What happened in chernobyl? An explanation
- 1. Nuclear Power Plants Nuclear Power Plants Disasters and their possible Disasters and their possible meltdowns meltdowns
- 2. A little about nuclear power plants A little about nuclear power plants Most reactors have a “core” where the Most reactors have a “core” where the reaction takes place. Inside the core are reaction takes place. Inside the core are fuel rods and assemblies, the control rods, fuel rods and assemblies, the control rods, the moderator, and the coolant. the moderator, and the coolant. Outside the core are the turbines, the heat Outside the core are the turbines, the heat exchanger, and the cooling system. exchanger, and the cooling system.
- 3. Nuclear power plant diagram Nuclear power plant diagram
- 4. Chernobyl Chernobyl Located in the Ukraine, the Chernobyl Located in the Ukraine, the Chernobyl nuclear power plant was the site of the nuclear power plant was the site of the worst nuclear disaster to date. worst nuclear disaster to date.
- 5. Chernobyl Chernobyl On April 25 On April 25th th -26 -26th th , 1986 the , 1986 the World's worst nuclear power World's worst nuclear power accident occurred at accident occurred at Chernobyl in the former Chernobyl in the former USSR (now Ukraine). USSR (now Ukraine). The Chernobyl nuclear The Chernobyl nuclear power plant located 80 miles power plant located 80 miles north of Kiev had 4 reactors north of Kiev had 4 reactors and while testing reactor and while testing reactor number 4. Numerous safety number 4. Numerous safety procedures were ignored. procedures were ignored. At 1:23 am the chain At 1:23 am the chain reaction in the reactor reaction in the reactor became out of control became out of control creating explosions and a creating explosions and a fireball which blew off the fireball which blew off the reactor's heavy steel and reactor's heavy steel and concrete lid. concrete lid.
- 6. The radiation cloud The radiation cloud The Chernobyl accident The Chernobyl accident killed more than 30 killed more than 30 people immediately. people immediately. As a result of the high As a result of the high radiation levels in the radiation levels in the surrounding 20-mile surrounding 20-mile radius 135,00 people had radius 135,00 people had to be evacuated. to be evacuated. The picture to the right The picture to the right shows how far radiation shows how far radiation had spread by May 6 had spread by May 6th th . .
- 7. Area of radiation cloud Area of radiation cloud How much land was affected by the How much land was affected by the original radiation cloud on April 26 original radiation cloud on April 26th th ? ? There was a radius of 20 miles, so how There was a radius of 20 miles, so how can you calculate the square miles can you calculate the square miles affected by the original blast? affected by the original blast?
- 8. Effects on the environment Effects on the environment In some local ecosystems In some local ecosystems lethal doses were reached lethal doses were reached particularly for coniferous particularly for coniferous trees and small mammals trees and small mammals within a 10 km radius of the within a 10 km radius of the reactor. reactor. However in 1989 the natural However in 1989 the natural environment of these environment of these ecosystems began to ecosystems began to recover but there is the recover but there is the possibility of long term possibility of long term genetic effects. genetic effects. Increased cancer was Increased cancer was often seen. Researchers often seen. Researchers also found that 64% of all also found that 64% of all Ukrainian thyroid cancer Ukrainian thyroid cancer patients age 15 or patients age 15 or younger lived in the most younger lived in the most contaminated regions the contaminated regions the provinces of provinces of Kiev, Chernigov, Zhitomir, Kiev, Chernigov, Zhitomir, Cherkassy Cherkassy
- 9. Other long term effects? Other long term effects? Can you find anymore long term effects Can you find anymore long term effects that the accident might have caused? that the accident might have caused? Either in humans, animals, or on just the Either in humans, animals, or on just the environment itself. There have been many environment itself. There have been many other sicknesses linked to the disaster, other sicknesses linked to the disaster, discuss some of the possibilities based on discuss some of the possibilities based on radiation poisoning. radiation poisoning.
