On December 6, 11:48 local time the first reactor unit of the Leningrad NPP was shut down by the automatic safety system. The reason of the shut down is still not clear. The new sensitive safety system could react to some personnel actions or some disturbances in the control system could trigger the safety shutdown system. The reactor can be back in operation not before December 9, Interfax reported. The press-department representative of the Leningrad NPP said to Interfax that in such cases the reactor can be launched in two days or even later.
The radiation levels reported to be normal. This is the second incident with the oldest Chernobyl type reactor at the Leningrad NPP after its recent reconstruction. The unit received new safety system but all equipment was not changed. So, on October 10, after two days after the reactor start, the automatic safety shutdown system was triggered. The investigation commission concluded it happened due to the breaking-in of the new and old parts of the equipment.