Nuclear weapons are the most destructive devices on earth. The technology used to create these weapons involves nuclear fusion reactions. The man who first developed the idea of a nuclear chain reaction was Hungarian physicist Leó Szilárd. In 1934, Szilárd patented the idea of the atomic bomb. In 1939, he wrote a letter to Albert Einstein in search of Einstein’s signature. The letter resulted in the U.S. Manhattan Project and the creation of the atomic bomb. The Manhattan Project assembled the most talented physicists from the United States, Great Britain, and Canada. The secret project was in response to atomic bomb developments in Nazi Germany. The Third Reich was in the process of creating a nuclear weapon. The Allies became well aware of the Nazi’s nuclear program on June 23, 1942 when the first major nuclear accident was recorded. A poorly developed nuclear reactor exploded in Leipzig, Germany.
The first successful detonation of a nuclear weapon was performed by the U.S. on July 16, 1945. The bomb was named Trinity and it was detonated southeast of Socorro, New Mexico. Since that time, thousands of nuclear tests have been carried out all over the world. With the majority coming from the five superpowers, including the United States, the former Soviet Union, the United Kingdom, France, and China. Many devastating nuclear accidents have occurred over the years. The details surrounding nuclear weapons programs fall under the highest security standards in all nations will the technology. When a major nuclear event occurs, limited information is released to the public. Many times, scientific studies are not conducted to measure the true radiation damage caused by a nuclear accident. This has caused confusion in reporting the true environmental damage of the world’s nuclear accidents. During the nuclear arms race of the 1950s and 60’s, many Broken Arrow events occurred and nuclear warheads were lost. A Broken Arrow is a nuclear accident that does not create the risk of a nuclear war.
10. The Demon Core
On August 21, 1945, an American physicist named Harry Daghlian made a critical mistake while performing neutron reflection experiments on a subcritical mass of plutonium. Daghlian accidently dropped one of the neutron-reflective tungsten carbide bricks on the core making it critical. The event produced a burst of neutron radiation that irradiated Daghlian. He died 25 days later.
On May 21, 1946, Canadian physicist Louis Slotin and other scientists were in a Los Alamos laboratory conducting an experiment that involved creating a fission reaction by placing two half-spheres of beryllium (a neutron reflector) around the same plutonium core. In the experiment, Slotin was holding a screwdriver separating the hemispheres when his hand slipped and the hemispheres of the beryllium reflector closed. This caused the plutonium core to become supercritical and it released an extremely high dose of radiation on the scientists. Slotin reacted very quickly and pulled the two halves apart, stopping the chain reaction, saving the lives of the seven other men in the laboratory. Louis Slotin died nine days later from acute radiation poisoning. The scientist assisting in the experiment received a high radiation dose, which caused serious injuries.
The Fallout
Following the accidents, the 6.2-kilogram (14 Ib) subcritical mass of plutonium was given the nickname The Demon Core. The two events and subsequent deaths were the only major nuclear accidents to occur during The Manhattan Project. The Demon core was used in the ABLE detonation test on July 1, 1946.
9. Goldsboro B-52 Crash
On January 24, 1961 an American B-52 bomber was on a 24-hour airborne alert mission over the Atlantic seaboard. The aircraft was carrying two Mark 39 nuclear weapons onboard. During the mission, the B-52 was scheduled to meet with a tanker for mid-air refueling. While the plane was being refueled, the B-52 captain, Major W.S. Tullock, was notified that his aircraft had a leak in its port wing fuel cell. The plane was directed to assume a holding pattern off the coast until the majority of fuel was used up. However, the captain soon reported that his plane had lost 37,000 pounds (17,000 kg) of fuel in three minutes. He was immediately ordered to land at Seymour Johnson Air Base, which is located in Goldsboro, North Carolina. As the plane descended to 10,000 feet, the pilots were no longer able to control the aircraft. The captain ordered the crew to eject, which they did at 9,000 feet (2,700 m). The plane broke apart as it spiraled to the ground and the nuclear weapons were separated from the craft.
The Fallout
The wreckage of the plane and its two nuclear warheads landed in a 2-square-mile (5.2 km2) area of tobacco and cotton farmland near Goldsboro, North Carolina. Five crewmen attempted to parachute to safety, but three died. One of the nuclear weapons discovered had become active. Five of the six arming devices on the nuclear warhead activated, causing it to carry out many of the steps needed to arm itself, such as the charging of the firing capacitors and the deployment of a retardation parachute. The pilot’s safe and arm switch was not activated preventing detonation. However, nuclear material was released into the atmosphere.
