skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Evaluation of sodium bentonite and crushed basalt as waste package backfill materials

Abstract

Preliminary hydrothermal experiments were completed at 300/sup 0/C, 300 bars and 200/sup 0/C, 300 bars in the basalt/groundwater system to determine the chemical stability of crushed basalt. Analysis of solution data from the 300/sup 0/C experiments as a function of time and reaction products indicated that the primary reaction was the alteration of the basalt glass phase to illite and/or smectite clays and quartz. The establishment of steady state pH values of about 6, the apparent rapid occurrence of a highly reducing environment in the system, and an insignificant increase in the solution concentration of potentially corrosive aqueous species were observed. These data indicate that a waste package backfill containing a significant amount of crushed basalt will provide a near-field geochemical environment favorable to the chemical stability of metal canister materials. A preliminary experiment was also completed in the sodium bentonite/groundwater system at 300/sup 0/C, 300 bars. Analyses of the reacted solutions and solids show that bentonite remains essentially stable with only minor alterations to albite. Sorption data were generated on crushed basalt, secondary minerals in basalt, and sodium bentonite at 60 to 65/sup 0/C under oxic and anoxic conditions. These data indicate that Cs and Sr will be completelymore » contained in a waste package backfill due to the formation of insoluble secondary minerals, ion exchange, and specific adsorption. Under reducing conditions, Np will be retained beyond 1000 yr and U and Pu will be retained under reducing conditions over 300 yr. An increase in retention time can be expected to occur with an increase in temperature. Theory, calculations, and a limited data base have been used to propose a reference waste package. The backfill component consisting of 25% sodium bentonite and 75% crushed basalt with an initial density of 2.1 g/cm/sup 3/ and a thickness of 0.152 m.« less

Authors:
; ;
Publication Date:
Research Org.:
Rockwell International Corp., Richland, WA (USA). Rockwell Hanford Operations
OSTI Identifier:
6508789
Report Number(s):
RHO-BW-ST-21-P
ON: DE83007029
DOE Contract Number:  
AC06-77RL01030
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; 58 GEOSCIENCES; BACKFILLING; MATERIALS TESTING; BASALT; ROCK-FLUID INTERACTIONS; SORPTIVE PROPERTIES; BENTONITE; CESIUM; SORPTION; NEPTUNIUM; STRONTIUM; URANIUM; EXPERIMENTAL DATA; GROUND WATER; HIGH-LEVEL RADIOACTIVE WASTES; RADIOACTIVE WASTE DISPOSAL; SODIUM COMPOUNDS; STABILITY; ACTINIDES; ALKALI METAL COMPOUNDS; ALKALI METALS; ALKALINE EARTH METALS; CLAYS; DATA; ELEMENTS; HYDROGEN COMPOUNDS; IGNEOUS ROCKS; INFORMATION; MANAGEMENT; MATERIALS; METALS; NUMERICAL DATA; OXYGEN COMPOUNDS; RADIOACTIVE MATERIALS; RADIOACTIVE WASTES; ROCKS; SURFACE PROPERTIES; TESTING; TRANSURANIUM ELEMENTS; VOLCANIC ROCKS; WASTE DISPOSAL; WASTE MANAGEMENT; WASTES; WATER; 052002* - Nuclear Fuels- Waste Disposal & Storage; 580300 - Mineralogy, Petrology, & Rock Mechanics- (-1989)

Citation Formats

Wood, M I, Aden, G D, and Lane, D L. Evaluation of sodium bentonite and crushed basalt as waste package backfill materials. United States: N. p., 1982. Web.
Wood, M I, Aden, G D, & Lane, D L. Evaluation of sodium bentonite and crushed basalt as waste package backfill materials. United States.
Wood, M I, Aden, G D, and Lane, D L. Fri . "Evaluation of sodium bentonite and crushed basalt as waste package backfill materials". United States.
@article{osti_6508789,
title = {Evaluation of sodium bentonite and crushed basalt as waste package backfill materials},
author = {Wood, M I and Aden, G D and Lane, D L},
abstractNote = {Preliminary hydrothermal experiments were completed at 300/sup 0/C, 300 bars and 200/sup 0/C, 300 bars in the basalt/groundwater system to determine the chemical stability of crushed basalt. Analysis of solution data from the 300/sup 0/C experiments as a function of time and reaction products indicated that the primary reaction was the alteration of the basalt glass phase to illite and/or smectite clays and quartz. The establishment of steady state pH values of about 6, the apparent rapid occurrence of a highly reducing environment in the system, and an insignificant increase in the solution concentration of potentially corrosive aqueous species were observed. These data indicate that a waste package backfill containing a significant amount of crushed basalt will provide a near-field geochemical environment favorable to the chemical stability of metal canister materials. A preliminary experiment was also completed in the sodium bentonite/groundwater system at 300/sup 0/C, 300 bars. Analyses of the reacted solutions and solids show that bentonite remains essentially stable with only minor alterations to albite. Sorption data were generated on crushed basalt, secondary minerals in basalt, and sodium bentonite at 60 to 65/sup 0/C under oxic and anoxic conditions. These data indicate that Cs and Sr will be completely contained in a waste package backfill due to the formation of insoluble secondary minerals, ion exchange, and specific adsorption. Under reducing conditions, Np will be retained beyond 1000 yr and U and Pu will be retained under reducing conditions over 300 yr. An increase in retention time can be expected to occur with an increase in temperature. Theory, calculations, and a limited data base have been used to propose a reference waste package. The backfill component consisting of 25% sodium bentonite and 75% crushed basalt with an initial density of 2.1 g/cm/sup 3/ and a thickness of 0.152 m.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1982},
month = {10}
}

Technical Report:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that may hold this item. Keep in mind that many technical reports are not cataloged in WorldCat.

Save / Share: