Monday, March 18, 2013

SCE says San Onofre can be operated safely. Facts say otherwise.

SCE's plan to run San Onofre at 70% power for five months, submitted to the Nuclear Regulatory Commission last October, is based on faulty assumptions which defy logic.

And yet, incredulously, today SCE announced that they believe they could run Unit 2 at 100% power for 11 months without going over the 35% tube wear limit on ANY of the nearly 20,000 tubes inside the two "new" steam generators in Unit 2!

Some of those tubes inside those steam generators are already worn more than 20% of their thinner-than-a-dime thickness. None have been inspected with the most thorough equipment available, which can detect stress corrosion cracking, not just tube wall wear.

Yet SCE is sure that they can run Unit 2 without causing "high void fractions" in the steam/water mixture, and without causing excessive turbulence, which was about as bad as anything the industry had ever seen in Unit 2 as well as in Unit 3, which no one is about to try to claim can be restarted.

And presumably, SCE is claiming they could run at 100% power for 11 months without an unreasonable risk of another tube rupture like what happened January 31st, 2012, which shut down the two reactors.

However, SCE has yet to prove their case for restart, and these are just additional speculative claims to confuse and inappropriately reassure the public that restart is safe, and to prod the NRC into a favorable and inappropriate decision. San Onofre cannot be safely restarted. Period. It CAN'T be proven safe, because it's already been proven unsafe. Real-world experience and test results top the fanciest mathematical equations and computer software programs.

Despite this new announcement -- a "trial balloon" in the political sense -- SCE still plans to only run the Unit 2 reactor for 5 months at 70% power... but by doing this, they are obfuscating the dangers, making it sound like additional wear is the only problem, followed by a single tube rupture at some point if things go wrong. This is not the case. In fact, the main worry is that the wear that has occurred is more than they realize because their inspections are inadequate, coupled with concern that a main steam line break (coupled with the failure of an accompanying isolation valve to close) could lead to "fluid elastic instability" and a multiple-tube rupture, as illustrated in my animation available online here:

Click the triangles in the upper left to go to various screens; and click on MSLB when a steam generator is on the screen to see the event I am referring to. It might only take a couple of seconds or minutes, and happens whether the reactor is SCRAMed successfully or not. The steam line breaks, the water in the steam generator almost instantly turns to steam, it rushes out the top of the steam generator, the u-tubes start fluttering, and .... they break away in clusters.

Last year, eight tubes ruptured during "MSLB" testing, three of those did so below the pressure differential that an actual main steam line break would incur. The requirements include a margin of error of about 180%, and the other 5 tubes failed that part of the test. Only about 1.5% of all the tubes were pressure tested -- the ones that were going to be taken out of service anyway because they were located in areas of highest wear and thus, it's presumed, the areas of highest heat and highest fluid velocities as well. (And highest void fractions.)

San Onofre has no answer for the problem indicated by those test results. However, lucky for them, the Nuclear Regulatory Commission has deemed a multi-tube rupture scenario "not credible" as stated at the last NRC hearing, February 12, 2013 at the Church of the God Loving Beach People. But under oath, with experts cross-examining the NRC's own experts or San Onofre's, I don't think they would be able to deny this is a real and reasonable possibility. Not only is it a possibility, but a main steam line break is probably about ten times more likely than a severe earthquake (one cause of a main steam line break might be an earthquake, but it's not the only possible cause. Rust is another.).

Experts not tied to the nuclear industry (anymore...) believe a cascading tube rupture scenario, such as that depicted by the main steam line break animation, is plausible.

And although it's not guaranteed to cause a meltdown all by itself -- there are a few backup systems that might still work -- it would bring SoCal frighteningly close to our own Fukushima. A main steam line break can produce sonic-level sound vibrations, inhibiting communication. The loss of numerous sensors and controls is very likely to accompany such an event. The operators in the control room might need some time to figure out what happened: They might not have that time. But what if they try to isolate the WRONG steam generator, for example? What if the break is inside the containment dome and the burst pressures are exceeded because, unknowingly or covered-up, the dome cut to insert the steam generators didn't go as well as they thought it had, like at Crystal River in Florida? The engineers thought they had closed that one up pretty good too, and then cracks developed...

