On March 11, 2011 an earthquake and tsunami severely damaged four nuclear reactors at the Fukushima Number 1 power plant on the northeast coast of the Japanese island of Honshu.

            The Unit Four reactor is a boiling water design fueled with about eighty tons of uranium dioxide in zirconium alloy fuel rods. The primary concrete containment vessel surrounds the core of the reactor and the secondary concrete containment vessel included upper levels which contained pools for storing fuel rods and irradiated equipment.

            When the earthquake struck on March 11, the Unit 4 reactor was shut down. The fuel rods had been removed and placed in the pool on the upper level. On March 15 at 6 AM a hydrogen gas explosion at nearby Unit 3 blew two large holes in the walls the upper level of the Unit 4 building. Around 10 AM the spent fuel pool at Unit 4 caught fire releasing radioactive contamination. Employees were evacuated as the radiation in the Unit 4 building rose. The fire was extinguished by noon. Later, it was reported that there had been no sustained release of dangerous radioactive materials.

            At 4 PM on March 15 there was concern that the water in the pool might be boil and exposing the fuel rods. Visual inspections and analysis of the water in the pool at the end of April determined that the fuel rods were mostly undamaged. As of 10:30 PM the workers were unable to add water to the pool. TEPCO considered using helicopters to drop water into the Unit 4 building but it was postponed in favor of a plan to use high pressure fire hoses instead.

            Photographs from March 16 showed that a large part of the outer wall of the Unit 4 building had collapsed. There was an ongoing debate over whether the water in the Unit 4 spent fuel pond had boiled off completely. By 8 PM on the 16th, there was a plan to use a police water cannon to spray water into the pool. On March 18 it was discovered that the water in the spent fuel pool was vanishing faster than could be explained by evaporation which indicated that the water was leaking out. On March 20 military trucks were used to spray more water into the pool. For several days, seawater was poured into the pool with a concrete pump and also injected with the existing cooling system. Fresh water replaced seawater on March 29.

            Analysis of the water in the pool in mid-April indicated that a small number of fuel rods had been damaged and had released cesium-134 and 137 into the environment. Water continued to be pumped into the pool during April to control the rising temperature. There was a fear that too much water could structurally weaken the Unit 4 building. TEPCO decided that the disappearing water was being boiled off and not leaking out. TEPCO began constructing new columns in the Unit 4 building because of a fear that the building might collapse.

            In June it was found that there was only one third of the normal amount of water in the spent fuel pool and that some of the fuel rods were exposed. The fuel pool was refilled to the regular level to lower the radiation and temperature that prevented work on the pool. The new steel and concrete columns were completed by the end of June.

            Although the spent fuel pool at Fukushima Unit 4 is stable and under control at present, there is widespread concern over the vulnerability of the pool to future earthquakes. Japan is a very seismically active country and another major quake in the Fukushima area is likely. There is over eighty times the radioactive material in the Unit 4 pool than was released at Chernobyl which caused problems over much of Europe. Some say that the radiation that could be released from Unit 4 might threaten the very survival of the human race. Other are more conservative but do agree that the release of the fuel in Unit 4 into the environment would result in serious health and environmental consequences. A group of civic organizations has appealed to the United Nations to help clean up Unit 4. Authorities in the United States consider the Unit 4 pool to be a national security threat. Currently, the Unit 4 spent fuel pool is probably the number one environmental danger in the world.

            On March 11, 2011 an earthquake and tsunami severely damaged four nuclear reactors at the Fukushima Number 1 power plant on the northeast coast of the Japanese island of Honshu.

            The Unit Three reactor is a boiling water design fueled with both uranium dioxide zirconium alloy fuel rods and mixed uranium and plutonium oxide zirconium alloy fuel rods in zirconium alloy fuel rods. A solution of plutonium dioxide in water has a high boiling point and is not as prone to release into the environment during loss of coolant and steam venting. The primary concrete containment vessel surrounds the core of the reactor and the secondary concrete containment vessel included upper levels which contained pools for storing fuel rods and irradiated equipment.

