On the radiological behaviour of first wall fusion structural materials

The present report examines the radiological behaviour of low-activity structural materials for the first wall and blanket of nuclear fusion reactors. In this context the allowable concentration limits for all the stable elements are discussed for the neutron irradiation conditions of commercial fusion reactors. Some long-term activation properties of low-activity alloys proposed as structural materials are determined and methods of reducing their residual radiological hazard are examined. The way in which the accuracy of the results depends on the completeness and the uncertainty associated with the neutron cross-section data is discussed and some examples are given of relatively poorly-defined reaction cross-sections the values of which could have important implications for the conclusions. (author)