Composite backfill materials for radioactive waste isolation by deep burial in salt

Conference · Tue Jan 01 04:00:00 EST 1980

OSTI ID:6932789

Nowak, E J

Bentonite and hectorite were found to sorb Pu(IV) and Am(III) from concentrated brines with distribution coefficients K/sub d/ > 3000 ml/g. The permeability of bentonite to brine was less than 1 microdarcy at a confining pressure of 18 MPa, the expected lithostatic pressure at the 800 m level in a salt repository. Getters for sorption of TcO/sub 4//sup -/ (K/sub d/ approx. 300 ml/g), I/sup -/ (K/sub d/ greater than or equal to 30 ml/g), Cs (K/sub d/ greater than or equal to 30 ml/g) and Sr (K/sub d/ greater than or equal to approx. 100 ml/g) from brines were identified. Their sorption properties are presented. Thermal conductivity results (>0.5 W/mK) and evidence for bentonite stability in brines at hydrothermal conditions are also given. It is shown by calculated estimates that a 3-ft-thick mixture of bentonite with other getter materials could retain Pu, Am, and TcO/sub 4//sup -/ for >10/sup 4/ years and I/sup -/ for > 10/sup 3/ years. Another tailored mixture could retain Cs for approx. 600 years, Sr for approx. 700 years, TcO/sub 4/ for approx. 4000 years and I/sup -/ for approx. 400 years. The backfill can offer a significant contribution to the isolation capability of a waste package system.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6932789
• Report Number(s): SAND-80-1377C; CONF-801124-6
• Country of Publication: United States
• Language: English

Related Subjects

052002* -- Nuclear Fuels-- Waste Disposal & Storage
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ACTINIDES
ADSORBENTS
ADSORPTION
ALKALI METALS
ALKALINE EARTH METALS
AMERICIUM
ANIONS
BACKFILLING
BENTONITE
CESIUM
CHARCOAL
CHARGED PARTICLES
CLAYS
ELEMENTS
GEOLOGIC DEPOSITS
GETTERS
HALOGENS
INORGANIC ION EXCHANGERS
IODINE
ION EXCHANGE MATERIALS
IONS
MANAGEMENT
MATERIALS
MEDIUM PRESSURE
METALS
MINERALS
MONTMORILLONITE
NONMETALS
OXYGEN COMPOUNDS
PERMEABILITY
PERTECHNETATES
PHYSICAL PROPERTIES
PLUTONIUM
RADIOACTIVE WASTE STORAGE
SALT DEPOSITS
SAND
SORPTION
SORPTIVE PROPERTIES
STORAGE
STRONTIUM
SURFACE PROPERTIES
TECHNETIUM COMPOUNDS
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSPLUTONIUM ELEMENTS
TRANSURANIUM ELEMENTS
UNDERGROUND STORAGE
WASTE MANAGEMENT
WASTE STORAGE