OVERVIEW OF ARIES-RS NEUTRONICS AND RADIATION SHIELDING - KEY ISSUES AND MAIN CONCLUSIONS

The neutronics and radiation shielding issues were assessed for the AR IES-RS power plant. The assessment addresses the breeding level, servi ce lifetime, radiation damage, shielding requirements and design, and personnel protection. Major efforts were devoted to fulfil the top-lev el requirements which include the demonstration of a closed tritium fu el cycle, generation of no radioactive waste greater than Class C, and production of electricity at a competitive cost. The material optimiz ation was one of the themes of this study as it influences the neutron ics results and helps meet the requirements while minimizing cost. An important outcome of the neutronics and shielding analyses is the spec ification of the radial builds that contain key component parameters i n terms of sizes and optimal compositions. The shielding system compri ses a major element of the fusion power core (FPC). The primary functi on of the shield is radiation protection: protection of superconductin g magnets, vacuum vessel, workers and the public. As an element of the power core, the bulk shield meets other requirements for power produc tion and service lifetime. In addition, it serves as a heat sink for t he FW/blanket decay heat during a loss-of-coolant accident. All shield ing elements are integrated with the remainder of the FPC to meet the assembly, mechanical support and attachments, and maintenance requirem ents. The system requirements developed for the shield stem from these essential shielding functions. The work reported herein illustrates t he strong impact of numerous factors (such as service lifetime, blanke t segmentation, shield optimization, radial builds, and unit costs of materials) on the economics of power production. (C) 1997 Elsevier Sci ence S.A.