How Diablo Canyon’s
likely delayed decommissioning will be extremely costly and comes with risks
KCLU | By Michelle
Loxton
Published November 25, 2022 at 12:00 AM PST
California's last operational nuclear power plant is perched on
the ocean’s edge near the City of San Luis Obispo on the Central Coast. Diablo
Canyon was due to close in 2025 – it’s unlikely that’s going to happen. But,
ultimately one day it will be decommissioned. We look at the costs and risks
for the local community.
The story comes from KCLU’s podcast The One Oh
One. You can listen to the full episode here.
California’s largest single source of electricity, about 10% of it, comes
from Diablo Canyon Nuclear Power Plant. And that electricity is carbon free.
This plant sits on the edge of the Pacific Ocean, west of San
Luis Obispo and south of Morro Bay.
A lot of power plants loom large in the communities they reside
– this one – not so much. The plant is miles from the closest community and
perhaps the only reason you’d be traveling in that direction is to hike the
beautiful nature trails of the state park that neighbors the plant.
“Diablo Canyon’s tucked away seven miles down a road, out of
sight to a large number of people out of mind,” said Bruce Gibson, the current
Chair of the San Luis Obispo County Board of Supervisors. He’s been a
supervisor since 2007.
“My guess is that 85 to 90% of the population hardly ever think
of it,” said Gibson.
It’s not on the radar of many people – even the locals.
So why should we care about this plant?
Even if it's not going to happen on its original
schedule, Diablo Canyon will eventually be decommissioned.
And, that decommissioning process will not be quick. It could take decades; cost billions of dollars;
with the end product possibly being a hundred plus canisters of spent nuclear
waste stored at the site in perpetuity.
That impacts San Luis Obispo County and its residents of course,
but the cost and risks to decommissioning should be something we all pay
attention to.
We need a case study
To fully understand what this process will be like, it helps to
have a case study of sorts.
Luckily there is something like that – the now decommissioned
Humboldt Bay Nuclear Power Plant, located over 500 miles north of Diablo
Canyon, also on the California coast.
Mike Manetas
/
After operating for only 13 years, Humboldt Bay Nuclear Power
Plant went offline in 1976, after the discovery of an earthquake fault below
it. From the moment it went offline to the end of the decommissioning, the
process took 45 years.
“I've been here since 1966 and I've been living in the same
place for the last 50 years actually,” said Mike Manetas, a longtime Humboldt
Bay resident and a retired professor from Humboldt Bay State University, now
known as Cal Poly Humboldt.
As part of the Environmental Engineering Department for over 20
years he taught a class on the decommissioning of the Humboldt Bay Nuclear
Power Plant and was appointed to the community advisory board following that
decommissioning – which meant many trips to the plant over the years.
“Because nobody knew anything about what was going on. And so I
learned a lot myself. And I brought in all kinds of expertise to examine what
the process was,” said Manetas.
Why is Humboldt Bay a good case study for us
to use?
Well, firstly that decommissioning has been completed. The whole
process is done. It’s also – like Diablo Canyon – right on the ocean’s edge
with some of the same concerns like earthquake faults and marine impacts. And
lastly, they’re both operated by Pacific Gas and Electric or PG&E.
A note here: despite multiple requests to PG&E for an
interview for this episode, I never heard back.
So by studying Humboldt Bay’s decommissioning we can get an idea
of what to expect.
With everyone I spoke to for this story, the two most important
factors about decommissioning came down to the costs and the risks.
Let’s start with the costs.
After operating for only 13 years, Humboldt Bay Nuclear Power
Plant went offline in 1976, after the discovery of an earthquake fault below
it.
“Everything in the facility is to be removed and the site will
be restored back to what it naturally was before the plant was built there,”
explained Manetas.
So it went offline in the mid-1970s. Actual decommissioning only
started in 2009. The site was completely decommissioned last year – 2021 –
meaning from the moment it went offline to the end of the decommissioning, the
process took 45 years.
Manetas kept a tab on the money being spent to decommission.
“The cost of decommissioning is something that's enormous and
it's really incalculable,” said Mike Manetas.
