Are sand erosion and rising seas a concern for San Onofre’s ocean-front nuclear waste storage?

A “No Parking Anytime” sign nailed to a wooden post was being tossed around the slamming shore break, plucked by the raging sea from a nearby dirt parking road at San Onofre State Beach – a sign of the times as sand erosion shrinks the coastline.

The combination of high tide and strong surf a few weeks ago also caused waves to slam onto a big bluff between the popular surf beach and the tucked away San Onofre Nuclear Generating Station, at times leaving no sandy shore exposed before pounding against the tall walls.

When high tides and big swell merge – as can happen several times a year – waves can crash over the rock barrier at the edge of the sandy beach and onto the public pathway in front of the power station, simply dubbed SONGS. Behind that is a concrete sea wall – when the tide is at its highest the wall extends about 20 feet above the water – that serves as a protective shield to guard what’s stored about 100 feet away: 3.6 million pounds of nuclear waste set in stainless-steel canisters encased in a “concrete monolith.”

The San Onofre Nuclear Generating Station was shuttered in 2013, with the last of its nuclear waste put in a partially buried dry-storage system in August 2020. There the hazardous byproduct is expected to sit until the federal government moves it off site – and that plan has no clear timeline.

In the meantime, coastal erosion and rising sea levels have become a hot topic in Southern California in recent years as shorelines continue to thin, especially during big swell and high-tide events that can chomp away at sand buffers that once protected homes, roads and infrastructure.

  • The moon rises over San Onofre Nuclear Generating Station as big waves and a high surf pound the concrete wall below the station that supports the path connecting north and south San Onofre State Beach in San Diego County on Wednesday, June 23, 2021. South-facing beaches were pummeled by a storm surge that caused waves in the 4-foot to 7-foot range in addition to extreme high tides nearing 7-feet by nightfall. (Photo by Leonard Ortiz, Orange County Register/SCNG)

  • The San Onofre Nuclear Generating Station is seen from Trail 1 at San Onofre State Beach south of San Clemente on Tuesday, August 27, 2019. (File Photo by Leonard Ortiz, Orange County Register/SCNG)

  • A no parking sign and post rolls in the surf at San Onofre State Beach in San Diego County on Wednesday, June 23, 2021. South-facing beaches were pummeled by a storm surge that caused waves in the 4-foot to 7-foot range in addition to extreme high tides nearing 7-feet by nightfall. (Photo by Leonard Ortiz, Orange County Register/SCNG)

  • Gary Headrick, co-founder of San Clemente Green, runs down the beach as the moon rises San Onofre Nuclear Generating Station while big waves and a high surf pound the beach at at San Onofre State Beach in San Diego County on Wednesday, June 23, 2021. South-facing beaches were pummeled by a storm surge that caused waves in the 4-foot to 7-foot range in addition to extreme high tides nearing 7 feet by nightfall. (Photo by Leonard Ortiz, Orange County Register/SCNG)

  • Big waves pound the concrete wall below San Onofre Nuclear Generating Station that supports the path that connects north and south San Onofre State Beach in San Diego County on Wednesday, June 23, 2021. South-facing beaches were pummeled by a storm surge that caused waves in the 4-foot to 7-foot range in addition to extreme high tides nearing 7 feet by nightfall. (Photo by Leonard Ortiz, Orange County Register/SCNG)

  • The moon rises over San Onofre Nuclear Generating Station as big waves and a high surf pound the concrete wall below the station that supports the path connecting north and south San Onofre State Beach in San Diego County on Wednesday, June 23, 2021. South-facing beaches were pummeled by a storm surge that caused waves in the 4-foot to 7-foot range in addition to extreme high tides nearing 7-feet by nightfall. (Photo by Leonard Ortiz, Orange County Register/SCNG)

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So while removing the nuclear waste from San Onofre remains stuck in a bureaucratic limbo, some worry about what could happen if the sea’s reach stretches too far inland as the shoreline shrinks.

“When you think about all the wrong things coming together at the right  time – a storm surge, some sort of tsunami event, a freak high tide – it’s just very vulnerable,” worries Gary Headrick, founder of San Clemente Green, an environmental group that has pushed for relocation of the nuclear waste for years.

Southern California Edison, the shuttered station’s custodian, recognizes climate change is a concern for the current location, meant to be a temporary solution, and has put “a lot of effort into ensuring spent fuel storage safety,” company spokesperson John Dobken said.

“That’s our top priority – maintain the spent fuel in a safe manner while it’s here,” he said, “while at the same time working to get it moved off our coastline.”

Battle with nature

It’s a worry San Clemente-based Surfrider Foundation has also had on its radar in recent years, asking in 2019 for the State Lands Commission to require Southern California Edison to do an annual Sea Level Rise Vulnerability Report, the first of which was released a few months ago.

“Sea level rise, coastal flooding and exacerbated coastal storms due to climate change are absolutely concerns Surfrider has when it comes to the long-term storage of spent fuel at SONGS,” Katie Day, Surfrider’s environmental science and policy manager, said in an e-mail. “The current sea wall is just a temporary blockade, and as coastal erosion continues to occur at San Onofre, the risk of future inundation of the site increases.”

The vulnerability report released in March details the state of the eroding beach lining SONGS, as well as a rock revetment wall in front of the nuclear waste storage area that needed to be expanded and stabilized in recent years due to damage by the sea.

“When the beach is narrow or water level unusually high, or both, waves breaking on the revetment can cause dislocation of individual rocks, which contributes to revetment instability,” the report’s authors said.

In 2018, Southern California Edison had to place imported rock riprap along 500 linear feet of the southern portion of the public access walkway and elevate the access ramp to compensate for sand loss, the report said. SCE did more work in 2019, adding about 150 feet of rock riprap, as well as 70 feet of rocks near the south end of the public walkway.

With regular maintenance, the report said the revetment is likely to tolerate wave forces with “acceptable rock movement” for about 30 years.

More than 1 million cubic meters of sand were placed on the San Onofre beach during the 20 years of construction on the nuclear power plant, which started in 1964.

But as time passed, the beach started to narrow again.

From the early 1990s to last year, the long-term average erosion rate at San Onofre beach has been between 2.3 feet and 4.3 feet a year, the report said.

The erosion, as well as the geological instability of the surrounding area because of local fault lines – all close to densely populated areas – are a concern and regular monitoring is needed, Day said.

This Google Earth image shows how close the expanded dry storage area for spent nuclear waste will be to the shoreline at San Onofre Nuclear Generating Station. (Image courtesy of Google Earth)

Erosion is a problem plaguing large sections of the Southern California shoreline.

Just a few miles north of SONGS, Capistrano Beach is crumbling, with so little sand left a basketball court fell victim to the ocean’s force and more damage is occurring to cement walkways and the parking lot each time a high tide and swell coincide. A few miles south in San Diego, erosion threatens an ocean-front stretch of railroad and nearby multi-million dollar homes lining the coast. Just next door in San Clemente, the city might resort to moving its Marine Safety Headquarters inland to get it away from the waves.

The storage should at least be moved to a higher part of the station now, away from the ocean before it’s too late, argues San Clemente Green’s Headrick.

“I’m more concerned about the generation that follows. This is going to continue eroding and we’re going to realize ‘Oh, this is happening faster than we thought’ and we will have to move it again,” he said.  “And that’s a dangerous thing.”

The California Coastal Commission in its permits for San Onofre’s dry storage system has consistently brought up concerns related to coastal hazards, including sea level rise and erosion, and the risks associated with seismic and tsunami events, said commission spokeswoman Noaki Schwartz.

“We believe the (system) is designed and managed to withstand coastal hazards over the short term, but the coast is not a good place to store spent nuclear fuel over the long term,” she wrote in an e-mail. “However, until the federal government identifies and approves a site for long-term storage for spent nuclear fuel, we are stuck with it on our coast.”

Officials at Southern California Edison say they’re also eager for the waste to be moved off site – and away from the 8 million people who live in a 50-mile radius.

But until the national paralysis on finding a permanent home for the nation’s nuclear waste is overcome, that’s not going to happen. The company announced a new coalition in March to try to push the feds to action.

The U. S. Department of Energy agreed 40 years ago to accept waste for permanent disposal. Utility customers pumped billions into the Nuclear Waste Fund to pay for it.

More than $10 billion was spent on efforts for at repository at Nevada’s Yucca Mountain. But $43 billion languishes in the fund — about $1 billion of it from Edison’s customers.

The Department of Energy has not accepted an ounce of commercial waste, and most say there appears to be no permanent solution in sight.

Settlements from utilities’ lawsuits against the Department of Energy is what is funding the temporary storage systems, like what has been built at San Onofre.

“Our hope is that federal action and careful monitoring of the site will prevent canister exposure to corrosive saltwater,” Day said. “But the risk of future inundation increases with each day, so swift action is needed by the federal government to find an alternative offsite location as soon as possible.”

The storage system

Picking the location was a compromise after the Navy nixed property near its Camp Pendleton on the inland side of the 5 Freeway.

Image courtesy Holtec

The Nuclear Regulatory Commission has only licensed a handful of companies to build these temporary dry storage systems. In 2014, Edison chose Holtec’s HI-STORM UMAX, a partially underground system described as a “concrete monolith.”

Holtec says the system – with corrosion-resistant, stainless steel fuel canisters encased in reinforced concrete 3- to 4-feet thick, topped with 24,000-pound steel and concrete lids —  “provides underground storage of used nuclear fuel that is unperturbed by flood, high water table, tsunamis, or hurricanes, and is seen by the industry observers as the ultimate foil to the kind of terror that struck on 9/11.”

It’s designed to withstand submersion under 125 feet of water, Edison spokesman’s Dobken said.

A study of earthquake risks off San Onofre’s coast pegged the maximum credible tsunami threat at less than 10 feet.

The nuclear plant itself was designed to withstand a magnitude 7 quake five miles away or peak ground acceleration of 0.67 Gs (G-forces). The dry storage systems are more than twice as robust, designed to withstand peak ground acceleration of 1.5 Gs, officials said.

In addition to getting the NRC’s blessing to construct the Holtec system, Edison had to get permission from myriad state agencies as well. That came with even tougher requirements than what’s mandated by the NRC, including the swift development of an inspection system to monitor the canisters within the vaults as they age. Edison has also developed a robot that can repair canister scratches  while they’re still in the vaults.

Officials know climate change is an issue. The Holtec system’s support foundation is about 3.5 feet above the groundwater table, according to 2020 survey data. The foundation itself is 2-feet-9-inches thick, sitting atop a 3-inch layer of concrete. Together, that provides an additional three-foot separation between possible rising groundwater levels and the vaults containing the fuel canisters, Edison said in a written statement.

Every year, Edison must file the report with the State Lands Commission on the site’s vulnerability to sea-level rise. And, the Coastal Commission’s permit for the storage system is for 20 years; Edison will have to complete a climate change analysis before it can be renewed, officials said.

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