18 Matching Results

Search Results

Advanced search parameters have been applied.
in creator/contributor: "Finch, R."  
Results: 1 - 18
open access

Catalog of known hot springs and thermal place names for Honduras

Description: Thermal place names were compiled from all 1:50,000 topographic quadrangle maps for the Republic of Honduras as of July 1986, from other published maps, and from several sources of unpublished data. Known hot spring sites include those visited by Empresa Nacional de Energia Electrica (Honduras) geologists, sites visited by Los Alamos geologists in 1985, and other sites known to R.C. Finch. The number of known hot spring sites in Honduras with temperatures >30/sup 0/C is 125. In addition, 56 the… more
Date: August 1, 1986
Creator: Finch, R. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Secondary Uranium-Phase Paragenesis and Incorporation of Radionuclides into Secondary Phase

Description: The purpose of this analysis/model report (AMR) is to assess the potential for uranium (U) (VI) compounds, formed during the oxidative corrosion of spent uranium-oxide (UO{sub 2}) fuels, to sequester certain radionuclides and, thereby, limit their release. The ''unsaturated drip tests'' being conducted at Argonne National Laboratory (ANL) provide the basis of this AMR (Table 1). The ANL drip tests on spent fuel are the only experiments on fuel corrosion from which solids have been analyzed for … more
Date: June 5, 2001
Creator: Finch, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Oxidative corrosion of spent UO{sub 2} fuel in vapor and dripping groundwater at 90{degree}C.

Description: Corrosion of spent UO{sub 2} fuel has been studied in experiments conducted for nearly six years. Oxidative dissolution in vapor and dripping groundwater at 90 C occurs via general corrosion at fuel-fragment surfaces. Dissolution along fuel-grain boundaries is also evident in samples contacted by the largest volumes of groundwater, and corroded grain boundaries extend at least 20 or 30 grains deep (> 200 {micro}m), possibly throughout millimeter-sized fragments. Apparent dissolution of fuel … more
Date: April 29, 1999
Creator: Finch, R. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Geology of the Azacualpa geothermal site, Departamento de Comayagua Honduras, Central America: Field report. Geologia del area geotermica de Azacualpa Departamento de Comayagua, Honduras, America Central: Informe de camps

Description: Thermal waters at the Azacualpa geothermal site are surfacing along fractures in the Atima Formation associated with the main north-south-trending Zacapa fault and the subordinate north-south-trending splays of the main fault. Permeability appears to be related to these fractures rather than to formation permeability in either the limestones of the Atima Formation or the Valle de Angeles Group red beds. Attitudes of lower Valle de Angeles Group red beds do not vary appreciably with distance awa… more
Date: March 1, 1987
Creator: Eppler, D.; Baldridge, S.; Perry, F.; Flores, W.; Paredes, J.R. & Finch, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Direct investigations of the immobilization of radionuclides in the alteration phases of spent nuclear fuel. 1998 annual progress report

Description: 'In an oxidizing environment, such as in the proposed repository at Yucca Mountain, rapid alteration rates are expected for spent nuclear fuel. Lab.-scale simulations have repeatedly shown that the dominant alteration products under repository conditions will be uranyl phases. There is an inadequate database that relates to the effects of the alteration products on the release of radionuclides, but this information is essential to provide a radionuclide release estimate. It is likely that many … more
Date: June 1, 1998
Creator: Burns, P. C. & Finch, R. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

UO{sub 2} corrosion in high surface-area-to-volume batch experiments.

Description: Unsaturated drip tests have been used to investigate the alteration of unirradiated UO{sub 2} and spent UO{sub 2} fuel in an unsaturated environment such as may be expected in the proposed repository at Yucca Mountain. In these tests, simulated groundwater is periodically injected onto a sample at 90 C in a steel vessel. The solids react with the dripping groundwater and water condensed on surfaces to form a suite of U(VI) alteration phases. Solution chemistry is determined from leachate at the… more
Date: December 8, 1997
Creator: Bates, J. K.; Finch, R. J.; Hanchar, J. M. & Wolf, S. F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Microscopic Examination of a Corrosion Front in Spent Nuclear Fuel

Description: Spent uranium oxide nuclear fuel hosts a variety of trace chemical constituents, many of which must be sequestered from the biosphere during fuel storage and disposal. In this paper we present synchrotron x-ray absorption spectroscopy and microscopy findings that illuminate the resultant local chemistry of neptunium and plutonium within spent uranium oxide nuclear fuel before and after corrosive alteration in an air-saturated aqueous environment. We find the plutonium and neptunium in unaltered… more
Date: June 20, 2006
Creator: Fortner, J. A.; Kropf, A. J.; Finch, R. J. & Cunnane, J. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Thermodynamic stabilities of U(VI) minerals: Estimated and observed relationships

Description: Gibbs free energies of formation ({Delta}G{degree}{sub f}) for several structurally related U(VI) minerals are estimated by summing the Gibbs energy contributions from component oxides. The estimated {Delta}G{degree}{sub f} values are used to construct activity-activity (stability) diagrams, and the predicted stability fields are compared with observed mineral occurrences and reaction pathways. With some exceptions, natural occurrences agree well with the mineral stability fields estimated for … more
Date: December 31, 1996
Creator: Finch, R. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Retention of neptunium in uranyl alteration phases formed during spent fuel corrosion