            Around 3 PM Unit 3 was shut down in response to the earthquake. Around 5:30 PM all the electrical power generated by the reactor stopped with the arrival of the tsunami. Emergency batteries took over to provide power for monitoring and control systems and the coolant level was kep stable. When the water level began to drop again, the isolation cooling system and core sprayers were shut down and the high pressure coolant injection system was started. The injection systems failed on March 13th and could not be restarted. For a period of time, the top nine feed to the mixed uranium and plutonium oxide fuel rods were uncovered and radiation levels increased in the reactor building.

            Around 9 AM on March 13, steam was manually vented from the primary containment vessel and operators began using a fire truck to pump sea water mixed with boric acid into the reactor core but a malfunctioning gauge led to confusion about the actual level of water in the reactor. Around noon on March 13th, a government spokesman reported that hydrogen gas was building up in the Unit 3 primary containment vessel. At noon on March 14th the hydrogen gas was ignited and an explosion blew out the upper level walls of the Unit 3 reactor building. Eleven people were killed by the explosion and others were injured.

            There was concern that the Unit 3 fuel assembly could reach criticality and a self sustaining fission reaction would lead to massive releases of radioactive materials. Later analysis would show that criticality was never reached.

            On March 16th white plumes were seen rising from the Unit 3 reactor building. These plumes were assumed to be steam generated from water boiling off fuel rods stored in a pool at the top of the building. Helicopters were dispatched to dump cooling water on the top of the Unit 3 reactor but the mission was cancelled due to the high level of radioactivity. In August, the existing undamaged coolant injection system at Unit 3 was restarted. There were still problems with high temperatures in the upper levels of the containment building.

            Helicopters dropped loads of water on Unit 3 on March 17th. Fire engines sprayed sea water on Unit 3 for the next week to cool the reactor. On March 25th, fresh water replaced sea water in the spraying operation. There was a report on that date that the containment vessel at Unit 3 might have been breached and that radiation may have been released into the environment.

            It was estimated in April that thirty percent of the fuel rods had been damaged. In May it was reported that water sprayed into Unit 3 had been leaking back into the environment. In late June, it was revealed that chemical reactions in the injected water had become highly alkaline and was threatening to corrode the aluminum racks holding the fuel rods. This might have resulted in criticality, a self-sustaining fission reaction. By late September the cooling efforts successfully lowered the temperature in most of Unit 3 to under 100 degrees Celsius.

            On March 11, 2011 an earthquake and tsunami severely damaged four nuclear reactors at the Fukushima Number 1 power plant on the northeast coast of the Japanese island of Honshu.

            The Unit Two reactor is a boiling water design fueled with about eighty tons of uranium dioxide in zirconium alloy fuel rods. The primary concrete containment vessel surrounds the core of the reactor and the secondary concrete containment vessel included upper levels which contained pools for storing fuel rods and irradiated equipment.

            Around 3 PM Unit Two was shut down in response to the earthquake which shook the reactor and broke pipes. Around 5:30 PM all the electrical power generated by the reactor stopped. Emergency batteries were supposed to take over to provide power for monitoring and control systems but Unit 2’s backup batteries were damaged when the tsunami struck and could not provide emergency power. Fifteen minutes later, TEPCO, the company that managed Fukushima Number 1, declared a Nuclear Emergency Situation because they could not confirm that emergency cooling systems were injecting coolant into the core of Unit 2. Radioactive steam was released into the secondary containment vessel to reduce pressure in the primary vessel.

            At first, after the quake, TEPCO used the isolation condenser system to cool Unit 2 but after ten minutes, they shut down the isolation condenser and turned on the emergency cooling injection system which sprayed coolant into the reactor core. After a half hour, the loss of electrical power to the reactor disabled the spray cooling system but the operators were able to manually activate the cooling system. At 5 PM on March 12th, the cooling system shut down and restarted again at 9 AM on March 13th. Some building pressure was vented around midnight on March 12th. The operators worked problems with the fuel rod storage pool of Unit 2.

            Around noon on March 13th there was an explosion in the Unit 3 reactor building next to Unit 2. The explosion blew holes in the wall of Unit 2 and damaged four of the five cooling pumps in Unit 2.  The fifth pump shut down when its fuel was exhausted.  By 9 PM on March 14th, the cooling system was still operating and power had been restored from a mobile generator.

