Aletho News

ΑΛΗΘΩΣ

California’s San Onofre nuclear plant to shut down permanently – owner

RT | June 7, 2013

Southern California Edison (SCE) has decided to permanently retire two units of its San Onofre Nuclear Generating Station (SONGS) on California’s Pacific coast, Edison International said in a press release.

“SONGS has served this region for over 40 years,” said Ted Craver, Chair and CEO of Edison International, the parent company of SCE, “but we have concluded that the continuing uncertainty about when or if SONGS might return to service was not good for our customers, our investors, or the need to plan for our region’s long-term electricity needs.”

Units 2 and 3 of the troubled plant have been shut down since January 2012, when a radiation leak led to the discovery of significant damage to several generator tubes. Many feared that the worsening conditions at the atomic power station would result in a Fukushima-like meltdown in California.

The plant’s generators have been malfunctioning for months. Today’s decision to permanently shut down the twin-domed facility comes after the US Nuclear Regulatory Commission’s Atomic Safety & Licensing Board ordered a hearing on Edison’s plan to restart Unit 2 at 70 percent of full power. The company’s officials claimed that operating the least-damaged reactor at that capacity would ensure its safety by reducing vibrations in the generator’s tubes.

It may take over a year for a final decision on the future of the reactor to be made, Edison said in its statement on Friday. It added that throughout that period the company will bear the costs of ensuring the reactor is prepared for a restart – a costly prospect for both the owner and its clients. SCE said it would rather focus its efforts on “planning for the replacement generation and transmission resources which will be required for grid reliability.”

The company also plans to reduce its current staff of about 1,500 to around 400 employees within the next 12 months, but vowed to handle the layoffs “fairly.”

It will take years to fully decommission the two San Onofre reactors. Edison said its “top priority will be to ensure a safe, orderly, and compliant retirement of these units.”

The US has 104 nuclear power reactors, 13 of which are currently being decommissioned, according to the NRC.

June 7, 2013 Posted by | Nuclear Power | , , , | Leave a comment

Nuclear station insider says San Onofre should stay closed

RT | April 30, 2013

A safety engineer from the San Onofre nuclear power plant has warned that “there is something grossly wrong” with the plant and that it faces the prospect of a full or partial meltdown if it is restarted

The safety engineer, who has worked in the nuclear field for 25 years, told ABC 10 that due to broken tubes carrying scalding water, there could easily be a main steam line break, which would cause the nuclear reactor core to overheat and result in a Fukushima-like meltdown.

The Los Angeles City Council last week demanded that the Nuclear Regulatory Commission refrain from making a decision about restarting the San Onofre unit until it conducts a “prudent, transparent and precautionary” investigation. Days after the unanimous city council decision, an insider from the San Onofre plant spoke to the media for the first time about the dangers associated with a restart.

“There is something grossly wrong,” the inside source told ABC, asking for anonymity because of fears for his safety.

Dr. Joe Hopenfeld, a former NRC employee, mirrored the insider’s fears, claiming that the manufacturer of San Onofre’s generators did not have experience in sizing the unit for the plant. In 2010 and 2011, San Onofre paid the Japanese manufacturer Mitsubishi Heavy Industries (MHI) to build replacement generators, which were shut down in just 11 months due to a radiation leak.

“The manufacturer didn’t have experience in this size unit,” Hopenfeld told ABC. “I have reviewed thousands of pages of assessment and reports that Edison has submitted.”

Due to the leak, officials also discovered problems with the generator tubes carrying the hot water to and from the reactor core, which creates steam that turns the turbines and creates energy. The tubes operate under high pressure and are placed in rows, very close to one another. There is no protection between the tubes, resulting in many of them to hit each other and crack.

An NRC report found that of the 19,400 tubes, more than 17 percent were damaged. The cracking caused several tube failures, and the worst case scenario is a main steam line break, Hopenfeld and the insider explained.

“Many tubes, and I don’t know how many, have exhausted their fatigue life – they have no fatigue life left,” Hopefeld said.

With a main steam line break, the reactor core can quickly overheat and cause a Fukushima-like nuclear meltdown that would endanger the lives of those near the plant, which is located in San Diego County, Southern California.

“If an accident like this happens, (an) emergency plan is not geared to handle such a public safety devastation,” the inside source said. “Those things have never been practiced or demonstrated in a drill scenario.”

Officials at Southern California Edison, which owns the plant, have proposed a solution for a partial restart of the plant, claiming that operating Unit 2 at 70 percent capacity would ensure its safety by reducing the vibrations of the generator tubes. But Hofenfeld and the insider believe this would only reduce the risk – not diminish it.

“Maybe the vibrations wouldn’t be as severe, but it doesn’t mean they are going away,” Hopenfeld said.

“I am not trying to scare anybody — you can live there, but you should know what the risk is,” he added.

In the coming weeks, the NRC is expected to make a decision on whether or not the San Onofre nuclear power plant should be allowed to partially restart its operations. It has been out of service since January 2012.

May 1, 2013 Posted by | Nuclear Power | , , , , , | Leave a comment

Tube wear detailed at San Onofre, California nuke plant

By Tony Cadwalader | Daily Energy Dump | July 13, 2012

Costs and scrutiny continue to mount

Federal regulators have released the most detailed information to date on damage at California’s idled San Onofre nuclear power plant, according to KFI-AM in Los Angeles reporting an Associated Press story. (Via Drudge)

“Records posted Thursday show the extent of wear in 3,400 tubes that carry radioactive water in the plant’s troubled steam generators. The tube wear caused by vibration and friction was found in 15,000 places at varying degrees of erosion. The report has implications for the fate of the plant shut down since January.”

A fuller version of the story at the AP site said: ”The steam generators, which resemble massive steel fire hydrants, are one of the central pieces of equipment in a nuclear plant. At San Onofre, each one stands 65 feet high, weighs 1.3 million pounds, with 9,727 U-shaped tubes inside, each three-quarters of an inch in diameter.

“The alloy tubes represent a critical safety barrier – if one breaks, there is the potential that radioactivity could escape into the atmosphere. Also, serious leaks can drain protective cooling water from a reactor.

“Gradual wear is common in such tubing, but the rate of erosion at San Onofre startled officials since the equipment is relatively new. The generators were replaced in a $670 million overhaul and began operating in April 2010 in Unit 2 and February 2011 in Unit 3.

“Tubes have to be taken out of service if 35 percent – roughly a third – of the wall wears away, and each of the four generators at the plant is designed to operate with a maximum of 778 retired tubes.

“In one troubled generator in Unit 3, 420 tubes have been retired. The records show another 197 tubes in that generator have between 20 percent and 34 percent wear, meaning they are close to reaching the point when they would be at risk of breaking.

“More than 500 others in that generator have between 10 percent and 19 percent wear in the tube wall.”

Related articles

July 13, 2012 Posted by | Nuclear Power | , , , , | Leave a comment