Faulty fire protection door at the Philippsburg nuclear facility
On August 20, 2025, a fire protection door at the Philippsburg Nuclear Power Plant, Unit 2, remained open after a closure request during a monthly inspection. The operator of the plant, EnBW (Energie Baden-Württemberg AG), has publicly stated its focus on renewable energy rather than restarting old nuclear reactors.
The incident was classified as Category N (Normal report); INES 0 (no or very low safety significance). This classification falls under the International Nuclear Event Scale (INES), which is a tool used to assess reportable events in nuclear power plants. The INES scale, managed by the International Atomic Energy Agency (IAEA), the Nuclear Energy Agency (NEA) of the Organisation for Economic Co-operation and Development (OECD), and designed to provide a rapid and understandable assessment of an event for the public, consists of seven levels: Anomaly, Incident, Serious Incident, Accident with local consequences, Accident with wider consequences, Severe Accident, and Major Accident.
The affected fire protection door is located in a firewall outside the control area between the auxiliary building and a connecting passage. The cause of the malfunction was a malfunction in the pressure-driven opening assist. As a precaution, the opening assist was disabled until the root cause was determined. No immediate action was required as there was no danger to people or the environment.
Temporary unavailability of components/systems intentionally caused by procedures specified in the operating manual is not reportable if this is adequately considered in the safety specification of the operating manual. However, events that cannot be classified into the scale (1 to 7) according to the INES handbook are assigned the "Level 0" based on national assessment, regardless of their safety significance.
Category N events are reportable to the supervisory authority within five working days, allowing potential safety weaknesses to be detected early. The Atomic Safety Supervisor and Reporting Ordinance - AtSMV requires the reporting of events significant for nuclear safety. For further information, the Ministry of Environment, Climate and Energy can be contacted via the Press Office or the Citizen Liaison Officer.
In normal operation, the door is open and closes automatically or manually upon request. Manual closure by the fire department would have been possible in this incident. These events are of low safety significance and typically go beyond routine operational events under prescribed plant condition and operation.
EnBW has emphasised its commitment to maintaining the highest safety standards at the Philippsburg Nuclear Power Plant, Unit 2, and will continue to work closely with the relevant authorities to ensure the safety and security of the plant and the surrounding area.
