Moody’s: U.S. Nuclear Operators Exposed to Physical Climate Risks

Increasing physical climate hazards affect the operations and costs of nuclear plants due to their water needs and reliance on critical equipment. In its report, Nuclear Operators Face Growing Climate Risk but Resiliency Investments Mitigate Impact, Moody’s Investors Service leverages Four Twenty Seven’s physical climate risk data to explore the exposure of nuclear power plants to climate hazards, including heat stress, water stress, flooding and hurricanes.

The analysis found that nuclear power plants are vulnerable to increasing frequency of extreme weather conditions such as flooding and storm surge, due to their need for water cooling which means many plants are adjacent to large bodies of water. Technology and equipment required for safe plant operation are susceptible to damage and nuclear plants along the East Coast and the Gulf of Mexico are particularly exposed to floods from sea level rise.

Clustered in the Midwest and eastern part of the U.S., market-based plants face less risk of hurricanes or sea level rise than regulated/cost-based plants. However, they face increased heat stress and water stress which can reduce plants’ cooling capacity. The credit impact for market-based plants can be more significant than the regulated plants that are more easily able to make-up costs through rate recovery programs.

Nuclear plant operators face physical and economic risks due to extreme events driven by climate change, and operators and owners will have to consider these risks and explore increased resilience options, as they approach license expiration and renewal processes between 2030 and 2050.

Moody’s subscribers can read the full report here.


To learn more about Four Twenty Seven’s climate risk data, check out our solutions for investors, banks and corporations or read our report on Assessing Global Wildfire Potential.