The California legislature has signaled its intent to cancel a $400 million loan payment intended to help finance a longer lifespan for the state’s last nuclear power plant, Diablo Canyon.

During state budget debates, the votes in the state senate and assembly last week on funding for the two-unit plant exposed a disagreement between lawmakers on one side and Gov. Gavin Newsom on the other. Newsom has said that the power generated by Diablo Canyon is critical to safeguarding energy supplies amid a warming climate, according to the Associated Press. The disagreement also set up a public friction point involving one of the governor’s signature proposals—Diablo Canyon—which he has championed alongside the state’s rapid push toward solar, wind, and other renewable sources.

A closer look: The dispute unfolded in Sacramento as environmentalists and antinuclear activists warned that the estimated price tag for keeping the seaside reactors running beyond a planned closing by 2025 had ballooned to nearly $12 billion, roughly doubling earlier projections. That also raised the prospect of higher fees for ratepayers.

Pacific Gas & Electric, operator of Diablo Canyon, called those figures inaccurate and inflated by billions of dollars.

Another view: In an opinion piece in the Sacramento Bee, Maureen Zawalick, vice president of business and technical services at Diablo Canyon, argues that the plant has been the backbone of California’s clean-energy ambitions for decades. And it remains a provider of 9 percent of the state’s electricity, all delivered clean and emissions free.

“I believe Californians deserve a full accounting of both the costs and financial benefits of operating California’s largest source of clean energy,” Zawalick wrote. “The math is clear that keeping Diablo Canyon open through 2030 will not only ensure that California can keep the lights on without backsliding on its climate goals, it will also save customers $200 million per year on average—or more than $1 billion—over the duration of the extended operations period.”