The total projected cost was originally put at $95 million, he
says, but ended up being just over a billion dollars.
Before decommissioning began – 1976 to 2008 – Manetas estimates
another half a billion dollars was spent caretaking the plant after it went
offline.
And the costs aren’t over. There are six casks on the site today
– these are huge canisters of the spent high-level nuclear waste left over
after decommissioning. They have to be kept safe and that costs money.
“The PUC, the Public Utilities Commission, has authorized
PG&E to collect $150 million to safeguard that waste to the year 2035,”
said Manetas.
And those canisters could be there for a very, very long
time. There’s been talk for years about a federal site for high-level nuclear
waste – spent fuel – but that hasn’t happened yet so like many sites across the
U.S., Humboldt Bay is stuck with its nuclear waste.
And that waste stays highly radioactive for thousands of years.
“The waste that literally is going to stay with us in the
environment for 10,000 years,” said Manetas.
He says they have been told these storage vessels are sufficient
for up to 80 years.
“The industry says originally they told us, ‘Oh, it's good for
40 years’ now they're saying, ‘Oh, they're good for 60 years’, gee, maybe 80
years,” said Manetas. “Okay, that's beside the point. The point is, is that at
the end of 80 years or 60 years or 40 years, what happens to these casks?
They're going to degrade.”
So they have to keep an eye on what to do with the aging
canisters storing waste that lasts for thousands of years.
The safe storage of the waste adds up to a lot of money for
taxpayers for a plant that ran for just over a decade a long time ago.
“The analogy I use is you buy an automobile, you buy a Cadillac,
and ten years later, it's run its course and you either sell it or take it to
the junkyard,” said Manetas. “And then for the rest of your life, you're going
to get a bill, $1 or $2 a month, because you owned that Cadillac to take care
of the muffler that is highly radioactive and has to be watched over for 10,000
years. I mean, it's mind boggling.”
Ok, so those are the mind-boggling costs, as Manetas puts it.
In our case study let’s move onto risks.
During decommissioning there are risks to dismantling a plant –
you know, the actual buildings and everything in it.
“They have to go in and very carefully remove that either
robotically or with people with suits,” said Manetas.
Mike Manetas
/
As a member of the community advisory board following the decommissioning
of Humboldt Bay Nuclear Power Plant, Mike Manetas was able to visit the site
many times and take photographs. He says divers had to scrape the walls of the
spent fuel pool as part of the process. These are the suits they would wear.
16,000 truckloads of the low-level waste from reactor operations
were transported offsite, Manetas says.
“It's a very, very expensive, difficult technology to take this
stuff apart and then to package it and then to ship it someplace wherever it's
going to go,” said Manetas.
Then there are the environmental and external risks. What
happens if there’s an earthquake or tsunami – think Fukushima in Japan. What
about war – Europe's largest nuclear plant – Zaporizhzhia –
wasn’t on many people’s radar until Russia invaded Ukraine.
And then there’s the more likely and imminent threat to the
Humboldt Bay site specifically – sea level rise.
Jennifer Marlow is the assistant professor of
Environmental Law at Cal Poly Humboldt.
“The bluff upon which the spent nuclear fuel at Humboldt Bay is
stored – it's 115 feet away from the shoreline and 44 feet above sea level. And
so it used to be 96 feet about high and now it's 44 feet high,” said Marlow.
“And so it's a particularly erosive part of Humboldt Bay. Over time, as erosion
accelerates, as sea level rises, and as that seawall currently protecting the
bluff might be breached.”
Marlow explains what this means for
the rip rap retainer wall, also known as a seawall, currently protecting the
site and shoreline.
“With 1.5 meters of sea level rise, there would be chronic or
monthly overtopping of that rip rap wall,” said Marlow. “And with 2 meters of
sea level rise, that rip rap wall would be overtopped daily at high tide, and
it would make the spent nuclear fuel site, an island with everything around it
submerged by the rising sea.”