The second bomb plunged into a muddy field at around 700 miles per hour. It disintegrated and the bombs tail was discovered about 20 feet (6.1 m) under the earth. Some of the nuclear weapon was recovered, including the tritium bottle and all the plutonium. However, excavation was abandoned due to uncontrollable ground water flooding. Most of the thermonuclear stage, containing uranium, was left in the North Carolina ground. It is estimated to lie around 55 feet (17 m) below the earth. The Air Force purchased the land to prevent interference with the nuclear remnants.
8. Baneberry Blast
The Nevada Test Site is a U.S. Department of Energy reservation located in southeastern Nye County, Nevada, about 65 miles northwest of the city of Las Vegas. The site was established for the testing of nuclear devices on January 11, 1951. It is composed of approximately 1,350 sq mi (3,500 km2) of desert and mountainous terrain. Between 1951 and 1992, there were a total of 928 announced nuclear tests at Nevada Test Site, which included 828 underground explosions. Sixty-two of the underground tests included multiple, simultaneous nuclear detonations. The site was the primary testing location of American nuclear devices. About a third of the nuclear tests were conducted directly in aquifers, while others were well above the water table. When the final test was performed in 1992, the U.S. Energy Department estimated that more than 300 million curies of radiation remained in the area, making the site one of the most radioactively contaminated places in the U.S.
One of the most notable nuclear accidents at the Nevada Nuclear Site was the Baneberry blast which occurred on December 18, 1970, during the Operation Emery series of nuclear tests. The Baneberry bomb was detonated as planned at the bottom of a sealed vertical shaft 900 feet below the Earth’s surface. However, after the explosion, the bombs energy cracked the soil of the ground in an unexpected way. This caused a plume of hot gases and radioactive dust to be released three and a half minutes after ignition. The reaction continued for many hours.
The Fallout
As a result of the accident, government officials had nuclear fallout rain down on them. It was estimated that 6% of the explosion’s radioactive products were released into the atmosphere. The plume released 6.7 MCi of radioactive material, including Iodine-131 and a high ratio of noble gases. The winter weather did not help the situation and the hot cloud was carried to three separate altitudes and dispersed through the jet stream. This caused radionuclide-laden snow to fall in Lassen and Sierra counties in northeast California. The radioactive snow was also reported in northern Nevada, southern Idaho and some eastern sections of Oregon and Washington State. The explosion was felt in Canada, the Gulf of Mexico, and over the Atlantic Ocean. After the accident, a six month moratorium was placed on the U.S. nuclear testing program.
7. Soviet Submarine K-219
The K-219 submarine was a ballistic missile sub used by the Soviet Union during the Cold War. It carried 16 missiles equipped with an estimated 34 nuclear warheads. On October 3, 1986, the submarine was on patrol 680 miles (1,090 km) northeast of Bermuda when the seal in one of the missile hatch covers failed. This allowed seawater to leak into the missile tube and react with residue from the missile’s liquid fuel, producing nitric acid. The K-219 suffered a subsequent explosion and fire in the missile tube.
The Soviet Navy claimed that the leak was caused by a collision with the submarine USS Augusta. However, the United States Navy has challenged the claim because the K-219 had previously experienced a similar problem, and one of the submarines missile tubes was disabled and welded shut because of the accident. After the explosion occurred in silo six, the remains of the RSM-25 rocket and its two nuclear warheads were ejected into the sea. The vessel quickly surfaced to permit its twin nuclear reactors to be shut down. The submarine was then strapped to a Soviet freighter, and an attempt to tow the vessel was made. However, the flooding had reached a point beyond recovery and the K-219 sank to the bottom of the Hatteras Abyssal Plain, in 18,000 feet (5,500 m) of water.
The Fallout
The K-219’s full arsenal of nuclear weapons and reactors went down with the vessel. In 1988, the Soviet hydrographic research ship Keldysh positioned itself over the wreck and reported that the submarine was sitting in the upright position on the bottom of the ocean. It had broken into sections and it appeared that several missile silo hatches had been forced open, and the missiles, along with the nuclear warheads they contained, were gone. Soviet leader Mikhail Gorbachev privately communicated news of the disaster to U.S. President Ronald Reagan before publicly acknowledging the incident. The K-219 Soviet submarine nuclear accident was one of the most controversial events of the Cold War.
