Can America’s aging nuclear plants survive more severe weather?

The Biden administration is aiming to extend the lifespan of U.S. nuclear reactors to meet its climate goals, but a new report finds that regulators aren’t examining whether increasingly extreme weather could threaten the safety or viability of plants built primarily in the 1970s and 1980s.

On August 10, 2020, a powerful derecho storm struck the Duane Arnold Nuclear Power Plant in Iowa. Winds of up to 130 mph caused power outages and toppled the 50-year-old plant’s wooden cooling towers. This caused the reactor to automatically shut down and switch to backup generators to power the cooling system. The U.S. Nuclear Regulatory Commission (NRC) concluded that the plant’s defenses in depth had avoided the risk of a radioactive release, but the reactor was not restarted. The plant was scheduled to be closed, but the owner decided not to repair the damage.

“A weather-related event caused Duane Arnold to close permanently, ahead of schedule,” said Jeff Mittman, a nuclear risk consultant and former NRC engineer who now campaigns on safety risks at aging nuclear plants, who points to Duane Arnold as an example of how vulnerable such plants are to extreme natural disasters that could be exacerbated by climate change.

The nation’s 54 operating nuclear power plants are designed to withstand numerous external threats, including the most extreme weather-related events known to occur based on historical records, but most were built in the 1990s. 40 years agoWhile many experts say nuclear power is necessary to curb emissions from fossil fuels, a new study finds that these plants may still be vulnerable to unprecedented dangers posed by climate change.

by report A report released earlier this month by the U.S. Government Accountability Office (GAO), a congressional investigative arm, found that all U.S. nuclear power plants are located in areas where climate change will worsen floods, extreme heat, storms, wildfires, extreme cold, or a combination of these. But the NRC, responsible for America’s nuclear safety, hasn’t done the analysis needed to know whether nuclear plants are prepared for these changing conditions.

The report did not suggest that any nuclear plant is necessarily vulnerable to these hazards — that would require a plant-by-plant analysis — but it said the NRC had not fully considered whether more extreme weather could lead to nuclear plants shutting down or reducing power more frequently or posing safety risks.

The findings could have implications for debate about the country’s future. Aging fleet The Biden administration aims to keep nuclear reactors open for as long as possible to meet its goal of achieving net-zero emissions by 2050. Nearly all of the U.S.’s nuclear reactors have already reached the end of their operating lives. Extension That could be extended to 2060, but meeting the U.S. climate goals would require many plants to operate for much longer. Currently, 11 plants are operational. Different stages Regarding re-licensing procedures.

In its response to the GAO report, the NRC said that while it does not currently consider climate change in its licensing process, existing protections are so conservative that they are sufficient to protect the nation’s reactors from “all natural hazards and combinations of natural hazards that may occur at the site, including those that may result from climate change, during the reactor’s licensed operating life.” But an NRC spokesman said: Yale Environment 360 The agency will be reviewing U.S. nuclear safety in light of the climate risks identified in a recent climate change report. National Climate AssessmentThis may affect licensing decisions.

U.S. nuclear power plants are highly protected facilities, with the reactors at their core protected by redundant safety systems designed to withstand everything from earthquakes to terrorist attacks. But even the most protected plants can be vulnerable to extreme weather events.

As with Duane Arnold, storms can cause damage or cause power outages, forcing plants to switch to backup power to run safety systems needed to cool the reactors. Fires can also cause damage or prevent workers from reaching the facilities. Extreme heat can increase the temperature of the water used in the cooling systems, forcing plants to cut power, while droughts can limit water supplies. Nuclear plants are typically built near waterways or coastlines to ensure access for cooling, putting them at risk of flooding.

“A lot of it comes down to water,” says Erin Sikorski of the Center for Climate Security, a think tank in Washington, D.C. “You either have too little water or too much water,” she says, citing the example of a French nuclear reactor being forced to shut down in 2022. Reduce power consumption Drought and summer heat limited access to river water for cooling purposes. There is no consensus on how climate change has affected nuclear power plants around the world, but one researcher said: found The rate of nuclear reactor shutdowns linked to climate-related disruptions has been increasing since 1990. Researchers project that by the middle of this century, about 1 percent of nuclear power generation will be lost due to climate-related disruptions.

