When people are asked about NPP accidents then the majority immediately recalls the tragedy on Chernobyl nuclear power plant and on Fukushima.
This article contains the most serious accidents at nuclear power plants around the world.
WiKi
Radiation-related emergencies are classified according to the IAEA INES scale at one of 8 levels. The spread of radioactivity is classified on this scale from 2 to 7 levels, higher levels correspond to greater danger. Thus, the risk of exposure of the population arises only at INES levels of 4 and higher.
- December 12, 1952 - Chalk River Laboratory Accident - Canada - INES 5
- September 29, 1957 - Kyshtym accident - USSR - INES 6
- October 10, 1957 - Windscale Accident - UK - INES 5
- 1960, 1961 - K-8 (submarine) - USSR
- July 4, 1961 - K-19 - USSR
- 1965 - K-11 - USSR
- January 17, 1966 - Plane crash over Palomares January 17, 1966 - Spain
- January 21, 1968 - Plane crash over Thule base - Greenland
- May 24, 1968 - K-27 - USSR
- January 18, 1970 - Radiation accident at the Krasnoye Sormovo plant
- October 2, 1974, August 24, 1978 - Nuclear explosions in Yakutia - USSR
- January 24, 1978 - Cosmos-954
- March 28, 1979 - Three Mile Island Nuclear Power Plant Accident - USA - INES 5
- 1980 - Saint-Laurent-des-Eaux - France- INES 4
- 1983 - Cosmos-1402 - USSR
- August 10, 1985 - Radiation accident in the Chazhma Bay - USSR
- April 26, 1986 - Accident at the Chernobyl nuclear power plant - USSR, - INES 7
- May 4, 1986 - Breakdown of the fuel rod delivery mechanism. Attempts by the operator to correct the situation led to the destruction of the reactor vessel and a large release of radiation - Hamm-Wentrop, Germany
- 1989 - Fire at the Vandellos nuclear power plant - Spain - INES 3
- 1993 - Accident at the Siberian Chemical Plant - Russia - INES 3 [source not specified 1371 days] or INES 4
- September 30, 1999 - Accident at the Tokaimura nuclear facility - Japan - INES 4
- 2005 - Sellafield - England - INES 3
- 2006 - Fleurus (2006)
- March 11, 2011 - Accident at the Fukushima-1 nuclear power plant - Japan - INES 7
Other cases of radioactive contamination
- From 1949 - Techa - USSR
- Since October 1951 - Lake Karachay - USSR
- 1980-1989 - Radioactive contamination in Kramatorsk - USSR
- 1987 - Radioactive contamination in Goiânia - Brazil - INES 5
- 1985-1987 - Therac-25 - USA and Canada
The world's first serious accident at a nuclear power plant. A technical error of the personnel led to overheating and partial melting of the core. Thousands of curies of fission products got into the external environment, and about 3800 cubic meters of radioactively contaminated water was dumped directly on the ground, in shallow trenches near the Ottawa River. Jimmy Carter, then a nuclear engineer in the Navy, was part of the team that was involved in the environmental clean-up of the station (The Careless Atom, 1969).
An accident in the cooling system of an experimental nuclear reactor caused a partial meltdown of the core. The staff managed to manually stop him. It took a year and a half to restart the reactor at full power (Let the Facts Speak, 1992).
When refueling in an operating reactor, the operator mistakenly loaded into the fuel channel not a fuel assembly, but a device for regulating the gas flow rate. As a result of the melting of five fuel elements, about 50 kilograms of molten fuel fell into the reactor vessel. There was a release of radioactive products into the environment. The reactor was shut down for one year (Soloviev, 1992; Weaver, 1995).
A fire at one of the largest American nuclear power plants that lasted for 7 hours and caused direct material damage of $ 10 million. Two reactor blocks were out of service for more than a year, resulting in additional losses of another $ 10 million. The fire was caused by non-observance of safety measures during the work on sealing the cable entries passing through the wall of the reactor hall. The verification of this work was carried out in the most primitive way; by the deflection of the flame of a burning stearin candle. As a result, the materials of the insulation of the cable holes ignited, and then the fire penetrated into the premises of the reactor hall. It took a lot of effort to bring the reactor to a trouble-free mode and extinguish the fire (Savelyev, 2003; List of nuclear accidents, 2004).
