(.... more on the test, April
25)
That the production of electricity started on 20 December is quite
remarkable, because usually there is a time lapse of about six months between
the completion of the construction and the plant becoming operational.
All the components have to be tested before the actual production process
is started. But, in Unit 4 at Chernobyl there was a celebration in March
1984 (only three months after the reactor was operational) to mark the
fact that already one million kilowatt hours had been produced, even though
at that time not all the components had been thoroughly tested.
One of the tests incompletely carried out before the reactor becoming
operational was on the functioning of the turbine in the case of a defect.
If a defect is present, the turbine should then slow down, but continue
to produce electricity. This electricity is necessary to work the circulation
pump and control rods, and to provide lighting for the control room and
control panel. This supply of electricity is essential for the safety of
the reactor, and on no account should it fail.
Because it takes twenty seconds for the control rods to reach their
most extreme position in the case of a defect, it is of vital importance
to know whether the turbine can produce the necessary electricity for those
twenty seconds, until the emergency generator is able to take over the
supply of electricity. This test was carried out on the night of 25 - 26
April 1986, and was the cause of the disaster.
This test should have been carried out before the power plant was put
into operation. In actual fact, such a test was carried out earlier - but
failed. This became apparent in July and August 1987 during the trial of
the six people held to be responsible for Chernobyl. The judges' verdict
states that on 31 December 1983, director Bryukhanov signed a document
declaring that all the tests had been carried out successfully.