[Shutsanonofre] Concerns about San Onofre are real, but experts debate level of risk

[Ray Lutz]

https://www.sbsun.com/2024/03/31/concerns-about-san-onofre-are-real-but-experts-debate-level-of-risk/


  Concerns about San Onofre are real, but experts debate level of risk


    Column: Dueling experts share their greatest worries about the
    nuclear waste

Dry storage of used fuel rods at the San Onofre Nuclear Generating 
Station on Thursday, December 16, 2021. (Photo by Jeff Gritchen, Orange 
County Register/SCNG)
Dry storage of used fuel rods at the San Onofre Nuclear Generating 
Station on Thursday, December 16, 2021. (Photo by Jeff Gritchen, Orange 
County Register/SCNG)

Author
ByTERI SFORZA 
<https://www.sbsun.com/author/teri-sforza/>|tsforza at scng.com| Orange 
County Register
PUBLISHED:March 31, 2024 at 7:00 a.m.| UPDATED:March 31, 2024 at 7:00 a.m.
The San Onofre Nuclear Generating Station is seen from Trail 1 at San 
Onofre State Beach south of San Clemente on Tuesday, August 27, 2019. 
(File Photo by Leonard Ortiz, Orange County Register/SCNG) 
<https://wpdash.medianewsgroup.com/wp-content/uploads/2020/08/OCR-L-SANO-0807-01.jpg>San 
Onofre Nuclear Generating Station in 2019. (File Photo by Leonard Ortiz, 
Orange County Register/SCNG)

Let’s all agree that storing 3.6 million pounds of highly radioactive 
nuclear waste on a bluff beside the ocean in an earthquake zone near 8 
million people is, at the risk of gross understatement, not ideal.

Let’s all agree that it should leave San Onofre and be safely ensconced 
in a federal graveyard as soon as humanly possible (if not sooner).

And let’s attempt to separate fact from fancy as we wait, and wait, and 
wait for that to happen — teasing what might be worth worrying about 
from, say, more performative panic. To that end, we’ll curate a debate 
between two nuclear experts who have very different ideas on what we 
should fret over when it comes to the spent fuel in dry storage at San 
Onofre Nuclear Generation Station.

The highest predicted ground water levels near San Onofre's dry storage 
systems would still be below the floor of the waste storage system, 
Edison says (Source: Southern California Edison) 
<https://wpdash.medianewsgroup.com/wp-content/uploads/2024/03/san-o-ground-water.png>The 
highest predicted ground water levels near San Onofre’s dry storage 
systems would still be below the floor of the waste storage system, 
Edison says (Source: Southern California Edison)


Dave Lochbaum 
<https://wpdash.medianewsgroup.com/wp-content/uploads/2024/03/1517254521335.jpeg>Dave 
Lochbaum


        Meet the experts!

On one side we have David Lochbaum, recently retired director of the 
Nuclear Safety Project for the nonprofit Union of Concerned Scientists. 
Lochbaum has a degree in nuclear engineering and worked in the industry 
before becoming one of its leading watchdog/critics.

On the other side, we have Paul Blanch, nuclear industry whistleblower, 
consultant and expert witness on regulatory matters. Blanch’s degree is 
in electrical engineering, and he worked in the nuclear industry as well.

What do they worry about? Very different things

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Paul Blanch 
<https://wpdash.medianewsgroup.com/wp-content/uploads/2024/03/1517671040389.jpg>Paul 
Blanch

Let’s start with Blanch. “The bottom line is that there is a probability 
of flooding of the canisters in our present location. Should this occur, 
the impact on Southern California would be unimaginable.”

Blanch’s nightmare scenario plays out like this: A giant tidal wave 
inundates the “concrete monolith” that is San Onofre’s Holtec dry 
storage system. Most of the waste is inside canisters, inside vaults, 
inside that concrete monolith, just a few hundred feet from the ocean.

In this nightmare scenario, salt water and debris fill the vaults. The 
canisters inside are cool, as far as nuclear waste goes, at several 
hundred degrees. They’re kept cool by airflow — a passive system that 
sucks in cool air and releases hot air, not needing any electricity to 
get the job done. But what would happen if the vaults were submerged in 
water?

Well, water was fine when the waste was cooling in spent fuel pools (it 
cools in those pools for years after its tour of duty in the reactor 
core is done). So why fear water now? The presence of boron in cooling 
pool water, and the precise spacing between fuel assemblies, kept things 
under control, Blanch argues. Salt water would not have boron. Waste 
might not be spaced well enough to prevent “criticality.” After water 
boiled away, salt and debris could remain inside the vaults, potentially 
blocking cooling airflow to the hot canisters. Big trouble, he said.