Lloyd Stine
/
44feetabovesealevel.Com
An image taken in 1952, of the coastline and protective seawall
close to the site of the Humboldt Bay Nuclear Power Plant, where the high-level
nuclear waste leftover after decommissioning is stored today.
Abigail Lowell
/
44feetabovesealevel.Com
And image taken in 2020 of the seawall close to the Humboldt Bay
Nuclear Power Plant site. Researchers have looked into how sea level rise could
overtop that seawall and affect the site storing leftover high-level nuclear
waste.
Marlow said credible tsunami risks have also been looked into,
and reports suggest the maximum tsunami run up level is 43 feet – dangerously
close to where the site sits currently at 44 feet.
“What we don't know is how sea level rise is going to impact
this tsunami run up estimates into the future,” said Marlow.
So how does this all compare to Diablo
Canyon?
Of course, we can’t do a complete apples to apples comparison,
but we can make some educated assumptions.
Let’s first look at the size and lifespan of the plants for
comparison and what that means for the leftover nuclear waste.
Humboldt Bay was a 65-megawatt nuclear power plant. Diablo
Canyon is over 30 times bigger at over 2,000 megawatts.
Humboldt Bay operated for 13 years. Diablo Canyon has been
operating for 37.
Essentially this all means a lot more nuclear waste. Far more
than the six canisters at Humboldt Bay. Mike Manetas has done some math and he
puts the eventual number at Diablo Canyon at around 300 canisters.
I put this eye-popping number to another one of my sources –
David Weisman, the legislative director for the Alliance for Nuclear Responsibility.
The alliance opposes nuclear power because it says it’s too
expensive and cumbersome for what it delivers. It has been actively involved in
the decommissioning plans.
So, how many nuclear waste canisters would be stored on the site
after decommissioning? Weisman lives in Morro Bay, just north of Diablo Canyon.
His estimate is a lot less than Manetas’ 300.
“My number was like 138. In other words, if the plant runs to
the end of its life, that has planned – 2025, they have 70 up there now and
they’ve ordered another 68, 70 from this new vendor,” said Weisman.
Either way, it’s a huge number compared to Humboldt Bay. A lot
more highly radioactive waste to keep an eye on and store safely for those
thousands of years.
“The biggest question we would have also of the longevity of the
canisters is – it's the marine environment. It may not be immediately impacted
by tsunami or erosion. But you've got the fog, the cold air, the mist. And
they're absolutely going to have to maintain a vigilant program to make sure
that rust and corrosion…”
… Doesn’t affect the canisters.
And Diablo Canyon, because of its size and how long it's been
operating, has a ton of that low-level waste as well.
“All the toxics involved in the building have to be carefully
wrapped and transported away,” said Weisman.
Weisman says at first the plan was to transport thousands of
loads of this waste off site by truck – like they did at Humboldt Bay.
“Avila Valley roads, a little winding road that leads from the
plant. There were going to be thousands of truckloads and the local people are
like, ‘What?’ So a decision was made for most of the bulky stuff – we're going
to build a dock where the intake is, load it on a barge and send it down to
Port Hueneme or something like that,” said Weisman.
Low-level waste on barges or trucks – all of this, as with the
theme of this piece, has risks and costs a lot of money.
Let’s now turn to environmental and external factors. Weisman
has already pointed to one of them – marine impacts. Let’s look at some others.
Sea Level rise is not as much of a concern for Diablo Canyon as
in Humboldt Bay, Weisman says. The canisters are stored up the hill 200 feet
above sea level.
What about earthquakes? Well PG&E has long maintained that the
plant could withstand an earthquake. But the plant is located
close to several earthquake faults and many locals have voiced concern about
its safety for decades.
One of the main factors in the original plans to
shut down Diablo Canyon was the high cost of retrofitting it to meet updated
environmental regulations.
Talking about money. Let's look at the total cost of
decommissioning. In 2021, the California Public Utilities Commission approved
an estimated $3.9 billion needed to
safely decommission the plant.
But remember our professor from Humboldt Bay – Mike Manetas –
and how he kept an accounting of that decommissioning. He believes the costs
will go up.
