4.

Using his bare hands he lowered the engine’s siphon into the nearest cooling pool to suck up water for his colleagues as they battled 300 fires around the complex. Within seconds he began to feel the effects of the gamma rays that were bombarding his internal organs.

He started vomiting about every 30 seconds. He grew dizzy and weak. After two hours he could not stand.

Doctors later gave him a certificate indicating that he had received 260 ber (biological equivalents of roentgen), equivalent to 1,000 years of background radiation.

But experts estimate that the radiation that he absorbed was even higher, and enough to cause acute radiation sickness (ARS).

'I’m amazed he survived,' Michael Repacholi, the top radiation expert at the World Health Organisation, said.

'It was a hugely heroic effort, andI suspect anyone who understood how much radiation was there would never have gone in.'

Twenty years on Mr Birkun knows he is lucky to be alive and living in Moscow with his wife, Nadezhda, and his daughters, Lyudmila and Valentina.

Of the 134 'liquidators' with a diagnosis of ARS, 28 died in 1986, including at least six firefighters. Mr Birkun, now 56, is proud of the sacrifice that his team made to reduce the cloud of smoke that spread radioactive particles across Europe and even as far as Japan.

'These were the people who saved Europe,' he said, fingering a black-and-white photograph of his former colleagues. 'If they had not done what they did, the fire would have spread to Reactors 1, 2 and 3.'...”

It's the still anonymous technicians and