And some of the waste canisters suffered scratches on their way into the 
vaults. If a scratched canister came into contact with cool water, would 
it crack like a 400-degree Pyrex bowl suddenly submerged in ice?

Image courtesy Holtec 
<https://wpdash.medianewsgroup.com/wp-content/uploads/2017/06/holtec-hi-storm-umax-from-sce1.jpg>Image 
courtesy Holtec

Edison and the NRC say this is just not a credible threat scenario. The 
area is prone to tsunamis in the 6-foot range, not the 30-foot range 
that could reach and flood the dry storage area. And if monster waves 
came anyway, the water would cool the canisters, then recede.

The seawall, which is not required, provides some protection from a 
tsunami — but it’s redundant, as the older storage system (NUHOMS) is 
designed to withstand complete submergence up to 50 feet, and the new 
Holtec HI-STORM UMAX is designed to withstand complete submergence up to 
125 feet, Edison spokesman Jeff Monford said.

Not credible.

“What do you mean by ‘credible’?” Blanch asked. “They won’t define it. 
I’ll agree that getting hit by a meteorite is not credible because the 
probability is so low. But what is the probability here? One in a 
thousand years, one in a million years? What we’re really looking for is 
the analysis that shows, should these become flooded, what are the 
consequences? I cannot get an answer.”

A hydrology analysis was done in the 1970s by Basil Wilson, when the two 
newest reactors were planned — below sea level. San Onofre has had many 
serious issues over the years — culminating in its shutdown — but 
serious flooding has not been among them. Wilson’s hydrology analysis 
has been updated over the years, and potential flooding has been 
considered by the California Coastal Commission, the California Lands 
Commission, etc., and Edison must dostate-mandated studies of sea level 
rise near the plant regularly. 
<https://www.ocregister.com/2024/03/09/king-tides-groundwater-rise-threats-to-nuclear-waste-at-san-onofre/>

Big waves pound the concrete wall below San Onofre Nuclear Generating 
Station, where 3.6 million gallons of nuclear waste is kept. Rock rip 
rap were put in front of a sea wall with hopes it will help keep the sea 
from damaging the facility. (Photo by Leonard Ortiz, Orange County 
Register/SCNG) 
<https://wpdash.medianewsgroup.com/wp-content/uploads/2022/12/OCR-L-SAND-EROSION-XXXX-50-05.jpg>Big 
waves pound the concrete wall below San Onofre Nuclear Generating 
Station, where 3.6 million gallons of nuclear waste is kept. Rock rip 
rap were put in front of a sea wall with hopes it will help keep the sea 
from damaging the facility.(Photo by Leonard Ortiz, Orange County 
Register/SCNG)

Blanch argues that’s not enough. He says updates are based on Wilson’s 
very old study and fresh investigation should be done.

“A major accident is acceptable in the nuclear field if it’s one in 10 
million in one year. That’s what we’re looking for. That’s more than 
safe. One in a million would probably be safe to me. But someone needs 
to say it. I don’t know what the probability is. They have not done it.”

He’s not saying flooding/is/a problem. But he wants to see an analysis 
showing it/isn’t/a problem, he said.


        Other worries

Lochbaum, meanwhile, probably couldn’t disagree more.

“I have zero concerns about the spent fuel in dry storage at San Onofre 
being vulnerable to flooding from tsunamis,” he said. “Forget Dr. 
Wilson’s studies from the 1970s — SCE has commissioned more recent 
assessments that show the threat to be negligible. Zero concerns. At most.

“I do have concerns about dry storage of spent fuel, at San Onofre and 
elsewhere. But none are tsunami-related. None.”

This Google Earth image shows how close the expanded dry storage area 
for spent nuclear waste will be to the shoreline at San Onofre Nuclear 
Generating Station. (Image courtesy of Google Earth) 
<https://wpdash.medianewsgroup.com/wp-content/uploads/2020/06/OCR-L-SANO-LEVIN-0625-01.jpg>This 
Google Earth image shows how close the dry storage area for spent 
nuclear waste is to the water at San Onofre Nuclear Generating Station. 
(Image courtesy of Google Earth)

Instead, Lochbaum’s concerns center on the dry storage systems 
themselves and what will happen to them over time.

Casks containing the waste are vulnerable to wear and tear and 
degradation as they age. Once ensconced in steel and concrete and locked 
away, it can be hard to assess how time is treating them.

“NRC requires — or ‘suggests,’ more accurately — and a very few casks 
get inspected every now and then,” Lochbaum said. “Not a safety 
spotlight, more like a very infrequent safety strobe light flashing, 
perhaps, once in awhile.

“Fortunately, a dry cask experiencing a through-wall crack isn’t like a 
balloon popping — all the contents won’t be swiftly released,” he said. 
“But the safety margins protecting the public will be reduced. That’s bad.”

