Grid · Analysis

San Onofre is coming down. Its fuel is staying on the beach.

A coastal plant that once made on the order of 2,200 megawatts stopped running in 2012 and is now mid-teardown. Its spent fuel sits in dry casks above the surf at San Clemente, with no federal site to take it.

BY THE RENEWABLE ENERGY LA EDITORS · FILED OCTOBER 28, 2026 · 6 MIN READ ·

How a coastal giant switched off

A nuclear plant makes heat, and heat boils water into steam that spins a turbine. SONGS ran two reactors, Units 2 and 3, each on the order of 1,100 megawatts, for a combined total of roughly 2,200 megawatts. In early 2012 a tube inside one of the plant's fairly new replacement steam generators (the large heat exchangers that carry heat from the reactor loop to the water that drives the turbine) sprang a small radioactive leak.

Inspectors then found unexpected wear on hundreds of tubes in those replacement units, a problem serious enough that restarting was never going to be simple. After more than a year of study and argument, Southern California Edison announced in 2013 that both units would retire for good. A plant built to run for decades more was suddenly done.

What filled the hole

Losing about 2,200 megawatts of around-the-clock coastal power is not a small thing, and the grid did not replace it with one clean swap. At first the gap was filled largely by burning more natural gas, which pushed regional emissions up for a few years and leaned on aging coastal gas plants the state had hoped to close.

Since then the mix has shifted. California has added a large and growing fleet of grid batteries (banks that charge on cheap midday solar and discharge into the evening peak), along with more rooftop solar across the basin and power imported over long transmission lines from other states. The California Independent System Operator, the nonprofit that runs the state grid, now leans on that storage to get through hot evenings. It is a looser, more weather-dependent substitute for a plant that simply ran.

The fuel that is not leaving

Here is the part that stays local for a very long time. The plant's spent fuel, the used uranium that is intensely radioactive and hot, sits in dry cask storage a few hundred feet from the water. Dry casks are steel canisters, each sealed and packed into a concrete structure cooled by nothing more than moving air. At last public report there are roughly 120 of these canisters on the San Onofre pad.

Under federal law the Department of Energy was supposed to begin hauling this fuel to a national repository years ago. That site, long proposed at Yucca Mountain in Nevada, has no funding and no timeline, so the fuel stays put. Southern California Edison keeps the pad, the Nuclear Regulatory Commission inspects it, and a decommissioning trust that ratepayers funded (on the order of four billion dollars) pays for the teardown. For readers, the plain fact is this: the reactors will be gone, and the waste will still be on the beach.

Worth watching this month

1. The Nuclear Regulatory Commission's SONGS decommissioning page posts teardown milestones and inspection findings, mostly routine, but worth a periodic check.

2. Southern California Edison's community site lists dates for the public engagement panel that reviews cask storage and dismantling, which is where local questions actually get aired.

3. The California Public Utilities Commission continues to oversee how the multibillion-dollar decommissioning trust is spent, a slow proceeding but the one that touches your bill.

4. Any federal movement toward interim or consolidated spent-fuel storage would matter here more than almost anywhere, though progress has been glacial for decades.

5. The California grid operator's seasonal reliability assessments show whether batteries and imports are comfortably covering the kind of demand SONGS once met.

Where this dispatch reads

U.S. Nuclear Regulatory Commission, San Onofre decommissioning, www.nrc.gov/info-finder/decommissioning/power-reactor, The federal nuclear regulator's status pages for SONGS teardown, cask storage, and inspection findings.
Southern California Edison, SONGS Community, www.songscommunity.com, SCE's public decommissioning site, with the teardown schedule, cask-loading status, and community panel dates.
California Independent System Operator, www.caiso.com, The California grid operator; its reliability assessments show how supply stays balanced after plant retirements.
California Public Utilities Commission, www.cpuc.ca.gov, The state regulator overseeing SONGS decommissioning costs and the ratepayer-funded trust that pays for the teardown.
California Energy Commission, www.energy.ca.gov, State energy agency tracking generation, storage, and imports across California.

Questions readers have asked

Is the spent fuel safe sitting by the ocean?

Regulators say the dry casks are built to withstand earthquakes, flooding, and corrosion, and the Nuclear Regulatory Commission inspects them. The honest caveat is that this was always meant to be temporary storage, not a permanent home, and it has already lasted far longer than planned.

Why can't the fuel just be moved somewhere else?

There is no federal site willing and able to take it. The long-proposed Yucca Mountain repository has been stalled for years, and no interim site has been built, so for now the fuel stays where it is.

Did my electric bill pay for the shutdown?

In part, yes. Decommissioning is funded through a trust built up from ratepayer charges over the plant's life, and the California Public Utilities Commission reviews how that money is spent.

Will anything be built on the site when the teardown is done?

The reactor structures are being removed, but the spent-fuel pad will remain as long as the fuel has nowhere to go. The rest of the land's future is undecided and depends partly on the Navy, since the plant sits on Camp Pendleton.