Swedish Radiation Safety Authority collecting NPP experience from this summer’s heatwave

The long uninterrupted period of very high temperatures over the past summer has required various actions to be taken at the Swedish NPPs, and has also affected their operation. In order to collect experiences owing to the extreme weather situation, the Swedish Radiation Safety Authority will ask the licensees to submit information.

During the summer, different measures were taken at Swedish nuclear power plants due to the high air and seawater temperatures. At several of the NPPs, output was periodically reduced, and the Ringhals 2 PWR was shut down during a limited period when the seawater became too warm. The reasons in all these cases were requirements in the plants' Technical Specifications on maximum allowed cooling water temperature.

"The main impact of the heatwave was not on nuclear safety at the plants, but rather on their availability, in other words, how much power they produced," says Director Michael Knochenhauer of the Swedish Radiation Safety Authority.

Over the next six months, the Authority will compile the operational experience of the NPPs. Dialogue has been initiated with the licensees. The Authority plans to request more comprehensive reports on how the facilities are affected by changes in normal weather conditions. Besides high temperatures, aspects of interest may include larger quantities of precipitation, higher air humidity, more violent thunderstorms, and forest fires in the vicinity of the plants.

"This is neither an injunction nor a matter of new requirements that we are imposing on the plants, but rather about getting an overview of how higher temperatures and other conceivable changes to normal weather patterns may impact on nuclear power plants," says Mr Knochenhauer.

For more information, please contact: Michael Knochenhauer, Director, Tel. +46 8 799 41 30, or, alternatively, the Authority's duty press officer on Tel. +46 8 799 40 20.