From ALAN CHATTAWAY
Nowhere does your excellent article on engineering failures refer to
Chernobyl (‘The fallible engineer’, 2 November), but the accompanying photo
of the ruined power station was captioned: ‘As the Chernobyl accident in
April 1986 showed, automatic safety systems do not guarantee that nuclear
power stations can never run out of control.’
The several accounts I’ve read in the engineering press all say that
Chernobyl had several independent safety systems, any of which would have
shut down the reactor, but all were deliberately disabled to permit a test
at a power level well below the reactor’s designed operating range-something
the safety system designers considered dangerous enough to prevent.
Even then things might have gone well under manual control, but the
test was temporarily suspended on political authority. When the technicians
were allowed to resume the test, accumulated products of low-power operation
made the reactor behave in unexpected ways, causing the explosion.
So, while Chemobyl proves automatic safety systems may not protect you,
it proves nothing about such systems when they are switched on.
Advertisement
Alan Chattaway Surrey British Columbia Canada
