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Report of tritide study at the Responsive Neutron Generator Product Deployment Center

Coffey, Jaime

This report documents a study of sample counting results for wipes from routine surface area monitoring conducted at the Responsive Neutron Generator Product Deployment Center (RNGPDC) at Sandia National Laboratories (SNL). The study was initiated in November 2006, with two samples suspected of containing erbium tritide, after some samples were found to exhibit higher tritium counting rates upon recount at a later time. The main goal of the study was to determine whether the current practice of analyzing tritium wipe samples once, within a few days of sample collection, is adequate to accurately quantify the amount of tritium on the sample when tritides may be present. Recommendations are made toward routine recounting of vials suspected of containing particulate forms of tritium.

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TYPE SAND Report YEAR 2008
DOIOSTI

Computational and Experimental Study of Nanoporous Membranes for Water Desalination and Decontamination

Debusschere, Bert; Zendejas, Frank Z.; Adalsteinsson, Helgi; Tran, Huu; Najm, Habib N.; Chinn, Douglas A.; Kent, Michael S.; Simmons, Blake

Fundamentals of ion transport in nanopores were studied through a joint experimental and computational effort. The study evaluated both nanoporous polymer membranes and track-etched nanoporous polycarbonate membranes. The track-etched membranes provide a geometrically well characterized platform, while the polymer membranes are more closely related to ion exchange systems currently deployed in RO and ED applications. The experimental effort explored transport properties of the different membrane materials. Poly(aniline) membranes showed that flux could be controlled by templating with molecules of defined size. Track-etched polycarbonate membranes were modified using oxygen plasma treatments, UV-ozone exposure, and UV-ozone with thermal grafting, providing an avenue to functionalized membranes, increased wettability, and improved surface characteristic lifetimes. The modeling effort resulted in a novel multiphysics multiscale simulation model for field-driven transport in nanopores. This model was applied to a parametric study of the effects of pore charge and field strength on ion transport and charge exclusion in a nanopore representative of a track-etched polycarbonate membrane. The goal of this research was to uncover the factors that control the flux of ions through a nanoporous material and to develop tools and capabilities for further studies. Continuation studies will build toward more specific applications, such as polymers with attached sulfonate groups, and complex modeling methods and geometries.

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TYPE SAND Report YEAR 2008
DOIOSTI
Results 76501–76525 of 99,299
Results 76501–76525 of 99,299