NorthWest Arkansas Community College
Melody Thomas, Instructor

Steven Thomas and
Zac Colvin

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http://www.youtube.com/watch?v=G1jtWR_tcX4

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4 RBMK reactors completed between 1970 and 1983
22 square kilometer artificial lake
115000-130000 people lived within a 30 km radius

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 Build up in steam bubbles (voids) lead to increase in temperature.
 Power builds to 100 times normal capacity

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 http://science.howstuffworks.com/nuclear-power1.htm
http://www.youtube.com/watch?v=G1jtWR_tcX4 https://www.britannica.com/EBchecked/topicart/421629/19492/Sequence-of-events-in-the-fission-of-auranium-nucleus http://www.world-nuclear.org/info/chernobyl/inf07.html
http://nuclearinfo.net/Nuclearpower/TheScienceOfNuclea rPower

 Before dawn on April 26, 1986, less than two miles south of what was then a city of 50,000, the Chernobyl Nuclear
Power Plant's number four reactor exploded.
Amy Daniels, Randi Walker, Erika Palos, Stormy Clary and Ashton Pepple

13:05 • Plant power decreasing, signifying the start of the reactor shutdown
14:00 • Emergency Core Cooling System disconnected, automated regulation system is shut off, power decreased to 30 mwt.
23:10
• Power reduction Resumed

1:00 • Increased power to 200mwt by withdrawing rods.
1:07
• Two additional recirculation pumpsrunning.
• Decreased void
• All but 6 rods withdrawn
• Emergency Protection signals blocked by operators.

1:19
• Increased feed water flow to stream drums
• Control room printout of core reactivity showed the excess reactivity required immediate shutdown- warning ignored and tests initiated.
1:22:30
• Feed water flow to stream drums decreased to very low value.
• 30 seconds later reactor inlet temperature begins to rise.

1:23:04 Turbine feed valves closed
1:23:04 Test was over
1:23:40
Emergency scram initiated by button.
Power went up
Operator saw rods moving on core map

1:23:43
• Power increasing rapidly due to positive void coefficient
1:23:48
• Explosion occurs followed by a second explosion a few seconds later.
• This explosion blew the 1,000 ton steel and cement filled biologic shield off the top of the reactor , destroying the roof and exposing the hot core to the atmosphere

1:28
All firemen arrived on the scene
2:00
The largest fires on the roof of the reactor hall were brought under control by a group of
Firefighters called in from Pripyat
5:00 Most of the fires were put out, but graphite fire had started,
Causing the dispersion of radionuclides high in the atmosphere.

 The immediate cause of the
Chernobyl accident was a mismanaged electrical-engineering experiment.
 Engineers with no knowledge of reactor physics were interested to see if they could draw electricity from the turbine generator of the
Number 4 reactor unit to run water pumps during an emergency when the turbine was no longer being driven by the reactor but was still spinning initially.

 The experiment was delayed due to an electrical demand. The experimenters tried to make up for lost time by lowering the power level rapidly.
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That mistake caused a rapid buildup of neutron-absorbing fission by products in the reactor core, which poisoned the reaction.
To compensate, the opera tors withdrew a majority of the e reactor’s control rods, but even with the rods withdrawn, they were unable to increase the power level

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This made the system increasingly unstable and led to the loss of more control rods.
They also bypassed most of the safety system which included the emergency core- cooling system. They disconnected the backup electrical system and the diesel generator.

This led to an explosion of reactor Number 4. The explosion was caused by a simple test of the emergency systems to be used in a power failure. Anyone who had any knowledge of nuclear technology would have known that the test program was inherently unsafe.

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Control rods had a design flaw that now proved deadly: their tips were made of graphite.
The graphite tip went in first, which rather than reduce the reaction, they increased it.
The control rods displaced water from the rod channels as well, increasing reactivity further.

The reactor had no sort of containment structure which was a huge design flaw.
If there would have been some sort of containment structure, like the ones in the United
States, then most likely none of the radioactivity would have escaped, and there would have been no injuries or deaths.

http://www.youtube.com/watch?v=9_Mj5IbXwW0&feature=youtu.be

 The radiation field held the strength for the 10 days that the Chernobyl fire continued, slowly falling off to near background levels by the end of three weeks .

Within a few weeks the radioactive effluents had both diffused and decay to undetectable levels. While the radiation field intensity eventually fell back to normal levels, exposure due to internally deposited radioactive effluents continued to provide a threat to the population.

