California ISO braces for San Onofre nuclear outage to extend into 2013

The California Independent System Operator (ISO) said Sept. 13 it is starting to plan for the possibility that the ongoing outage at Southern California Edison’s (SCE) dual unit San Onofre nuclear plant might extend into the summer of 2013.

As part of its contingency planning for an extended outage at San Onofre Units 2 and 3, the California ISO said that it plans additional reliance on two fossil power units owned by another Edison International (NYSE: EIX) subsidiary,

Topping the list of recommended mitigation actions, which the ISO has presented its board of governors, is converting Huntington Beach units 3 and 4 into synchronous condensers. The units were brought back into service this year to fill the void left by the nuclear plant shutdown. As synchronous condensers, the Huntington Beach units do not produce electricity and therefore, no air emissions credits are required, California ISO said in a statement.

Instead, the condensers, acting somewhat like spinning flywheels, adjust to grid conditions by providing the voltage support, normally supplied by the nuclear plant, to the local 230 kV switchyard. Megavars, instead of megawatts, would be produced and used to push megawatts through the grid, much like water pressure helps push water through a hose.

Huntington Beach 3 and 4 are owned by Edison Mission Energy (EME) and operated by AES (NYSE: AES).

In a related note, the Board today approved the staff recommendation to designate the Huntington Beach units as reliability must-run for voltage support in 2013.

SCE eyes first NRC major NRC response in October

The roughly 2,000-MW San Onofre nuclear complex in San Diego County been idle since January when unexpected tube-wear problems were found in steam generators. SCE said in August that it would defuel Unit 3 because it did not foresee that generator coming back online in the near future.

The company has publicly said that the tube wear problems are not as extensive at Unit 2 and appeared to hint that Unit 2 could return to service before Unit 3.

During a Sept. 12 hearing before the Senate Committee on the Environment and Public Works, new Nuclear Regulatory Commission (NRC) Chair Allison Macfarlane testified that NRC had yet to receive any request from the company to restart either reactor. Macfarlane also said that once NRC receives such a request it will probably take months to decide if the restart should move forward.

During that hearing, Sen. Barbara Boxer, D-Calif., who chairs the committee, told NRC that San Onofre must not be allowed to restart until NRC is satisfied that it’s safe. NRC has scheduled a public meeting on San Onofre Oct. 9 in Dana Point, Calif.

A Southern California Edison spokesperson told GenerationHub Sept. 14 that restarting Unit 2 would be a multi-part project. First, SCE must respond to NRC’s confirmatory action letter (CAL) about the plant. In that response, which could come in early October, SCE will try to show that it understand the cause of the problem and what it will take to repair the plant. After the CAL response, SCE would subsequently file a restart plan with NRC, the spokesperson said.

In its most 10-Q quarterly report to the Securities & Exchange Commission, SCE detailed under what conditions it might restart Unit 3. Because Unit 2 experienced considerably less tube-to-tube wear, it is currently anticipated that it could restart in advance of Unit 3; however, in order to do so, it is expected that pending further repairs and analysis, it would operate at reduced power levels and with mid-cycle scheduled outages to provide assurance of safe operation.

SCE’s share of further incremental costs to commence start-up of Unit 2 at the reduced power levels are expected to be roughly $25m, although there is no assurance that start-up of Unit 2 will occur as expected, SCE said.

In addition to SCE, Sempra Energy (NYSE: SRE) subsidiary San Diego Gas & Electric (SDG&E) as well as the city of Riverside, Calif., are part owners of the nuclear power facility.

About Wayne Barber 4201 Articles
Wayne Barber, Chief Analyst for the GenerationHub, has been covering power generation, energy and natural resources issues at national publications for more than 20 years. Prior to joining PennWell he was editor of Generation Markets Week at SNL Financial for nine years. He has also worked as a business journalist at both McGraw-Hill and Financial Times Energy. Wayne also worked as a newspaper reporter for several years. During his career has visited nuclear reactors and coal mines as well as coal and natural gas power plants. Wayne can be reached at