Investigation of kilovolt ion sputtering quarterly progress report

Investigation of cesium ion sputtering of monocrystalline copper using radioactive tracer techniqu

Investigation of kilovolt ion sputtering Quarterly progress report, Feb. - Apr. 1966

Sputtering of single crystals of electrode material under cesium and mercury ion beam bombardmen

Investigation of kilovolt ion sputtering Quarterly progress report, May - Jul. 1966

Aluminum sputtering, and neutron activation analysis after cesium ion bombardmen

Investigation of kilovolt ion sputtering Quarterly progress report, Aug. - Oct. 1966

Sputtering yields, angular and energy distribution of atoms, and implanted ion distribution in cesium and mercury surface interaction

Waste package performance in unsaturated rock

The unsaturated rock and near-atmospheric pressure of the potential nuclear waste repository at Yucca Mountain present new problems of predicting waste package performance. In this paper we present some illustrations of predictions of waste package performance and discuss important data needs. 11 refs., 9 figs., 1 tab

Migration of radionuclides through sorbing media analytical solutions--II

This report presents analytical solutions, and the results of such solutions, for the migration of radionuclides in geologic media. Volume 1 contains analytical solutions for one-dimensional equilibrium transport in infinite media and multilayered media. One-dimensional non-equilibrium transport solutions are also included. Volume 2 contains analytical solutions for transport in a one-dimensional field flow with transverse dispersion as well as transport in multi-dimensional flow. A finite element solution of the transport of radionuclides through porous media is discussed. (DMC

Nuclide migration from areal sources into a fracture

This document shows analytic solutions to the problem of hydrogeologic transport of radionuclides released from finite areal sources into a planar fracture. It illustrates the solutions through numerical and graphical displays of the spatial and temporal distribution of the radionuclides as a result of advection in the fracture, transverse dispersion and surface sorption, as well as diffusion into and sorption in the rock matrix. The numerical illustrations indicate that sufficient distances away from the sources equivalent single sources give acceptable approximations. 2 refs., 3 figs

Gas flow in and out of a nuclear waste container

We analyze the flow of gases out of and into a high-level-waste container in the unsaturated tuff of Yucca Mountain. Containers are expected to fail eventually by localized cracks and penetrations. Even though the penetrations may be small, argon gas initially in the hot container can leak out. As the waste package cools, the pressure inside the container can become less than atmospheric, and air can leak in. {sup 14}C released from the hot fuel-cladding surface can leak out of penetrations, and air inleakage can mobilize additional {sup 14}C and other volatile radioactive species as it oxidizes the fuel cladding and the spent fuel. In an earlier paper we studied the gas flow through container penetrations occurring at the time of emplacement. Here we analyze the flow of gas for various penetration sizes occurring at 300 years. 3 refs., 2 figs

Transient and steady-state radionuclide transport through penetrations in nuclear waste containers

In this paper we analyze the transport of radionuclides through penetrations in nuclear waste containers. Penetrations may result from corrosion or cracks and may occur in the original container material, in degraded or corroded material, or in deposits of corrosion products. We do not consider how these penetrations occur or the characteristics of expected penetrations in waste containers. We are concerned only with the analytical formulation and solutions of equations to predict rates of mass transfer through penetrations of specified size and geometry. Expressions for the diffusive mass transfer rates through apertures are presented. We present numerical illustrations for steady-state mass-transfer rates through a circular hole, including concentration isopleths. The results are extended to multiple holes, including a criterion for hole spacing wherein superposition of single-hole solutions can be used. Results illustrated for holes in thin-walled containers show that significant mass transfer can occur even if a small fraction of the container area is perforated. We also illustrate the case of holes facing a water gap, instead of being in intimate contact with porous rock. In this case the radionuclide flux from many small holes approaches that from a bare waste cylinder

Waste-package release rates for site suitability studies

Performance-assessment calculations in support of the site- suitability effort for the Yucca Mountain Project will address radionuclide transport arising from various disruptive scenarios. Here we present release rates of radionuclides from individual waste packages for scenarios involving various postulated forms of water intrusion, including increased infiltration rate as well as rock immediately surrounding an individual waste package becoming saturated with ground water. We examine: (1) effect of increased water infiltration rate on release rates; increases in radionuclide release rates resulting from water filling the annulus between the waste container and the surrounding rock, as well as water saturating the pores and fractures in the rock surrounding the waste package; (3) the effect of flow in fractures in the saturated rock on release rate; and (4) release of radionuclides to the mountain surface resulting from an exploratory borehole shaft intersecting a waste package. The radionuclides considered are Tc-99; I-129; Cs-135; Np- 237; Pu-239,240,242; and Am-241,243. Release rates are calculated for both the wet-drip bathtub and the wet-continuous water-contact modes, as described in the Working Group 2 report, applying equations as published by Sadeghi, et al., [1990] and as extended in the present report