6. Tybee Island B-47 Crash
In 1958, an American B-47 bomber was sent on a simulated combat mission over the United States. The plane left from Homestead Air Force Base in Florida and was carrying a single 7,600-pound (3,400 kg) Mark 15 hydrogen bomb. The Mark 15 nuclear bomb was the first relatively lightweight thermonuclear bomb created by the United States. At about 2:00 AM, the B-47 bomber collided with an F-86 plane over Tybee Island near Savannah, Georgia, USA. After impact, the F-86 crashed, however the B-47 was able to stay airborne, despite being severely damaged. The plane’s crew requested permission to drop the bomb in order to reduce weight and prevent the bomb’s exploding during an emergency landing. The request was granted and the Mark 15 nuclear bomb was released from the plane at 7,200 feet (2,200 m). The plane was traveling about 200 knots. The crew reported not seeing an explosion when the bomb struck the waters off Tybee Island. They managed to land the B-47 safely at Hunter Army Air Field.
The Fallout
Starting on February 6, 1958, the Air Force and 100 Navy personnel equipped with hand held sonar detectors conducted a search for the weapon, but it was never discovered. Based on a hydrologic survey, the bomb is thought to lie buried under 5 to 15 feet (2 to 5 m) of silt at the bottom of Wassaw Sound, near Georgia. The 12-foot (4 m) long Mark 15 bomb bears the serial number 47782. It contains 400 pounds (180 kg) of conventional high explosives and highly enriched uranium. The Air Force maintains that the bomb’s nuclear capsule, used to initiate the nuclear reaction, was removed prior to its flight aboard the B-47. However, according to the 1966 Congressional testimony of Assistant Secretary of Defense W.J. Howard, the Tybee Island bomb was a “complete weapon, a bomb with a nuclear capsule.” In 2001, the United States Air Force conducted a study to determine whether the bomb posed a threat to residents in the surrounding area.
They determined that the weapon could pose an environmental or proliferation threat. The U.S. government will not disturb the bomb in fear of an explosion. In 2004, retired Air Force Colonel Derek Duke claimed to have found the possible resting spot of the Mark 15. He apparently located the spot by trawling the area in a boat with a Geiger counter in tow. The Air Force released a report in June 2005, which stated that high radiation measurements in the area are from naturally occurring radioactive materials. According to military officials, the location of the bomb is still unknown. Had the weapon detonated with its full design yield of 3.8 megatons, the city of Savanah, Georgia would have been incinerated.
5. Windscale Fire
In 1946, the Second World War ended and the United States government passed legislation that removed all nuclear weapons programs in other countries. Many British scientists participated in the Manhattan Project, and the British government did not want to be left behind in the nuclear arms race, so they created a nuclear weapons program. Nuclear reactors were constructed near the tiny village of Seascale, Cumberland, and were known as Windscale Pile 1 and Windscale Pile 2. The facilities produced plutonium for the first British atom bomb. After the successful testing of the British nuclear weapon, the U.S. designed and exploded a hydrogen bomb, which requires tritium.
Britain did not have any facility to produce tritium and decided to use the Windscale piles. Higher temperatures are required to produce tritium. The decision was made to reduce the size of the nuclear cooling fans used at the site. This enabled the production of tritium, but it also created three separate hot spots in Pile 1. The precise cause of the accident is not clear, but on October 10, 1957 parts of the nuclear reactor overheated and a fire started in the Windscale Pile 1. The resulting fire burned for days, damaging a significant portion of the reactor core.
The Fallout
The nuclear fire released radioactive gases into the surrounding countryside, primarily in the form of iodine-131. It was estimated that 20,000 curies of iodine-131 and around 1,000 curies of caesium-137 were released. However, like any nuclear accident, claims have been made that the contamination was much more severe. No people were evacuated from the surrounding area, but there was a concern that milk might be dangerously contaminated. Milk distribution was banned in a 200-square-mile (520 km2) area around the reactor for a month. Thousands of gallons of contaminated milk were dumped in the Irish Sea. Subsequent investigations have suggested that the official records may have been altered in an attempt to cover up the possibility that during the radiation leak the wind was blowing out to sea, significantly increasing the contamination dose to Ireland and the Isle of Man.
The direct damage to the surrounding area is unclear and a 1987 report by the National Radiological Protection Board predicted the accident would cause as many as 33 long-term cancer deaths. Windscale Pile 1 was unsalvageable and after the removal of some damaged fuel cell rods it was left alone. In 2008, the British government announced that it would continue decontaminated the site. No air-cooled reactors have been built since the Windscale fire disaster. Modern technology uses water as a cooling agent. The Windscale fire was considered the world’s worst reactor accident until the Three Mile Island incident of 1979. The Three Mile Island nuclear disaster was a partial core meltdown in Unit 2 at the Three Mile Island Nuclear Generating Station in Dauphin County, Pennsylvania. However, the details of the Soviet Kyshtym nuclear disaster that occurred on September 29, 1957 was not made public for many years.
