Castle Bravo Nuclear Test: How U.S. Turned the Paradise Islands into a Dead Zone
Castle Bravo: a Man-Made Nuclear Disaster
In the second half of the 20th century, the United States conducted the Castle Bravo test with many other dangerous nuclear tests in the Pacific Ocean, which turned out to be, without exaggeration, the worst nuclear disaster with huge radiation in the history of mankind. To this day, the islands that served as test sites have radiation levels higher than those at Fukushima and Chernobyl.
Where was Castle Bravo dropped? The Marshall Islands are an archipelago in the Pacific Ocean, home to the tiny republic of the same name. White sandy beaches, azure stripes of shallow water, lagoons, and coral reefs with a great variety of fish. These islands are considered to be paradise islands. For two thousand years, on these barely distinguishable above the ocean level islets and atolls lived natives, whose home once became a zone of interest of Spain, then the German Empire, then Japan, and finally the United States, which conducted 67 nuclear tests in 12 years on the archipelago. Today there are nine holidays on the Marshallese calendar and one commemorative date, Memorial Day for Victims of Nuclear Tests, celebrated on March 1. This day is special, as the Castle Bravo shot killed a lot of native inhabitants of the Marshall Islands.
The “apocalypse” on the archipelago began in 1946. The Second World War, in the course of which the U.S. acquired the Japanese Marshall Islands, had just ended, and the Cold War began. The USSR did not yet possess nuclear weapons when Hiroshima and Nagasaki bombings happened in 1945. This act was considered to be a simple show of force, an act of terror to the transoceanic rival. The well-known fact, that there was no need to drop bombs on cities with a civilian population, it was just the U.S. whim. Harry Truman insisted on continuing the tests.
Already in the early 1950s, the nuclear arms race was in full swing, and the United States lagged behind the USSR in it. The Soviet military had a thermonuclear bomb ready to be dropped from an airplane in 1953, while the United States did not. The tests with the code-name Operation Castle Bravo, which began on the first day of spring 1950, were intended to solve this problem.
Why was this Castle Bravo location chosen? It was no accident that the Marshall Islands and, in particular, Eniwetok Atoll and Bikini Atoll, inhabited by Aborigines at the time, were chosen for the bombings. The islands had just come into American possession, the indigenous population of the islands was small, and they were mostly Asians. The population was told the story that in the name of peace on earth they must leave their homeland and, as the people of Israel, find the Promised Land. The fact was that Protestant missionaries had reached the archipelago before the Americans. The uninhabited atoll of Rongerik, 206 kilometers from Bikini, turned out to be the Promised Land. In the remaining photos, you can see that people’s faces are far from religious ecstasy – they simply had no choice. The islands were occupied by the U.S., and the UN soon enshrined the archipelago as a U.S. Trust Territory of the Pacific Islands. The U.S. immediately began building a military base on Kwajalein Atoll, from where the Castle Bravo nuclear tests were monitored.
Crossroad: The First Marshall Islands Operation
Under Operation Crossroads, which preceded the Castle Bravo explosion, the United States was going to carry out three explosions, with the main purpose of the test being formulated after it had been decided to conduct the tests. The purpose was to study the effects of nuclear weapons on ships and vessels.
They brought 95 ships to the Marshall Islands: battleships, cruisers, destroyers, submarines, and even two aircraft carriers. Among them were several trophy ships, including the famous battleship Nagato, which had led the defeat of the U.S. Navy at Pearl Harbor. 100 tons of dynamite were detonated to ensure the ships’ passage into the lagoon through the coral reefs. The ships were refueled, provided with the usual equipment and ammunition, and five thousand animals were placed inside for research: pigs and goats, together with guinea pigs, mice, and rats. The press and special guests were invited to watch the explosions, including several scientists from the Soviet Union, who were to observe firsthand what American weapons could do.
On July 1, 1946, the first bomb, the Able, 23 kilotons TNT equivalent, exploded in the air over the target fleet. For some reason (one version was due to a defect in the explosive device itself, another to a mistake by the bomber pilot), the bomb exploded away from its intended target, which reduced the scale of destruction.