Description: Uranyl oxide hydrate phases are known to form during contact of oxide spent nuclear fuel with water under oxidizing conditions; however, less is known about the fate of fission and neutron capture products during this alteration. We describe, for the first time, evidence that neptunium can become incorporated into the uranyl secondary phase, dehydrated schoepite (UO{sub 3}.8H{sub 2}O). Based on the long term durability of natural schoepite, the retention of neptunium in this alteration phase ma… more
Date: September 1, 1997
Creator: Buck, E. C.; Finch, R. J.; Finn, P. A. & Bates, J. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Corrosion mechanisms of spent fuel under oxidizing conditions

Description: The release of {sup 99}Tc can be used as a reliable marker for the extent of spent oxide fuel reaction under unsaturated high drip rate conditions at 90{degrees}C. Evidence from the leachate data and from scanning and transmission electron microscopy (SEM and TEM) examination of reacted fuel samples is presented for radionuclide release, potential reaction pathways, and the formation of alteration products. In the ATM-103 fuel, 0.03 of the total inventory of {sup 99}Tc is release in 3.7 years u… more
Date: September 1, 1997
Creator: Finn, P. A.; Finch, R. J.; Buch, E. C. & Bates, J. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Corrosion mechanisms of spent fuel under oxidizing conditions

Description: The release of {sup 99}Tc can be used as a reliable marker for the extent of spent oxide fuel reaction under unsaturated high-drip-rate conditions at 90{degrees}C. Evidence from leachate data and from scanning and transmission electron microscopy (SEM and TEM) examination of reacted fuel samples is presented for radionuclide release, potential reaction pathways, and the formation of alteration products. In the ATM-103 fuel, 0.03 of the total inventory of {sup 99}Tc is released in 3.7 years unde… more
Date: September 27, 1997
Creator: Finn, P.A.; Finch, R.; Buck, E. & Bates, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

YUCCA Mountain project.

Description: This report describes the experimental work performed at Argonne National Laboratory (ANL) during fiscal year 2004 (FY 04) under the Bechtel SAIC Company, LLC (BSC) Memorandum Purchase Order (MPO), contract number B004210CM3X. Important results related to the technical bases, uncertainties, validation, and conservatism in current source term models are summarized below. An examination of specimens of commercial spent nuclear fuel (CSNF) that had been subjected to corrosion testing for up to 10 … more
Date: March 28, 2005
Creator: Ebert, W. L.; Fortner, J. A.; Finch, R. J.; Jerden, J. L. & Cunnane, J. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Plutonium silicate alteration phases produced by aqueous corrosion of borosilicate glass.

Description: Borosilicate glasses loaded with {approx}10 wt % plutonium were found to produce plutonium-silicate alteration phases upon aqueous corrosion under a range of conditions. The phases observed were generally rich in lanthanide (Ln) elements and were related to the lanthanide orthosilicate phases of the monoclinic Ln{sub 2}SiO{sub 5} type. The composition of the phases was variable regarding [Ln]/[Pu] ratio, depending upon type of corrosion test and on the location within the alteration layer. The … more
Date: November 22, 1999
Creator: Fortner, J. A.; Mertz, C. J.; Bakel, A. J.; Finch, R. J. & Chamerlain, D. B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Retention of neptunium in uranyl alteration phases formed during spent fuel corrosion

Description: Uranyl oxide hydrate phases are known to form during contact of oxide spent nuclear fuel with water under oxidizing conditions; however, less is known about the fate of fission and neutron capture products during this alteration. We describe, the first time, evidence that neptunium can become incorporated into the uranyl secondary phase, dehydrated schoepite (UO{sub 3}{lg_bullet}0.8H{sub 2}O). Based on the long-term durability of natural schoepite, the retention of neptunium in this alteration … more
Date: October 1, 1997
Creator: Buck, E. C.; Finch, R. J.; Finn, P. A. & Bates, J. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

YUCCA Mountain Project - Argonne National Laboratory, Annual Progress Report, FY 1997 for activity WP 1221 unsaturated drip condition testing of spent fuel and unsaturated dissolution tests of glass.

Description: This document reports on the work done by the Nuclear Waste Management Section of the Chemical Technology Division of Argonne National Laboratory in the period of October 1996 through September 1997. Studies have been performed to evaluate the behavior of nuclear waste glass and spent fuel samples under the unsaturated conditions (low-volume water contact) that are likely to exist in the Yucca Mountain environment being considered as a potential site for a high-level waste repository. Tests wit… more
Date: September 18, 1998
Creator: Bates, J. K.; Buck, E. C.; Emery, J. W.; Finch, R. J.; Finn, P. A.; Fortner, J. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development and Testing of a Glass Waste Form For the Immobilization of Plutonium

Description: The United States has declared about 50 metric tons of weapons-grade Pu surplus to national security needs. The President has directed that this Pu be placed in a form that provides a high degree of proliferation resistance in which the surplus Pu is both unattractive and inaccessible for use by others [I]. Three alternatives are being evaluated for the disposal 2048 of this material: (1) use of the Pu as a fuel source for commercial reactors; (2) immobilization, where Pu is fixed in a glass or… more
Date: December 31, 1996
Creator: Chamberlain, D. B.; Hanchar, J. M.; Emery, J. W.; Hoh, J. C.; Wolf, S. F.; Finch, R. J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen