Southern California Edison made the announcement in an out-of-court settlement filed in San Diego between the utility and two 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 are also mentioned.
Edison executives also committed on 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 the San Onofre station 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.
Edison 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 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 they [Edison] wouldn't take at all if it weren't for the lawsuit that we filed."
The agreement sets a series of timetables for Edison to reach, both in regards to coming up with alternative locations for the San Onofre plant's nuclear waste and assembling its panel of experts.
A request for 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.
Monthly reports will be required, progress on moving the spent fuel to the Palo Verde plant will need to be cited and by 2020 Edison must develop a contingency plan in case any of the canisters holding the waste crack or leak.
"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" the San Onofre plant.
Although Monday's agreement offers a possible path to move the nuclear plant's waste, significant hurdles remain.
Plus, while the spent fuel is Edison's responsibility, the waste eventually must be handed over to the U.S. Department of Energy, and moving any waste across state lines would assuredly 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 San Onofre plant's waste has been particularly controversial.
California's history of seismic activity unnerves many of the 8.4 million people who live within 50 miles of the plant that runs right up against the Pacific on its west side and Interstate 5 to its east side.
Some of the San Onofre facility's waste 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 being constructed. The fuel now cooling in "wet storage" — in a deep pool of water — will eventually be moved to 73 thick, vertical casks.
Aguirre has called for moving the 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 of the New Mexico group, called the 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 the San Onofre plant 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 the do the right thing for everybody," Lutz said. "This is not a 'not in my backyard' issue."