- 10. Closure of the plant Closure of the plant The Chernobyl plant was closed on December The Chernobyl plant was closed on December 15 15th th , 2000. , 2000. More than 8,000 deaths have been blamed on More than 8,000 deaths have been blamed on the accident. the accident. The concrete tomb built to encase the exploded The concrete tomb built to encase the exploded reactor is leaking, threatening the world with reactor is leaking, threatening the world with another catastrophe. another catastrophe. Forty tons of radioactive dust has accumulated Forty tons of radioactive dust has accumulated inside, and some experts believe that it could inside, and some experts believe that it could lead to an even bigger explosion than the one lead to an even bigger explosion than the one that occurred before. that occurred before.
- 11. Three mile island Three mile island A nuclear power plant located near A nuclear power plant located near Harrisburg, Pennsylvania. Harrisburg, Pennsylvania. On March 27 On March 27th th , 1979 there was a near , 1979 there was a near meltdown. meltdown.
- 12. The near miss The near miss The plants main feed The plants main feed water pumps in the water pumps in the secondary non-nuclear secondary non-nuclear cooling system failed. cooling system failed. From that point there was From that point there was a series of events that a series of events that occurred from either a occurred from either a mechanical or electrical mechanical or electrical failure. failure. A large part of the core A large part of the core melted and the system melted and the system was highly radioactive. was highly radioactive. Over the next week the Over the next week the steam and hydrogen steam and hydrogen were removed from the were removed from the reactor using a reactor using a recombiner and, more recombiner and, more controversially, by venting controversially, by venting straight to the straight to the atmosphere atmosphere.
- 13. Clean up efforts Clean up efforts The reactor cleanup started in August The reactor cleanup started in August 1979 and officially ended in December 1979 and officially ended in December 1993 at a cost of around $975 million. 1993 at a cost of around $975 million. From 1985 to 1990 almost 100 tons of From 1985 to 1990 almost 100 tons of radioactive fuel were removed from the radioactive fuel were removed from the site. TMI-2 had been online only three site. TMI-2 had been online only three months. TMI-1 was restarted in 1985. months. TMI-1 was restarted in 1985.
- 14. What’s used? What’s used? See if you can find what radioactive See if you can find what radioactive materials nuclear power plants use in their materials nuclear power plants use in their processes. There maybe more than one processes. There maybe more than one correct answer. What radioactive material correct answer. What radioactive material was used at the Three Mile Island plant? was used at the Three Mile Island plant?
- 15. After the accident After the accident Approval ratings for nuclear power Approval ratings for nuclear power dropped from near 70% to about 50% with dropped from near 70% to about 50% with the accident. Write a paper on how you the accident. Write a paper on how you feel about nuclear power. feel about nuclear power. Give the pros and cons and make a strong Give the pros and cons and make a strong argument as to your opinion and why you argument as to your opinion and why you feel that way. feel that way.
- 16. South Texas Project South Texas Project Located 13 miles southwest of Bay City, Located 13 miles southwest of Bay City, Texas or 90 miles southwest of Houston. Texas or 90 miles southwest of Houston. The plant and surrounding areas are home The plant and surrounding areas are home to many wildlife species. to many wildlife species.
- 17. The plant itself The plant itself South Texas Project South Texas Project (STP) reactors went (STP) reactors went online in August 1988 online in August 1988 and June 1989. and June 1989. The plant contains two The plant contains two identical steam identical steam generating units. generating units. The permits for these The permits for these units expire in 2027 and units expire in 2027 and 2028. 2028. Located on 11,000 acres Located on 11,000 acres of land adjacent to the of land adjacent to the Colorado river Colorado river
- 18. More plant facts More plant facts Largest nuclear plant Largest nuclear plant in the U.S. in the U.S. Ownership of the Ownership of the units is divided units is divided between between Texas Genco Texas Genco (30.8%), San Antonio (30.8%), San Antonio City Public Service City Public Service Board (28.0%), Texas Board (28.0%), Texas Central Co. (25.2%) Central Co. (25.2%) and Austin Energy and Austin Energy (16.0%). (16.0%).
