representative canisters of actual high-level waste. Manpower requirements are estimated at 65 scientist man-years during the first 5 years and 30 scientist man-years during the second 5 years. (auth)
Date: December 1, 1975
Creator: Mendel, J E
Partner: UNT Libraries Government Documents Department

Chemical Engineering Division waste management programs. Quarterly report, January--March 1975

Description: Development work on the study of consolidation techniques for Zircaloy fuel-cladding hulls included scouting tests on volatility schemes for separating the zirconium as the volatile tetrachloride and ignition tests on several Zircaloy materials to further characterize the pyrophoric behavior of Zircaloy. All tests were with nonirradiated metal pending acquisition of irradiated samples. Installation is nearly complete of a glovebox facility for studies on the salvage of alpha-contaminated metals by pyrochemical methods. Disposal of a major portion of fission product tritium formed in light water reactor fuels by deep- well injection of the low-level aqueous waste from plants reprocessing such fuels is being evaluated. The question of siting is a very important factor in determining the feasibility of this particular disposal option. A review is given of the status of information for U. S. sedimentary basins, the areas most likely to be generally suitable for siting of waste wells. Work on the reliability of high-level-waste canisters included an examination of creep, shot- peening, and subcooling of the filler canister below storage temperatures, as methods of relieving stresses induced in canisters due to differential contraction of canister and glass during cooling. A method was investigated for relieving stresses in calcine-filled canisters. Properties of fission product oxides were examined to elucidate possible adverse corrosive effects at the canister-waste interface. (LK)
Date: June 1, 1975
Creator: Steindler, M.J.; Levitz, N.M.; Mecham, W.J.; Seefeldt, W.B.; Trevorrow, L.E.; Winsch, I.O. et al.
Partner: UNT Libraries Government Documents Department

Radiation effects in solidified high-level waste. Part I. Stored energy

Description: Buildup and release behavior of radiation-induced stored energy was investigated for several synthetic solidified high-level waste forms: two borosilicate glass formulations, calcine, calcine on Al$sub 2$O$sub 3$, and a hot press compact of 50 percent waste oxide--50 percent quartz. Fused silica and Al$sub 2$O$sub 3$, without waste oxides, were also investigated. Average heat capacities of some of the materials were also measured. The materials were irradiated either by internal alpha radiation $sup 244$Cm or by neutron irradiation in ORR. The irradiations simulated the effects resulting from self- irradiation of the waste for storage periods up to nearly 1000 years for wastes from PWR-UO$sub 2$ fuel [equivalent to periods of approximately 10 years for mixed wastes from UO$sub 2$ fuel ($sup 2$/$sub 3$) and plutonium recycle fuel ($sup 1$/$sub 3$)]. Results showed that the amounts of stored energy over a period of about 10 years at relatively low storage temperatures following reprocessing are such that only moderate temperature increases (less than 200$sup 0$C) in the wastes would occur in the event of sudden release of the stored energy. Extrapolation to longer storage times in a geologic repository indicated that saturation of energy storage would occur at 50 cal/g or less for each of the waste types; the $delta$T corresponding to release of 50 cal/g would be about 250$sup 0$ for most of the waste types. The experimental results also showed no apparent way in which a sudden release could occur except as a result of sudden large increases in waste temperature caused by a heat source other than the stored energy.
Date: January 1, 1976
Creator: Roberts, F P; Jenks, G H & Bopp, C D
Partner: UNT Libraries Government Documents Department