San Onofre Nuclear Plant To Close Permanently

Norris McDonald at San Onofre in 2005

Edison International said Friday that it would permanently close two reactors at its San Onofre plant in California.  A Jan. 31, 2012 steam leak revealed cracks in the steam generator system and the plant has been close since the incident. 

The two reactors, built at a cost of about $2.1 billion, once provided 17 percent of the power delivered by the utility.

This closure clearly represents a blow to electricity delivery reliability, particularly if there is an unusually hot summer.  Wildfires are also threatenning transmission and distribution lines.

The Center supports the operation of the San Onofre reactors, which were relicensed to operate until 2022. We hope this is not a final decision by Edison International.  We suppor Edison's proposal to the NRC to allow Unit 3 to operate at 70% power for five months.  We believe it is a prudent proposal and know that Edison would shut down immediately again if there were any steam tube leaks.  We believe unit 2 could operate safely this summer too.

It is frustrating that the Mitsubishi Heavy Industries steam generator replacement, designed to last 20 years, failed in less than 2 after vibrations caused a few of the 9,727 heavy alloy tubes in each steam generator to rub against one another, rupture and leak.  The new steam generators were installed in
reactor unit 2 in 2009 and unit 3 in 2010.  Unit 2 was already closed for maintenance, but unit 3 was shut down after an 82-gallon-a-day leak was discovered.

San Onofre nuclear generating station

Craver said that seeking a license amendment, and fending off legal challenges, would delay a restart enough that it would no longer be worthwhile. (San Onofre unit 1 operated from 1968 to 1992.)

Edison International willld seek compensation from Mistubishi for the faulty steam-generator design. And consumer groups are seeking the refund of extra costs, including for replacement fuel. Craver said costs subject to potential refund amounted to about $1.3 billion. Edison International said it would take a charge of $450 million to $650 million and cut its earnings outlook by 20 cents a share. The company’s shares closed at $47.61 a share, up $1.25. (Wash Post, 6/7/2013)