Sunday, March 18, 2012

It's definitely time to decommission San Onofre!

Dear Readers,

It's time to decommission San Onofre Nuclear Generating Station. It's the only sensible thing to do. It makes economic sense for just about everybody, and spares us the possibility of "Fukushima USA" here in SoCal.

Right now, neither of San Onofre's two reactors are operating. Southern California Edison is already predicting there could be rolling blackouts during the summer if they can't get the reactors running by then. The threat of blackouts is at odds with the historic record of energy usage, which clearly shows that there is more than enough electrical generating capacity and transmission line capacity in SoCal to replace San Onofre.

Nevertheless, SoCal residents can EXPECT rolling blackouts -- because SCE wants them to happen: It may cost as much as a billion dollars (or more) to repair San Onofre. Instead SCE could be securing contracts NOW for summer energy use. They could be building a billion dollars' worth of solar rooftops, offshore wind turbines, turbine peaker plants, cogeneration plants, energy storage reservoirs, geothermal energy systems, etc..

But they don't want to, because when San Onofre is operating, it's "easy money": A million dollars per day per reactor! So instead they'll want to "prove" that SoCal "needs" San Onofre, so they won't prepare, the blackouts will happen, and then they'll expect us, the ratepayers, to pay for it all!
Meanwhile, there is still NO solution to the problem of long-term storage of nuclear waste, which has been piling up for decades in dangerous "temporary" locations at every nuclear power plant in the country (and nor will there ever be a good solution). And NOR is there a solution to the dangers of nuclear weapons proliferation, which SanO exacerbates by producing plutonium and tritium. Additionally, the dangers from terrorism, or from mother nature's fury, remain unsolved too. San Onofre is built on or near several fault lines, and along the coast, nearly at sea level. It's tsunami-prone and earthquake-prone. And surrounded by about eight million people within 50 miles (noting that the U.S. Government recommended U.S. citizens evacuate from within 50 miles of Fukushima, Japan -- and ALSO noting that even that might not be far enough!).

Furthermore, San Onofre continues to have problems with worker harassment (intimidation of workers to prevent them from reporting dangers) AND, paradoxically, worker safety complaints (that safe procedures aren't being followed). San Onofre is officially (Nuclear Regulatory Commission's own data) the worst-run commercial nuclear facility in the nation on BOTH counts.

A meltdown at San Onofre would be the ruination of SoCal. And we don't need a tsunami or "the big one" to cause it: It's not inconceivable that a thing as simple as a flashlight dropped in the reactor water could start a cascade of failures, leading to a meltdown "just like" Chernobyl or Fukushima. That's why they have regulations to prevent things like dropped flashlights (I mention this specifically because it happened there last month, and the contract worker, a temporary employee at the plant, who violated workplace rules by dropping the flashlight, then further violated the rules by trying to retrieve it -- and falling in!)

SCE doesn't want to be responsible for ANY of the costs to fix the reactors. They just want to fix them any way they can, so they can restart them as soon as possible, so they can go back to making money -- and creating a ton a week of highly dangerous "spent fuel" which will be the real legacy of San Onofre's decades of operation: Millions of pounds of deadly poison sitting on our shoreline just waiting to be released by accident/sabotage, etc.. Southern California Edison will be long out of business, all of us will be long dead, California will be a nation unto itself (perhaps), but the waste will still be here.

The cause of San Onofre's current shutdown is defective replacement Steam Generators (SGs) made in Japan by Mitsubishi Heavy Industries. MHI has been building SGs for nuclear power plants since the 1970s and have manufactured, shipped and installed well over 100 SG units around the world. MHI's current annual report indicates they plan to double their nuclear steam generator business several times in the next three years to almost $10 billion annually. So this is a big setback for them as well as for SanO's owners. The problem is almost surely the result of incorrect manufacturing procedures: This didn't have to happen. What other SGs around the world are in trouble?

Steam Generators are massive things used in Pressurized Water Reactors (PWRs). PWRs have three coolant loops: Water under very high pressure in the primary loop goes through the reactor core, gets heated (and irradiated), and then goes through thousands of very thin tubes inside the steam generators.

San Onofre's two SGs each have nearly 9,500 long, thin U-shaped tubes (the tube's walls are about the thickness of a credit card). Because the water inside the thin tubes is highly pressurized, it does not boil. The water on the other side of the tubes (the secondary coolant loop) comes in contact with the hot tubes and turns to steam. The steam is piped out of the containment domes and into the turbine room, where it is used to turn the turbines which generate electricity. A third coolant loop (ocean water) condenses the steam in the second loop, and that condensate is then pumped back into the steam generators again.

