Tank Vapor Characterization Project: Tank 241-BX-103 headspace gas and vapor characterization results from samples collected on August 1, 1996

This report presents the results from analyses of samples taken from headspace of waste storage tank 241-BX-103 (Tank BX-103) at the Hanford Site in Washington State. Tank headspace samples collected by Westinghouse Hanford Company (WHC) were analyzed by Pacific Northwest National Laboratory (PNNL) to determine headspace concentrations of selected non-radioactive analytes. Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Vapor concentrations from sorbent trap samples are based on measured sample volumes provided by WHC. No analytes were determined to be above the immediate notification limits specified by the sampling and analysis plan (SAP). Hydrogen was the principal flammable constituent of the Tank BX-103 headspace, determined to be present at approximately 0.385% of its lower flammability limit (LFL). Total headspace flammability was estimated to be <0.633% if the LFL. Average measured concentrations of targeted gases, inorganic vapors, and selected organic vapors are provided in Table S.1. A summary of experimental methods, including sampling methodology, analytical procedures, and quality assurance and control methods are presented in Section 2.0. Detailed descriptions of the analytical results are provided in Section 3.0

Measuring proliferation in breast cancer: practicalities and applications

Various methods are available for the measurement of proliferation rates in tumours, including mitotic counts, estimation of the fraction of cells in S-phase of the cell cycle and immunohistochemistry of proliferation-associated antigens. The evidence, advantages and disadvantages for each of these methods along with other novel approaches is reviewed in relation to breast cancer. The potential clinical applications of proliferative indices are discussed, including their use as prognostic indicators and predictors of response to systemic therapy

Analysis of kerogen in Precambrian stromatolites

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Organic solvent alteration of hydraulic properties of sedimentary rocks of low permeability: a review

A review of the current literature on hydrophysical interactions of organic solutes with sedimentary rocks of low permeability is presented. The motivation was the premise that low permeability rocks may act as secondary (aquifer) barriers for the containment of hazardous organic wastes, thus preventing these wastes from contaminating the groundwater. However, this premise may be incorrect if organic wastes can affect the hydraulic conductivity of these rocks. The results indicate that very little work has been done concerning interactions of organics with consolidated subsurface materials. Available information on three related topics was summarized: the effect of organic compounds on the hydrophysical properties of clays, case studies concerning the interactions of organic compounds with clays and sedimentary rocks, and the effect of shales on inorganic transport. These studies give an indication of some research areas that need to be explored with regard to the effect of organic compounds on the hydrophysical properties of sedimentary rocks; these research needs are briefly summarized. 42 refs

Screening for organic solvents in Hanford waste tanks using organic vapor concentrations

The potential ignition of organic liquids stored in the Hanford Site high-level radioactive waste tanks has been identified as a safety issue because expanding gases could potentially affect tank dome integrity. Organic liquid waste has been found in some of the waste tanks, but most are thought to contain only trace amounts. Due to the inhomogeneity of the waste, direct sampling of the tank waste to locate organic liquids may not conclusively demonstrate that a given tank is free of risk. However, organic vapors present above the organic liquid waste can be detected with a high degree of confidence and can be used to identify problem tanks. This report presents the results of a screening test that has been applied to 82 passively ventilated high-level radioactive waste tanks at the Hanford Site to identify those that might contain a significant amount of organic liquid waste. It includes seven tanks not addressed in the previous version of this report, Screening for Organic Solvents in Hanford Waste Tanks Using Total Non-Methane Organic Compound Vapor Concentrations. The screening test is based on a simple model of the tank headspace that estimates the effective surface area of semivolatile organic liquid waste in a tank. Analyses indicate that damage to the tank dome is credible only if the organic liquid burn rate is above a threshold value, and this can occur only if the surface area of organic liquid in a tank is above a corresponding threshold value of about one square meter. Thirteen tanks were identified as potentially containing at least that amount of semivolatile organic liquid based on conservative estimates. Most of the tanks identified as containing potentially significant quantities of organic liquid waste are in the 241-BY and 241-C tank farms, which agrees qualitatively with the fact that these tank farms received the majority of the PUREX process organic wash waste and waste organic liquids

Review of Mass Spectrometry Data from Waste Tank Headspace Analyses

Numerous analytes have been categorized as tentatively identified compounds (TICs) in air samples from the headspaces of the Hanford Site high-level radioactive waste tanks. The tentative identification of these compounds was based mainly on the agreement between the observed mass spectra and a library of published mass spectra with consideration given to the gas chromatographic conditions and retention times. Many of the TICs were found in a limited number of tanks, were identified by only one laboratory or by one method, and/or were thought to be unlikely components of the waste or its degradation products. Consequently, the mass spectra of selected analytes have been reviewed to determine if their tentative identifications were correct. From our current review of 49 TICs, we found 25 that were misidentified and recommend that 54 of the associated results be flagged as suspect and 22 of the associated results be assigned a different compound name