PNNL research and development supports the commercialization and licensing of advanced nuclear reactors, including small modular reactors.

Small modular reactors and other advanced reactors are expected to reduce economic, security, technical, perceived safety, and regulatory barriers to the accelerated establishment in the United States of the next generation of nuclear power.

PNNL’s sponsors and collaborators include the U.S. Department of Energy (DOE) Office of Nuclear Energy (NE), the U.S. Nuclear Regulatory Commission (NRC), the National Reactor Innovation Center (NRIC), and the nuclear power industry.

Advanced reactor expertise

Research at PNNL supports new reactor concepts and designs. PNNL scientists and engineers contribute advanced instrumentation and controls, advanced materials and cladding, accident-tolerant fuel, metal fuel fabrication technology, and radiochemical processes.

The Radiochemical Processing Laboratory (RPL), a Hazard Category 2 nuclear research facility, provides a radiological analysis environment for testing and post-irradiation examination of advanced alloys, advanced fuels, and other materials and processes. RPL projects range from basic research and development and data generation to support for reactor licensing applications. 

PNNL’s expertise and project portfolio extends to Generation IV reactors, in particular, liquid metal fast reactors, molten salt reactors, and high-temperature gas reactors. PNNL received DOE-NE vouchers and DOE-NE Industry Funding Opportunity Announcement (FOA) funding in order to partner with industry to bring reactor concepts closer to licensing.

For more than two decades, PNNL has stewarded design information, operations, and safety data from the Fast Flux Test Facility (FFTF), a liquid-metal-cooled fast reactor operated for 10 years a few miles north of PNNL. The aim of stewarding this information is to help industry and DOE resolve core plant performance questions related to new reactor concepts. 

For the development of molten salt reactors (MSRs), PNNL uses modeling to predict the life of materials subjected to erosion and corrosion from flowing molten salt. In collaboration with an industry partner, PNNL is developing MSR Unit Operations to facilitate fuel and coolant management. Researchers are also developing advanced alloys, sensors, and instrumentation that can withstand the combined effects of elevated temperature, radiation, stress, and contact with molten salt.

A 2018 white paper provides more details on PNNL’s capabilities and achievements related to MSRs.

Technical support for licensing

PNNL works with the NRC, other government agencies, and industry to support the licensing of advanced and small modular reactor concepts. Lab experts help develop the required regulatory infrastructure for advanced reactor designs—in particular, standards for safety and environmental review. PNNL experts developed design-specific review standards for small modular reactors and led the NRC environmental review of the early site permit for the Clinch River site in Tennessee.

The NRC also uses templates developed at PNNL for risk-informed review procedures for the design and siting of new power plants.

As the nuclear power sector transforms itself, PNNL continues to deliver scientific and technological innovation to help sustain this important energy source into the future.