>ace, is this really the case that san onofre came close to blowing?
[see below for the comment she was responding to]
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6/18/2012
Dear Readers,
On January 31st, 2012 San Onofre came a lot closer to meltdown than should ever be allowed. The steam generator tube that failed could have flung into another one and another one, in a cascade of failed tubes (David Lochbaum made the statement that this could happen first, back in February I believe, and Arnie Gundersen has backed it up [pointing out the pressure difference between the inner and the outer loops is about a 1000 pounds per square inch]).
A cascading failure would have done two things: 1) Destroyed one of only two steam generators, "vital" (NRC's word) to remove decay heat from the reactor (most PWRs have more than two SGs), and 2) Thrown metal shards throughout the system, blocking water flow paths, valves, and piping. Enormous losses of primary coolant would have resulted in large radiation releases and a "large break LOCA" would be in progress -- (LOCA = Loss Of Coolant Accident).
Could SanO still survive? Sure -- if the never-tested ECCS (Emergency Core Cooling System) worked as designed -- but the sump pumps have been a problem there -- they apparently can get clogged with debris [thank Lochbaum again for pointing this out]. And nobody really knows if an ECCS would work at all, especially with BOTH SGs broken. (The flying metal shards from one could damage the other, leading to TWO cascading SG tube failure situations.) Numerous backup systems that have failed tests or been improperly inspected year after year would be called into play.
Thousands of tubes in each SG had been significantly weakened by the time one ruptured. Blocked flow paths within the reactor could lead to core melt in a matter of seconds.
Sincerely,
Ace Hoffman
Carlsbad, CA
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FIVE FUNDAMENTAL AND UNREPAIRABLE FLAWS AT SAN ONOFRE:
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1) It generates fission products such as cesium and strontium, as well as plutonium, tritium, and other radioactive byproducts. There is not, and never will be, a safe and cost-effective containment for these materials. They are generated in vastly larger quantities than can be safely managed -- 500 pounds per day at SanO, when it's operating (hopefully, never again).
2) SanO is decades old. Parts are rusted, corroded, embrittled, worn out, worn down, worn through. A portion of a 24-inch diameter pipe for the Emergency Core Cooling System had to be replaced recently because its clampdowns had rusted through -- two inches of metal gone. Why wasn't the problem discovered sooner? Improper inspection procedures! About the only thicker piece of metal in a reactor is the reactor pressure vessel itself (about 8 inches). And Unit II's RPV head had rusted away so much it had to be replaced last outage, and I believe Unit III's RPVH has also been, is being, or will soon be, replaced. The Davis Besse reactor nearly melted down in 2002 due to age/rust/negligent maintenance procedures. The whole eight inches of steel had been eaten away there, and only a stainless steel liner remained -- and it was bulging outward. SanO is also rusting away.
3) SanO has two Steam Generators per reactor. This is a flawed design because it leaves so little backup for heat removal if one of them fails catastrophically.
4) A bad work environment is inevitable at San Onofre because it IS falling apart and there ARE numerous things to complain about, and the public SHOULD be up in arms about what is happening there, and WILL get that awful plant closed sooner or later. But they don't like being told to close, so they cover more and more stuff up as the activists get more vocal. Which means the sooner we succeed, the safer. Because the least safe thing to do would be to ignore the danger, even if complaining alone actually makes things even less safe. There is no other way.
5) The Big One is coming to California, and nobody needs another study to know it. We'll lose thousands of lives when it comes, mostly the poor souls who will be caught in improperly-built building collapses, and people who try to run out of buildings instead of getting in doorways, and get hit by falling debris. We don't want radiation victims added to our problems that day. We don't want permanent evacuations because of the fallout. We don't want "shelter in place" as the deadly clouds drift over us. We'll have other problems and would like a distributed, reliable energy source so that after The Big One, we can get power back again quickly. SanO will go down at the first sign of a shake IF everything goes well, and won't come back up for weeks. That's assuming it was running in the first place, of course.
There are many other "fatal flaws" of nuclear power generally and San Onofre in particular. It should be decommissioned immediately and forever.
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Original message:
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Subject: Definitely maybe: NRC admits it messed up at SanO really badly...
6/18/2012
Dear Readers,
In eager anticipation of today's hearing in San Juan Capistrano, AP has released an "exclusive" report -- that says virtually nothing!
The closest thing that comes to a new statement is where the speaker is definitive, and then immediately takes it back: "The phenomenon that we think causes this tube-to-tube interaction is definitely proportional to the power," Collins said. "At least in some theoretical sense, that might be part of the answer."
More interesting is that Collins -- that's Nuclear Regulatory Commission Region IV Administrator Elmo "Ask Elmo, he won't tell you" Collins -- admits there were "significant" design changes to San Onofre's steam generators -- therefore admitting they were NOT "like for like" and the NRC had been seriously hoodwinked by the utility.
Will they fine themselves for being negligent and nearly costing SoCal a nuclear meltdown similar to what happened at Fukushima? Because that's what actually happened. We almost lost SoCal.
Will people go to jail for their negligence, greed, and dishonesty?
No, of course not! We don't live in a dream-world where the wicked are punished and bad deeds are undone. We live in the real world, where cover-ups are followed by cover-ups of the cover-ups, whitewashed explanations, and more business-as-usual.
Sincerely,
Ace Hoffman
Carlsbad, CA
At 01:32 PM 6/18/2012 +0100, AP wrote:
>AP Exclusive: Feds: Design Led to Nuke Plant Woes
>
>By MICHAEL R. BLOOD Associated Press
>CAPISTRANO BEACH, Calif. June 18, 2012 (AP)
>
>After months of investigation, federal regulators have determined that design flaws appear to be the cause of excessive wear in tubing that carries radioactive water through California's troubled San Onofre nuclear power plant, a top federal regulator said.
