SLAVUTYCH (Ukraine), April 26 -- Nikolay Solovyov was on shift the night of April 26, 1986 when the Chernobyl nuclear power plant exploded. Instead of fleeing, he chose to fight his "first war" against radiation.

Four decades later, a second war - Russia's invasion of Ukraine - has taken his son.

Solovyov, 67, a hard rock fan, still wears his hair long, though it has turned grey.

On the night of the world's worst nuclear accident, he was working as a turbine mechanic in unit number two, a few hundred metres from reactor number four, which exploded during a safety test.

"It felt like an earthquake. I didn't hear the explosion-the turbines were still running, with a very loud noise," he recalled, his voice quiet and gentle.

The alarms ...