An accident occurred with the release of a large amount of radioactive substances. It was caused by the melting of several fuel elements in one of the technological channels, which led to the partial destruction of the reactor core of the first power unit. 1.5 million Ci of radioactivity were released into the external environment. Residents of the surrounding areas were not notified of the danger. It was an incident of the third level on the INES scale (Medvedev, 1989; Belluna, 2004).
There was an accident related to refueling. A massive leak of "hot" radioactive gas killed two station workers. The emergency exit, through which they could leave the scene of the emergency, was blocked (to "prevent frequent cases of theft"). The population was not warned about the accidental release of radioactivity (Let the Facts Speak, 1992).
February 22, 1977. Czechoslovakia, Jaslovske Bohunice, Bohunice NPP
Accident when loading nuclear fuel at the first power unit of the station. The protective coating was not removed from the fresh fuel assembly, which resulted in partial melting, rupture of the process channel and leakage of heavy water. A further rapid increase in humidity in the primary circuit system led to damage to the fuel elements in the reactor core and contamination of this circuit with fission products. The reactor internals were also damaged.
After this accident, it was decided to terminate the operation of the station, since the repair of equipment to restore its operability was considered too costly. In 2004, residents of the town of Jaslovske Bohunice filed a claim against the state and demanded to compensate them for the damage caused by the accident at the nuclear power plant in 1977, in the amount of 50 million euros. The municipality of the city also put forward its demands. His experts believed that the accident led to a sharp drop in land prices and adversely affected agricultural activities in the area (List of nuclear accidents, 2004).
Fire at the second power unit of the nuclear power plant, which arose from the fall of the overhead slab of the turbine hall on the oil tank of the turbine generator. The entire control cable is burnt out. The reactor was out of control. When emergency cooling water was supplied to it, eight people were overexposed (Kuznetsov, 2000).
The largest accident in the history of US nuclear power. As a result of a series of equipment failures and operator errors, 53 percent of the reactor core was melted at the second power unit of the nuclear power plant. What happened was like a domino effect. First, the water pump went bad. Then, due to the interrupted supply of cooling water, the uranium fuel melted and left the cladding of the fuel assemblies. The resulting radioactive mass destroyed most of the core and almost burned through the reactor vessel. If this happened, the consequences would be catastrophic. However, the station personnel managed to restore the water supply and reduce the temperature. During the accident, about 70 percent of the radioactive fission products accumulated in the core passed into the primary coolant. The exposure dose rate inside the vessel, which contained the reactor and the primary circuit, reached 80 R / h. An inert radioactive gas, xenon, and iodine were released into the atmosphere. In addition, 185 cubic meters of low-level radioactive water was dumped into the Saskugana River. From the area exposed to radiation, 200 thousand people were evacuated. The most affected were residents of Dauphin County, who lived near the nuclear power plant. A two-day delay in the decision to evacuate children and pregnant women from the 10-kilometer zone around the nuclear power plant had serious negative consequences. The cleanup of the second power unit, which was almost completely destroyed as a result of the accident, took 12 years and cost $ 1 billion, which effectively bankrupted the company that owned the station (The Report of the President "s Commission, 1979; Staff Reports to The President" s Commission, 1979; The Greenpeace Book of the Nuclear Age, 1989; The Tribune-Review, 2004).
Leakage of about 4,000 gallons of highly radioactive water through a crack in the bottom of a building where spent fuel assemblies were stored. 56 workers were exposed to radiation in this case. In total, during the period from January 10 to March 8, 1981, there were four such leaks. During emergency recovery operations, 278 NPP workers received increased exposure (Let the Facts Speak, 1992).
Explosion of a generator at the first power unit of the Armenian NPP. The powerhouse was seriously damaged by fire. Most of the personnel left the station in panic, leaving the reactor unattended. The task force that arrived by plane from the Kola NPP helped the operators who remained at their workplaces to save the reactor (Medvedev, 1989; Calendar of Nuclear Accidents, 1996).
January 27, 1984 USSR, Energodar, Zaporizhzhya NPP
Fire at the first power unit during its preparation for launch. After spontaneous combustion of one of the relay units, the fire shaft rushed about a 50-meter cable shaft for 18 hours. As it turned out, the cause of the fire was the use of PVC insulation at the station, which ignited, melted and, breaking off, set fire to bundles of cables at the lower elevations. The entire filling of the mine was burnt out: over 4 thousand control units, 41 electric motors, 700 kilometers of various cables. After this incident, all NPP units under construction in the USSR began to use cables with only fireproof insulation (Gaev, 1999).
