Activists hail San Onofre nuclear power plant reactor shutdown

Closing of reactors at 40-year-old San Onofre power plant reflects harsh economics facing ageing fleet of US reactors

The Fort Calhoun nuclear reactor in Nebraska was shut down in 2011. Photograph: AP Photo/Nati Harnik

America’s nuclear reactor fleet moved deeper into middle-aged crisis on Friday when operators decide to shut down two reactors at the troubled San Onofre power plant in California.

They were the third and fourth reactors to be permanently retired this year, underlining the harsh economics facing America’s ageing fleet of nuclear reactors, forced to pay for expensive upkeep at a time of increased competition from cheap natural gas and renewable energy.

The two reactors at the San Onofre Nuclear Generating Station (Songs) in southern California had been off-line since January 2012, after the discovery of a radioactive steam leak in one of the units.

Southern California Edison, which runs the plant, had been pushing to re-start one of the reactors on a limited basis.

But there was strong public opposition, and the risk of legal action after the Democratic Senator, Barbara Boxer, last week asked the Justice Department to investigate the plant.

The former nuclear regulator, Greg Jaczko, further set back prospects for a re-start at San Onofre when he told a nuclear safety conference in San Diego that the idea was “not one that instills tremendous confidence in me”.

On Friday morning, the company said it had decided it was uneconomic to try to stay in operation. “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,” Ted Craver, the company’s chief executive said in a statement on Friday..

Boxer said she was “greatly relieved” at the decision.”Modifications to the San Onofre nuclear plan were unsafe and posed a danger to the eight million people living within 50 miles of the plant,” she said in a statement.

The decision to shut down Units 2 and 3 reduced the number of licenced reactors to an even 100 – the lowest number in two decades.

The plant had been in operation for 40 years. But age caught up to the plants in January 2012 when operators detected a leak inside a steam generator in Unit 3.

The leak was inside a new steam generator, made by Mitsubishi Heavy Industries, which had been installed in 2009.

But nuclear experts said maintenance and upkeep of reactors had become increasingly challenging – especially with heightened safety requirements introduced by the Nuclear Regulatory Commission in the wake of the Fukushima disaster.

“Reactors have basically hit their middle-aged crisis. They are through their performance plateau. They are starting to experience ageing issues across the board and maintaining safety is expensive,” said Jim Riccio, a nuclear safety analyst for Greenpeace. “You are having reactors with a lot of ageing problems and the NRC is catching up with problems that hadn’t been fixed for a long time.”

Four nuclear reactors have been shut down so far just this year. In addition to the two reactors at San Onofre, operators permanently retired the Crystal River reactor in Florida in February, after running into significant problems with repairs. The Kewaunee reactor in Washington shut down last month because operators said they could not compete with the prices of natural gas.

A number of other nuclear plants are off-line for repair, such as Fort Calhoun in Nebraska which has been shuttered since April 2011 because of flood risks and other safety problems. Some of those plants, especially those with single reactors, could also be in line for shut-downs by the end of the decade, said David Lochbaum, nuclear safety expert at the Union of Concerned Scientists.

Or as Jaczko the former regulator told the nuclear safety conference earlier this week: “I think it’s time that we need to reconsider prolonging the lifetime of many of these reactors.”