The four individuals were performing routine maintenance tasks on fire fighting systems at the Asco nuclear power plant in the province of Tarragona. Firefighters received notice of the event shortly after 7 p.m., local time, on Wednesday.
Of the three injured men, one is believed to be in critical condition.
Measurements are being conducted to determine the scope of the gas leak. The leak is believed to have originated in a four-story building far from the radiological site of the power plant. It is not believed that there are any issues with the operation of the plant and that no radiological hazards are present. It was determined that a fault in the plant's fire prevention system caused the gas leak.
Carbon dioxide is an odorless and colorless gas. Co2 is naturally occurring and makes up approximately 0.4% of the the Earth's atmosphere, however, when Co2 concentrations surpass 1% it can have adverse effects. At levels above 1% Co2 concentration, breathing rate, heart rate, heart rhythm, and consciousness can be impaired.
At levels approaching 10% concentration, convulsions, coma, and death can occur.
The Asco and the neighboring Vandellos II nuclear power plants account for approximately 50% of Catalonia's electrical grid.
In August of 2021, the Vandellos II nuclear power plant suffered an anomaly in a pressure transmitter that provides a signal on a remote shutdown panel.
Spain has begun the process of phasing out its nuclear power plants by 2035, in a bid to fully power the nation using renewable energy by 2050.