The Biblis Nuclear Power Plant is in the South Hessian municipality of Biblis and consists of two units: unit A with a gross output of 1200 megawatts and unit B with a gross output of 1300 megawatts. Both units are pressurized water reactors. The operator of this nuclear power plant is the German RWE ("Rheinisch-Westfälisches Elektrizitätswerk AG"), an electrical utility based in Essen. unit A began operation on July 16, 1974 and entered commercial service on August 25, 1974. unit B reached criticality on March 25, 1976.

On December 17, 1987 an incident (INES 1) occurred: Coworkers overlooked a stop valve that had not been closed. In order to close the armature a valve was opened. Radioactive primary cooling agent discharged for a short time into the annular space. Because the discharge of the reactor cooling water took place outside of the reactor containment, there was no feedback from the sump over the safety feeding pumps and/or cooling pumps. The incident became public one year later, when an article in an American technical periodical (Nucleonic Weeks) was published. There have been other incidents afterwards, none of which has been rated over 1 on INES scale.

In the course of a routine swap of unit A's fuel assembly in September 2010 a malfunction of its emergency system was detected. The automated switchover of the power supply from unit B to A proved broken, which meant that the ability to perform countermeasures would have been severely impaired in case of an emergency. Previous demands by Germany's Green party and the IPPNW to construct an external control stand were refused by Hessen's environment minister Lucia Puttrich (CDU) on the ground that both units could provide each other with energy should an incident occur.

Biblis Nuclear Power Plant is the partner power station of the Balakovo Nuclear Power Plant.

Biblis Nuclear Power Plant
Country Germany
Locale Biblis
Status Operational
Construction began 1969
Commission date August 25, 1974
Operator(s) RWE
Constructor(s) Siemens

Turbine information
Manufacturer(s) Siemens

Power generation information
Installed capacity 2,525 MW
Annual generation 15,306 GW·h
Net generation 439,973 GW·h