“Diablo Canyon right now they're saying, ‘Oh, we're going to do
it for $4 billion’. Well, if you look 30 years down the road, that $4 billion
could easily become $10 billion. $20 billion,” said Mike Manetas.
And finally let’s turn to the timeline.
Compared to Humboldt it seems decommissioning at Diablo Canyon,
when it does actually start, will be a lot quicker.
PG&E has details on their website about their plans for
decommissioning – on its page dedicated to the process, it
says, after the plant is shut down… “Decommissioning will begin promptly and
the process will take approximately ten years.”
David Weisman and I discussed what this would look like if
shutdown plans were still going ahead on the original timeline
David Weisman: In theory, by about 2035 the soil would be flat. The domes
in the structures are gone. They’d regrade the hillside planted with native
vegetation. And so by the mid to late 2030s, it should have looked like nothing
had ever been there.
Michelle Loxton: Except for the waste that's sitting in the
canisters?
David Weisman: Two football fields or three football fields up on the
hill. But again, the benefit is the entire security perimeter shrinks to just
that area. That opens up the land, which is what the REACH people and these
others were looking at, or the native tribes and indigenous tribes are now
looking at it as well.
The REACH people Weisman is referring to there, is a regional
economic group that has put forward a plan to turn the fully decommissioned site into a Clean Energy Innovation Tech Park with
desalination, battery storage, wind energy and a community center. This was a
plan that many local political leaders and community groups had signed on to.
What it all means for San Luis Obispo County
I wanted to end this piece with the reason why I decided to tell
the story of Diablo Canyon in the first place – why we should care.
Beyond the cost to rate and taxpayers across the state, the
risks associated with having a nuclear power plant and its left-over waste
nearby, is mostly on the local community.
PG&E
/
California’s largest single source of electricity, about 10% of
it, comes from Diablo Canyon Nuclear Power Plant. This plant sits on the edge
of the Pacific Ocean, west of San Luis Obispo and south of Morro Bay.
Bringing Bruce Gibson back in here, the San Luis Obispo County
Supervisor.
“The risk of those things, the impact of an accident, a bad
outcome, and any of those issues rests physically on San Luis Obispo County,”
said Gibson.
Gibson has a background in geophysics and has been involved in
monitoring Diablo Canyon’s operations for many years.
“Diablo Canyon has been a big deal in San Luis Obispo County for
a very long time, and there's a great diversity of view about it,” said Gibson.
“There are those who have long objected to its construction and its operation,
and there are those who are extremely supportive of it because of its impact on
our economy. It is easily the single largest private employer in our county and
has provided a great number of well-paying head of household jobs.”
Despite the polarizing local opinions about the plant, he says
he understands why it needs to stay open a little longer.
“I am comfortable with its operation. And I certainly understand
the case to be made that extending its life for a certain amount of time in the
time we are transitioning to renewable energy could provide some benefits to
the entire state of California,” said Gibson.
He says he tries to stay neutral when representing the overall
interests of his community.
“I see my job as holding PG&E and the other regulatory
bodies accountable for doing the best possible job of mitigating those
impacts,” said Gibson. “There's the risk of an accident while the plant’s
operating – that's obviously very much top of everybody's mind. But more than
that, there's the issue, for instance, of the spent fuel that's still stored on
that site. And so far as we can see, it is going to be there for the rest of my
life.”
“I can't be one of those folks that just lets it go. I have to
be thinking about it,” said Bruce Gibson.
I asked him about how he approaches an issue that will remain
relevant far beyond the lifespan of his political career.
“But that whole business of burdening generations for 10,000
years to take care of something that cannot escape into the environment is a
huge ethical question. So we benefited from this. And ‘Hey, kids, here's your
legacy’. Right? We talk all the time about the programs we have to put in place
for that are much longer than terms in office,” said Gibson.
For Gibson, in the end it all comes down to never being able to
disengage from what is happening at Diablo Canyon.
“I can't be one of those folks that just lets it go. I have to
be thinking about it,” Gibson said. “Never lose sight of its benefit and risk…
I think we can get successfully to the next phase. And I'm certainly hopeful
for that.”
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