From: Ace Hoffman, Carlsbad, CA, local resident, member: CREED, ROSE, SCGreen, NukeFreeCal, San Onofre Safety
Phone: (760) 720-7261
******** FOR IMMEDIATE RELEASE ********
Steam generators for Pressurized Water Reactors such as San Onofre are massive things: Huge towers filled with thousands -- or even tens of thousands -- of individual steel tubes.
Inside these tubes flows -- very quickly -- very hot, very high pressure water. Outside the tubes, but still inside the steam generators (which are inside the containment domes, alongside the reactors themselves) water fills the lower portion of the steam generator, and steam bubbles up and fills the upper area, and then exits the steam generator (and the containment dome) to turn the turbines (located in another building nearby). The turbines generate the electricity, then the steam is condensed back into water, and returned to the steam generator to be boiled to steam again.
Inside the tubes the extremely hot, highly pressurized water comes into direct contact with the zirconium-clad nuclear fuel rods in the reactor. Consequently, it is highly radioactive, mainly with short-lived noble gasses such as krypton and xenon, but also with various amounts of tritium (radioactive hydrogen). Also, there are lesser quantities of uranium and plutonium, which have escaped the fuel rods through microscopic (or larger...) cracks. In addition to the uranium and plutonium (thousands of times more harmful than the uranium) there are radioactive products of the fission process such as cesium, strontium, polonium, iodine and about a hundred other elements. Pound for pound, many of these are also thousands of times more toxic than uranium.
The sudden rupture of one of the thousands of credit-card-thin metal tubes inside a steam generator is a very violent thing. On one side is extremely hot water that would just love to violently turn to steam, but is normally under pressure so it can't. The pressure differential is enormous.
Cascading failures of the tubing in multiple steam generator tubes, leading to a burst or blocked cooling pipe or ruptured steam generator is just the latest nearly-realized potentially catastrophic problem for nuclear power plants everywhere -- and for San Onofre in particular, in densely-populated Southern California.
And the word "catastrophic" is hardly an exaggeration. Such a failure can lead to a complete inability to cool the reactor, and a meltdown. Fukushima USA would be a disaster which would dwarf Katrina, 9-11, Pearl Harbor, or anything else America has ever experienced. It might even dwarf Fukushima itself.
Did we almost lose Southern California earlier this week? They wouldn't tell us if we did, but it sounds like we came mighty close.
On the other side of the country, Three Mile Island's steam generators, which were made by AREVA, are also full of problems, and that reactor is also shut down and "assessing the problem". La Salle also installed new AREVA steam generators recently and they're having problems as well.
San Onofre's steam generators were made by Mitsubishi in Japan. Mitsubishi's steam generators are cracking unexpectedly early in other nuke plants -- it's a generic problem in the industry. But reportedly, San Onofre's problems are among the worst, if not THE worst "teething pains" anyone's ever seen in any nuclear steam generator anywhere!
At San Onofre Unit II, about 10% of the tubes have 10% or greater wear after little over a year in operation -- about 1% have 20% wear or more! Weakened tubes make cascading accidents more likely.
And they want to re-license this hunk of junk for ANOTHER 20 years? They want to restart it?!?! It's time to shut it down forever!
Stop work, decommission San Onofre, move on to clean energy (including offshore wind farms right here off our coast). Now is a really good time: It will save us all a lot of money to do it now rather than later. Later might be way too late, and even if nothing goes catastrophically wrong, leaving the plant open means nuclear waste is piling up with nowhere to put it at the phenomenal rate of 500 pounds per day (when the reactors are both operating). The Nuclear Regulatory Commission just announced that the waste will probably be stored here for at least 250 to 300 years! The accidental release of even one day's production of fission products would be catastrophic. Every day we keep the plants operating, we increase the risk for our children, our children's children, and everyone else, for thousands of years.
This latest incident -- which they refuse to call an accident -- caused a brief burst of radiation into the environment. If you happened to be driving by San Onofre when it happened, with your infant in the back seat, it might have been a very strong dose. No one knows what might have been released because the plant itself doesn't have very good information, and whatever data the plant has, they're not sharing.
Many of the isotopes that were probably released were very short-lived, with half-lives measured in minutes. That's some very nasty stuff, but it decays away completely in an hour or so. But in that hour the deadly poison can drift 15 miles in a light breeze. If you were bicycling past the plant and going with the wind, you could have been breathing some pretty nasty vapors for a long time and not even know it! (There were citizen reports of large amounts of steam coming out of the plant the day of the event.)
Thank you, San Onofre Nuclear Generation Station -- again! We appreciate yet-another wake-up call.
The author is a technical advisor on nuclear issues for several environmental organizations in Southern California and is the author of The Code Killers: An Expose of the Nuclear Industry, available for free download from his web site: www.acehoffman.org