U.S. Arms Control and Disarmament Agency. still other complex
and subtle processes, global in scope, which could seriously
threaten the health of distant populations in the event of an
all-out nuclear war. Up to now, many of the important
discoveries about nuclear weapon effects have been made not
through deliberate scientific inquiry but by accident. And as
the following historical examples show, there has been a series
of surprises. "Castle/Bravo" was the largest nuclear weapon ever
detonated by the United States. Before it was set off at Bikini
on February 28, 1954, it was expected to explode with an energy
equivalent of about 8 million tons of TNT. Actually, it produced
almost twice that explosive power--equivalent to 15 million tons
of TNT. If the power of the bomb was unexpected, so were the
after-effects. About 6 hours after the explosion, a fine, sandy
ash began to sprinkle the Japanese fishing vessel Lucky Dragon,
some 90 miles downwind of the burst point, and Rongelap Atoll,
100 miles downwind. Thou