Coolant flow around the fuel pins in a light water reactor core plays a critical role in determining the reactor’s performance. For yet-to-be-built small modular reactors, a thorough understanding of coolant flow will be key to successfully designing, building, and licensing first-of-a-kind reactors.

The definition of a microreactor is ambiguous. But whether your upper cutoff is 10 MW or 20 MW, the Microreactor Applications Research Validation and Evaluation (MARVEL) reactor that the Department of Energy plans to build is, at 100 kW, on the tiny side of micro.

TerraPower has a design for a sodium-cooled fast reactor and federal cost-shared demonstration funding from the Department of Energy. Its partner, PacifiCorp, has four operating coal-fired power plants in the state of Wyoming. On June 2, together with Wyoming Gov. Mark Gordon and others, the companies announced plans to site a Natrium reactor demonstration project at a retiring coal plant in Wyoming, with a specific site to be announced by the end of 2021.

U.S. energy secretary Jennifer Granholm and French minister for the ecological transition Barbara Pompili issued a joint statement on May 28 in which they pledged to work together to meet shared climate goals.

“France and the United States share common goals and common resolve in fighting climate change and working toward reaching the ambitious target set forth by the Paris agreement,” the statement read. “We are united in a common ambition on both sides of the Atlantic: achieving net-zero carbon emissions by 2050. Reaching this common objective will require leveraging all currently existing emission-free technologies available to us while simultaneously intensifying research, development, and deployment across a suite of zero-emissions energy sources and systems. Ensuring that these energy systems are efficient and reliable, integrating larger shares of renewables coupled with nuclear energy, which is a significant part of today’s electricity production in both our countries, will be crucial to accelerate energy transitions. Reaching this common objective will also require a wide variety of favorable financing conditions across the range of zero-emitting power sources and systems.”

The viability of nuclear power ultimately depends on economics. Safety is a requirement, but it does not determine whether a reactor will be deployed. The most economical reactor maximizes revenue while minimizing costs. The lowest-cost reactor is not necessarily the most economical reactor. Different markets impose different requirements on reactors. If the capital cost of Reactor A is 50 percent more than Reactor B but has characteristics that double the revenue, the most economical reactor is Reactor A.

The most important factor is an efficient supply chain, including on-site construction practices. This is the basis for the low capital cost of light water reactors from China and South Korea. The design of the reactor can significantly affect capital cost through its impact on the supply chain. The question is, how can advanced reactors boost revenue and reduce costs?

The White House Environmental Justice Advisory Council (WHEJAC) would appear to be not a fan of nuclear energy. In a May 13 report issued to the White House Council on Environmental Quality, WHEJAC lists “The procurement of nuclear power” under the heading “Examples of the Types of Projects That Will Not Benefit a Community.” (Other projects listed include fossil fuel procurement, carbon capture and storage, and cap and trade.) The 90-page report does not provide an explanation for the opposition.

The Department of Energy has announced up to $40 million in funding for a new Advanced Research Projects Agency-Energy (ARPA-E) program to conduct research and development into technologies for reprocessing and ultimately disposing of used nuclear fuel. The program, “Optimizing Nuclear Waste and Advanced Reactor Disposal Systems” (ONWARDS), announced on May 19, targets both open (once-through) and closed (reprocessing) fuel cycles to reduce the amount of waste produced from advanced reactors tenfold when compared to light water reactors.

Nonproliferation, safeguards, and security were on the agenda for the fifth public information-gathering meeting of the National Academies’ Committee on Merits and Viability of Different Nuclear Fuel Cycles and Technology Options and the Waste Aspects of Advanced Nuclear Reactors. Moderated by committee chair Janice Dunn Lee and NAS study director Charles Ferguson, the two-day public meeting was convened on May 17 and was to be followed by a closed committee session on May 19.

The National Reactor Innovation Center (NRIC) wants to hear from developers and end users interested in integrated energy systems for advanced reactors. Battelle Energy Alliance (BEA), the managing and operating contractor for Idaho National Laboratory, has issued a call for Expressions of Interest for a potential multi-phase demonstration program for innovative uses of nuclear energy, to be carried out by NRIC and the Crosscutting Technology Development Integrated Energy Systems (CTD IES) program. The final date for responses is May 21.

The health and safety of the public and protecting people from the consequences of a significant release of radioactive material has been a top priority since the early days of the civilian nuclear energy program. After World War II, it was realized that the core inventory of radionuclides is a potential hazard. From this knowledge, emergency planning zones (EPZs) for nuclear power plants were established.

The second day of the 2021 ANS Virtual Student Conference, on April 9, hosted by North Carolina State University opened with the plenary, “Student Opportunities within the Nuclear Community.” The session featured three panelists, each representing a different sector of the nuclear community.

North Carolina State University was finally able to host the ANS Student Conference, April 8 to 10. After the 2020 event was canceled due to the global coronavirus pandemic, the 2021 version is being held virtually for the first time.

The conference's opening session is available for registered attendees to view online.

