Why California is Rethinking its Nuclear Exit

California’s only remaining active nuclear power plant, Diablo Canyon on California’s Central Coast, was supposed to shutter in 2025, but a series of heat waves and stress on the grid prompted state leaders to keep it running through 2030. And now, as demand for electricity skyrockets, a new push is growing to reverse the state’s decision to abandon nuclear power, and to extend the plant’s life through 2045. We’ll talk to advocates who have been fighting the nuclear plant since the very beginning about the risks of continuing operations, and from those who believe nuclear power is necessary to meet California’s mandate to switch to 100% carbon-free energy by 2045.

Guests:

• Michael Wara, policy director for the Sustainability Accelerator at the Doerr School of Sustainability and director of the Climate and Energy Policy Program and senior research scholar at the Woods Institute for the Environment, Stanford University
• Laura Klivans, climate reporter, KQED
• Adrian Covert, senior vice president of public policy, Bay Area Council
• Jane Swanson, president and spokesperson, San Luis Obispo Mothers for Peace

This is a computer-generated transcript. While our team has reviewed it, there may be errors.

Alexis Madrigal: Welcome to Forum, I’m Alexis Madrigal. California has had a remarkable turn toward renewable energy for the last couple of decades. Wind and solar now power a big chunk of our electrical grid. We’ve gone away from gas and imported coal-fired electricity. Nuclear has never been a huge part of our energy mix, but we do have one plant still sending electrons into the grid, Diablo Canyon.

That power station, located near San Luis Obispo, is a massive facility that alone generates something like 9% of the state’s electricity and more than 15% of the state’s carbon-free kilowatt-hours. But this is an old facility. It’s in a fault zone. There are risks with nuclear power that simply don’t exist for solar and wind. Maybe this particular type of power plant belongs to an old regime that’s being outmoded by new renewables and batteries.

So that’s the setup. Here to talk with us about Diablo Canyon, we’re joined first by Laura Klivans, climate reporter for KQED. Welcome.

Laura Klivans: Thank you.

Alexis Madrigal: And we’ve got Michael Wara, senior research scholar at the Stanford Woods Institute for the Environment. Welcome, Michael.

Michael Wara: Good morning.

Alexis Madrigal: So, Laura, just tell us, give us the quick sort of narrative of what has happened with Diablo Canyon, you know, over the last 10 years.

Laura Klivans: Okay, so 2016, PG&E, labor unions and environmentalists came to this agreement saying, “We’re going to close Diablo Canyon.” There are a bunch of reasons for that. You’ve mentioned some of them. It’s near fault lines. That’s scary to people. Anti-nuclear sentiments were up after Fukushima in 2011. They also use ocean water for cooling, which harms submarine life. And so that’s something. And the licenses were already going to expire in 2024 and 2025 anyway.

Also, energy demand, interestingly, at the time, was flat. So it was kind of like, not in the place now where it’s just — pre-AI data center land.

Yeah, yeah, and electrifying everything as much as we are now. So we were also building out a ton of renewables. So it’s like, okay, let’s close it.

Then 2020, we’re all in this hellscape of COVID and heat, and the climate effects are really being felt in this state. And so there was a ton of stress on the grid, and we had some rolling blackouts. In California, that’s a politically really charged issue. We have had recalls for governors if they have been through blackouts. People want the grid to work. They want us to work.

So Newsom legislation acted in 2022. They extended the life of Diablo Canyon and said it’s not going to be decommissioned anymore. Also, we did not build out the renewables at the pace we were hoping to, even though we have had a huge growth.

Um, so — and then we also started to see this demand for more power with our electrification of buildings and cars, and now with data centers, too. So now we are on track to be open to 2030 for Diablo Canyon, but people — there’s a growing movement for that to extend longer, to 2045.

Alexis Madrigal: Um, Michael, I wanted to just ask you: What is involved, you know, if we think we’re going to shut down a plant and then we decide to keep it going? Did it have to get retrofitted? Were there things that had to be done and paid for there?

Michael Wara: Yeah, the plant had been in this kind of “we’re going to close” mode, and that involved, as Laura mentioned, workforce issues, getting people ready to be retired or moved to other parts of the company. And that’s really significant because, actually, to run nuclear power plants in the United States, the team that runs it has to be trained on that power plant. So you can’t just move around like you can for other jobs, which is probably good from a safety perspective.

Also, there were components of the plant that had reached the end of their lives. And it was sort of like with an old car: If you know you’re going to get rid of it, maybe you don’t replace the transmission. But this power plant in particular needed new high-pressure turbines, which are very expensive components in the power plant that have, since the decision to run it for another decade, been replaced at a cost of tens of millions of dollars. And who paid for that? PG&E customers.

Alexis Madrigal: Yeah. Yeah, yeah, yeah. Michael, how would you contextualize the 9% of the electricity grid that Diablo Canyon provides? Is that a lot? Is it a special kind of 9%? How should people be thinking about this in the scheme of things?

Michael Wara: Well, it is special in the sense that Diablo provides power — especially, this is special, especially for California — Diablo provides power when it’s dark. And that is an especially valuable kind of power for California because our renewables transition is so dependent on solar.

Alexis Madrigal: Mm-hmm.

Michael Wara: And increasingly, especially even relative to 2020 when this decision was made, dependent on solar plus batteries that last for about four hours. And so, as you get into the middle of the night, the alternatives shrink. They really involve imports, some hydroelectric power, Diablo Canyon, and then a lot of natural gas-fired power plants.

And so getting rid of Diablo right now would be a choice to burn more natural gas.

Alexis Madrigal: And do we even have the capacity to do that, or would we be importing from Nevada, I suppose, or something?

