What went wrong at Chernobyl?
Learn how a runaway reaction led to a nuclear disaster…
On 25 April 1986, engineers at the nuclear plant at Cher nobyl began a test that wou ld lead to the worst nuclear disaster in histor y. The power plant, loc ated around 130 k ilometres nor th of K iev, Ukraine, was completed in 1983. Three years later, engineers ran an experiment to see how long the turbines cou ld continue producing energ y in the event of a power cut.
The first fatal error made by the technicians that day was to turn off the crucial safety systems in the facilit y. They wou ld have affected the experiment, which involved running the plant at low power, but this ac tion prevented worker s realising the dire sit uation they were soon to put themselves in.
The process of creating nuclear fission is regulated by cont rol rods, which, when inser ted into the reac tor core, absorb neut ron s and slow produc tion. The idea was to lower lots of these rods to reduce the power out put and see what happened. Un for t u nately, too many were lowered and the out put d ropped at too high a rate. Rods were then raised again to increase out put, returning to about 12 per cent.