TRANSMUTATION AND ACTIVATION EFFECTS IN HIGH CONDUCTIVITY COPPER ALLOYS EXPOSED TO A FIRST WALL FUSION NEUTRON FLUX
Transmutation and activation characteristics are calculated for a number of high conductivity copper based alloys exposed to 2.5 years continuous irradiation in the first wall neutron flux of the Culham Conceptual Tokamak Reactor IIA with neutron power loading of 7 MWm**-2. The computations are based on a modified form of the ORIGEN code and the cross section data library UKCTRIIIA. It is found that the copper base transmutes to other elements, principally nickel and zinc, at the rate of 0.28 weight percent per MWym**-2. The probable effect of these unintended alloying additions on the thermal conductivity is briefly discussed. Since their activities are generally dominated by that of the copper component, the dilute alloys studied exhibit very similar activation and decay properties. The long-term surface dose rate of alumina dispersion strengthened alloys may, however, be dominated by the gamma decay of 26-Al with half life 7.4 x 10**5 y. Comparison is made with the activation characteristics of type 316 austenitic steel and the martensitic steel HT-9. It is noted that the long-term activity of copper alloys may in practice be governed by their silver impurity content, unless this can be reduced to about 1 ppm.
Bibliographic Reference: WRITE TO THE LIBRARIAN, UKAEA, CULHAM LABORATORY, ABINGDON, OXON OX14 3DB (UK), MENTIONING REPORT CLM-P733, 1985
Record Number: 1989124061600 / Last updated on: 1987-01-01
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