In the United States, nuclear power plants have so far appeared to have minimized disruptions from extreme weather. report According to a report published by the Electric Power Research Institute, a nonprofit energy research organization, US operators reported 120 weather-related events that led to reduced power generation between 2011 and 2020. Combined, these events lost less than 0.1% of the total power generated by US nuclear reactors during that period. The report therefore concludes that the impact of weather on nuclear power generation is “essentially negligible” and that nuclear power is the most reliable of all zero-carbon power sources. It also concludes that there is “no evidence” that extreme weather, exacerbated by climate change, poses safety risks that are not considered in the existing nuclear power plant licensing process, given the extreme conditions that were considered when nuclear power plants were designed.

Jessica Lovering of the Good Energy Collective, a progressive nuclear advocacy group, said nuclear plant operators may be considering climate hazards. But even if it turns out to be overreach, she said, it would be reasonable for the NRC to look at climate hazards more explicitly. “I’m not sure that’s an issue.”

This uncertainty remains even though the NRC conducted a detailed reassessment of natural hazards for U.S. nuclear power plants several years ago. Following the 2011 Fukushima Daiichi nuclear accident in Japan, where an earthquake and subsequent tsunami disabled backup power needed to cool the reactors and led to the meltdown of three reactors, the NRC asked U.S. nuclear plant operators to reassess their earthquake and flood hazards.

Nuclear industry spokespeople cited the review as an example of taking climate change into account, but operators are not required to use climate projections in their flood risk analyses, and it’s not clear to what extent they did, the GAO report noted. But the review process Identified Of the 61 nuclear power plants in operation at the time, the risk of flooding at 55 plants exceeded the design control standards at the time of construction.

The flood risks were primarily due to increased precipitation, but also included the possibility of river flooding, storm surges, and the failure of upstream dams. But following the findings of the 2019 report, NRC commissioners voted 3-2 not to require operators to update protections to reflect these “beyond design basis events,” arguing that existing measures were sufficient. NRC Commissioner Jeff Baran dissented. letter The decision is “pointless”

The debate is playing out again in a fight over the future of nuclear power plants nearing the end of their design lives. Paul Gunter of the anti-nuclear advocacy group Beyond Nuclear argues that continued vulnerability to climate disasters is a reason the NRC should deny relicensing applications for some plants, such as the North Anna nuclear plant in Virginia. Gunter plans to specifically cite the GAO report’s flooding findings for that plant. About two-thirds of U.S. nuclear plants are located in areas with high flood risk, according to the report.

Beyond Nuclear, along with a chapter of the Sierra Club, has cited climate change in its campaign to close the Oconee nuclear plant in South Carolina. For decades, some NRC whistleblowers have Faced retaliation Officials say the plant’s cooling system is vulnerable to large flood waves in the extremely unlikely event of an upstream dam failing. Duke Energy, which operates the plant, has strengthened flood protection for the cooling system, but Oconee’s critics argue that Duke has not considered climate change, which increases the risk of the dam failing, and that the changes to strengthen flood protection are insufficient. “We believe that existing regulations, frameworks and processes are effective in maintaining and managing the plant as new information comes to light,” a Duke Energy spokesman said.

Similar interventions have also delayed relicensing at Turkey Point Nuclear Power Plant on Florida’s southeast coast. The NRC approved a 20-year extension to the plant’s operation in 2019, but environmental groups stepped in, arguing that the plant’s operators had not properly considered climate change. David Lochbaum, a former nuclear safety advocate with the Union of Concerned Scientists who was involved in the effort, said the operator’s sea-level rise projections project that water levels will stop rising in 2033, just 2 inches below the plant’s existing seawall. “The NRC accepted this false assessment and granted the 20-year extension,” he said. The NRC accepted this false assessment and granted the 20-year extension. Paused The relicensing extension will be in place in 2022 for further consideration.

Dozens of U.S. nuclear power plants face decisions over the next few years to close or get license extensions, and a new generation of small reactors could be built to replace them. passed it This bipartisan bill eases the licensing hurdles for these reactors, many of which could potentially operate in a much warmer world decades from now. But in any scenario, our nation’s existing reactors will play a critical role in reaching our climate goals, and we now have even more reason to be confident that they are up to the task.

James Dinnen A Colorado native and New York-based science and environmental journalist, see his work here. Source:Research for this article was supported by grants from the Council for the Advancement of Science Writing and the Brinson Foundation.