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Abstract  

We describe tests of EiChrom Industries' Ni-selective ion exchange resin for use in analysis of63Ni in Savannah River Site high level waste. We report measurement of63Ni content in two sets of Savannah River Site glass product from the Defense Waste Processing Facility. The63Ni β-decay activity was chemically separated in quintuplicate from fission product and plutonium α-β activities of up to 103 times the observed63Ni content. The separation used a Ni-dimethlyglyoxime precipitation followed by radiochemical purification using the Ni-selective extraction chromatography resin. Further removal of interfering activity was based on diagnosis of observed radioactivity in each successive product phase. We analyzed eleven plant glass product samples using seven spiked standard addition duplicates to measure63Ni recovery in the separations. Selected liquid scintillation β-decay spectra are shown to validate the method. Interpretation of accuracy is based upon three distinct comparisions to predicted63Ni content.

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Abstract  

The use of solid phase extraction (SPE) disks was studied for the quantification of selected radionuclides in aqueous solutions. The extraction of four radionuclides using six types (two commerical, four test materials) of 3M EmporeTM RAD disks was studied. The radionuclides studied were: technetium-99 (two types of disks), cesium-137 (two types), strontium-90 (one type), plutonium-238 (one type). Extractions were tested from DI water, river water and seawater. Extraction efficiency, kinetics (flow rate past the disk), capacity, and potential interferences were studied as well as quantification methods.

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Abstract  

Highly radioactive waste from defense-related activities at the Savannah River Site in South Carolina are to be incorporated into a borosilicate glass in the Defense Waste Processing Facility (DWPF) for long-tem geological isolation. Processing and repository safety considerations require the determination of 24 radioisotopes that meet the reporting criteria. These isotopes include fission products, activation products, and daughter nuclei that grow into the waste. Four isotopes,137Cs,90Sr,238Pu and238U will be routinely measured in the DWPF operation for process control. This work shows that the concentrations of the other 20 reportable radioisotopes in the final glass product can be predicted from a thorough characterization of the high level waste (HLW) tanks and a knowledge of the concentrations of the major non-radioactive components in the vitrification process.

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Abstract  

Waste cleanup efforts underway at the United States Department of Energy’s (DOE) Savannah River Site (SRS) in South Carolina, as well as other DOE nuclear sites, have created a need to characterize 79Se in radioactive waste inventories. Successful analysis of 79Se in high activity waste matrices is challenging for a variety of reasons. As a result of these unique challenges, the successful quantification of 79Se in the types of matrices present at SRS requires an extremely efficient and selective separation of 79Se from high levels of interfering radionuclides. A robust 79Se radiochemical separation method has been developed at the Savannah River National Laboratory (SRNL) which is routinely capable of successfully purifying 79Se from a wide range of interfering radioactive species. In addition to dramatic improvements in the Kd, ease, and reproducibility of the analysis, the laboratory time has been reduced from several days to only 6 h.

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Abstract  

This paper describes development work to obtain a product phase of 151Sm pure of any other radioactive species so that it can be determined in US Department of Energy high level liquid waste and low level solid waste by liquid scintillation b-spectroscopy. The technique provides separation from mCi/ml levels of 137Cs, Pu a- and 241Pu b-decay activity, and 90Sr/90Y activity. The separation technique is also demonstrated to be useful for the determination of 147Pm.

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Abstract  

Savannah River Site (SRS) is immobilizing the radioactive, high-level waste sludge in Tank 51 into a borosilicate glass for disposal in a geologic repository. A requirement for repository aceeptance is that SRS report the concentrations of certain fission product and actinide radionuclides in the glass. This paper presents measurements of many of these concentrations in both Tank 51 sludge and the final glass. The radionuclides were measured by inductively coupled plasma mass spectrometry and α, β, and γ counting methods. Examples of the radionuclides are90Sr,137Cs,238U and,239Pu. Concentrations in the glass are 3.1 times lower due to dilution of the sludge with a nonradio-active glass forming frit in the vitrification process. Results also indicated that in both the sludge and glass the relative concentrations of the long lived fission products insoluble in caustic are in proportion to their yields from the fission of235U waste in the SRS reactors. This allowed the calculation of a fission yield scaling factor. This factor in addition to the sludge dilution factor can be used to estimate concentrations of waste acceptance radionuclides that cannot be measured in the glass. Examples of these radionuclides are79Se,93Zr, and107Pd.

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Abstract  

Batch equilibrium measurements were conducted at 25±2 °C with a granular resorcinol-formaldehyde (RF) resin to determine the distribution coefficients (K d) for cesium. In the tests, Hanford Site actual waste sample containing radioactive cesium (137Cs) and a pretreated waste sample that was spiked with non-radioactive 133Cs were used. Initial concentrations of non-radioactive cesium in the waste sample were varied to generate an equilibrium isotherm for cesium. Majority of the tests were conducted at 25±2 °C using a liquid to solid phase ratio of 100 ml/g and at a contact time of 72 hours. Two additional tests were conducted at a liquid to solid phase ratio of 10 and at contact time of 120 hours. The measured distribution coefficient (K d) for radioactive cesium (137Cs) was 948 ml/g, the K dfor non-radioactive cesium (133Cs) was 1039 ml/g. The K dfor nonradioactive cesium decreased from 1039 to 691 ml/g with increased initial cesium concentration from 8 to 64 g/ml. Very little change of the K dwas observed at initial cesium concentration above 64 g/ml. The maximum sorption capacity for cesium on granular RF resin was 1.17 mmole/g dry resin. This value was calculated from the fit of the equilibrium isotherm data to the Dubinin-Radushkevich equation. Previously, a total capacity of 2.84 mmole/g was calculated by Bibler and Wallace for air-dried RF resin.

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Abstract  

The short survey concerns the discovery of adsorbents and the measurement of the adsorptivity. In the investigation of adsorption very sensitive instruments are needed, developed only recently. Two methods, however, are very old: the volumetric and the gravimetric measurement of the adsorbed amount. In the Bible we find a thorough description of a volumetric adsorption experiment. The systematic research began in 1773 when Scheele, Fontana and Priestley observed the adsorption of air by charcoal. The volumetric apparatus of Brunauer, Emmett and Teller set the prototype for many instruments devoted to measure adsorption isotherms. The first gravimetric adsorption measuring instruments were hygrometers, described by Nicholas of Cues in 1450, Alberti and Leonardo da Vinci. In 1833 Talabot installed 39 drying balances in a Lyon laboratory for humidity control of raw silk imported from China. In 1912 Emich described an electronic beam microbalance to investigate adsorption and a coil spring balance. Today isotherms are measured gravimetrically by means of electro-dynamically compensating microbalances. Also oscillating systems are being used which allow weighing down to the zeptogram region.

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historical development’ and ‘Instrumentation’ (with B. D. Mitchell). The book still represents a bible on DTA applications, dealing with different problems such as theory, experiments, geosciences, nomenclature and history. He helped to improve the

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