Biblis A nuclear power plant, which was shut down on April 18 this year, will not be restarted under its present licence owing to “safety faults of grave significance”, according to the Federal Ministry for the Environment.

Following the carrying out of repair work, it was discovered that the ports for the emergency coolant pumps were only 5.9 m2 in cross section. German reactor safety codes require them to have an area of at least 7.3 m2. The actual effective cross section was as little as 3 m2, when the smaller filter area was taken into account. The TÜV concluded that sufficient cooling of the core during an accident could therefore not be guaranteed.

  It has not yet been determined whether the fault has existed since 1974, when the plant was first commissioned, or whether it resulted from later modifications requiring the installation of horizontal pipework.

  RWE said that the actual cross section of the filter was 4.8 m2, and that the fault could be eliminated by a relatively simple technical measure. On the strength of this it has made a new licence application. The suggested modification consists of opening up two inspection ports already fitted with filters, which would result in an unimpeded cross section of nearly 10 m2.