Click amount to donate direct to CounterPunch
  • $25
  • $50
  • $100
  • $500
  • $other
  • use PayPal
Keep CounterPunch ad free. Support our annual fund drive today!

Restarting a Broken Nuke


The Nuclear Regulatory Commission has determined that (in their opinion) Southern California Edison did NOT mislead the NRC about design changes to their failed replacement steam generators for San Onofre Nuclear (Waste) Generating Station.

The billion-dollar mistake was done according to the rules.  They admit that the rules might need to be changed, but the rules were followed, according to the NRC.

Actually, though, SCE arrogantly described their efforts to avoid a proper “10CFR50.59 review process” which would have entailed not just heightened NRC scrutiny, but even some citizen’s public scrutiny as well!  But the NRC doesn’t care what SCE said in those industry publications, where SCE bragged specifically about circumventing 10CFR50.59, which requires an open regulatory review process for significant design changes at a nuclear power plant.

It should be noted that the followed string of changes actually occurred, all without need for a “10CFR50.59” review: The tube material was changed to a newer, more durable, but significantly less thermally conductive alloy, requiring 10% more surface area for the same thermal output.  Hence more tubes, and hence they eliminated the stay cylinder in the center (to pack in even more tubes), and hence ALL the tubes were packed in a bit tighter than before.  The tighter-packed tubes were too tight around the U-bends, near where the anti-vibration bar goes along for the ride (it’s not connected to anything but the tubes themselves).  (See section 8.b.1)

The whole thing was basically redesigned to flutter!  Ooops!  And yet it passed 10CFR50.59 after-the-fact “scrutiny”!  It feels like a foregone conclusion.

So much for finding the real “root cause” of why San Onofre has been inoperable since January.  One key phrase turned up: “The replacement steam generators were designed and fabricated in accordance with quality assurance requirements, and 10CFR50.59 does not require the licensee to presume deficiencies in the design or fabrication.” (p. 36)

Rushing to make a shipping schedule probably isn’t considered a deficiency the licensee needed to presume might occur, either.   But in fact a decision was made: „not to control the positive pressure, the dew point of nitrogen, and the oxygen content on the primary and secondary side of the Unit 3 replacement steam generators [during transport from Japan] to accelerate delivery schedule.‰ (p. 45)  The NRC is still reviewing whether “corrective action” will be taken on that and several other issues.

Also presumed not germane to 10CFR50.59 was whether shipping the entire steam generator in other than a “gravity-neutral position” (in fact 45 degrees OFF from that position) would have any impact.  It seems the lifting points made rotation to a gravity-neutral shipping position difficult.  Shucks.

One of Unit 3’s SGs was apparently damaged in handling: “Unit 3 replacement steam generator 3E0-88 accelerometers indicated up to a 1.23 g spike with a simultaneous recording on all three of the attached accelerometers.  Mitsubishi provided an evaluation of the forces which showed loads were within allowable stress limits but exceeded stress for an operating basis earthquake.  The team was not able to determine if this was properly considered.” (p. 46)  A steam generator weighs well over a million pounds.  Don’t drop it.  Don’t bump it.

Additional fabrication problems required extensive rewelding, nearly doubling the number of rotations of the Unit 3 SGs during fabrication. (p. 63)

As for computer modeling, they have a nice phrase for an error: “nonconservative results”.  Such “nonconservative results” (p. 47) from one computer program which calculates flow rates were diligently fed into another computer program to determine resultant vibrations, which, of course, were way below what actually happened.  Garbage In, Garbage Out.

That’s why it’s good to use real-world modeling, not just computer modeling.  Or, as the Augmented Inspection Team put it: “The accuracy of calculating fluid-elastic instability is limited based on inputs that are best determined by design-specific mockup test data.  Mitsubishi did not perform design-specific mockup tests.” (p. 49)

In one attempt to use “conservatisms” in their vibration analysis, a multiplier of 1.5 was inserted… but the multiplier was actually required to match real-world testing results! (p. 50)

It should be noted that in trying to isolate which software model failed, it was admitted (p. 56) that the models only predict “bulk fluid behavior based on first principles and empirical correlations”. So the models don’t actually handle fabrication differences between steam generators, or structural differences, etc..  In fact, someone with a slide rule did some calculations to check on these wonderful “computer programs”.  They’re that basic.

Back in the real world, here’s what happens: “If operating velocities reach [a] critical value, vibration amplitudes can increase rapidly and fluid-elastic instability forces can lead to rapid pulsation and damaging of tubes.” (p. 49)

The U-bend region of the tubes is most susceptible, but the industry believed everything would hold together — until San Onofre proved otherwise: “This event at SONGS is the first US operating fleet experience of in-plane fluid-elastic instability, sufficient to cause tube-to-tube contact and wear in the U-bend region.”

Shocked, are we?  Well, then I should add that there is no standard for what margin of safety should actually be designed into steam generators to avoid fluid-elastic instability.  Each manufacturer has a different value.

So, what about restarting San Onofre?

The AIT report indicates the only way SCE might be able to restart the reactors is by changing the operational parameters, because: “SONGS replacement steam generators were not designed with adequate margin to preclude the onset of fluid-elastic instability” which can cause “tube leakage and/or tube rupture.” (p 56)

Replacing the steam generators will take several years and cost about a billion dollars.  And what design would they use? And who would fabricate them?  The old SGs weren’t much better:

“The original steam generators installed throughout the domestic fleet of pressurized water reactors, including SONGS, experienced widespread corrosion of the tubes and tube support plates, stress corrosion cracking of the tubes, and wear at tube supports.  These problems led to the replacement of nearly all of the original steam generators, in most cases well before the end of their design lifetime.” (p. 41)

And they can’t simply make the old design out of the new alloy, because the heat transfer characteristics are so different.

