Nuclear Operators Scramble To Make Reactors Flexible Enough For New Energy Economy

Arizona Public Service is studying the possibility of using excess energy from its Palo Verde Nuclear Power Plant, when solar energy is flooding the grid, to desalinate brackish water.

In Illinois, Exelon is looking at repurposing a reactor to produce hydrogen when there's plenty of wind energy on the grid, then using the hydrogen for steelmaking, ammonia production or fuel-cell vehicles.

Across the country, nuclear operators are trying to figure out whether they can ramp down their reactors, which are optimized to run at maximum capacity, during those hours or seasons when renewable energy is abundant.

"What I want you to walk away with today is that nuclear power plants are flexible, and they are able to integrate with the grid to support some of the increasing grid variability," said Sherry Bernhoft of the Electric Power Research Institute (EPRI).

"Flexible operations are being implemented right now at some plants and there are impacts, but they are being safely managed."

The Arizona and Illinois examples are case studies undertaken by the utilities, EPRI, and the Department of Energy to repurpose nuclear energy when it's not needed for electricity production.

Reactors could provide electricity or heat for industry, for hydrogen production or water production or for chemical processes, said Shannon Bragg-Sitton of Idaho National Laboratory.

"We are looking at other ways in which we can generate energy system flexibility such that our nuclear plants can continue to provide the reliable baseload services that they do right now to the grid and maintain really strong economic performance by providing electricity and or heat to other applications," Bragg-Sitton said.

German officials recently boasted of achieving 100 percent renewables penetration on their grid, saying flexibility made it possible. Germany contends that flexibility renders obsolete the concepts of baseload and peak, and it has decided to close all its nuclear plants by 2022.

But the United States continues to seek ways to keep alive its aging fleet of reactors. Bernhoft and Bragg-Sitton revealed some of those ways during a webinar last month hosted by the Clean Energy Solutions Center. It included a economic analysis and an update from Canada, which is focused on coupling small modular reactors with hydrogen production.