By comparison, the Fat Man bomb dropped on Nagasaki had a yield of 21 kilotons, and the Hiroshima Kid had a yield of 20 kilotons. However, all this statistical data is nothing to compare with the Castle Bravo yield, which was about 15 megatons!
On July 25, 1946, the first underwater nuclear bomb tests were conducted. At a depth of 27 meters beneath the target fleet, the Baker exploded. The spectacle was very different from what is commonly referred to as a nuclear mushroom. The explosion generated a 28-meter-high tsunami that tossed some ships ashore and covered them with sand. Because the fission products could not ascend into the stratosphere, they caused severe contamination of the environment. Radioactive water doused the target ships; only nine of the survivors could be decontaminated and sold for scrapping. A third explosion as part of Operation Crossroads, scheduled for 1947, was canceled due to unintended consequences. But Washington had not stopped that time and was about to conduct another test, this time with the Castle Bravo bomb.
Castle Bravo Effects and Radiation Victims
The most powerful explosion in the Marshall Islands was the testing of the U.S. Castle Bravo hydrogen bomb. It happened on Bikini Atoll in 1954, just on March 1. The bomb was a 177-inch cylinder long with a diameter of 53 inches.
For the first time, the Americans used lithium deuteride as a thermonuclear fuel, which was placed in a shell of natural uranium. The power of the explosion was 2.5 times greater than estimated and amounted to 15 megatons. It was officially stated that the Castle Bravo blast radius was about 6500 feet. The Castle Bravo mushroom cloud soared to a height of 25 miles, the diameter of the “cap” unfolded to 62 miles. The explosion completely vaporized the island where the explosive device was located, partially destroyed two other islands, and left behind a Castle Bravo crater 6500 in diameter and more than 250 feet in depth. The USSR in 1961 tested its own nuclear bomb, the Tsar Bomb. Its yield reached 50 megatons. However, in the revival of Castle Bravo vs Tsar Bomb, the USA won.
Seventy-two hours before the test, the command received the information that the wind had changed direction toward residential islands, but the government did not cancel the test. The Castle Bravo fallout was that the radiation patch traveled toward Rongerik atoll, where Bikini residents were relocated and stretched more than 310 miles. Radiation levels reached up to 1000 X-rays per hour on some islands, while a dose of 600 X-rays is considered deadly for humans. On March 2, U.S. military personnel were evacuated from Rongerik to Kwajalein with exposures ranging from 70 to 100 roentgens.
A layer of radioactive dust two centimeters thick fell on several islands. The islanders were not made aware of the danger of the test, and the children played in the radioactive dust until they began to show signs of contamination: severe vomiting, weakness, hair loss. Two days later, the U.S. began evacuating and providing medical care. Residents of Rongelap, Rongerika, and other islands were exposed to radiation. The Castle Bravo before and after: that is how the affected people could describe their lives.
Radioactive dust fell on the ship, which was 105 miles away from Bikini, and its layer reached one centimeter in thickness. All crew members were exposed to about 300 X-rays and became disabled, while the schooner’s radio operator, Atskichi Kuboyama, died seven months later from cirrhosis of the liver.
In all, 856 Japanese fishing boats with about 20,000 people on board and 50,000 tons of fish were destroyed. The story had little political fallout. The U.S. paid compensation to the surviving crew members affected by the Castle Bravo detonation, and Japan received more than $13 million in compensation.
According to independent reports and other Castle Bravo footage, more than a thousand Marshall Islanders died of cancer and other illnesses associated with radioactive contamination caused by the Castle Bravo nuke, and women began giving birth to babies mutilated by radiation. After resettlement, which was often forced, the former Bikini population faced starvation. In the 1960s, the U.S. notified the residents of Bikini and Rongelap that they could return home. Background radiation dropped to normal levels, but the soil, plants, fish, and fruit continued to contain huge portions of radiation. In 1978 the people of Bikini were evacuated again, a few years later the people of Rongelap as well.
As for the relationship between the U.S. and the Marshall Islands – in 1986, the parties signed a Treaty of Free Association, which recognizes the independence of the republic with one condition: the disposition of the American military bases on its territory.