During the "hot run-in" of the first power unit without fuel loading, a pipeline rupture occurred and 300-degree steam began to flow into the room where people worked. 14 people were killed. The accident happened due to erroneous actions of inexperienced personnel (Medvedev, 1989; Kuznetsov, 2000).
The largest radiation catastrophe in world history (event of the seventh level on the international scale INES). At 1:23 a.m. 49 seconds (Moscow time), at the fourth unit of the Chernobyl nuclear power plant, during the design tests of one of the safety systems, two powerful explosions sounded, which destroyed part of the reactor block and the turbine hall. The TNT equivalent of these explosions is estimated at about 100-250 tons of TNT. In the period from April 26 to May 10, 1986, when the destroyed reactor was finally shut down, according to official information, about 190 tons (50 mCi) of radioactive substances (approximately 4 percent of the total activity of the fuel in the reactor) were released into the atmosphere. Other estimates put 90 to 100 percent of the fuel ejected from the reactor. The territory of 160 thousand square kilometers is polluted. The most affected were the northern part of Ukraine, western Russia and Belarus. Radioactive fallout occurred (to one degree or another) on the territory of 20 states.
From radiation damage received when extinguishing a fire that broke out on the night of the accident, 28 people died (6 firefighters and 22 station workers), 208 were diagnosed with radiation sickness. About 400 thousand citizens were evacuated from the disaster zone. From 600 thousand to 800 thousand people (200 thousand from Russia) took part in the work to eliminate the consequences of the disaster. According to the UN report, the number of people directly or indirectly affected by the Chernobyl accident is 9 million, of which 3-4 million are children. The disaster cost the Soviet Union more than three times more than the total economic effect accumulated as a result of the operation of all Soviet nuclear power plants operated in 1954-1990 (IAEA, 1986; Hudson, 1990; Nuclear Society of the USSR, 1991; UNSCEAR, 2000; Checherov , 2002).
May 23, 1986 In the same place
Fire at the emergency fourth power unit of the Chernobyl nuclear power plant. The ignition occurred in the area where the main circulation pumps of the unit are located. The dose rate of gamma radiation in this place was 50-200 R / h. Firefighters were brought to the scene of the fire in armored personnel carriers. Due to the high levels of radiation, they extinguished it in small groups - five people each. The working time of each of them was no more than 10 minutes. In extinguishing the fire, which lasted about 8 hours, 268 firefighters took part. Of these, 11 people received radiation doses over 20 R, seven people - from 50 to 100 R (Mikeyev, 2000; 3 archives of the VUCHK-GPU-NKVD-KGB, 2001a).
August 19, 1986. In the same place
The accident that occurred in the immediate vicinity of the fourth emergency power unit of the Chernobyl nuclear power plant was a derailment of a special railway carriage with spent nuclear fuel. Civilian specialists could not cope with the accident, and soldiers of the railway troops of the USSR Ministry of Defense were involved in its elimination. Two days later, the destroyed railway track was restored. Then, within several hours of selfless labor of soldiers and officers, a 180-ton carriage with nuclear fuel was put on the railroad tracks and removed from the territory of the emergency nuclear power plant. Radiation levels at the work site were 1-1.5 R / h (Shevchenko, 1998).
As a result of the breakthrough of the secondary circuit pipeline, 120 cubic meters of superheated radioactive water and steam were released. Eight workers at the plant were caught in a boiling stream. Four of them died from their burns. The cause of the accident was the corrosive wear of the pipeline, which led to a decrease in the thickness of the pipe walls (from 12 to 1.6 mm) (Riccio, 1988; List of accidents, 1996).
An unauthorized increase in the reactor power, which led to the melting of 12 fuel elements, contamination of the core with cesium-137 and the release of radioactive substances outside the nuclear power plant (Yablokov, 2000).
