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Castle Bravo

Bikini Atoll is an atoll in one of the Micronesian Islands in the Pacific Ocean, part of Republic of the Marshall Islands. It consists of 23 islands surrounding a central lagoon. As part of the Pacific Proving Grounds, Bikini Atoll was the site of more than 20 nuclear weapons tests between 1946 and 1958.  Castle Bravo was the code name given to the first U.S. test of a dry fuel thermonuclear hydrogen bomb.  The test was performed on March 1, 1954, at Bikini Atoll, Marshall Islands.  The nuclear bomb was the first practical deliverable fusion bomb in the U.S. arsenal.  When the weapon was detonated, it formed a fireball almost four and a half miles (roughly 7 km) across the sky within a second.  The explosion left a crater of 6,500 feet (2,000 m) in diameter and 250 feet (75 m) in depth.  Castle Bravo was the most powerful nuclear device ever detonated by the United States, with a yield of 15 Megatons.

The Fallout

The yield of 15 Megatons was far exceeding the expected yield of 4-6 Megatons.  This gross miscalculation led to the most significant accidental radiological contamination ever caused by the United States.  In terms of TNT tonnage equivalence, Castle Bravo was about 1,200 times more powerful than the atomic bombs which were dropped on Hiroshima and Nagasaki during World War II.  The largest nuclear explosion ever produced was a test conducted by the Soviet Union.  The Tsar Bomb was detonated on October 30, 1961 over the Mityushikha Bay nuclear testing range, north of the Arctic Circle on Novaya Zemlya Island in the Arctic Sea.  The Tsar Bomb had a yield of 50 Megatons.

The radiation cloud produced by Castle Bravo contaminated more than seven thousand square miles of the surrounding Pacific Ocean, including small islands like Rongerik, Rongelap and Utirik.  These islands were evacuated, but many of the Marshall Island natives have since suffered from birth defects.  A Japanese fishing boat, Daigo Fukuryu Maru, also came into contact with the nuclear fallout.  It caused many of the crew to take ill with one fatality.  The test resulted in an international uproar and raised many concerns, especially with regard to the possible contamination of fish and land.  The nuclear fallout spread traces of radioactive material as far as Australia, India, Japan, the U.S. and parts of Europe.  Many of the instruments that were designed to retrieve data were destroyed by the blast.  Castle Bravo remains one of the worst nuclear accidents ever recorded....

Bikini Atoll bomb test remembered
Former crew member Matashichi Oishi, 70
Japanese survivor Matashichi Oishi wants government compensation
Peace activists in Japan have marked the 50th anniversary of an atomic bomb experiment in the Pacific which killed one person and injured dozens more.

The US test on tiny Bikini Atoll in the Marshall islands contaminated a passing Japanese fishing boat and showered nearby villagers with radioactive ash.

The bomb was 1,000 times more powerful than the one dropped on Hiroshima.

Those affected still claim to suffer from radiation exposure, and Bikini Atoll islanders are exiled as a result.

About 2,000 peace activists marched in Yaizu, the home port of the contaminated Japanese fishing trawler the Lucky Dragon. They went to the grave of radio operator Aikichi Kuboyama, who died several months after the 1 March, 1954 bombing, at the age of 40.

His dying wish was to be the last victim of an atomic bomb.

"The tragedy 50 years ago must not be repeated in the 21st century," survivor Yoshio Misaki, 78, told an assembly in the city.

Eleven of Kuboyama's colleagues have also since died, many perishing in their 40s or 50s from cancer, liver disease or hepatitis.

For the inhabitants of Bikini Atoll, the test has left a devastating legacy.

The 1 March 1954 test - codenamed Bravo - exploded with far greater power than scientists predicted.

The Bikinians were evacuated, but nevertheless some of the atolls they were moved to - including Rongelap, about 125 miles east of Bikini - were irradiated.

John Anjain, the community leader of Rongelap Island at the time, visited Yaizu for the anniversary.

"On the day of the hydrogen bomb blast, white powder fell on us like snow," he said. "We soon began to feel sick and our hair started falling off."

Both the surviving Japanese fishermen and the former inhabitants of Bikini Atoll are still agitating for compensation.

Unlike the victims of Hiroshima and Nagasaki, the crew of the Lucky Dragon are not entitled to medical and financial support from the Japanese government because the US agreed to pay each crew member an average of 2m yen ($18,350) as "sympathy money" in a political settlement.

Dozens of US military and civilian personnel received high doses of radiation during the test, but only a few have successfully claimed compensation.

The Bikinians are still unable to return to their atoll because its land-based food chain remains contaminated.

Tibon Bejiko, a 72-year-old islander, who left Bikini in 1946, told the BBC that the atoll's inhabitants agreed to co-operate with the US then because they were promised that Washington would look after them.

He said financial compensation was not adequate; that he wanted the US to clean up Bikini so he could return.

"I'm an old man now... I haven't been able to go back and live on my homeland Bikini, my gift from God," he told the World Service programme The World Today.

He, like many of the other Bikini inhabitants, now lives on Kili island, where the islanders were resettled in 1948. Kili is far more difficult to fish from than Bikini.

"Now I'm getting ready to die and I know I'm not going to see Bikini cleaned before I'm gone," Mr Bejiko said.

Gy = gray, radiation dose received during 4 days after detonation
10 Gy is a lethal dose


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I hear the whispering voice of spring,
the thrush's trill, the catbird's cry.
Oliver Wendell Holmes
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