In some ways, Carole Means' teenage years on a farm in southeastern Wash­ing­ton state in the 1950s sound so wholesome, almost idyllic. She ate homegrown fruit and vegetables, fish from the nearby Columbia River, and drank milk from the family cows that grazed along its banks.

The farm commanded a view across the river of the Hanford Nuclear Reservation, the world's first full-scale plutonium reactor. Hanford produced most of the material for the U.S. arsenal of nuclear bombs, including the one dropped on Nagasaki, Japan, in 1945. For local residents, the plant was a source of pride — their unique contribution to winning World War II — and of jobs, employing 50,000 people at its peak.

It was also catastrophically toxic. Starting in 1944, the plant silently released huge amounts of radiation into the air, water and soil — sometimes intentionally, the government now admits.