Michael Wara: Well, our gas plants could run a bit more. I think the way that our system works, we’d be looking for the most cost-effective sources of energy and also capacity, and Diablo can be one of those. It’s not always — you know, when there’s a lot of solar on the grid, all kinds of other resources start to be uncompetitive with, you know, the sun.

But at night, and especially also with the advent of much more available battery storage, right? Even during the day, you can buy Diablo Canyon power, store it and serve it to customers at night. And that’s much more feasible today than it was five years ago.

Alexis Madrigal: Laura, what is KQED — what does KQED — what’s PG&E saying about what they’d like to do?

Laura Klivans: Yeah, they would like to extend it to 2045. So what they have is they have permission to do that from the Nuclear Regulatory Commission. And so they applied for their license, and they applied for the maximum license, which is 20 years, and so they got it.

And so now what is hanging in the balance here is legislation. So we need state legislation to make it possible for them to keep going.

Alexis Madrigal: And do you see, like, who are the sort of forces here that are aligned, you know, for and against, Laura?

Laura Klivans: Yeah, I mean, it’s really — I think you can speak to this, too, Michael — but it’s really changed over time. But there’s a lot of people who are for nuclear power at this point. I think as climate change — we’re really seeing the effects of that and feeling it. People are seeing, hey, this is a carbon-free power source.

So we’ve got PG&E and we’ve — but, um, we’ve got — we also have, like, a bunch of business folks who are lining up behind this. They’ve created a coalition. I think we’re going to hear from somebody on the show about this later, like the Bay Area Council. They would like to see it.

On the flip side, people against it are — we’ve had these staunch groups. For example, there’s one group that’s been around since the sixties or seventies, who we’ll also hear from, I believe, in this hour: Mothers for Peace.

Alexis Madrigal: Mothers for Peace, yeah.

Laura Klivans: Who also say, you know, the risk is still there. Diablo Canyon and other nuclear power plants still produce waste that we do not have a solution for. And then you have other entities. There’s, like, the Coastal Commission that is concerned about the impact on marine life because of the cooling system that the plant uses.

Alexis Madrigal: Um, I want to get into some of the trade-offs here that might exist for Diablo Canyon. Like, were we to try and make up for this with solar capacity — like, Michael, like, how much would it be? I mean, we’re talking probably seven gigawatts of, like, so what does that look like in terms of sort of —

Michael Wara: Look like in terms of sort of industrial scale? So I just want to make one additional point about kind of the situation that’s changed since 2020. At the time when we made the decision to extend the life until 2030, we also were assuming that we would be building significant amounts of offshore wind.

And because of the Trump administration’s decisions about wind, because of their role that the federal government plays in permitting offshore wind, and especially offshore wind in federal waters, which this would be, I think it’s not realistic to think that we’re going to have that additional generation in place when we thought we would. And so that increases the value of Diablo Canyon.

It is true, Alexis, that in order to replace it with a mix of solar and batteries, you would need to build a multiple of the nameplate capacity. That’s the amount of energy it can produce in any given second or moment. In solar, and even then it’d be hard to replace. You’d also have to build a lot of battery storage because the value of Diablo Canyon is firm capacity. Like, it’s always available. It’s gonna be — well, except when it’s shut down for refueling — but it’s a kind of power plant that you can sort of depend on no matter what the weather looks like, no matter the season.

Solar obviously is less productive during the winter. Winter is going to become a source — a time when there’s more energy demand than at present, as we electrify cars and buildings. And so that is an increasing challenge for us.

So there’s a lot of characteristics of a nuclear power plant that make it especially valuable.

Alexis Madrigal: Well, and some folks have talked about this kind of baseload power eventually being provided by something like enhanced geothermal, which might have those same properties. But are we, like, ready to roll out, you know, a two-gigawatt enhanced geothermal plant right now?

Michael Wara: Not yet. And I’m really excited to see the future for enhanced geothermal. There are contracts that have been signed, especially by Southern California Edison, to provide a lot of enhanced geothermal. We’re going to see that technology proved out or not in the next few years, at which point we’ll be able to make a much more intelligent decision about whether to kind of put our chips on enhanced geothermal as an alternative to nuclear, a zero-carbon firm energy source, or whether it’s too expensive.

And I would just emphasize one thing that’s changed about the conversation with nuclear: There are many people that are supportive of nuclear that were not in the past, if it is affordable. And the key question is cost, and cost relative to alternatives that are also firm and also zero-carbon.

And so Diablo might be a great deal for the state of California to get some — approximately 10% of its power and capacity from zero-carbon energy sources — but not if it costs an arm and a leg. And that’s an important part of the conversation.

Alexis Madrigal: Well, at least my understanding — and Laura, maybe you can correct me if I’m wrong in this one — basically, older nuclear power plants, their power ends up being quite cheap because the cost has already sort of been paid for the construction and all the loans. And so what ends up coming out of the plant is really inexpensive relative to building a new nuclear power plant.

Laura Klivans: Yeah, I mean, we’ve paid back. We were about to decommission it. So we’ve — we pretty much paid off this loan to build this huge thing, which is a very impressive facility when you go and see it.

Um, and so you’re seeing estimates from both the CPUC and then folks at Stanford, MIT, where Diablo Canyon can save us tons of money, billions of dollars by some estimates, over a period of like 10 years.

But the criticism that comes up from a bunch of researchers as well is that the deal that was struck in 2022 was a bad one financially for ratepayers.

Alexis Madrigal: We’re talking about the future of California’s last functioning nuclear power plant. We are joined by Laura Klivans, climate reporter for KQED, of course, and Michael Wara, senior research scholar at Stanford Woods Institute for the Environment.

Of course, we’re gonna take your calls, too. What do you think? 866-733-6786, [email protected]. I’m Alexis Madrigal. Stay tuned.