>
>The twin-reactor plant between Los Angeles and San Diego has been idle since January, after a tube break in one of four, massive steam generators released traces of radiation. A team of federal investigators was dispatched to the plant in March after the discovery that some tubes were so badly corroded that they could fail and possibly release radiation, a stunning finding inside the virtually new equipment.
>
>Flaws in fabrication or installation were considered as possible sources of the rapid tube decay but "it looks primarily we are pointed toward the design" of the heavily modified generators, Nuclear Regulatory Commission Regional Administrator Elmo Collins told The Associated Press in an interview Sunday.
>
>Collins couldn't rule out that one or more of the generators, installed in a $670 million overhaul in 2009 and 2010, might have to be replaced.
>
>Eight tubes failed during earlier pressure tests in the Unit 3 reactor and "we have not seen that in the industry before," Collins said.
>
>"It's these four steam generators that either have, or are susceptible to, this type of problem," Collins said, referring to the unusual damage caused when alloy tubes vibrate and rattle against each other or brackets that hold them in place.
>
>So far, a fix has remained elusive.
>
>"It's not too hard to frame up the problem," he added. "The answers are very difficult, or they already would have emerged."
>
>The disclosure will rivet new attention on a series of alterations to the equipment design, including the decision to add 400 tubes to each generator and installing V-shaped supports that were intended to minimize tube wear and vibration.
>
>It's possible operator Southern California Edison could face penalties stemming from the federal investigation, Collins said.
>
>The generators were designed to meet a federal test to qualify as "in-kind," or essentially identical, replacements for the original generators, which would allow them to be installed without prior approval from federal regulators.
>
>An environmental group, Friends of the Earth, has claimed Edison misled the NRC about the changes that it has identified as the likely culprit in excessive tube wear. The federal agency previously disputed that charge, but Collins said that's under review as part of the investigation.
>
>Inside the guts of the machinery, the original steam generators and the replacements "look substantially different," Collins added.
>
>The NRC is scheduled to discuss its findings Monday evening at a meeting near the plant.
>
>Collins said safety would remain the first consideration at San Onofre. About 7.4 million Californians live within 50 miles of San Onofre, which can power 1.4 million homes.
>
>"These are significant technical issues. They are not resolved yet," Collins said.
>
>Cracked and corroded generator tubing has vexed the nation's nuclear industry for years.
>Decaying generator tubes helped push San Onofre's Unit 1 reactor into retirement in 1992, even though it was designed to run until 2004. The following year, the Trojan nuclear plant, near Portland, Ore., was shuttered because of microscopic cracks in steam generator tubes, cutting years off its expected lifespan. Westinghouse Electric Corp. weathered a legal battle with five utilities in the 1990s that wanted the company to replace steam generators it manufactured for the Beaver Valley nuclear power plant in Pennsylvania after tubing corroded.
>
>But the troubled San Onofre generators, manufactured by Mitsubishi Heavy Industries, might be a unique case because of the extensive modifications. Only one other U.S. nuclear plant uses Mitsubishi generators, the Fort Calhoun Nuclear Station, about 20 miles north of Omaha, but its generators are smaller than those at San Onofre and have not displayed excessive tube decay, federal officials say.
>
>The cause of the unusual wear has been eagerly anticipated, as Edison prepares to submit a proposal to the NRC to restart one or both of the reactors. The company has suggested the reactors would run for a test period under reduced power to reduce vibration.
>
>"The phenomenon that we think causes this tube-to-tube interaction is definitely proportional to the power," Collins said. "At least in some theoretical sense, that might be part of the answer."
>
>The company has announced that 510 tubes have been plugged, or retired from use, in the Unit 2 reactor, and 807 tubes in its sister, Unit 3. Each of the generators has nearly 10,000 tubes, and the number retired is well within the limit allowed to continue operation.
>
>What's at issue is why so many tubes degraded so quickly, when the design changes were intended to improve the plant's performance and longevity.
>
>The steam generators two in each reactor function something like a car radiator, which controls heat in the vehicle's engine. The generator tubes circulate hot, radioactive water from the reactors, which then heats non-radioactive water surrounding them. That makes steam, which is used to turn turbines to make electricity.
>
>The tubes have to be thin enough to transfer heat, but thick enough to hold up under heavy pressure. They represent a critical safety barrier if a tube breaks, there is the potential that radioactivity can escape into the atmosphere. Also, serious leaks can drain protective cooling water from a reactor.
>
>The trouble began to unfold in January, when the Unit 3 reactor was shut down as a precaution after a tube break. Traces of radiation escaped at the time, but officials said there was no danger to workers or neighbors. Unit 2 had been taken offline earlier that month for maintenance, but investigators later found unexpected wear in tubes in both units.
>
>The NRC has said there is no timetable to restart the reactors.
>
>Edison has been facing pressure from some nearby communities and anti-nuclear activists that have raised safety concerns, while the company looks for a solution to the tube problem and a path to restarting the plant, an important source of power in Southern California. The design of the generators is also under congressional scrutiny.
>
>The plant is owned by SCE, San Diego Gas & Electric and the city of Riverside. The Unit 1 reactor operated from 1968 to 1992, when it was shut down and dismantled.
>
>----
>
>Follow Michael R. Blood at http://twitter.com/MichaelRBloodAP
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© Ace Hoffman
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Ace Hoffman
Author, The Code Killers:
An Expose of the Nuclear Industry
Free download: acehoffman.org
Blog: acehoffman.blogspot.com
YouTube: youtube.com/user/AceHoffman
Carlsbad, CA
Email: ace [at] acehoffman.org
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