Researchers in the US have developed a modeling approach that could allow nuclear power plants to adjust electricity production to changing grid demand without repeatedly reducing reactor output.
The system combines molten salt reactors with thermal energy storage, allowing excess heat to be stored when power needs are low and used to generate additional energy when demand increases.
The approach developed by researchers at the University of Central Florida (UCF) could help nuclear power plants operate alongside solar and wind farms, whose electricity production changes depending on weather conditions and time of day.
Researchers combined thermodynamic modeling with economic analysis to examine how storing and releasing reactor heat could improve operational flexibility and help nuclear power plants respond to fluctuating electricity prices.
Heat retention between tips
In contrast to solar and wind turbines, conventional nuclear power plants are usually designed to continuously produce electricity. Adapting their production to rapid changes in demand can create operational challenges.
As renewable energy accounts for a larger share of electricity generation, nuclear power plants may need to become more flexible without compromising the stable operation of their reactors.
“Nuclear power needs to be flexible, while nuclear reactors run at a steady pace as grid demand fluctuates throughout the day, and this is particularly pronounced in grids with high levels of solar radiation, which typically peaks around midday and decreases toward evening,” said Augusto Delavald Marques, a graduate student involved in the study.
Thermal energy storage provides a way to separate heat generation from electricity generation.
Instead of sending all of the heat produced by a reactor directly to the power generation system, some could be diverted to storage when power demand is low.
The stored heat could then be released to generate additional electricity during times of higher demand.
This arrangement would allow the reactor to maintain a relatively stable level of operation while the power generation system adjusts its output.
Researchers focused on molten salt reactors, an advanced nuclear reactor design that uses molten salts to operate. The study examined how these reactors could be integrated with thermal storage to enable more flexible power generation.
Matching edition with prices
The study also examined how electricity market conditions could affect the operation of nuclear power plants equipped with thermal storage.
Electricity prices fluctuate throughout the day as demand and available generation change. Prices may fall when renewable energy production is high and rise when demand increases or renewable energy production declines.
By storing heat during times of lower prices and releasing it when electricity becomes more valuable, nuclear power plants could potentially increase the revenue from their generation.
The researchers used thermodynamic models to examine the operation of the proposed system and an economic optimization approach to assess how it might respond to changing market conditions.
Their analysis included a rolling horizon approach, in which operational decisions are evaluated over successive periods rather than assuming a fixed schedule.
However, the research remains a model study. The team has not demonstrated the integrated system at an operating nuclear power plant.
Concrete figures on efficiency improvements, additional income or the costs of installing heat storage units were also not mentioned in the university’s announcement.
Further technical and economic evaluations would be required to determine whether the proposed approach could be commercially viable.
The study was published in Journal of Energy Resources Technology, Part A: Sustainable and Renewable Energy.
