New model diverts excess heat to adjust power output without slowing reactors

Researchers in the US have developed a modeling approach that could allow nuclear power plants to adjust electricity output to changing grid demand without repeatedly reducing reactor power. The system combines molten salt reactors with thermal energy storage, allowing excess heat to be stored when electricity demand is low and used to generate additional power when demand increases. Developed by researchers at the University of Central Florida (UCF), the approach could help nuclear plants operate alongside solar and wind farms, whose electricity production changes with weather conditions and the time of day. The researchers combined thermodynamic modeling with an economic analysis to examine how storing and releasing reactor heat could improve operational flexibility and help nuclear plants respond to fluctuating electricity prices. Storing heat between peaks Unlike solar and wind installations, conventional nuclear power plants are generally designed to produce electricity continuously. Adjusting their output to match rapid changes in demand can introduce operational challenges. As renewable energy contributes a larger share of electricity generation, nuclear plants may need to become more flexible without compromising the steady operation of their reactors. “Nuclear power needs to be flexible while nuclear reactors operate at a steady pace because grid demand varies throughout the day, and this is especially pronounced in grids with high solar penetration, which typically peaks around noon and diminishes toward night,” said Augusto Delavald Marques, a doctoral researcher involved in the study. Thermal energy storage offers a way to separate heat production from electricity generation. Instead of sending all the heat produced by a reactor directly to the power generation system, some could be diverted into storage when electricity demand is low. The stored heat could then be released to produce additional electricity during periods of higher demand. This arrangement would allow the reactor to maintain a relatively steady operating level while the electricity generation system adjusts its output. The researchers focused on molten salt reactors, an advanced nuclear reactor design that uses molten salts in its operation. The study examined how these reactors could be integrated with thermal storage to provide more flexible electricity generation. Matching output with prices The research also examined how electricity market conditions could influence the operation of nuclear plants equipped with thermal storage. Electricity prices vary throughout the day as demand and available generation change. Prices can fall when renewable energy production is high and rise when demand increases or renewable output declines. By storing heat during lower-price periods and releasing it when electricity becomes more valuable, nuclear plants could potentially improve the revenue earned from their generation. The researchers used thermodynamic modeling to examine the proposed system’s operation and an economic optimization approach to assess how it could respond to changing market conditions. Their analysis included a rolling-horizon approach, which evaluates operating decisions over successive time periods rather than assuming a fixed schedule. However, the research remains a modeling study. The team has not demonstrated the integrated system at an operating nuclear power plant. The university’s announcement also did not provide specific figures for efficiency improvements, additional revenue, or the cost of installing thermal storage. Further engineering and economic assessments would be needed to establish whether the proposed approach could be commercially practical. The study was published in the Journal of Energy Resources Technology, Part A: Sustainable and Renewable Energy. Get the latest in engineering, tech, space & science - delivered daily to your inbox.With over a decade-long career in journalism, Neetika Walter has worked with The Economic Times, ANI, and Hindustan Times, covering politics, business, technology, and the clean energy sector. Passionate about contemporary culture, books, poetry, and storytelling, she brings depth and insight to her writing. When she isn’t chasing stories, she’s likely lost in a book or enjoying the company of her dogs.