Nuclear Power PlantsNuclear Power Plants

Disasters and their possible Disasters and their possible meltdownsmeltdowns

A little about nuclear power plantsA 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.

Nuclear power plant diagramNuclear power plant diagram

ChernobylChernobyl

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.

ChernobylChernobyl On April 25On April 25thth-26-26thth, 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.

The radiation cloudThe 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 6had spread by May 6thth. .

Area of radiation cloudArea of radiation cloud

How much land was affected by the How much land was affected by the original radiation cloud on April 26original radiation cloud on April 26thth? ? 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?

Effects on the environmentEffects 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, CherkassyCherkassy

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.

Closure of the plantClosure of the plant The Chernobyl plant was closed on December The Chernobyl plant was closed on December

1515thth, 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.

Three mile islandThree mile island

A nuclear power plant located near A nuclear power plant located near Harrisburg, Pennsylvania. Harrisburg, Pennsylvania.

On March 27On March 27thth, 1979 there was a near , 1979 there was a near meltdown. meltdown.

The near missThe 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 atmosphereatmosphere.

Clean up effortsClean 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.

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?

After the accidentAfter 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.

South Texas ProjectSouth 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.

The plant itselfThe 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 riverColorado river

More plant factsMore 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%).

Find the location of the plantFind 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.

If there was a meltdownIf 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?