            The emergency cooling system was shut down by dropping pressure in the primary reactor vessel around 7:30 PM on March 14th. The fuel rods were exposed by dropping coolant levels and there were concerns about a possible core meltdown. The reactor was partly filled with water but rods were still exposed. The fuel rods were exposed because a monitoring gauge had been accidentally shut off preventing flow of coolant into the reactor. Seawater was pumped into the reactor on March 14th.

            There was an explosion in the Unit 2 reactor around 6 AM on March 15 but TEPCO and the Japanese government continued to report no significant breach of the reactor vessel though temperature and radiation levels were dangerously elevated. It was revealed by TEMPCO in May that the fuel rods in Unit 2 had melted down  around March 15th.

            By March 26th external electrical power had been restored to Unit 2.  Water was moved from the condensers in the reactor building to trenches and waste water treatment facilities. In May it was revealed that much of the cooling water injected into Unit 2 had leaked out of the containment vessel.

            Work continued through the summer of 2011 to reduce the temperature in Unit 2 with mixed results. In September of 2011was still too high at 114 degrees Celsius and more water was pumped into the reactor.

            In November, the detection of xenon-133 and 135 indicated that fission reactions were still occurring in the Unit 2 reactor. Huge amounts of boric acid were injected into the core to prevent the fissions reactions from achieving a self-sustaining criticality.

            In February of 2012, the temperature began fluctuating again. Temperature monitoring was hampered by damaged thermometers which could not be replaced due to high radiation in the reactor building of Unit 2. However, the temperatures did not exceed the 100 degree Celsius limit for considering a reactor to be in cold shutdown status.

            On March 11, 2011 an earthquake and tsunami severely damaged four nuclear reactors at the Fukushima Number 1 power plant on the northeast coast of the Japanese island of Honshu.

            The Unit One reactor is a boiling water design fueled with about eighty tons of uranium dioxide in zirconium alloy fuel rods. The primary concrete containment vessel surrounds the core of the reactor and the secondary concrete containment vessel included upper levels which contained pools for storing fuel rods and irradiated equipment.

            Around 3 PM Unit One was shut down in response to the earthquake which shook the reactor and broke pipes. Around 5:30 PM all the electrical power generated by the reactor stopped. Emergency batteries were supposed to take over to provide power for monitoring and control systems but Unit 1’s backup batteries were damaged when the tsunami struck and could not provide emergency power. Fifteen minutes later, TEPCO, the company that managed Fukushima Number 1, declared a Nuclear Emergency Situation because they could not confirm that emergency cooling systems were injecting coolant into the core of Unit 1. Radioactive steam was released into the secondary containment vessel to reduce pressure in the primary vessel.

            At first, after the quake, TEPCO used the isolation condenser system to cool Unit 1 but after ten minutes, they shut down the isolation condenser and turned on the emergency cooling injection system which sprayed coolant into the reactor core. After a half hour, the loss of electrical power to the reactor disabled the spray cooling system. The operators were unable to restart the isolation condensers for a half hour and they functioned intermittently after that. The condensers should have been able to cool the core for eight hours but they failed to perform as expected. It was revealed later that TEPCO had changed the original arrangement of pipes feeding the isolation condensers without notifying government regulator. This may have contributed to the problems at Unit 1.

            By midnight, the core coolant levels were dropping and TEPCO announced that there might be a release of radioactivity from Unit 1. Early on March 12th radiation levels were rising in the Unit 1 turbine building. TEPCO said that they might need to relieve the pressure by venting the rising pressure which would release radioactivity into the environment. This was excused on the premise that there would be very little radioactivity and it would be blown out to sea by prevailing winds. During the night, the isolation cooling system failed and around noon on March 12th, the pressure was relieved by venting and water was injected into the system.

            The heat continued to rise in the core as the cooling water was boiled off and released as steam. The lost of electrical power interfered with the operation of coolant pumps and fans. Increasing radioactivity was detected outside the reactor complex including cesium-137 and idodine-131 which indicated that the coolant levels in the core had dropped so low that the fuel rods were exposed and were melting. Building pressure had to be relieved by manually opening the valves because of the loss of electrical power.

