Regulatory delay closes San Onofre

07 June 2013

San Onofre (SCE) 460
San Onofre (Image: SCE)

Both reactors at the San Onofre nuclear power plant in California are being retired due to the lengthy and uncertain regulation surrounding their return to service.

"We have concluded that the continuing uncertainty about when or if San Onofre 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," said Ted Craver, chairman and CEO of Edison International - the parent company of San Onofre owners Southern California Edison (SCE).

The plant's problems began in January 2012 with a fault in one of two new steam generators installed as part of an uprate and modernization program of unit 3. The reactor shut down automatically when a minor amount of radioactive material was detected coming from a worn tube in the steam generator, but the radiation aspect of the issue led to the mobilization of an anti-nuclear campaign against the plant, its majority owner Southern California Edison (SCE), and Mitsubishi Heavy Industries which supplied the faulty component.

The issue with unit 3 is exacerbated by the outage at unit 2, which has been kept from restarting from maintenance because it shares the same steam generator design, although tube wear and vibration issues have been found to be less serious. SCE proposed to restart unit 2 at reduced power to provide an additional safety margin for the steam generators, but the Nuclear Regulatory Commission's (NRC's) review processes have so far taken eight months without reaching any conclusion.

Around 900 jobs will be lost with the closure of both units as SCE scales back its plant workforce from 1500.

Now, said SCE, decisions by the NRC's Atomic Safety and Licensing Board have "created further uncertainty," adding that "additional administrative processes and appeals could result in delay of more than a year." During this time, SCE would have to purchase replacement power for its customers as well as maintain the plant in a state of readiness to operate.

SCE said it cannot afford to wait for permission to restart unit 3 without income from the operation of unit 2. The reactors produce 1080 MWe and 1070 MWe respectively and have licenses to operate until 2022. During this period the units would have avoided over 7 million tonnes of carbon dioxide emissions compared to the gas generation likely to replace them.

Around 900 jobs will be lost with the closure of both units, said SCE, as it scales back its plant workforce from 1500. "This situation is very unfortunate. This is an extraordinary team of men and women. We will treat them fairly," said Pete Deitrich, chief nuclear officer of SCE.

The wider region will be affected by a tightening balance of power supply and demand. "Thanks to consumer conservation, energy efficiency programs and moderate summer, ther region was able to get through last summer without electricity shortages. We hope for the same positive result this year, although generation outages, soaring temperatures or wildfires impacting transmission lines would test the system" said Ron Litzinger, SCE president.

San Onofre is owned 78% by SCE, 20% by San Diego Gas and Electric and 2% by the city of Riverside.

Researched and written
by World Nuclear News