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Alpha-Radiolysis of Aqueous Solutions

Published online by Cambridge University Press:  28 February 2011

Hilbert Christensen
Affiliation:
Studsvik Energiteknik AB, S-611 82 Nyköping, Sweden
Erling Bjergbakke
Affiliation:
Risö National Laboratory, DK-4000 Roskilde, Denmark
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Abstract

The effects of the radiolysis of water exposed to mixed alpha- and beta-radiation originating from spent fuel have been calculated. The water is assumed to have penetrated the copper canister and fuel cladding, and then to exist as a 30 μm thin surface film on the fuel pellets.

The combined effects of alpha and beta-radiation, and the presence of iron in the water have been found to be important parameters. The beta-radiation will lower the yield of hydrogen, as will the presence of low concentrations of iron ions. The most likely conditions for water exposed fuel give rise to a total production of 1 mol H2 per m2 fuel surface after 1 million years. A stoichiometric amount of oxygen is also formed.

Calculations have also been carried out in connection with experiments on alpha-radiolysis from Am-241 or from spent fuel pellets. In the case of alpha-radiolysis from Am-241 it was calculated that a 20 cm2 thin layer of 4 mCi Am-241 produced 1.4 × 10−3 cm3 hydrogen per day.

Calculations simulating the conditions of experiments on the leaching of spent fuel have shown that both alpha- and gamma-radiation accelerate the dissolution. The rate is strongly dependent on the dose rate and on the area of the water film covering the fuel surface and fuel fissures.

Type
Research Article
Copyright
Copyright © Materials Research Society 1985

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