            At 3 PM on March 12th, there was an explosion in the Unit 1 reactor building which blew out the walls on the upper levels and collapsed the roof. The exposure of the zirconium alloy fuel rods to live steam resulted in a reaction that generated hydrogen which resulted in the explosion. The primary containment was not breached but significant radioactivity was released. There was concern that some of the fuel rods may have dropped through the bottom of the core.

            At 10 PM, the Japanese government order that seawater be pumped into the Unit 1 reactor to cool the core although this would ruin the reactor. Boric acid was added to the seawater as it was pumped in by fire trucks. After taking about ten hours to fill the core, the seawater took about ten days to cool down the core. Over the next few days, repairs continued and electrical power was restore to Unit 1. Pressure continued to build requiring reduction of water flow and steam venting. Salt water corroded the zirconium alloy shell of the fuel rods. By March 24 it was determined that the fuel rods in the upper level cooling power had been exposed.

            Work continued for the next several months to bring the core temperate down and restore the various monitoring and control. Temperature of the core was reduced to under 100 degrees Celsius by August, bringing the reactor closer to “Cold Shutdown Status.” By October, a concrete cover for the Unit 1 reactor had been completed.

            The Hanford nuclear facility contains fifty three million gallons of high-level radioactive and chemical waste. These wastes were generated when corrosive chemicals were used to dissolve spent fuel rods to retrieve plutonium. The result was hot radioactive corrosive liquid was. The waste is stored near the Columbia River in huge underground tanks in what is called the Hanford Tank Farm. There are one hundred and seventy seven tanks and most of them are well past their design lifetime. One third of the tanks are known to have leaked some of their contents.  Estimates of the amount leak vary from a million gallons to six million gallons. In addition to being highly radioactive and toxic, the material in the tanks also generates gases that must be vented in order to prevent explosions.

            One hundred and fourty nine single-shell tanks were built between 1943 and 1964. During World War II, there was a shortage of stainless steel so they used cheaper and weaker carbon steel on tanks build during the war. Even after the war when the supply of stainless steel returned to normal levels, they continued to use carbon steel to build the tanks. The twenty double-shell tanks were built between 1977 and 1986 and they were also constructed with carbon steel. The tanks were designed to last 20 years and were never intended as a permanent storage system. The waste is acidic and highly corrosive. It has been eating away at the lining of the tanks since they were filled. One third of the tanks have been eaten thought completely in places and they are leaking the waste into the environment.

            The operators at the site monitor the conditions in the tanks and move waste from older single-shell tanks to twenty eight newer double-shelled tanks when required but space in the new tanks is limited. Robotic systems have been developed to handle the extremely dangerous and toxic waste but they are not always employed and workers are endangered when required to deal with the waste. The single-shelled tanks are considered “closed” when ninety nine percent of the waste has been removed. To date, only seven of the one hundred and fourty nine old tanks have been closed.

            The only way to permanently stabilize the waste is to create glass logs to contain the waste in a solid form. This process is called vitrification. A vitrification plant is being built that will be able to process some of the waste but not all of it. 

            It is not known exactly what is happening at the Hanford Tank Farm because the government has denied the severity of the problem for years and has never adequately funded a complete analysis of the site. A number of clean-up projects have been proposed, funded and started over the years but the site is still the most serious nuclear waste problem in the United States. The main priority of the cleanups is to minimized further leakage from the aging tanks and to stabilize the waste to prevent catastrophic explosions. Three hundred million dollars a year are being spent to operate the Tank Farm.

 

            In 1943 the US government established a nuclear research site in south-central Washington State at the town of Hanford on the Columbia River. That area had been used by Native American tribes for thousands of years and was the location for a reservation. The Yakima Indians were moved to another reservation west of the old reservation in 1943 to make way for the construction of the Hanford nuclear site. They still retain the right to monitor the health of the natural environment at the Hanford nuclear site.

            The Hanford site currently covers about six hundred square miles of desert with the Columbia River forming the north and east boundaries of the site. The area gets less than ten inches of rainfall annually. The site was considered idea because of its isolation and abundant water supply. Some of the people living nearby were moved to other locations. There are three separate areas for reactors, chemical separation facilities and waste storage. Some of the land that was originally part of the Hanford site has been returned to civilian use.