When any company receives $800 million worth of equipment, it invariably inspects that new equipment very carefully to make sure it's exactly what they ordered. San Onofre's replacement steam generators were inspected when they arrived at the plant in 2009, and found to be defective. MHI had to send out a special team to SoCal to reweld them. Like the defects that are appearing now, those defects SHOULD NEVER HAVE MADE IT OFF THE FACTORY FLOOR.

You can be sure numerous additional inspections were done after the problems were discovered in 2009. The additional inspections and repairs took about six months. Then they put the steam generators in the reactors (two SGs in each of two reactors) and just over a year later... problems, problems, problems!

The first problems to show up were in Unit II, the older of the two operating reactors and the one to get its steam generators replaced first. Excessive wear was discovered on the thin U-shaped tubes inside the SGs, when were inspected during Unit II's first refueling outage after the SG replacement. The outage was already far from "routine" despite repeated assurances by the utility that it was "just" a routine refueling outage: The Reactor Pressure Vessel Head was being replaced, which is another massive (and expensive!) part which had worn out prematurely. Neither the RPVH nor the SGs were ever supposed to wear out in the entire life of the plant.

Unit II's SG wear is significant: Two tubes had at least 30% wear, and nearly 70 tubes had at least 20% wear, and about 700 tubes had at least 10% wear. The new SGs are expected to last 40 years or longer -- but all of this excessive wear was detected after only about 14 months of operation! PWRs rely on the SGs to remove excess heat from the reactor. They are a vital safety component of the reactor, which is one reason there is a minimum of two SGs per reactor (sometimes more than two) in every PWR in the world -- in case one fails.

San Onofre's engineers were quick to explain to the media and the public that the wear they found on Unit II was probably just wear from "settling in": The parts merely had to "get comfortable" with each other. I actually heard SanO employees using these "engineering" terms!

Then Unit III's steam generators failed, too -- and it was "discovered" the hard way: A rupture. One of the nearly 20,000 tubes inside Unit III's SGs suddenly burst, and the subsequent release of primary coolant -- which is highly radioactive -- into the secondary coolant loop -- which normally isn't very radioactive -- caused the control room operators to have to shut down that reactor as well. Some radiation was released to the atmosphere (and to the public) when the radioactive steam condensed back to water at atmospheric pressure.

Calling what happened Last January merely a "leak" is being too nice: It was an extremely violent flashing to steam of super-heated, super-pressurized radioactive water and chemicals. (If you passed your arm accidentally over the breach, it would take your arm off (by steaming it off!) in an instant. (But at least the stump would be sanitized.))

Such steam generator tube ruptures are rare, and it's a good thing: The real danger would be that one burst tube would damage the tube next to it, which would burst too, and so on in a cascade of failures that would throw metal parts throughout the primary and secondary coolant loops, damaging valves and reactor fuel assemblies, blocking water flow, and damaging the other SG. And then what? Fukushima USA: An inability to cool the reactor -- a meltdown.

San Onofre avoided that, but their troubles had only just begun.

After letting the reactor cool for several days, technicians went in and started trying to discover what had gone wrong with Unit III's new steam generators. Was it "just" wear, like Unit II was experiencing? It doesn't appear to be the same problem: SanO employees identified 129 tubes that appeared to be excessively worn, and started pressure-testing them. This involves increasing the pressure in one tube at a time to about three times the normal operating pressure. Seven tubes have failed these tests already, and they've only just begun that phase of the testing!

Will it ever be safe, or reasonable, to restart these reactors with Mitsubishi Heavy Industry's steam generators? When BOTH units are having problems? (Exactly ONE tube in Unit II was pressure tested in light of the problems with Unit III. That one tube passed the test. All pressure tested tubes are plugged up permanently, and can no longer be used.)

There can be little doubt now that MHI has been delivering products with criminally-negligent workmanship, and San Onofre has been accepting those parts and using them.

One meltdown at SanO -- or two -- would destroy everything we love about SoCal. Why spend billions of dollars just to restart THAT risk? Right now we just have the spent fuel to deal with -- the radioactive waste pile. It's deadly, difficult to manage, and will cost a fortune. But at least it's NOT GROWING at the moment, and that's good. In fact, slowly but surely, it's cooling and becoming less hazardous.

Restarting San Onofre is just plain stupid!

Ace Hoffman
Concerned Citizen
Carlsbad, CA

The author is an educational software developer. His programs on mechanical pumps, the human heart, statistics and the periodic table are used in over 1000 universities around the world. His book on nuclear issues, The Code Killers, is available for free download or online viewing from his web site: . His essays have been republished many times.


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