- 19. Find the location of the plant Find the location of the plant On the map where would this plant most On the map where would this plant most likely be located? Look at a Texas map likely be located? Look at a Texas map and guess where you think the plant is and guess where you think the plant is located. (Remember 90 miles southwest located. (Remember 90 miles southwest of Houston, 13 miles southwest of Bay of Houston, 13 miles southwest of Bay City, and 12 miles Northeast of Palacios). City, and 12 miles Northeast of Palacios). Use the map on the next slide to guess the Use the map on the next slide to guess the location of the plant. location of the plant.
- 21. If there was a meltdown If there was a meltdown Guesstimating that if Guesstimating that if there was a there was a meltdown, that it meltdown, that it would be of would be of equivalence to that in equivalence to that in Chernobyl, what Chernobyl, what surrounding areas surrounding areas would be effected? would be effected? Do you think that Do you think that since the power plant since the power plant is so close to the Gulf is so close to the Gulf of Mexico, that it of Mexico, that it would do more or less would do more or less damage to the damage to the environment than environment than when the Chernobyl when the Chernobyl accident happened? accident happened?
Editor's Notes
- #3: Inside the reactor of an atomic power plant, uranium atoms are split apart in a controlled chain reaction. In a chain reaction, particles released by the splitting of the atom go off and strike other uranium atoms splitting those. Those particles given off split still other atoms in a chain reaction. In nuclear power plants, control rods are used to keep the splitting regulated so it doesn't go too fast. If the reaction is not controlled, you could have an atomic bomb. But in atomic bombs, almost pure pieces of the element Uranium-235 or Plutonium, of a precise mass and shape, must be brought together and held together, with great force. These conditions are not present in a nuclear reactor. The reaction also creates radioactive material. This material could hurt people if released, so it is kept in a solid form. This chain reaction gives off heat energy. This heat energy is used to boil water in the core of the reactor. So, instead of burning a fuel, nuclear power plants use the chain reaction of atoms splitting to change the energy of atoms into heat energy. This water from around the nuclear core is sent to another section of the power plant. Here it heats another set of pipes filled with water to make steam. The steam in this second set of pipes powers a turbine to generate electricity. Pressurized Water Reactorss keep water under pressure so that it heats, but does not boil. Water from the reactor and the water in the steam generator that is turned into steam never mix. In this way, most of the radioactivity stays in the reactor area.
- #7: Area of a circle is (pi)r^2 So in this case (3.14)(20)^2 Or 1257 square miles was effected by the radiation cloud on the 26th of April.
- #9: Like mentioned before, there was increased cancer in many people surrounding the immediate plant disaster area. The ecosystem was damaged and is still recovering to this day. The radiation sickness becomes worse with prolonged exposure to the radiation. These have also been symptoms discovered as possible symptoms associated with radiation sickness Anxiety Depression Helplessness and despair leading to, social withdrawal and loss of hope for the future. Other disorders attributable to mental stress Ground water was contaminated and is still a problem today. The radiation was high enough surrounding the reactor area to kill most plants and animals.
- #14: Most nuclear power plants use Uranium-235 in their reactors. Some other radio active materials include, Plutonium-239, Xenon-133, Iodine-131. Uranium is considered the most stable in the process so it is used more widely than any other radioactive material. Uranium was used at the Three-mile Island plant.
- #19: The plant is located just south of Bay City on the Texas map. This is in very close proximity to the Gulf of Mexico. If Bay City is not on the map, then 90 miles or so south-southwest of Houston is where the plant is located.
- #21: Surrounding areas being effected would be, Bay City, Matagorda, Palacios, Sargent, Wharton, Lake Jackson, Angleton, as well as many other small towns. The effects of the disaster would have an impact on the metropolitan area of Houston as well. With the dense population in the area, a nuclear disaster could have very profound effects on the Texas coastline. The plant is located on the Colorado river which empties into the Gulf of Mexico just miles after the plant. A disaster would be devastating because of so many water sources that could be poisoned. The radiation cloud would most likely cover most of Texas and surrounding states, reaching into Mexico as well.