Recent technical progress in fusion research has been sufficient to encourage the development of conceptual designs for fusion power systems. These design efforts suggest that more attention should be paid to the safety and environmental effects of the radioactivity induced in the structural materials by the fusion neutrons. In particular, radioactivity from neutron activation of the structural components of a fusion power system will be a concern for occupational exposure of personnel. Careful choice of structural materials can significantly reduce this exposure. We propose the Remote Maintenance Rating (RMR) as a numerical means of comparing materials and machine designs with respect to occupational exposures. The RMR is defined as the dose rate at the surface of a uniformly activated, thick, infinite slab with the same composition and density as the machine component. We used the RMR rating system to evaluate the suitability of several different iron-based alloys. The specific fusion power system design used in our evaluation was a conceptual design from the Mirror Advanced Reactor Study (MARS). We determined that HT-9 is significantly better in terms of radiological dose rates at early times than the other iron-based alloys (by a factor of 3 to 7). We also calculated the …

Separate abstracts were prepared for 20 papers in this report. For several years the Department of Energy (DOE), Office of Health and Environmental Research (OHER), has supported a research program aimed at developing new experimental approaches for the improvement of cancer risk assessments. The central issue is to overcome the organizational, species and other barriers that make it difficult to extrapolate laboratory-based data to predict risk to man. Most of the participants at the meeting are involved in research aimed at understanding the mechanism(s) of chemical carcinogenesis. Complex mixtures of chemicals are associated with many energy technologies. DOE's initial program emphasis focused on semi-applied research aimed at quantitative evaluation of carcinogenic activity of complex materials. Since much progress has been made in DOE integrated technology-specific chemical-biological characterization studies, the number and kinds of chemicals of concern has been reduced to a relatively few well-defined classes. Although the classes of compounds seem to be unique to some of the synfuel technologies, they are quite similar to compounds of general interest, for example, poly-nuclear aromatic hydrocarbons. Special emphasis was placed on molecular and cellular dosimetry as one of the key requirements for quantitative comparison of effects at the cell level in vivo …