Chernobyl, Three Mile Island, and DavisBesse Nuclear Plants

1
Chernobyl, Three Mile Island, and Davis-Besse
Nuclear Plants

• A study of real and potential nuclear accidents

2
Nuclear Power Plants

• Chernobyl
• Three Mile Island
• Davis-Besse

3
Three Mile Island

• On the morning of March 28, 1979 a pressure
  valve malfunctioned at the Three Mile Island.
  What occurred was a combination of human error,
  technical failure, and bad luck which produced
  the worst nuclear accident in American history.
  For a year, the nuclear plant had been quietly
  generating electricity. The nuclear plant is
  located on the Susquehanna River. Just ten miles
  from Harrisburg and 100 miles from Philadelphia,
  Baltimore, and Washington, DC. The accident
  started at the plants Unit 2 reactor when a small
  valve failed to close, causing the cooling water
  to drain from the nuclear core. The core began
  to heat. Within minutes the operators control c
  board was lit up like a Christmas tree, one
  operator recalls. By Wednesday morning, March 28,
  the exposed part of the core was heated at 4,300
  degrees Fahrenheit. Just 700 degrees away from a
  meltdown. The operators still believed the core
  was safe and covered. Then contaminated water
  leaked into a joining building, releasing radio
  active gases inside the plant, forcing the
  operators to declare the first general emergency
  ever at a nuclear power plant in America.

4
Three Mile Island (continued)

• Word of the accident first came by radio. The
  message had just arrived days after the Hollywood
  movie came out called The China Syndrome. The
  China Syndrome is about a nuclear plant which
  threatens an area the size of Pennsylvania. A
  Meltdown is the worst possible nuclear accident.
  It is called the China Syndrome. After the
  information was released, 500,000 people faced a
  decision, leave or stay. More than 140,000 people
  would leave. Three days after the beginning of
  the disaster a new threat appeared. A hydrogen
  bubble had appeared at the top of the reactor
  core. Scientist argued all weekend on whether the
  bubble would explode at any moment. A few hours
  later President Jimmy Carter arrived. The crowds
  cheered as he arrived, because he was with
  them. Carters visit was the end of the
  disaster. Three years after the crisis they sent
  a robotic camera down to the Unit 2 core, showing
  the first look at what happened. We had a
  meltdown at Three Mile Island. Fifty percent of
  the core was destroyed or molten and something on
  the order of twenty tons of uranium found its way
  to the bottom head of the pressure vessel. Thats
  a core meltdown. No question about it. says a
  senior NRC engineer.

5
Chernobyl

• Chernobyl was the worst nuclear accident in
  worlds history. Traces of radiation were found
  all over the world. At the time of the accident
  the wind was blowing to east and twelve days
  after the disaster there were traces of the
  radiation on the east coast of America. On April
  27, 1986 at 200 pm radiation levels rose at the
  Swedish National Defense Research Institute in
  Stockholm. There were only two possible reasons
  for the increase in radiation and neither were
  good news. The first possible explanation was
  that there had been a nuclear accident or leakage
  from a plant or a fallout of a nuclear weapon.
  Meanwhile at Chernobyl men were trying subdue the
  fire of Chernobyls reactor. What had happened
  was reactor workers were heading an operation in
  which there was a technical flaw. At 123
  operators started to notice there situation had
  become hazardous. So a worker pressed a button to
  slow down the reactor but what happened next he
  did not expect. What intended to slow it down,
  within seconds had sped it up by 100 times. A
  series of explosions had then made the reactor to
  burn out radio active material into the air. As I
  said within twelve days radiation was twelve
  miles high and had gone almost all the way around
  the world.

6
Davis -Besse

• The possible accident of the Davis - Besse
  nuclear could have has sever as Chernobyl. What
  had happened was the cover of the reactor started
  to rust. Boric acid and rust ate away at the top.
  The operators saw the pictures of the lid and
  ignored it. There production goals clouded there
  vision and made it unsafe for it to operate.
  Scientist say within one year there could be a
  huge accident. Later when regulators searched the
  building they found the pictures of the rusted
  lid.

7
The China Syndrome

• The China Syndrome is the worst possible event
  that could happen at a nuclear plant. The nuclear
  fuel heats to 5,OO0 degrees Fahrenheit. The fuel
  melts through the cement bottom of the nuclear
  plant and bores through the earth. The white-hot
  core does not go to China, but stops at the water
  table underlying the planet. In a violent
  reaction with molten core and cold water
  combined, creating a steam explosion which can
  reach the containment of a thousand times of the
  Hiroshima A- bomb. It contained only 20 pounds
  of radioactive material but, more enriched. The
  China Syndrome can destroy a entire regions
  supple of water and kill many people, animals,
  and can infect many plants.

8
Nuclear vs. Other Power sources

• Nuclear power is a very clean resource until
  there is an accident. But once there is it is the
  most dangerous of all.On the other hand coal and
  fossil fuels arent great either. It pollutes the
  earth and the atmosphere. It is a non reusable
  recourse meaning it cannot be recreated. But
  there are a couple of energy sources that are
  reusable, safe, and does not hurt the earth in
  any way. These energy sources are solar and hydro
  powers. People say we cannot use them because
  they are not advanced enough. They also say they
  are spending money to clean there plants power
  up. If we could take that money and use it to
  research the power sources that are good for the
  earth then we could quickly be able to use solar
  power.