4. Stanislav Petrov
Stanislav Petrov is a retired lieutenant colonel of the Soviet Air Defense Forces. During the Cold War, Petrov worked at the Serpukhov-15 bunker near Moscow. The bunker housed the command center of the Soviet early warning system, code-named Oko. Petrov’s job included observing the satellite early warning network and notifying his superiors of any impending nuclear missile attack against the Soviet Union. If the early warning system was activated, the Soviet Union’s war strategy was to launch an immediate nuclear counter-attack against the United States. On September 26, 1983, shortly after midnight, the bunker’s computers accidentally identified and reported that an intercontinental ballistic missile was heading toward the Soviet Union from the U.S. Under standard Soviet doctrine, Petrov was ordered to contact high ranking officials regarding the situation. However, he dismissed the warning as a false alarm and did not immediately report the threat.
The Soviet satellite system had been under question in the past and Petrov was told that a first strike nuclear attack by the U.S. would contain hundreds of simultaneous missile launches. The system was reporting a limited number of incoming bombs, but they were coming in waves. If Stanislav Petrov would have followed standard Soviet procedures, high ranking commanders might have launched an assault against the United States, precipitating a corresponding nuclear war. Petrov also found it suspicious that ground radar systems was not picking up the nuclear weapons as they approached Soviet territory.
The Fallout
It was later determined that the false alarms had been created by a rare alignment of sunlight on high-altitude clouds. The error was corrected with a cross-referencing to a geostationary satellite. Stanislav Petrov underwent intense questioning by Soviet superiors regarding his actions. In the end, he was neither punished nor rewarded by the Soviet government. He was assigned to a less sensitive post and took an early retirement. The story was first published in the early 1990s, after the release of General Yury Votintsev’s memoirs. In January of 2006, Petrov traveled to the United States and was honored in a meeting at the United Nations in New York City. On the same day that Petrov was honored in New York City, the Russian Federation to the United Nations issued a press release stating that no single individual would be capable of starting or preventing a nuclear war.
At this time in history, a nuclear war between the U.S. and Russia was a real possibility. Only three weeks before the missile crisis, Soviet military shot down a South Korean passenger jet, Korean Air Lines Flight 007. The plane had entered into Soviet airspace. The crash killed all 269 people on board. Many Americans were killed in the attack, including U.S. congressman Larry McDonald. In November of 1983, NATO launched military exercise Able Archer 83. Many high ranking members of the KGB interpreted the mission as a preparation for a nuclear strike.
3. Palomares B-52 Crash
On January 17, 1966, an American B-52 bomber embarked on a mission from Seymour Johnson Air Force Base, North Carolina. The aircraft was carrying four Type B28 hydrogen bombs. The mission was part of the Cold War U.S. Operation Chrome Dome. The plane was scheduled to travel east across the Atlantic Ocean and Mediterranean Sea towards the European borders of the Soviet Union. The flight time required two mid-air refueling sessions over Spain. During the second aerial refueling, the B-52 bomber contacted the KC-135 tanker, while flying at 31,000 feet (9,450 m). The nozzle of the refueling boom hit the top of the B-52 fuselage, breaking the longeron and snapping off the left wing. The KC-135 was completely destroyed when its fuel load ignited, killing all four crew members. The B-52 broke apart, killing three of the seven crew members aboard. The aircraft and the nuclear weapons crashed to earth near the fishing village of Palomares, part of Cuevas del Almanzora municipality, in the Almeria province of Andalucía, Spain.
The Fallout
The conventional explosives in two of the nuclear bombs detonated upon impact, dispersing plutonium over nearby farms, residential areas, and woods. It was estimated that 2-square-kilometers of land was severely contaminated by radioactive plutonium. Of the four B28 hydrogen bombs, three were found on land near the small fishing village of Palomares. The fourth bomb fell into the Mediterranean Sea, and was recovered intact after a 2½ month-long search. It was located at a depth of 2,900 feet (880 m).
To defuse public alarm about the contamination, the Spanish minister of information and tourism Manuel Fraga and the U.S. ambassador Angier Biddle Duke swam on nearby beaches in front of press. The U.S. ambassador first swam at Mojácar and then the pair swam at the Quitapellejos beach in Palomares. Four days after the accident, the Spanish government announced that a NATO aircraft would no longer be permitted to fly over Spanish territory, either to or from Gibraltar. On January 25, 1966, the U.S. announced that it would no longer fly over Spain with nuclear weapons, and on the 29th the Spanish government formally banned U.S. flights over its territory that carried such weapons.