Building the nation’s first advanced reactor is the goal of a partnership formed between X-energy, Energy Northwest, and the Grant County (Washington) Public Utility District (PUD).

The TRi Energy Partnership will support the development and demonstration of X-energy’s Xe-100 high-temperature gas reactor, which was selected by the Department of Energy for a cost-shared commercial demonstration by 2027 through the DOE’s Advanced Reactor Demonstration Program (ARDP). The new partnership was announced on April 1, when Clay Sell, X-energy’s chief executive officer; Brad Sawatzke, Energy Northwest’s CEO; and Kevin Nordt, the Grant County PUD’s CEO, met in Richland, Wash., to sign a memorandum of understanding.

Amanda Lines, a PNNL chemist, develops real-time monitoring tools to pave the way for faster advanced reactor testing and design. (Photo: Andrea Starr/Pacific Northwest National Laboratory)

Advanced reactor development and testing could benefit from a Pacific Northwest National Laboratory innovation that combines remote, real-time monitoring of gaseous fission by-products with a software package designed with plant operators in mind, according to an article published online earlier this month.

The basics: “Real-time monitoring is a valuable tool, particularly in the development of next-generation reactors,” said Amanda Lines, a PNNL chemist. “This can help designers more efficiently and effectively design and test flow loops, mechanisms, or processes. Also, when they ultimately deploy their reactor systems, this gives operators a tool to better understand and control those processes.”

Nesbit

Knowing that many ANS members are heavily involved in the development and regulatory oversight of advanced reactors, ANS Vice President/President-elect Steve Nesbit envisioned a place where members involved in the field could pool their resources, exchange ideas, and support interactions with other organizations and government agencies.

Nesbit’s vision is becoming a reality with the formation of the ANS Advanced Reactor Group. For now, it is housed within the Operations and Power Division, but the ARG will be open to other divisions as well. In fact, OPD chair Piyush Sabharwall said that input from across the ANS membership is essential for the group.

A replacement rotor is lifted and staged for the upcoming Browns Ferry-2 turbine work. Photo: TVA

The Tennessee Valley Authority has begun a refueling and maintenance outage at Browns Ferry-2 that includes the largest scope of turbine deck work since the unit’s construction, as well as innovations in fuel assembly components, the utility announced on March 1.

On deck: All three of the 1,254.7-MWe boiling water reactor’s low-pressure turbines will undergo a comprehensive replacement of major components, including new rotors, inner casings, steam piping and bellows, and turbine supervisory instruments, requiring the support of more than 500 additional outage workers. TVA said that 600 crane lifts will need to be performed for some components, such as the rotors, which weigh up to 327,888 lb., and inner casings, which weigh up to 200,000 lb.

The Nuclear Innovation Alliance (NIA) and the Partnership for Global Security (PGS) have released a joint report laying out a comprehensive strategy for U.S. leadership in the commercialization of next-generation nuclear power.

The 34-page report, U.S. Advanced Nuclear Energy Strategy for Domestic Prosperity, Climate Protection, National Security, and Global Leadership, says that collaboration between government, industry, civil society, and other nations can bring advanced reactors to market to reduce global emissions, provide domestic jobs, and support national security.

The report was released with a 58-minute webinar available on YouTube.

A Montana Senate committee last week passed a joint resolution calling for the creation of a legislative panel to study the feasibility of replacing the coal-fired units at the state’s Colstrip power plant with advanced small modular reactors.

Two of Colstrip’s four coal boilers were permanently closed in January 2020, and most energy-sector observers expect the remaining two units to be retired within the next few years, given coal’s declining prospects in states such as Washington, which has passed legislation banning utilities from using coal power after 2025.

The resolution, known as SJ3, also calls on the panel to evaluate current Montana regulations that need revision in order to enable the construction and operation of advanced nuclear reactors. The study would need to be concluded before September 15, 2022.

The Nuclear Regulatory Commission has opened registration for its annual Regulatory Information Conference (RIC), the largest public meeting the agency hosts. Scheduled for March 8–11, the 33rd RIC will be an all-virtual event.

The full conference program and registration information can be accessed from the RIC Web page.

Details: In addition to remarks from the NRC commissioners and the executive director of operations, RIC 2021 will feature two special plenary sessions, including one in recognition of the 10th anniversary of the Fukushima Daiichi accident, and 28 technical sessions covering a wide range of topics, such as advanced reactors, accident tolerant fuel, artificial intelligence, cybersecurity, microreactors, and risk-informed decision making.

ANSI/ASME/ANS RA-S-1.4-2021, “Probabilistic Risk Assessment Standard for Advanced Non-Light Water Reactor Nuclear Power Plants,” has just been issued. Approved by the American National Standards Institute (ANSI) on January 28, 2021, this joint American Society of Mechanical Engineers (ASME)/American Nuclear Society (ANS) standard sets forth requirements for probabilistic risk assessments (PRAs) used to support risk-informed decisions for commercial nuclear power plants and prescribes a method for applying these requirements for specific applications.

ANSI/ANS-RA-S-1.4-2021 and its preview are available in the ANS Standards Store.