The largest accident in the history of the nuclear power industry in Spain (event of the third level on the INES scale). Fire at the first power unit of the nuclear power plant. A sudden stop of one of the turbines caused overheating and decomposition of the lubricating oil. The resulting hydrogen exploded, causing the turbine to ignite. Since the automatic fire extinguishing system did not work at the station, fire departments of neighboring cities were called, including those located at a distance of up to 100 kilometers from the nuclear power plant. The fight against the fire lasted more than 4 hours. During this time, the power supply systems of the turbines and the cooling of the reactor were seriously damaged. Firefighters working at the station risked their lives. They did not know the location and functions of its facilities, they were not familiar with the emergency plan for the nuclear power plant. They used water instead of foam to extinguish electrical systems, which could lead to electric shock. In addition, people were not warned about the risk of working in areas with high levels of radiation. So three years after Chernobyl, firefighters, already in another country, became hostages of the dangerous situation at the nuclear power plant. Fortunately, none of them were badly hurt this time (WISE News Communique, 1989).
An accident at a nuclear power plant 320 kilometers northwest of Tokyo. Due to the rupture of the pipe, 55 tons of radioactive water escaped from the cooling system of the reactor of the second power unit. No radioactive contamination of the personnel and the area was noted, but the incident was considered at that time the most serious accident at Japanese nuclear power plants (Chronology of accidents, 1999)
As a result of a short circuit in the electric cable, a fire occurred in the turbine room of the second power unit. As in the accident at the fourth block of the Chernobyl nuclear power plant in April 1986, the development of a fire stimulated the use of combustible materials during its construction: thermoplastic concrete, roofing material and bitumen. Nine spans of the roof were destroyed, turbine equipment was disabled (Yablokov, 2000).
Accident when pumping liquid radioactive waste to a special water treatment facility Due to the negligence of the personnel, the pump maintenance room was flooded, and then about 15 cubic meters of radioactive waste flowed out through a special drainage network into the cooling pond. The total activity of cesium-137 that got into it is 6 mCi. Incident of the third level on the international scale INES (Kuznetsov, 2000).
During the hurricane in the Kolenergo power system, high-voltage power lines were damaged and there was a loss of external power sources for the Kola NPP. The personnel of the station failed to start the emergency diesel installations of the first and second power units. For 1 hour and 40 minutes, these blocks remained without energy (Industry Report, 2001).
Alarm of the third level on the INES scale. There was a release of radioactive products into the premises of the station. One person died (List of nuclear accidents, 2004).
During the planned repair work at the second power unit of the NPP, inert radioactive gases and radioactive iodine were released into the atmosphere. The reason is damage to fuel assemblies during chemical cleaning of their surface in a special container. Accident of the third level on the INES scale (Reuters, 2003; Accidents at NPP, 2005).
An explosion occurred at a plant for the processing of radioactive waste from a nuclear complex 350 kilometers west of the city of Tokyo, resulting in a fire. An experimental nuclear reactor with a capacity of 165 MW, shut down in March 2003, was not affected by this incident (Accidents at the NPP, 2005).
Emergency shutdown of the fourth power unit of the nuclear power plant and release of radioactive steam. The reason is unauthorized pressing of the emergency button in the operating room of the fourth power unit. There were no casualties; for 2 hours, the vapor cloud moved towards the settlement of Kaporye (Accidents at the NPP, 2005).
An accident at a nuclear power plant located 320 kilometers west of Tokyo. A steam jet with a temperature of 270 ° escaped from the burst pipe of the second circuit of the cooling system of the third power unit and scalded the workers who were in the turbine hall. Four people died, 18 were seriously injured (lzvestia.ru, 2004; RBC.ru, 2004).
Large leak of radioactive water from the reactor cooling system of the second power unit of the nuclear power plant. According to the Spanish Radiation Safety Board, this is the most serious accident at this nuclear power plant since the fire in 1989.
The accident at the Fukushima-1 nuclear power plant is a major radiation accident of the maximum 7th level on the International Scale of Nuclear Events, which occurred on March 11, 2011 as a result of the strongest earthquake in the history of Japan and the subsequent tsunami. An earthquake and a tsunami hit disabled the external power supply and backup diesel generators, which caused the failure of all normal and emergency cooling systems and led to the melting of the reactor core at power units 1, 2 and 3 in the early days of the accident. A month before the accident, the Japanese department approved the operation of power unit No. 1 for the next 10 years.
In December 2013, the nuclear power plant was officially closed. Work continues on the territory of the station to eliminate the consequences of the accident. Japanese nuclear engineers estimate that it can take up to 40 years to bring an object into a stable, safe state.
The financial damage, including clean-up costs, decontamination and compensation costs, is estimated at $ 100 billion. As the remediation work will take years, the amount will increase.