            The first plutonium production reactor in the world was built at the Hanford site as part of the Manhattan Project to develop nuclear weapons during World War II. Plutonium was produced there for the first test nuclear bomb and for the bomb dropped on Nagasaki, Japan.

            During the period known as the Cold War following World War II, the site was expanded to include nine nuclear reactors and five plutonium processing installations. The plutonium installations produced plutonium for almost sixty thousand bombs in the U.S. nuclear weapons program. Scientists at Hanford developed many techniques and technologies used in the evolving nuclear industry. The site has been mostly decommissioned but still hosts the Columbia Generating Station’s nuclear reactor which generates power for the grid as well as research facilities including the Pacific Northwest National Laboratory.

            Most of the reactors were shut down by 1971 with the last reactor shut down in 1987. They were entombed in concrete. Unfortunately, radioactive isotopes were released into the air and into ground water that reached the Columbia River because the early safety and waste disposal techniques were still evolving and were not adequate. The health of the environment and people living in the area were impacted by the radioactive releases.

            Weapons production at Hanford ended in 1991 with the collapse of the Soviet Union and the end of the Cold War. Over fifty million gallons of high level liquid nuclear waste was left by the years of weapons production, most of it stored in metal tanks. Twenty five million cubic feet of solid nuclear waste was buried which contaminated over two hundred square miles of groundwater beneath the site.

            Hanford is the site of the biggest environmental cleanup project in the United States. Two thirds of the high-level nuclear waste in the United States is located at Hanford.

 

 

 

 

 

            On March 11, 2011 a tsunami was triggered by a powerful earthquake off the northeast coast of the Japanese island of Honshu. The huge wave crashed into the coastal Fukushima Number 1 nuclear power plant in Okuma, Fukushima Prefecture and caused a major nuclear disaster.

            The Daiichi plant contains six GE boiling water reactors operated by the Tokyo Electric Power Company. The plant was started operation 1971 and ultimately generated almost five gigawatts of electrical power making it one of the fifteen biggest commercial nuclear power plants in the world.

            On March 11, 2011 reactors 5 and 6 were in what is called cold shutdown where the pressure of the coolant is at regular sea level atmospheric pressure and the temperature is under two hundred degrees Fahrenheit. Reactor 4 had been defueled (had its fuel removed.)

            Following the earthquake, reactors 1, 2 and 3 automatically shut down and emergency diesel generators switched on to provide electricity for reactors controls and coolant circulation pumps. The tsunami caused by the earthquake hit the site and flooded the rooms containing the emergency generators. It also severed the connection of the plant to the electrical power grid. Access to the site was inhibited by the flooding. Newer generators had been built above the flood zone but their connection to the reactors was not protected and was flooded, preventing their use. Attempts to bring in mobile generators failed because they could not be connected to the site power grid.

            The reactors were designed for the coolant to continue to circulate for four to eight hours without the circulation pumps operating. After this time elapsed, the operating reactors began to overheat and eventually went into meltdown where the cores of the reactors become so hot that they melted. Hydrogen was generated from overheating of the zinc alloy sheaths of the fuel rods and this resulted in several explosions also occurred. The government ordered seawater to be pumped into the reactors to cool them which completely destroyed them. Water levels also dropped in the pools where fuel rods were kept when they were not in the reactor cores. This raises the prospect of fires and release of more radioactivity. People were evacuated from a circle around the site twelve miles in diameter. People working on the disaster suffered radiation poisoning. Electrical power was eventually restored to some of the reactors and allowed cooling systems to begin operation again. The melting fuel and the exposed rods in the cooling pools remain a grave concern more than a year after the

            Radioactive isotopes were released into the atmosphere, the soil and the ground water. Dangerous levels of cesium have been detected over 30 miles from the site. Sale of food grown near the site and use of tap water near the site have been restricted. The Japanese government and TEPCO have been criticized for incompetence in reacting to the disaster and poor communication with the public. Increased radioactivity from the Fukushima disaster has been measured in the Pacific ocean water, and in the air, water and soil of North America. The Fukushima disaster was ultimately rated as Level 7 on the International Nuclear Event Scale.

