Climate impacts on nuclear power reliability, safety

The US Government Accountability Office (GAO) published its congressional report on April 2, 2024 titled as a warning, “Nuclear Power Plants: NRC Should Take Actions to Fully Consider the Potential Effects of Climate Change.” Their report to Congress points to increasingly  severe and more frequent climate hazards including extreme heat, drought, wildfires, severe storms, atmospheric rivers, floods, hurricanes and sea level rise.  Congress’ investigative arm further determined that the U.S. Nuclear Regulatory Commission (NRC) does not adequately consider these climate change risks nor project the hazardous consequences on reactor safety in its licensing and relicensing processes.

Instead, the entrenched federal nuclear agency focuses on the projected climate benefits from nuclear power’s reduced carbon emissions. However, the GAO found that the NRC refuses to analyze and focus on climates’ worsening adverse impacts on future safe and reliable reactor operations by focusing only on historical meteorological data. This unheeded recklessness by the NRC and the nuclear industry is not unlike driving a car through its rear view mirror, unaware of the oncoming hazards that can result in severe radiological accidents.

Current news accounts confirm an accelerating climate crisis while exposing nuclear power’s unsustainability and vulnerability across Europe today as yet another example.

The Canadian (CANDU) heavy water pressurized water reactors at Romania’s two-unit Cernavoda nuclear power station is struggling to maintain reactor cooling water and remain operational. Current actions include raising the Danube River level if even by only centimeters. Romania’s only nuclear power station is on the verge of complete shutdown due to the falling river levels and warming water temperatures. Romania’s Navy has been  dynamiting along the Danube to redirect the river flow to keep the reactors’ cooling systems and electricity generation operational.

The four-unit Paks nuclear power station (Soviet Union-era VVER-440 pressurized water reactors) also on the Danube River in Hungary is reported to be on the verge of emergency shutdown of all units. Similarly, the record low water levels in the Danube River are falling and receding away from the reactors’ once through coolant system intake suction pipes. The shallower river is also heating up, dramatically contributing to the loss of reactor cooling efficiency.  The Danube is the only source of cooling water for the reactor cores which are now only “a few millimeters away from completely shutting down the Paks Power Plant.” The American Nuclear Society’s publication Nuclear Newswire reports, “The 1,916-MWe, four-unit Paks is Hungary’s only nuclear power plant and, according to the International Energy Agency, generates about 42% percent of the country’s electricity. But as of Sunday, it was only producing 240 MW of power.”

Europe’s climate-driven heat wave is  critically undercutting France’s electrical energy demand given the nation’s unsustainable and over reliance upon nuclear power (now reduced to 70%). The French state-owned nuclear operator, EDF, is also powering down and taking nuclear reactors off line to compensate for the loss of adequate and warming reactor cooling water sources. Bugey unit 3, Chooz unit 2 and Golfech 2 – operating on the Rhône, Meuse and Garonne rivers- have been taken offline to comply with operational technical specifications and regulations on reactor cooling water discharges. At least eight other reactors are operating and transitioning between reduced power and shutdown. Those affected reactors include: Saint Alban units 1 and 2; Bugey units 4 and 5; Blayais units 1 and 3; and Tricastin. These measures are environmental and aquatic protection requirements to avoid discharging too much hot water into rivers already impacted by the heatwave and drought.

At present, in Switzerland, the two-unit  Westinghouse Electric pressurized water reactors at Beznau nuclear power station are temporarily shut down, or operated at lower power due to loss of adequate reactor cooling efficiency because of high temperatures in the River Aare.

In a warming climate, nuclear power is not sustainable while its operational safety margins are also narrowing.  Inevitably, economic and political pressure on regulatory bodies threaten to relax and exempt nuclear operators from environmental protection standards for hotter cooling water discharges associated with increasing environmental damage and jeopardizing aquatic life while destroying habitat.

[Photo credit: Alisdare Hickson, Wikimedia Commons]