Millions of dollars were spent on the radioactive cleanup. However, 45 years after the accident radioactive material remains. In 2004, a study revealed that there was still significant amounts of contamination present in certain areas, and the Spanish government subsequently expropriated some plots of land, which would have otherwise have been slated for agriculture or housing. In early October 2006, the Spanish and United States governments agreed to decontaminate the remaining areas. Since the study began, reports have indicated that snails and other wildlife have been observed with unusual levels of radioactivity.
Two years after the Palomares nuclear disaster, another B-52 bomber involved with Operation Chrome Dome crashed. The plane was also carrying a load of four hydrogen bombs. The nuclear accident became known as the 1968 Thule Air Base B-52 nuclear crash. During the incident, a fire broke out in the navigator’s compartment of a U.S. B-52 near Thule Air Base, Greenland. The plane crashed 7 miles (11 km) from the air base, rupturing its nuclear payload of four hydrogen bombs. The nuclear weapons landed in North Star Bay, Greenland, resulting in widespread radioactive contamination.
The incident caused outrage and protests in Denmark, as Greenland is a Danish possession. After the accident, the United States and Denmark launched an intensive clean-up and recovery operation, although the decontamination effort was complicated by Greenland’s harsh weather. Tons of contaminated ice and debris were shipped and buried in the U.S. One of the nuclear weapons remains lost to this day. The U.S. project Chrome Dome was discontinued immediately after the incident. This nuclear accident directly led to more stable nuclear warhead development in the United States.
2. 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.
1. Chernobyl Disaster
The Chernobyl disaster was a nuclear accident that occurred at the Chernobyl Nuclear Power Plant in modern day Ukraine. On April 26, 1986, operators at the power plant conducted a scheduled test on the electric control system of one of the nuclear reactors. For an amount of time the reactors safety system was turned off. The reactor was also operating under improper and unstable conditions. These factors, along with faulty actions of some operators, caused an uncontrollable power surge to occur in nuclear reactor number four. This caused a fatal meltdown in the reactor. A chain reaction of nuclear explosions occurred that severely damaged the reactor building, completely destroyed the reactor, and caused the release of massive amounts of radioactive material. The fallout was propelled into the atmosphere and over an extensive geographical area. The nuclear fires burned at the Chernobyl Nuclear Plant for ten straight days.
The Fallout
The nuclear plume drifted over large parts of the western Soviet Union, Eastern Europe, Western Europe, and Northern Europe. Nuclear rain fell as far away as Ireland. Large areas in Ukraine, Belarus, and Russia were badly contaminated, resulting in the evacuation and resettlement of around 400,000 people. The event is widely considered to be the worst nuclear power plant disaster in history. It is the only level 7 event on the International Nuclear Scale. After the accident, millions of people were exposed to radiation from the nuclear cloud. A mass amount of radioactive material was deposited into the ground, plant, and animal life. The contamination of food and farmland became a major issue in surrounding areas.
A large collection of children were exposed to radioactive iodine after drinking contaminated cow’s milk. It has been estimated that five million people are living in areas with trace amounts of contamination caused by the Chernobyl accident. It remains unclear how many people developed cancer directly because of the incident. A 2005 report prepared by the Chernobyl Forum indicated that around 4,000 of the most highly exposed people have developed malignant tumors. People have challenged these results, claiming many more deaths. In comparison to the nuclear bombing of Hiroshima, four hundred times more nuclear fallout was recorded during the Chernobyl accident.
The zone of alienation is the 30 km/19 mi exclusion zone surrounding the site of the Chernobyl nuclear reactor disaster. It is located in the northernmost parts of Kiev Oblast and Zhytomyr Oblast of Ukraine, and adjoins the country’s border with Belarus. Approximately 3,000 workers are employed within the Zone of Alienation. Many people living in this area of the world have reported seeing various types of strange animal mutations. A few scientific studies have been conducted that suggest albinism is forming in swallows.
The wildlife populations in the zone of alienation appear to be flourishing due to significant reduction of human impact. Populations of traditional Polesian animals, such as wolves, wild boar, red deer, moose, and beaver have been multiplying and expanding outside the zone. Even extremely rare lynx have appeared, and there are reports of brown bear tracks, an animal that has not been seen in the area for several centuries. The rivers and lakes in the zone pose a significant threat to surrounding areas. This is due to the spread of polluted silt during the flood season. Until a significant scientific study can be performed in the area, we will not know for sure what creatures are lurking in the zone of alienation.source: http://www.toptenz.net/10-devastating-nuclear-events-and-accidents.php
