Development of Cable Insulation Materials for Small Modular Reactors

Electrical cables installed in advanced reactors will be subjected to harsher operating conditions than those present in the current fleet of light water reactors and, therefore, must be constructed with durable materials that can withstand higher temperatures/radiation levels and have longer lifetimes. Thus, developers must be supplied with the tools and information required to identify and select cable materials that are suitable for their reactor environments and service conditions. To support the development and deployment of advanced reactors, the proposed research will provide the guidance and tools needed to select and develop cable materials used by reactor designers, cable manufacturers, and material developers. This effort will involve assessing the survivability and limitations of existing and novel insulation materials when exposed to advanced reactor environments. In Phase I, the proposing firm demonstrated that a limited number of existing cable insulation polymers may be suitable for the high temperatures in advanced reactor designs. High-temperature resistant polymers samples were thermally aged and periodically tested using laboratory materials characterization techniques to assess changes in their material properties. Based on the Phase I initial findings, polyether ether ketone (PEEK) is the most promising candidate material of the polymers evaluated. However, additional research is needed to expand the types of candidate materials and address the effects of radiation exposure and the impact of other environmental extremes. The research and development effort proposed for Phase II will involve testing and evaluation of a wide range of material types subjected to various environments that encompass the harsh conditions that will be present in different advanced reactor designs. This will be accomplished by 1) acquiring candidate insulation materials, 2) exposing the materials to elevated temperatures that encapsulate a broad range of advanced reactor environments 3) performing radiation exposure and testing of the materials at a range of total doses and dose rates, and 4) verifying their performance under various design basis event simulations through electrical and materials testing. The results of the Phase II work will provide the advanced reactor industry with the environmental qualification, testing guidance, capabilities, and tools they need to develop and select insulation materials for electrical cabling. The commercialization of the project will initially be in terms of laboratory testing, qualification, and engineering services to new reactor developers and cable manufacturers. In the long-term, the technologies and expertise developed under this project will be leveraged to provide testing services for the safe and efficient operations of the next generation of reactors.