They’ve already plugged well over a thousand tubes, many because they were already severely worn, others in the hope of reducing the amount of steam compared to water in certain areas of the steam generators.

Restarting Unit III seems out of the question at this point, and to restart Unit II, SCE has already determined that it would have to be at a lower power setting. (p. 56)

But the only way to know for sure that a lower power setting will work is to try it.  And that might result in a tube rupture, possibly even followed by a cascading failure of one tube after another, resulting in a massive radiological release.

Zirconium cladding, hot fuel, loss of coolant… these are a dangerous combination!  Add in a multitude of companies and agencies each laying blame anywhere but on themselves, confusing and inadequate regulations and regulatory oversight, language barriers, proprietary manufacturing operations, whistleblower intimidation here (and undoubtedly in Japan too) and you have a recipe for … exactly what happened.

Or worse.  Let’s not restart San Onofre.  Ever.

Russell D. Hoffman lives in Carlsbad, California. He is an educational software developer and bladder cancer survivor, as well as a collector of military and nuclear historical documents and books. He is the author and programmer of the award-winning Animated Periodic Table of the Elements. He can be reached at:


More articles by:

2016 Fund Drive
Smart. Fierce. Uncompromised. Support CounterPunch Now!

  • cp-store
  • donate paypal

CounterPunch Magazine


October 26, 2016
John W. Whitehead
A Deep State of Mind: America’s Shadow Government and Its Silent Coup
Anthony Tarrant
On the Unbearable Lightness of Whiteness
Luke O'Brien
The Churchill Thing: Some Big Words About Trump and Some Other Chap
Mark Weisbrot
The Most Dangerous Place in the World: US Pours in Money, as Blood Flows in Honduras
Eric Draitser
Dear Liberals: Trump is Right
Chris Welzenbach
The Establishment and the Chattering Hack: a Response to Nicholas Lemann
Sabia Rigby
In the “Jungle:” Report from the Refugee Camp in Calais, France
Linn Washington Jr.
Pot Decriminalization Yields $9-million in Savings for Philadelphia
Pepe Escobar
“America has lost” in the Philippines
Pauline Murphy
Political Feminism: the Legacy of Victoria Woodhull
Lizzie Maldonado
The Burdens of World War III
David Swanson
Slavery Was Abolished
Thomas Mountain
Preventing Cultural Genocide with the Mother Tongue Policy in Eritrea
Colin Todhunter
Agrochemicals And The Cesspool Of Corruption: Dr. Mason Writes To The US EPA
October 25, 2016
David Swanson
Halloween Is Coming, Vladimir Putin Isn’t
Hiroyuki Hamada
Fear Laundering: an Elaborate Psychological Diversion and Bid for Power
Priti Gulati Cox
President Obama: Before the Empire Falls, Free Leonard Peltier and Mumia Abu-Jamal
Kathy Deacon
Plus ça Change: Regime Change 1917-1920
Robin Goodman
Appetite for Destruction: America’s War Against Itself
Richard Moser
On Power, Privilege, and Passage: a Letter to My Nephew
Rev. William Alberts
The Epicenter of the Moral Universe is Our Common Humanity, Not Religion
Dan Bacher
Inspector General says Reclamation Wasted $32.2 Million on Klamath irrigators
David Mattson
A Recipe for Killing: the “Trust Us” Argument of State Grizzly Bear Managers
Derek Royden
The Tragedy in Yemen
Ralph Nader
Breaking Through Power: It’s Easier Than We Think
Norman Pollack
Centrist Fascism: Lurching Forward
Guillermo R. Gil
Cell to Cell Communication: On How to Become Governor of Puerto Rico
Mateo Pimentel
You, Me, and the Trolley Make Three
Cathy Breen
“Today Is One of the Heaviest Days of My Life”
October 24, 2016
John Steppling
The Unwoke: Sleepwalking into the Nightmare
Oscar Ortega
Clinton’s Troubling Silence on the Dakota Access Pipeline
Patrick Cockburn
Aleppo vs. Mosul: Media Biases
John Grant
Humanizing Our Militarized Border
Franklin Lamb
US-led Sanctions Targeting Syria Risk Adjudication as War Crimes
Paul Bentley
There Must Be Some Way Out of Here: the Silence of Dylan
Norman Pollack
Militarism: The Elephant in the Room
Patrick Bosold
Dakota Access Oil Pipeline: Invite CEO to Lunch, Go to Jail
Paul Craig Roberts
Was Russia’s Hesitation in Syria a Strategic Mistake?
David Swanson
Of All the Opinions I’ve Heard on Syria
Weekend Edition
October 21, 2016
Friday - Sunday
John Wight
Hillary Clinton and the Brutal Murder of Gaddafi
Diana Johnstone
Hillary Clinton’s Strategic Ambition in a Nutshell
Jeffrey St. Clair
Roaming Charges: Trump’s Naked and Hillary’s Dead
John W. Whitehead
American Psycho: Sex, Lies and Politics Add Up to a Terrifying Election Season
Stephen Cooper
Hell on Earth in Alabama: Inside Holman Prison
Patrick Cockburn
13 Years of War: Mosul’s Frightening and Uncertain Future