Phase II Amount
$1,000,000
Recently, the Generation IV International Forum has established a set of nuclear reactors (advanced nuclear reactors), with main objectives to improve overall reactor safety, efficiency, sustainability, and proliferation resistance for economically viable nuclear energy. These advanced reactor technologies rely on novel fuels and materials that are resistant to radiation damage and corrosive environments, while withstanding significantly higher operating temperatures. However, the lack of data for most of these novel and advanced materials calls for renewed testing efforts performed in an intense fast neutron flux (E >0.1 MeV) while mimicking a fast reactor-like environment. Fast fluxes greater than 1015 n/cm2s provide an accelerated material radiation-damage rates of ~20 dpa/yr. These fluxes are conventionally achieved with fast reactors, which are not currently available in the US, since the shutdown of the Fast Flux Test Facility. Therefore, US researchers are required to ship samples overseas for long-term irradiations or utilize domestic thermal-spectrum test reactors; both of which have their own set of complications and drawbacks. To overcome this problem, Niowave proposed to develop a subcritical testbed that can provide a fast reactor-like environment to support experimentation and demonstration of novel fuels and materials, without the logistical and regulatory challenges and expenses of fast reactors. In this system, an electron linac with a lead-bismuth eutectic neutron converter is coupled to a HYbrid fast/thermal core configuration Subcritical Testbed (called HYST) to provide 1015 n/cm2s fast flux level. The fast core region contains a sufficient volume (?100 cm3) for testing advanced nuclear reactor materials. In Phase I, two candidate core designs were devised by modeling and examining the neutronics performance characteristics of the fast/thermal core and evaluating the linac-based external neutron source. Both core designs, HYST I and II, showed the feasibility of the hybrid core configuration concept and a noticeable reduction in the fission power and fissile loading compared to an all fast core design. In Phase II, Niowave proposes to license, construct, and operate a small-scale low-power demonstration system with Niowaves existing uranium fuel, based on HYST-I concept, and perform detailed core design and tradeoff studies of the targeted goal for HYST while establishing the NRC licensing roadmap. In Phase III, a prototype of HYST design will be licensed, built, and operated at ~200 kW fission power (1/100th of final design level), producing 1013 n/cm2s fast neutron flux level by 2025 with a budget <$10 million. The objective is to establish the prototype HYST facility for US companies and DOE funded researchers at a reduced cost and time. This will provide operational data, characterization, and evaluation of the performance of novel fuels, materials, instrumentations, components, new reactor designs, and safety features. It will also support the regulatory process for licensing novel technologies and the development of high-fidelity reactor codes. This work will be accomplished by leveraging the knowledge, tools, and expertise from Niowaves existing radioisotope program (thermal subcritical core operating at 210 kW by 2023) and partnering with additional collaborators such as US advanced reactor companies, national laboratories, and DOE. After demonstrating a 200 kW prototype HYST, the final phase will be focused on ultimately building the full scale HYST that offers 1015 n/cm2s fast flux level while supporting US companies with their efforts to license, construct, and build next generation advanced nuclear reactors.