Last September, Blanch, Lochbaum, Edison and others met to discuss such 
concerns. Lochbaum asked Edison if cask inspections would be required 
before shipping them off to federal storage somewhere (“in the 
off-chance that this day ever arrives,” he quipped).

Alas. Pre-shipment inspections are not required by the NRC. But Edison 
said it would inspect them anyway, because it’s a responsible actor.

Loading spent fuel into the Holtec dry storage system at sunset. 
(Courtesy Southern California Edison) 
<https://wpdash.medianewsgroup.com/wp-content/uploads/2019/12/loading.jpg>Loading 
spent fuel into the Holtec dry storage system at sunset. (File photo 
courtesy Southern California Edison)

“I have zero reason or evidence to doubt SCE’s sincerity,” Lochbaum 
said, “but I’d take more comfort in pre-shipment inspections being 
required by law rather than voluntary.

“If mandatory, and assuming San Onofre was not the first site to ship 
casks away, there’d be a database of inspections to show whether casks 
are, or are not, solid.”


        Edison

Ron Pontes, Manager of Decommissioning Environmental Strategy with 
Southern California Edison talks about the Areva NUHOMS above-ground 
storage system at the San Onofre Nuclear Generating Station in San 
Clemente, CA on Monday, March 18, 2019. The facility is in the process 
of decommissioning. The above-ground storage houses 51 canisters, 50 of 
which hold 24 spent nuclear fuel assemblies each. (Photo by Paul 
Bersebach, Orange County Register/SCNG) 
<https://wpdash.medianewsgroup.com/wp-content/uploads/2019/03/OCR-L-SANONOFRE-0319-PB-07.jpg>Ron 
Pontes of Southern California Edison at the NUHOMS above-ground storage 
system at the San Onofre Nuclear Generating Station in 2019. (Photo by 
Paul Bersebach, Orange County Register/SCNG)

San Onofre has two dry storage systems on that bluff over the blue Pacific.

The older one — the Orano TN-NUHOMS system that stores canisters 
horizontally — holds 50 canisters and is at that 20-year mark. In 
November 2021, Edison and Orano conducted a “baseline inspection,” 
finding no signs of degradation of inspected canisters, Edison said.

The other system is Holtec’s UMAX —the aforementioned “concrete 
monolith” — which stores canisters vertically. There are 73 waste 
canisters inside, the last of which were loaded in 2020.

Dry fuel storage systems are initially licensed for 20 years by the 
Nuclear Regulatory Commission. After that, an “aging management program” 
is required to evaluate “degradation mechanisms to determine if they 
could affect the ability of dry storage system components to fulfill 
their safety functions,” Edison explains. If all is well, the licenses 
can be renewed for 40-year intervals.

So while it won’t need an aging management program for the Holtec for 
years, Edison agreed to an “accelerated Inspection and Maintenance 
Program” nonetheless, including periodic canister inspections; a test 
canister program; radiation monitoring and reporting; and developing a 
way to inspect and repair canisters inside their vaults inside the 
concrete monolith.

In 2020, Edison sent repair robots — sort of like high-tech St. Bernards 
— into a test vault to find and fix a test-damaged canister. One robot 
carried inspection cameras. The other, a nozzle mounted on a movable 
arm. Using magnetic wheels to crawl around, the robots found the trouble 
spots and applied a metallic overlay of nickel, effectively sealing them.

When the time comes to move them to federal storage, each canister will 
be shipped inside a very heavy, shielded, sealed and helium leak-tested 
cask, adding another layer of containment, Monford said. Edison’s 
license does require that most, if not all, the canisters be inspected 
and/or tested prior to shipment.

Blanch doesn’t worry about flooding of the horizontal canister system — 
water can just drain out the bottom, he said — but he does worry about 
the vertical Holtec. “I don’t think, in the short term, we’re going to 
have any problems with spent fuel canisters, for the next 50 years or 
so,” he said. “But we’re going to start developing problems.”

The U.S. Government Accountability Office's map of sites storing spent 
nuclear waste in the United States. 
<https://wpdash.medianewsgroup.com/wp-content/uploads/2019/09/GAO-nuclear-waste-sites.jpg>The 
U.S. Government Accountability Office’s map of sites storing spent 
nuclear waste in the United States.

He’d feel a lot better if the dry storage systems were hoisted another 
20 feet in the air.

Lochbaum would feel a lot better if more regular and rigorous 
inspections of dry storage systems and canisters were required.

And all of us would feel a lot better if the federal government stopped 
dithering and finally found America’s commercial nuclear waste a 
permanent home, as it promised to do so many decades ago.


-- 
-------
Ray Lutz
Citizens' Oversight Projects (COPs)
http://www.citizensoversight.org
619-820-5321
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