ABSTRACT
The Chernobyl disaster occurring over the Easter weekend of 1986 was a landmark event by anyone’s standards, but-aside from living among radioactive sheep-it had a very special significance for me. A close examination of the operators’ behaviour leading to the explosion of the reactor’s core revealed two quite distinct types of unsafe act. There was an unintended slip at the outset of the fatal experiment that caused the reactor to operate at too low a power setting where it was subject to xenon poisoning. Unable to bring the power level up to the desired 20 per cent, the operators deliberately persisted with the trial and in so doing made a serious violation of safe operating procedures. They did this partly because they did not really understand the physics of the reactor, but also because of their determination to continue with the testing of the voltage generatorwhich, ironically, was intended as a safety device in the event of a power loss.
