The following story from North County Times is the most recent news report covering any problems at San Onofre:
SAN ONOFRE: Small problems delay restart of Unit 2 reactor
MEANWHILE, NRC SAYS PLANT LAGGED IN REPORTING MINOR SAFETY PROBLEM
By PAUL SISSON
January 12, 2010 6:05 pm
Imperfect welds and pinhole leaks have kept San Onofre's idling reactor from returning to service as planned, plant officials said this week.
Ross Ridenoure, chief nuclear officer for Southern California Edison ---- the company that runs the seaside nuclear power plant, said Tuesday that the problems have been repaired ---- but have delayed the return-to-service date for the plant's northern Unit 2 reactor by about three weeks. Ridenoure said the unit is not likely to power up until late January or early February.
In an unrelated incident, a report surfaced this week that plant officials waited 16 days before reporting a minor safety issue at San Onofre to federal regulators.
That issue involved the temporary shutdown of a mechanism that cools one of the plant's two spent fuel pools.
Plant officials said Tuesday that they didn't realize the maintenance shutdown needed to be reported to the Nuclear Regulatory Commission until an official with the agency notified them earlier this month.
The Unit 2 reactor has been out of service since late September, part of a $680 million project to replace worn parts housed inside each of the plant's two massive domes. That work is now largely complete, and inspectors are checking for problems.
Before the unit is brought back on-line, it must first pass several critical safety tests required because of a recently finished upgrade of two massive steam generators which are used to convert the heat of nuclear fission into clean steam that turns the plant's electricity-generating turbines.
Ridenoure said engineers have not yet conducted a pressure test on the concrete that now fills a 28-foot octagonal hole in the reactor's containment dome. The dome must be proven to hold up to 50 pounds per square inch of pressure before the reactor can be restarted.
Engineers must also finish tightening 82 thick steel tendons that run through the section of new concrete. The tendons are critical in helping the dome resist the shaking that could be generated by a serious earthquake. More than 1,000 workers have toiled to perform myriad routine maintenance activities during the outage, including replacing half of the reactor's uranium fuel.
Highly radioactive spent fuel is removed and stored in an adjacent 45-foot pool where it must be kept cool for about five years until it stops generating heat. It was maintenance of a cooling mechanism near the pool that prompted the recent NRC reminder about filing a safety report.
The plant uses a pair of heat exchangers, fed by cool ocean water, to keep the hot fuel from getting so hot that it could melt, a problem that could be dangerous to the surrounding environment.
On Jan. 8 plant officials reported to the U.S. Nuclear Regulatory Commission that both of the pool's two heat exchangers were taken off-line at the same time for about one hour on Dec. 23. The report eventually filed with the NRC stated that the pool could go for 23 hours before water inside would reach a maximum allowable temperature of 160 degrees Fahrenheit.
Ridenoure said one of the two heat exchangers was undergoing routine maintenance during the outage and the second was shut down to clear ocean debris from a grate that protects the reactor's saltwater cooling system which draws billions of gallons of water from the ocean each day.
He said the plant has performed similar procedures, which have temporarily left the fuel pool without cooling, but at the time, reporting those incidents was considered unnecessary.
"Oftentimes, because the rules tend to be very complicated, the way they're interpreted changes from time to time," Ridenoure said, adding that the plant has multiple other ways of cooling the pool if the main heat exchangers both fail.
Not so with welds in the reactor's main piping. Ridenoure said that X-rays of a main weld that connects a critical 48-inch in diameter pipe to one of the reactor's two new steam generators was found to have microscopic bubbles called occlusions. The weld, though it was made by a specialized robot, had to be ground out and redone several times, Ridenoure said, before the X-rays came up pristine.
Likewise, several small leaks were detected, he said, in a pipe that is intended to carry emergency cooling water into the reactor core in an emergency. While the pipe would have still worked, Ridenoure said Edison decided to replace the leaky section.
"The difficulty was the piping was in a very hard location to get to in a concrete tunnel," Ridenoure said.
Homer Simpson alert!!!
there is no indication of any danger
OK, somebody 'splain to me the point of having a siren again?
Biggest jugs on the west coast. Anyone who drives I5 knows what I'm talking about.
Oh dear.
Usta live in the shadow of that place. Nice area.
Hope it’s nothing real major.
Okay, if the sirens are going “off”, why are they working to turn them “off”.
Obama could use a good crisis about now...
The simple fact that they don’t have anyone there smart enough to turn of a simple siren sounds like a danger to the public to me.
It’s a liberal, environmental scam to bring attention to the dangers of Nuclear Energy and the need for GREEN ENERGY what ever the #!@$ that mean.
The weld, though it was made by a specialized robot, had to be ground out and redone several times, Ridenoure said, before the X-rays came up pristine...........................................................................What I wanna know is did they fire the robot for busting his weld???Curious minds want to know!
Follow-up:
Channel 7 KABC News just reported that the siren alarms have now been turned off at San Onofre Nuclear Power Plant in San Clemente, California.
They said that there is nothing to worry about. It is still unknown what caused the siren alarms to go off.
Seems it’s location would be a security/natural disaster nightmare.
But it is in Cali.
BILLIONS??
BILLIONS??
One billion gallons is a volume 20' by 20' by 63.3 MILES long!
Are they under attack by The Amish?
Turn the O-N-O-F-F switch to the O-F-F position.
“They are working on finding a way to turn the sirens off.”
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