yevgen goncharenko: it can't detect a thing. not a single particle. no radiation. reporter: there are some areas where no radiation can be detected. other areas are highly radioactive. in ukraine, goncharenko and others like him are called "stalkers." 16 years ago, goncharenko had a good i.t. job in the ukrainian capital kyiv. but he was fascinated by the situation here. the disaster also left behind many relics of the former soviet union. yevgen goncharenko: in this region, there are many objects that i would say have historical and cultural value, not only for ukraine but for the entire world. reporter: goncharenko also pays visits to the people who have come back to live in their old homes, people like ivan semenyuk. semenyuk and his family were resettled after the disaster. but they never felt at home in the apartment they had been assigned to in the city. so he returned with his wife, who is ill. they have chickens and grow what they can in the garden. they get firewood from the nearby forest. ivan semenyuk: i got ill in the place we were resettled to. i had a