The significance of leach rates in determining the release of radioactivity from vitrified nuclear waste

Journal Article · Wed Jun 01 00:00:00 EDT 1983 · Nucl. Technol.; (United States)

OSTI ID:5526340

Hughes, A E; Marples, J A.C.; Stoneham, A M

Most tests of the dissolution behavior of glasses quote the leach rate, often measured in flowing solutions. In the past, it has been pointed out that this may not be the rate-determining factor for the dissolution of glass in a radioactive waste repository because of the very small flow rate of water past the glass surface. Under these conditions, the rate of removal of elements from the glass would be controlled by the flow rate and the effective saturation solubility of the glass in the water, or, in stagnant conditions, by the rate of diffusion of species dissolved in the water away from the glass surface. Simple quantitative models are developed to provide a framework for the discussion of these effects, and they indicate that in cases of practical importance it is indeed solubility and either water access or diffusion that together limit the rate of dissolution of the glass. It can be concluded that effective leach rates in a repository will be below 10/sup -7/ g X cm/sup -2/ X day/sup -1/, a figure that in other studies has given a clear margin of long-term safety for radiological purposes.

• Research Organization: Atomic Energy Research Establishment-Harwell Materials Development Division, Didco, OX11 ORA
• OSTI ID: 5526340
• Journal Information: Nucl. Technol.; (United States), Vol. 61:3
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
RADIOACTIVE WASTE PROCESSING
VITRIFICATION
RADIOACTIVE WASTES
LEACHING
RADIOACTIVITY
DIFFUSION
DISSOLUTION
FLOW RATE
GLASS
RADIOLOGY
SATURATION
SOLIDIFICATION
SOLUBILITY
SURFACES
WATER
HYDROGEN COMPOUNDS
MANAGEMENT
MATERIALS
MEDICINE
NUCLEAR MEDICINE
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PROCESSING
RADIOACTIVE MATERIALS
SEPARATION PROCESSES
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
052000* - Nuclear Fuels- Waste Management