San Onofre nuclear generating station will be shut down permanently

Southern California Edison made the announcement this past Friday that the San Onofre Nuclear Generating Station, just north of Camp Pendleton, is to be permanently shut down.

Running since 1968, Unit 1 had been closed down in 1992. It was felt that a large earthquake could not safely be withstood by the unit. A shutdown of Unit 2, begun on January 9, 2012, for routine maintenance, is still in effect. Then, an emergency shutdown of Unit 3, due to a radioactive gas leak, occurred on January 31, 2012.

Since then officials from Edison have stated that the escape of gas was the result of an early failure of tubes inside the nuclear reactors. The reactors contain more than 19,000 tubes meant to contain steam under high pressure. The wearing down of the tubes to the point of failure occurred because of an excess of unexpected friction from the tubes rubbing against each other during vibrations in the structures as the equipment settled.

After transporting the radioactive steam away from the reactors, the tubes raise the temperature of the non-radioactive water they are immersed in. The non-radioactive steam created in this operation is used to turn the turbines that generate electricity.

In addition, the tubes form a critical wall between the radioactive and non-radioactive parts of the generating station.

Permission from the Nuclear Regulatory Commission for one unit of the plant to be tested at 70% of its operating power has been denied for five months.

Southern California Edison plans to attempt to recover monetary damages from the company that supplied the pipes in the steam generators. Edison said the parts, manufactured by the Japanese firm Mitsubishi Heavy Industries, exhibited unacceptable wear much sooner than they were supposed to, according to Mitsubishi’s specifications.

Because of the permanent closing of all units, more than one thousand employees will be let go by 2014.

There are approximately 1.4 million homes within 50 miles of the plant that had been getting their power from San Onofre. Nearly 7.4 million Californians living in those homes will be affected by the shutdown.

San Diego Gas and Electric Company is a 20% owner of the generating plant, and was getting that amount of the electricity generated there. Their plan is for new power transmission cables running from Imperial Valley to guarantee that there is enough juice for SDG&E’s 3.4 million customers in San Diego and Orange County.