γ-radiation induced corrosion of copper in bentonite-water systems under anaerobic conditions

• In this work we have experimentally studied the impact of bentonite clay on the process of radiation-induced copper corrosion in anoxic water. The motivation for this is to further develop our understanding of radiation-driven processes occurring in deep geological repositories for spent nuclear fuel where copper canisters containing the spent nuclear fuel will be embedded in compacted bentonite. Experiments on radiation-induced corrosion in the presence and absence of bentonite were performed along with experiments elucidating the impact irradiation on the Cu2+ adsorption capacity of bentonite. The experiments presented in this work show that the presence of bentonite clay has no or very little effect on the magnitude of radiation-induced corrosion of copper in anoxic aqueous systems. The absence of a protective effect similar to that observed for radiation-induced dissolution of UO2 is attributed to differences in the corrosion mechanism. This provides further support for the previously proposed mechanism where the hydroxyl radical is the key radiolytic oxidant responsible for the corrosion of copper. The radiation effect on the bentonite sorption capacity of Cu2+ (reduced capacity) is in line with what has previously been reported for other cations. The reduced cation sorption capacity is partly attributed to a loss of Al-OH sites upon irradiation.

Ämnesord

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Nyckelord

Aluminum compounds

Anoxic sediments

Copper

Copper corrosion

Corrosion

Irradiation

Positive ions

Radiation

Adsorption capacities

Anaerobic conditions

Compacted bentonite

Corrosion mechanisms

Deep geological repository

Protective effects

Sorption capacities

Spent nuclear fuels

Bentonite

hydroxyl radical

nuclear fuel

adsorption kinetics

anaerobic capacity

Article

embedding

environmental impact assessment

gamma radiation

water supply

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)