Southern California Edison made the announcement in an out-of-court settlement filed in San Diego between the utility and a pair of San Diego-area plaintiffs who sued after the California Coastal Commission in 2015 approved a 20-year permit for Edison to expand a storage system to place the plant's spent nuclear fuel into heavy, dry casks.
The settlement was approved Monday by Superior Court Judge Judith Hayes.
Under the agreement, Edison commits to make "commercially reasonable" efforts to relocate the spent fuel to another facility. Among the possible sites is the Palo Verde Nuclear Generating Station in Arizona, about 50 miles from Phoenix.
Locations in eastern New Mexico and west Texas also are mentioned.
Edison executives also committed Monday to assemble a team of experts to develop a plan to relocate San Onofre's spent fuel. The panel would be made up of authorities in engineering, radiation detection and nuclear waste siting and transportation.
In addition, Edison vowed to develop a more expedited inspection program for the waste at San Onofre and produce a contingency plan should any of the canisters crack or leak.
"This represents the coming together of the utility, the community and a group of experts committed to moving the radioactive waste at San Onofre to a location that's safer and more inland," said Michael Aguirre, one of the lead attorneys for the group that took Edison to court.
The utility is required to spend $4 million in consultant fees and other costs associated with the provisions in the settlement.
In a statement, Edison President Ron Nichols said, "SCE is proud to take a leadership role in what we expect will become an industry-wide effort over many years to work with the federal government and other key stakeholders to achieve off-site storage."
One of the plaintiffs in the case is Citizens Oversight, a San Diego-based civic group that has long opposed Edison's plans to store nuclear waste at the plant, which has not produced electricity since January 2012 and is in the process of being decommissioned.
"This [settlement] is about the best we can do, and I think it's pretty good," said Ray Lutz, national coordinator at Citizens Oversight. "It's a prudent step in the right direction and a step [Edison] wouldn't take at all if it weren't for the lawsuit that we filed."
The agreement sets a series of timetables for the utility for coming up with alternative locations for San Onofre waste and assembling its panel of experts.
A request for the proposal for qualified candidates for the panel must be delivered in 60 days, and the panel must be retained — with names of the panelists made public — within 90 days of receiving the proposals.
"Now there's a plan in place that will be implemented with progress reports," said Maria Severson, the other lead attorney for the plaintiffs. "Experts … will get on board and report back to the public as far as moving [waste] away from" San Onofre.
But while Monday's agreement offers a possible path to move nuclear waste, significant hurdles remain.
The U.S. Nuclear Regulatory Commission, which is charged with protecting public health and safety related to nuclear energy, would have to sign off on any transfer, Aguirre said.
Plus, while the spent fuel at San Onofre is the responsibility of Edison, the waste eventually must be handed over to the U.S. Department of Energy, and moving any waste across state lines would involve the U.S. Department of Transportation.
Aguirre described Monday's agreement as something that "can set a model for the rest of the nation." Nuclear plants across the country have accumulated nearly 80,000 metric tons of spent fuel, and about 2,200 tons are added each year.
The waste at San Onofre has been particularly controversial.
California's history of seismic activity unnerves many of the 8.4 million people who live within a 50-mile radius of the plant, which runs right up against the Pacific on its west side and the 5 Freeway on its east side.
"We've made the first step, and we have a mechanism in place to make sure that all the other steps happen," Aguirre said. "For the average San Diegan, before, there was no hope. That Sword of Damocles, the nuclear sword of Damocles, was hanging over their head indefinitely. Now, there is a specific plan, a specific timeline and the authority of the court to make sure it all happens."
Some of the waste at San Onofre sits in 50 canisters that are stacked horizontally in "dry storage" at an installation behind a seawall 27 feet high.
Another installation for the rest of the spent fuel is in the process of being constructed. The fuel now cooling in "wet storage" — in a deep pool of water — eventually will be moved to 73 thick, vertical casks.
Aguirre has called for moving San Onofre waste to the Palo Verde Nuclear Generating Station in Arizona, saying it's a logical place because Edison is a part-owner at Palo Verde, with a 15.8% stake.
The New Mexico and Texas sites are part of what the nuclear industry calls "consolidated interim storage," locations where multiple nuclear plants could send their waste, provided local governments in the respective sites sign off on them.
"One person's waste is another person's most valuable possession," said John Heaton, chairman New Mexico's Eddy-Lea Energy Alliance.
The contingent said if the project is approved, it could go online in as soon as five years — a quick turnaround when it comes to the slow pace of the bureaucracy and construction time associated with nuclear projects.
Potential sites in the agreement are not limited to Arizona, New Mexico and Texas.
There has been movement on Capitol Hill and by the Trump administration to bring back the Yucca Mountain nuclear waste repository in Nevada.
"Yucca, as far as I'm concerned, is very much an option," Aguirre said.
Lutz said he hoped the waste could get moved out of San Onofre in as little as five years but acknowledged the difficulties in reaching an agreement and opposition that would come from other states.
"People need to look at the big picture and say we need to do the right thing for everybody," Lutz said. "This is not a 'not in my backyard' issue."
Nikolewski writes for the San Diego Union-Tribune