Sample exchange/evaluation (SEE) report - Phase III

This report describes the results from Phase III of the Sample Exchange Evaluation (SEE) program. The SEE program is used to compare analytical laboratory performance on samples from the Hanford Site`s high level waste tanks

Determination of trace quantities of thorium in uranyl nitrate by x-ray emission spectrometry

Trace quantities of thorium in uranium were separated by precipitating thorium fluoride from a 1.0M HF-1.0M NH/sub 4/F matrix using yttrium as an internal standard and lanthanum as a carrier. The thorium precipitate was collected on a filter and analyzed by x-ray emission spectrometry. The method has a detection limit of about 15 mu g thorium per gram of uranium. The relative accuracy and precision at the 120- mu g thorium level was 95.5 plus or minus 1.5%. Studies on the rate of precipitation, sample size limitations, and the effect of varying molar fluoride-touranium ratios are discussed. The effects of potentially interfering anions, cations, and acids, which are commonly found in uranium system or form insoluble fluorides were studied. Radioactive tracer studies using /sup 234/Thh and /sup 88/Y were carried out at different levels of thorium and uranium to determine the absolute efficiency of the precipitation. The speed, selectivity, and precision of this x-ray method make it an excellent alternative to spectrophotometric methods. (auth

Effect of pH on the destruction of complexants with ozone in Hanford nuclear waste

Chemical processing of nuclear waste at Hanford has generated some waste solutions with high concentration (0.1 to 0.5M) of N-(hydroxyethyl)-ethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), and other organic complexing agents. These complexants must be destroyed bacause they affect radionuclide migration in soils, waste concentration, radionuclide removal, and other waste storage and processing considerations. Previous studies on actual waste solutions demonstrated that preozonation of the alkaline waste significantly improved radionuclide removal. A series of bench-scale experiments using synthetic waste has been performed to determine the optimum pH for most efficient ozone destruction of EDTA. Ozonation of EDTA in synthetic waste was carried out over the pH range of 1 to 14. Potential catalytic materials were examined at different pH levels. The EDTA-ozone reaction rates and stoichiometric requirements were compared and evaluated for the varying conditions

Privatization samples for envelopes A, B and C

This test plan describes the method for compositing tank supemates, adding reagents, sampling and analyses in preparation of shipment of composited tank supemates to private vendors for testing

Differential spectrophotometric determination of plutonium using the Cary Model 16 spectrophotometer

ABS>The application of a high-precision Cary Model 16 spectrophotometer to the differential spectrophotometric determination of plutonium(III) was investigated. The absorbances of plutonium(III) solutions were measured against colored glass filters at 560 nanometers. Selection of various instrument parameters and the determination of the best reference filter for the highest precision are discussed. Two sets of calibration points were analyzed, The absorbance for each set was measured once a day for three days. A statistical comparison between the three readings, the three least squares curves, and the two sets of calibration points are discussed. The standard deviation of the average reading about the line was plus or minus 0.0028 g/liter plutonium in the 11 to 15 g/liter plutonium range. Detailed procedures for standard preparation from plutonium nitrate and for operation of the Cary Model 16 are included. The advantages and disadvantages of the equipment and method are discussed and further experiments suggested. (auth

Actinide analytical program for characterization of Hanford waste

The objective of this program has been to develop faster, more accurate methods for the concentration and determination of actinides at their maximum permissible concentration (MPC) levels in a controlled zone. These analyses are needed to characterize various forms of Hanford high rad waste and to support characterization of products and effluents from new waste management processes. The most acceptable methods developed for the determination of /sup 239/Pu, /sup 238/Pu, /sup 237/Np, /sup 241/Am, and /sup 243/Cm employ solvent extraction with the addition of tracer isotopes. Plutonium and neptunium are extracted from acidified waste solutions into Aliquat-336. Americium and curium are then extracted from the waste solution at the same acidity into dihexyl-N,N-diethylcarbamylmethylenephosphonate (DHDECMP). After back extraction into an aqueous matrix, these actinides are electrodeposited on steel disks for alpha energy analysis. Total uranium and total thorium are also isolated by solvent extraction and determined spectrophotometrically