NA processes such as biodegradation, sorption, dilution dispersion, advection, and possibly sorption and diffusion are occurring in the Northeast and Northwest plumes. However, the overall biological attenuation rate for TCE within the plumes is not sufficiently rapid to utilize as remedial option. The mobility and toxicity of {sup 99}Tc is not being reduced by attenuating processes within the Northwest Plume. The current EPA position is that NA is not a viable remedial approach unless destructive processes are present or processes are active which reduce the toxicity and mobility of a contaminant. Therefore, active remediation of the dissolved phase plumes will be necessary to reduce contaminant concentrations before an NA approach could be justified at PGDP for either plume. Possible treatment methods for the reduction of dissolved phase concentrations within the plumes are pump-and-treat bioaugmentation, biostimulation, or multiple reactive barriers. Another possibility is the use of a regulatory instrument such as an Alternate Concentration Limit (ACL) petition. Biodegradation of TCE is occurring in both plumes and several hypothesis are possible to explain the apparent conflicts with some of the geochemical data. The first hypothesis is active intrinsic bioremediation is negligible or so slow to be nonmeasurable. In this scenario, the D.O., …

Aqueous, low-temperature oxidation rates for the polychlorinated biphenyl (PCB) congener 2,2`,3-trichlorobiphenyl have been measured in aqueous phosphate-buffered solutions using Dickson-type reaction vessels. Concentrations of the target compounds were determined by gas chromatography and compound identification was verified by gas chromatography - mass spectrometry. The reaction temperatures ranged from 131 {degrees}C to 165{degrees}C and the activation energy for the destruction of 2,2`,3-trichlorobiphenyl was estimated to be 134 kJ/mole. In a low concentration experiment (approximately 500 ng/g starting concentration), 2,2`,3-trichlorobiphenyl concentration reached non-detect in two days at 135{degrees}C. In a much higher concentration experiment (approximately 24,000 mg/g initial loading), nearly 40% of the initial 2,2`,3-trichlorobiphenyl concentration, or about 10,000 ng/g was destroyed at 161{degrees}C in 18 days. The 2,2`, 3-trichlorobiphenyl concentration of 24,000 ng/g measured at 131{degrees}C represents a greater than 100 fold increase in the aqueous solubility compared to the value of 200 ng/g at 20{degrees}C reported by Mackay et al. During the experiments the reacted portion of the 2,2`, 3-trichlorobiphenyl was completely mineralized, as indicated by a stoichiometric production of inorganic carbon and chloride ion, and no intermediates amenable to gas chromatography were observed during the HPO experiments. These preliminary experiments indicate that hydrous pyrolysis/oxidation (HPO) may be a useful …

Under the DOE CHAMMP/CLIMATE Program, a convective scheme was developed for use in climate models. The purpose of the present study was to develop an adjoint model of its tangent-linear model. the convective scheme was integrated within a single column model which provides radiative-convective equilibrium solutions applicable to climate models. The main goal of this part of the project was to develop an adjoint of the scheme to facilitate the optimization of its convective parameters. For that purpose, adjoint sensitivities were calculated with the adjoint code. Parameter optimization was based on TOGA COARE data which were also used in this study to obtain integrations of the nonlinear and tangent-linear models as well as the integrations of the adjoint model. Some inadequacies of the inner IFA data array were found, and did not permit a single numerical integration during the entire 4 months of data. However, reliable monthly radiative-convective equilibrium solutions and associated adjoint sensitivities were obtained and used to bring about the parameter optimization.

The Timesaver belt grinding machine has been selected by the Atlas collaboration for deburring the master and spacer plates after die stamping and laser cutting, respectively. However, the question has been raised as to whether or not the plates are sufficiently clean after going through the Timesaver machine to immediately be glued into a submodule assembly. This would greatly enhance the production of submodules because the task of cleaning individual master and spacer plates is labor intensive and time consuming as well as raises environmental issues with the detergent that is used. In order to investigate the possibility of using the Timesaver process to clean the plates as well as debur them, several plates were run through the machine and their cleanliness inspected before and after. In addition, several glue samples were subjected to the same process, glued, and then pulled apart in an attempt to gauge the cleanliness of the plates. From this series of tests it can be concluded that the wet Timesaver machine can adequately prepare the surface of the master and spacer plates as well as clean the plates for gluing. The machine was able to adequately remove all of the oil and grime from the …

Several sets of new calculations were performed to support the Spent Nuclear Fuel project nuclear criticality safety evaluation. These new calculations include partial loading of Mark IA inner elements after the outers have been loaded, a new, more robust design for the central pipe insert for the Mark IA fuel baskets, Single Pass Reactor fuel loading, the lowering of a Mark IV-loaded MCO through the concrete operating deck as-it is inserted into the Canister Storage Building storage array, and one additional scrap basket loading error. None of these calculations exceeded the criticality safety limit.

In May 1997, a historic deactivation project at the PUREX (Plutonium URanium EXtraction) facility at the Hanford Site in south-central Washington State concluded its activities (Figure ES-1). The project work was finished at $78 million under its original budget of $222.5 million, and 16 months ahead of schedule. Closely watched throughout the US Department of Energy (DOE) complex and by the US Department of Defense for the value of its lessons learned, the PUREX Deactivation Project has become the national model for the safe transition of contaminated facilities to shut down status.

This document provides guidance to contractor generator groups for developing and maintaining documentation of Pollution Prevention/Waste. Minimization (P2/WMin) Program activities. The program documentation is intended to demonstrate generator compliance with U.S. Department of Energy (DOE) requirements as well as state and Federal regulations.

This report provides status of Hanford activities in response to process deficiencies highlighted during and in response to the May 14, 1997, explosion at the Plutonium Reclamation Facility. This report provides specific response to the August 4, 1997, memorandum from the Secretary which requested a progress report, in 120 days, on activities associated with reassessing the known and evaluating new vulnerabilities (chemical and radiological) at facilities that have been shut down, are in standby, are being deactivated or have otherwise changed their conventional mode of operation in the last several years. In addition, this report is intended to provide status on emergency response corrective activities as requested in the memorandum from the Secretary on August 28, 1997. Status is also included for actions requested in the second August 28, 1997, memorandum from the Secretary, regarding timely notification of emergencies.

'Sheet silicates (e.g. micas and clays) are important constituents of a wide variety of geological formations such as granite, basalt, and sandstone. Sheet silicates, particularly clays such as bentonite are common materials in near-field engineered barriers in high-level nuclear waste (HLW) repositories. This is because migration of radionuclides from an underground HLW repository to the geosphere may be significantly reduced by sorption of radionuclides (e.g., Pu, U and Np) onto sheet silicates (e.g., clays and micas) that line the fractures and pores of the rocks along groundwater flowpaths. In addition to surface sorption, it has been suggested that some sheet silicates may also be able to incorporate many radionuclides, such as Cs and Sr, in the inter-layer sites of the sheet structure. However, theability of the sheet silicates to incorporate radionuclides and retard release and migration of radionuclides may be significantly affected by the near-field radiation due to the decay of fission products and actinides. for example, the unique properties of the sheet structures will be lost completely if the structure becomes amorphous due to irradiation effects. Thus, the study of irradiation effects on sheet-structures, such as structural damage and modification of chemical properties, are critical to the performance assessment …