Nuclear energy is increasingly being recognized as a valuable low-carbon, low-emissions energy source that can help meet clean energy targets being set by states, commissions, and utilities in the United States. Currently, nuclear power provides about one-fifth of the country's electricity. Nuclear power plants (NPPs) further provide the grid with all-weather season-long baseload capacity that is important to grid reliability and resiliency.An innovative revenue model that has been proposed for U.S. LWRs is to alternatively use the heat and electricity from nuclear reactors to produce indemand industrial products-hydrogen for use in fuel cell electric vehicles (FCEV), cofiring with natural gas (NG), petroleum and biofuel refining, ammonia production, direct-reduced iron (DRI) for steel production, and synthetic fuels (synfuels) and chemicals (synchems) such as methanol, polymers, formic acid, and others-via thermal and electrochemical processes during seasonal and daily periods of low grid-electricity market pricing (overgeneration) in lieu of being curtailed or producing electricity to the grid at a less-than-optimal electricity price. Repurposing NPPs to flexibly produce nonelectric products and clean-energy carriers could help alleviate the economic pressure on NPPs and enable decarbonization of the power sector, as well as the transportation and industrial sectors. Key AssumptionsParameters taken into account in this analysis are grouped as floating variables, which can be optimized (e.g., the size of the HTSE), fixed parameters (e.g., HTSE O&M costs), estimated parameters for which a range is provided (e.g., H2 demand distance), and key results that are derived as part of the analysis (e.g., H2 daily production rate, HTSE overcapacity, and HTSE CAPEX). The price of hydrogen,

The Non-Proliferation Treaty and other non-proliferation agreements are in place worldwide to ensure that nuclear material and facilities are used only for peaceful purposes. Antineutrino detectors, sensitive to reactor power and fuel changes, can complement the tools already at the disposal of international agencies to safeguard nuclear facilities and to verify the States’ compliance with the agreements. Recent advancement in these detectors has made it possible to leverage them to reduce the likelihood of an undetected diversion of irradiated nuclear material. Here we show the sensitivity of antineutrino monitors to fuel divergence from two reactor types: a traditional light-water reactor and an advanced sodium-cooled reactor design, a likely candidate for future deployment. The analysis demonstrates that a variety of potential diversion scenarios can be detected by such a system. We outline recent developments in monitoring capabilities and discuss their potential security implications to the international community.

Molten-salt reactors (MSRs) will likely require some level of irradiation testing as part of their licensing basis. An ideal experiment would consider the integrated effect of neutron flux and fission product generation in addition to circulating flow conditions. The feasibility of a natural-circulation irradiation salt loop in the Advanced Test Reactor (ATR) is assessed here. The flow is induced by the innovative combination of gas-gaps and fin-gaps along the capsule wall to finetune radial heat conductance and therefore drive an axial temperature gradient across the experiment height. Following multiple design optimizations, a promising configuration was identified. The 45-kW experiment would generate a 0.15 m/s flow velocity with 6 kg of fuel-bearing salt. This demonstrates the possibility of generating appreciable flow rates within manageable experimental conditions (e.g., total size and heat generation). An initial assessment of species mass tracking inside the experiment was also performed to gain an understanding of radionuclide behavior within the system. Results showed that significant quantities of Xe can be extracted in the off-gas (1.7 kCi) for 8% bubble removal efficiency rate. These results highlight the potential value of such experiments. Further work will involve detailed engineering drawings and analyses of the loop, as well as more computationally expensive modeling of species mass tracking.

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