 

 

 

 

 

 

            In April of 1986 there was a major nuclear accident at the Chernobyl nuclear power plant in Ukraine about two miles Prypiat, a city of about fifty thousand people on the Dnieper river near border with Belarus   Ukraine was part of the Soviet Union at that time and the power plant was under the direct control of authorities in Moscow. As with Kyshtym, there was not enough attention paid to safety systems and procedures.

            The Chernobyl power plant contained 4 reactors built between 1970 and 1983 based on a unique Soviet boiling water reactor design. Ordinary water was used as a coolant with graphite acting as a neutron moderator. Control rods were raised or lowered to control the power output of the reactors.

            As the reactor heats up, bubbles or voids of steam reduce the density of the water in the core which causes a drop in neutron absorption and an increase in the reactivity of the core. In this particular reactor design, the amount of bubbles or the void coefficient has a very strong influence over reactor temperature and output.

            On April 25 the operators were preparing the reactor number 4 for a test of the turbines ability to continue to spin and drive the circulation pumps after main electrical power was shut off. Early on April 26 automatic shut down mechanisms were disabled before the test.

            With the reactor in a very unstable condition, the control rods were inserted into the core and caused a severe power surge. The very hot fuel and cold water reacted to produce fuel fragmentation, increase in steam production and an increase in pressure. The pressure opened the one thousand ton reactor cap which ruptured the fuel channels and jammed the control rods which had only been inserted halfway. Water dumped into the core by the ruptured cooling system fed increased steam production throughout the core. A huge steam explosion released fission products into the atmosphere. A few seconds later a second explosion likely caused by hydrogen from zirconium alloy interacting with steam blew out fragments of the fuel and graphite from the core. About three hundred tons of graphite was thrown out of the core resulting in the fuel becoming incandescent and staring fires. These fires were the main cause of the release of around fourteen times ten to the eighteenth power Becquerels of radioactivity into the environment.

            For twelve hours, around three hundred tons of water per hour were dumped into the half of the reactor that hadn’t been destroyed but was ultimately stopped to prevent flooding of reactors 1 and 2. Over the next eight days, five thousand tones of boron, dolomite, sand, clay and lead were poured into the burning core from helicopters in an attempt to put out the fires and stop the release of radioactivity. Over half a million works were ultimately involved in trying to contain the disaster. The eighteen billion ruble cost of fighting the fires and cleaning up the site dealt a severe blow to the economy of the Soviet Union. Five years later the Soviet Union disintegrated.

            The Chernobyl accident was the worst release of radioactivity in history from a civilian nuclear power plant. Serious disruption of the social and economic life of large populations in Ukraine, Belarus, Russia and countries in Europe resulted. The radiation release spread over much of Europe Iodine-131 and cesium-137 were a major threat to public health. Thirty operators were killed in the accident and a few more died later. Over two hundred people received radiation injuries and around thirty later died from the effects of the radiation. Many children developed thyroid cancer as a result of exposure to iodine-131. The accident was rated as a level 7 on the International Nuclear Event Scale.

 

 

 

 

 

 

            In 1957, there was a serious nuclear accident in Ozyorsk, Russia at the Mayak nuclear fuel reprocessing plant. Ozyosk was one of the “closed cities” that the Soviet Union built to carry out for highly classified research and industry. Ozyorsk was not on any public maps so the disaster has been referred to under the name of the nearest town that was on public maps, Kyshtym.          

            In a rush to catch up with the United States in nuclear weapons development, the Soviets built the Mayak reprocessing plant between 1945 and 1948 without great concern for safety or the environment. The six reactors on the site discharged irradiated cooling water directly into Lake Kyzyltash and high-level radioactive waste was dumped into a nearby river.

            In 1953, they built storage for liquid nuclear waste underground. Steel tanks were mounted on concrete bases and a cooling system was created to deal with heat generated by continuing radioactive decay in the waste. The monitoring systems which were created were not sufficient to deal problems arising from the cooling systems and the contents of the tanks.

