Fukushima disaster revives interest in darker nuclear past

ISHIKAWA, Japan — Kiwamu Ariga skirted the paddies of ripening rice, moving briskly despite his 81 years to reach a pile of yellowish rocks at the foot of a steep, forested hillside.

It was here that, as a junior-high student in the final months of World War II, Ariga and his classmates were put to work hacking rocks out of the hill's then-exposed stone face until the blood ran from their sandaled feet. The soldiers told them nothing beyond instructing them to look for stones with brown or black spots.

Then one day, Ariga recalled, an officer finally explained what they were after: "With the stones that you boys are digging up, we can make a bomb the size of a matchbox that will destroy all of New York." Ariga said he did not learn other details of Japan's secrecy-wrapped efforts to build an atomic bomb until years after the war.

"We had no idea what we were doing here, in our bare feet, digging out radioactive uranium," Ariga said, standing between spindly cedar saplings. "Now, 66 years later, we are exposed to radiation again."...