DISCLAIMERPortions of this document may be illegible in electronic image products. Images are produced from the best available original document. AbstractSludge washing and parametric caustic leaching tests were performed on sludge samples fiom five Hadord tanks: B-101, . These studies examined the effects of both dilute hydroxide washing and caustic leaching on the composition of the residual sludge solids.the P, and 63 to 99% of the Na from the H d o r d tank sludge samples examined. The partial removal of these elements was likely due to the presence of water-soluble sodium salts of aluminate, chromate, hydroxide, nitrate, nitrite, and phosphate, either in the interstitial liquid or as dried salts.The response of Al to caustic leaching was v~a b l e .When leached with 3 M NaOH for one week at 95 to 100°C, the cumulative Al removals were 62,99,61,95, and 89% for the B-101, BX-110, BX-112, (2-102, and S-101 samples, respectively. For the B-101 and the BX-110 samples, Al dissolution was rapid, with the AI concentrations reaching >SO% of their final values within the first 5 h of leaching.Interestingly, for the BX-112 sample, A I removal decreased with increasing leaching time and temperature-a trend contrary to what was expected. We hypothesize that this is due to the formation of aluminosilicate minerals. For the C-102 sludge, there was clearly a benefit in increasing the NaOH concentration from 1 M to 3 M. Leaching with 1 M NaOH removed -20 to 30% of the Al from the dilute hydroxide-washed solids while 3 M NaOH removed -95% of the Al. Aluminum dissolved slowly from the S-101 sample, which is consistent with boehmite being the predominant Al-containing phase.all the sludge samples examined, Cr removal during caustic leaching was highly time-dependent, but the Cr dissolution did not fit simple zero-, first-, or second-order kinetic models. Consistent trends in the effects of temperature and hydroxide concentration on Cr removal were difficult to discern. P from the sludge samples examined. Except for the Tank C-102 sample, cumulative P removals,were 285%. For C-102, the cumulative P removals were only -60%. Increasing temperature or hydroxide concentration generally did not result in large improvements in P removal; that is, relatively mild conditions tended to be adequate to remove P. 'The projected 137Cs content for the low-level waste (LLW) resulting fiom immobilizing the sludge washinglleaching solutions would range fiom -50 to -540 CVm3 for the samples examined. Although these concentrations are below the U.S. Nuclear Regulatory Commission Class C LLW limit of 4,600 Cum3, they are well above the proposed guideline of 3 Cum3 for the immobilized LLW product fiom the proposed private-processing facilities. Thu, it is likely that I3'Cs will need to be removed fiom the washing and leaching solutions. On the other hand, transuranic and Sr removal would likely not be required for the washing and leaching solutions fiom processing the sludges examined here. An estimate of high-level waste (HLW) glass produced in im...

The uniquely well-resolved (99)Tc NMR spectrum of the pertechnetate ion in liquid water poses a stringent test of the accuracy of ab initio calculations. The displacement of the (99)Tc chemical shift as a function of temperature has been measured over the range 10-45 degrees C for the three isotopomers Tc((16)O)(4)(-), Tc((16)O)(3)((18)O)(-), and Tc((16)O)(3)((17)O)(-) at natural oxygen isotope abundance levels, and in addition the temperature dependence of the Tc-O scalar coupling was determined for the Tc((16)O)(3)((17)O)(-) isotopomer. Values for these parameters were computed using relativistic spin-orbit density functional theory with an unsolvated ion approximation and with treatments of the solvated ion based on the COnductor-like Screening MOdel (COSMO) approach. The temperature and isotope dependence of (99)Tc NMR parameters inferred by these methods were in good quantitative agreement with experimental observations. The change in the Tc-O bond length associated with the changes in temperatures considered here was determined to be of the order of 10(-)(4) A. Vibrational energies and Tc-O bond lengths derived from these models also compare favorably with previous experimental studies.