            In September of 1957, the cooling system failed in one of the tanks and was never repaired. The tank contained about eighty tons of liquid waste. The temperature in the tank continued to rise and the liquid waste was dried out through evaporation. The ammonium nitrate and acetates in the dried waste eventually exploded with a force equivalent to one hundred tons of TNT, blowing the one hundred and sixty ton concrete lid off the tank. Up to fifty microcuries of radiation were released into the atmosphere.

            Over the next twelve hours, the radioactive plume spread to two hundred miles northeast over the east Ural region of western Russia. Three hundred square miles of the landscape were contaminated with cesium-137 and strontium-90. This contaminated area has been given the name of the East-Ural Radioactive Trace. Over the next two years ten thousand people in twenty two villages were evacuated. Early evacuations took place without explanations to the people being moved.

            Because of the secrecy surround the Soviet nuclear program, only vague reports of a the release of radioactivity over Russia from a terrible accident appeared in April of 1958. In 1968, the Soviet Union created the East-Ural Nature Reserve and forbid any unauthorized access to the Reserve in order to conceal the effects of the accident. Eventually, it was revealed that supposed laboratory experiments on the effects of radiation on plants and animals published in Soviet scientific journals were actually reports on the impact of the accident on the environment. Finally, in 1976, Zhores Medvedev revealed what had really happened at Ozyosk. IN 1979, a Freedom of Information Act request filed with the CIA revealed that the CIA had learned about the accident in 1957 but had withheld the information in order to protect the new US nuclear industry. The Soviets finally declassified their records on the disaster in 1990.

            Ultimately, it is estimated that over eight thousand people died because of the accident at Ozyosk. The disaster is rated as a six on the International Nuclear Event Scale.

 

 

 

 

 

 

 

 

            In 1957, there was a serious nuclear accident in Ozyorsk, Russia at the Mayak nuclear fuel reprocessing plant. Ozyosk was one of the “closed cities” that the Soviet Union built to carry out for highly classified research and industry. Ozyorsk was not on any public maps so the disaster has been referred to under the name of the nearest town that was on public maps, Kyshtym.          

            In a rush to catch up with the United States in nuclear weapons development, the Soviets built the Mayak reprocessing plant between 1945 and 1948 without great concern for safety or the environment. The six reactors on the site discharged irradiated cooling water directly into Lake Kyzyltash and high-level radioactive waste was dumped into a nearby river.

            In 1953, they built storage for liquid nuclear waste underground. Steel tanks were mounted on concrete bases and a cooling system was created to deal with heat generated by continuing radioactive decay in the waste. The monitoring systems which were created were not sufficient to deal problems arising from the cooling systems and the contents of the tanks.

            In September of 1957, the cooling system failed in one of the tanks and was never repaired. The tank contained about eighty tons of liquid waste. The temperature in the tank continued to rise and the liquid waste was dried out through evaporation. The ammonium nitrate and acetates in the dried waste eventually exploded with a force equivalent to one hundred tons of TNT, blowing the one hundred and sixty ton concrete lid off the tank. Up to fifty microcuries of radiation were released into the atmosphere.

            Over the next twelve hours, the radioactive plume spread to two hundred miles northeast over the east Ural region of western Russia. Three hundred square miles of the landscape were contaminated with cesium-137 and strontium-90. This contaminated area has been given the name of the East-Ural Radioactive Trace. Over the next two years ten thousand people in twenty two villages were evacuated. Early evacuations took place without explanations to the people being moved.

            Because of the secrecy surround the Soviet nuclear program, only vague reports of a the release of radioactivity over Russia from a terrible accident appeared in April of 1958. In 1968, the Soviet Union created the East-Ural Nature Reserve and forbid any unauthorized access to the Reserve in order to conceal the effects of the accident. Eventually, it was revealed that supposed laboratory experiments on the effects of radiation on plants and animals published in Soviet scientific journals were actually reports on the impact of the accident on the environment. Finally, in 1976, Zhores Medvedev revealed what had really happened at Ozyosk. IN 1979, a Freedom of Information Act request filed with the CIA revealed that the CIA had learned about the accident in 1957 but had withheld the information in order to protect the new US nuclear industry. The Soviets finally declassified their records on the disaster in 1990.

            Ultimately, it is estimated that over eight thousand people died because of the accident at Ozyosk. The disaster is rated as a six on the International Nuclear Event Scale.