If a meltdown occurs, the containment area may not be enterable, as in the case of Fukushima, for years or even decades or centuries. And, like at Fukushima, our children will be most affected, our crops, our land will be lost, and no one will compensate us for the loss. It will be no different for hundreds of thousands of people around the plant, maybe millions. And Fukushima wasn't even as bad as it could be, not by two orders of magnitude at least: The cores did not fully explode vaporize in a massive steam explosion, for instance.... at least, not yet. But all of multiple core's noble gasses were released, their full loads of cesium and strontium... and some plutonium and uranium, but the majority of the plutonium and uranium is still inside the reactor buildings somewhere, at this time. Things could have been a lot worse there, and could be a lot worse than that here.

And even if there is no main steam line break, there are still a multitude of other problems. First of all, and perhaps most importantly, SCE's plan for restart has always depended on FRICTION FORCES to prevent "in-plane" vibration of the tubes inside the steam generators. Vibration in other directions has always been taken care of by having supports that the tubes butt up against, and it was assumed by the nuclear industry that if you solve the out-of-plane vibration problems, you will also have solved any in-plane vibration problems.

However, San Onofre Unit 3 proved that "rule-of-thumb" to be incorrect. and the industry needs to amend its thinking.

Another Achilles' Heal of the industry is the waste problem. Not mentioning it (as SCE never does) doesn't make it go away. In fact nothing makes it go away. The federal government will continue to break its promise to remove the waste from near the reactor, because there is no place to put the waste -- no national repository -- and we are many decades away from having such a place, if ever. So the less waste that sits here on our coast, exposed and dangerous as it sits there, its containers rusting in the sea breeze, its contents in constant need of attention and protection (and inert gasses under pressure), the better. It all costs money for tens of thousands of years, and the more radioactive trash there is, the greater the cost, the larger the land that's needed to store it, and the greater the risk.

Let's hope the CPUC will stop wasting the ratepayer's money on the hopes of restarting a fault reactor based on a faulty premise -- on a fault line. Let's hope the NRC will flat-out refuse to allow SCE to restart. Let's hope SCE gives up this foolish plan. And, since hoping won't change anything, let's decommission San Onofre starting right now. It's the only way forward for society.

Ace Hoffman
Carlsbad, CA

The following was left by an acquaintance of mine at the NRC Blog site today:

Sincere Thanks to Mr. Victor Dricks, Mr. Cale Young, Mr. Ryan Lantz, Mr. Randy Hall and entire NRC Staff. Thanks to NRC posting this blog

As a part of San Onofre Public Awareness and SCE/MHI Lessons Learnt Series, Brilliant NRC Staff should summarize for the benefit of General Public an Unbiased Gap Analysis on San Onofre Degradation before Unit 2 restart based on the plant data and a review of following reports:
1. NRC AIT and follow up reports
2. SCE Root Cause Analysis Evaluations (Safety Short Cuts and Avoidance of 10 CFR 50.90)
3. Westinghouse Operational Assessment
4. AREVA Operational Assessment
5. MHI Root Cause Analysis & Technical Reports (Safety Short Cuts and Avoidance of 10 CFR 50.90)
6. SCE Enclosure 2 and Remaining Operational Assessments
7. Internationally Known Chartered Engineer and Nuclear Scientist John Large Technical ASLB Paper
8. Internationally Known Nuclear Engineer Arnie Gundersen's Technical Papers
9. Professor Daniel Hirsch's Report
10. Mitsubishi AVB Testing for San Onofre RSG Repairs
11. Dr. Pettigrew's and other research papers published between 2016 and 2011 on FEI & FIRV
12. SONGS Special Tube Inspections & Insider Reports
13. NUREG 1841- Comparison of CE Replacement Generators with San Onofre
14. SCE Response to NRR RAI's
15. Fluid Elastic Instability, AVB Contact Forces and risks of Design Bases Accidents at 70% reduced power, Accuracy of Thermal-Hydraulic Computer Modeling and Reliability of SCE Operator Actions
16. Analysis of San Onofre Units 2 & 3 Operational Data and its impact on Units 2 & 3 Cause Root Cause Evaluations and how it relates to Fluid Elastic Instability, Flow-induced Vibrations, Mitsubishi Flowering Effect and AVB Contact Forces
17. SCE's Compliance with NRC CAL and NRC Justification of SCE 10CFR 50.59 and Assurance to 8.4 Million Southern Californians based on Scientific Facts and Operating Experience

Thanks…. HAHN BABA

Contact information for the author of this newsletter:


Ace Hoffman
Author, The Code Killers:
An Expose of the Nuclear Industry
Free download:
Carlsbad, CA
Email: ace [at]


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