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This repoq was preparedas an accountof work sponsoredby an agencyof the United StatesGovernment. Neitherthe UnitedStatesGovernmentnor anyagency thereof, nor BattelleMemorialInstitute,nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness,or usefulness of any information, apparatus, product, or process disclosed,or represents that its use would not infringe privately owned rights. Referencehereinto any specificcommercialproduc$ process,or serviceby tradename,trademark manufacturer, or otherwisedoesnot necessarily consthuteor implyits endorsementrecommendation, or favoringbythe UnitedStatesGovernment oranyagencythereof, or BattelleMemorialInstitute.The views and opinionsof authorsexpressedhereindo not necessarilystateor reflect those ofthe UnitedStatesGovernment or anyagencythereof. DISCLAIMER Portions of this document may be illegible in electronic image products.Images are produced from the best available original document. Summary and ConclusionsThis report describes work performed by Pacific Northwest National Laboratory (PNNL) for Numatec Hanford Corporation (NHC) to support the development of the K Basin Sludge Treatment System. For this work, testing was performed to examine the dissolution behavior of a K East Basin floor and Weasel Pit sludge composite, referred to as K East area sludge composite, in nitric acid at the following concentrations: 2 M, 4 M, 6 M and 7.8 M. With the exception of one high solids loading test the nitric acid was added at 4X the stoichiometric requirement (assuming 100% of the sludge was uranium metal). The dissolution tests were conducted at boiling temperatures for 24 hours. Most of the tests were conducted with -2.5 g of sludge (dry basis). The high solids loading test was conducted with -7 g of sludge.A large-scale dissolution test was conducted with 26.5 g of sludge and 620 mL of 6 M nitric acid. The objectives of this test were to 1) generate a sufficient quantity of acid-insoluble residual solids for use in leaching studies, and 2) examine the dissolution behavior of the sludge composite at a larger scale.Key observations, findings, and conclusions from this testing are summarized belowThe dissolution tests were successfully completed in a controllable manner. While brown times (most likely N02) were observed, offgas generation rates appeared to be low. Sludge additions to the dissolver flasks did.not resuk in excessive reactions.Throughout the dissolution tests, a significant quantity of fluf&, gel-like solids was observed floating in the solutions for all tests, except the 2~test. A heavy build-up of a translucent solid on the thermowell (glass) was observed during the 7.8 M dissolution test. Similar solids accumulated, but to a lesser extent on the thermowells in the 6 M (small-scale and scaled-up) and 4 M tests. Filtration of the residual solids from the small-scale testing took -5 to -45 min (7.8 M). Filtration of the rinsed solids from the largescale test proceeded very rap...

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DISCLAIMERPortions of this document may be illegible in electronic image products. Images are produced from the best available original document.The objective of this project is to determine the capacity for 137Cs uptake by mixed metal ferrocyanides present in Hanford Site waste tanks, and to assess the potential for aggregation of these '37Cs-exchanged materials to form "hot-spots'' in the tanks. This research, performed at Pacific Northwest Laboratory (PNL) for Westinghouse H a r d Company, stems from concerns regarding possible localized radiolytic heating within the tanks. After ferrocyanide was added to 18 high-level waste tanks in the 1950s, some of the ferrocyanide tanks received considerable quantities of saltcake waste that was rich in '37Cs. If radioactive cesium was exchanged and concentrated by the nickel ferrocyanide present in the tanks, the associated heating could cause tank temperatures to rise above the safety limits specified for the ferrocyanide-containing tanks, especially if the supernate in the tanks is pumped out and the waste becomes drier.For this study, two simulants, In-Farm-2 and U-Plant-2, were chosen to represent the waste generated by the cesium scavenging process. These simulants were formulated using protocols from the original cesium scavenging campaign. The effects from later additions of cesium-rich waste from various processes were also considered. The simulants were prepared and centrifuged to obtain a moist ferrocyanide sludge. This moist sludge was then used in three different sets of experiments: 1) batch equilibrium testing, 2) layering tests, and 3) intercalation of excess dissolved cesium into the settled sludge.The batch equilibrium testing was performed at room temperature to examine the effects of cesium and the cesium-to-nickel ferrocyanide ratio on the distribution coefficients 0. The maximum capacities of U-Plant-2 and In-Farm-2 simulants were also determined from these experiments. The maximum capacity of U-Plant-2 simulant was 0.50 mole of cesium per mole of nickel ferrocyanide and the maximum capacity of In-Farm-2 simulant was 0.80 mole of cesium per mole of nickel ferrocyanide. An evaluation of the effects of the sodium concentration and the sodium-to-cesium ratio indicated a slight but noticeable decrease in the distribution coefficients as the concentration of sodium was increased.Potential concentration mechanisms were also evaluated. A concentrated region of '"Cs nickel ferrocyanide could form in several ways, depending upon the settling and intercalation characteristics of the materials: 1) after exchange of cesium from solution, the cesium form of the nickel ferrocyanide could settle at a different rate than the sodium form of nickel ferrocyanide; 2) after exchange of cesium from solution, the cesium nickel ferrocyanide could settle at a different rate than the remaining solids present in the bulk of the waste (sodium salts). This concentration mechanism assumes a large portion of the nickel ferrocyanide exists as cesium nickel ferrocyanide. A concentr...

The effects of neutron irradiation on lithium aluminate ceramics and the transport and incorporation of tritium into surrounding components are primary concerns in the development of materials for use in tritium production. The high specific activity and volatility of the tritium in activated samples greatly increase the challenges of experimental analysis. This paper reports the determination of structural forms and concentrations of 3 H and 6 Li in irradiated and nonirradiated LiAlO 2 by nuclear magnetic resonance spectroscopy. The experiments find tritium uniformly distributed in hydroxyl groups bridging aluminum centers and lithium in four-and six-coordinated sites. These results demonstrate that measurements can be performed in a nondestructive, safe manner to obtain isotope-selective, quantitative information even on highly hazardous materials.