When the Japanese government announced in 1963 that it planned to build a nuclear-powered ship, there was widespread criticism. Memories of Hiroshima and Nagasaki were much too vivid for the Japanese people to accept even peaceful applications of atomic energy.
But the government went ahead, insisting that there would be no danger. In 1971 the $21 million, 8,214-ton freighter Mutsu, named for its home port in northern Japan, slid down the ways—and into trouble.
First local fishermen, fearing that radioactive discharges from the freighter would contaminate their rich scallop fishing grounds, pressured authorities to keep the ship in its berth for...