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•Hyper Physics Chernobyl section, C.R. Navy, hosted by department of Physics and Astronomy of Georgia State University,
2005.
•D. Marples, “the Social Impact of the Chernobyl Disaster.”
London, 1988, pp. 12-19
•Glenn Alan Cheney, “Chernobyl: The Ongoing Story of the
World’s Deadliest Nuclear Disaster, “Macmillan, 128pp. New
York, 1993.
•A.P.Hill, “Dose Estimates from the Chernobyl Accident,” ANS
Transactions, Winter 1987.
•R.A. Schlenker, “Internally Deposited Fallout from the
Chernobyl Accident, “ANS Transactions, Winter 1987

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Stone, Richard. "THE LONG SHADOW OF
CHERNOBYL." National Geographic 209.4 (2006): 32.
MasterFILE Premier. EBSCO. Web. 28 Feb. 2011.
Images provided by Google.
•www.hc-sc.gc.ca/ewh-semt/occuptravail/radiation/dosim/res-centre/glossary-lexiqueeng.php
•http://www.pbs.org/wgbh/pages/frontline/shows/reacti on/readings/chernobyl.html

India Dujay, Katie Drake, and Mary Beth
Teufel

While the long term effects of Chernobyl have been devastating to many, the immediate aftermath was completely shocking to those who were immediately affected by the nuclear disaster twenty five years ago.

The mapping of radionuclides over 200,000 square kilometers of Europe, varied by rain and winds.

“This ground is permanently closed.”
A week after the explosion in Chernobyl, the city council closed all playgrounds after detecting nuclear radiation levels.

Prypyat, which had
45,000 residents was totally evacuated in the first three days after the incident.

A calf with clef lip born shortly after the disaster
Four of the 30 cattle that died in transport to Italy. The remainder were sent back to Poland after showing high levels of radiation.

Destruction of all fresh vegetables which arrived in Italy,
Saturday, May 3, 1986 for fear of radioactive contamination.
A row of boxes of fresh vegetables lies unsold at Milan's fruit and vegetables general market Saturday, May 03, 1986.

People emptying milk from the cartons in
Berlin, Saturday, May 11, 1986 to protest radioactive levels in milk and other food.
A cow inspecting a radioactive warning sign in Michelstadt, West Germany,
May 5, 1986.

“ An accident has taken place at the Chernobyl power station, and one of the reactors was damaged. Measures are being taken to eliminate the consequences of the accident. Those affected by it are being given assistance.
A government commission has been set up.”

Their initial reports of the incident were vague, and were only announced after officials in Sweden, 700 miles away, discovered sharp increases in radiation which appeared to be coming from the Soviet Union.

On the morning of the 28th, official at the Forsmark nuclear plant near Stockholm Sweden were alerted to alarmingly high levels of radiation at their facilities.

Mikail Gorbachev further exacerbated the matter by remaining silent for 18 days, choosing not to speak publicly until 3 weeks after the incident.

 The United States
 The Netherlands
 Austria
 West Germany

The first display of Glasnost, the Soviet campaign to forgo secrecy, came in the communist newspaper, Pravda, 10 days after the incident.

Chernobyl Glasnost opened the door for scrutiny of other social and domestic issues.

In September 1986, 600 delegates, including scientist and government officials from 62 nations, met at a conference sponsored by the International Atomic
Energy Agency to discuss the incident at Chernobyl.

The conference was not just about Chernobyl, but about the future of Nuclear power throughout the world.

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 http://www.unscear.org/unscear/en/chernobyl.html
http://www.world-nuclear.org/info/chernobyl/inf07.html
http://photos.denverpost.com/mediacenter/2011/03/a-look-at-chernobyl-the-worlds-worst-nuclear-accident/#34 www.greenfacts.org/chernobyl http://library.thinkquest.org/3426/data/local-effects/agriculture.effects.html
http://www.iaea.org/newscenter/focus/chernobyl/faqs.shtml
"Chernobyl Cover-up a Catalyst for ‘glasnost’ -World News - Europe - Chernobyl Disaster: 20 Years Later -
Msnbc.com." Msnbc.com - Breaking News, Science and Tech News, World News, US News, Local News- Msnbc.com.
24 Apr. 2006. Web. 16 Apr. 2011. <http://www.msnbc.msn.com/id/12403612/ns/world_news-europe/>.
Greenwald., John. "5/12/86 DEADLY MELTDOWN." Breaking News, Analysis, Politics, Blogs, News Photos, Video,
Tech Reviews -TIME.com. 1996. Web. 16 Apr. 2011.
<http://www.time.com/time/daily/chernobyl/860512.cover.html>.
Greenwald, John. "6/2/86 THE POLITICAL FALLOUT." Breaking News, Analysis, Politics, Blogs, News Photos, Video,
Tech Reviews -TIME.com. 1996. Web. 16 Apr. 2011.
<http://www.time.com/time/daily/chernobyl/860602.polfallout.html>.
Moody, John. "6/30/86 GORBACHEV LOOSENS THE MEDIA'S REINS." Breaking News, Analysis, Politics, Blogs,
News Photos, Video, Tech Reviews -TIME.com. Web. 16 Apr. 2011.
<http://www.time.com/time/daily/chernobyl/860630.sovpress.html>.
Serrill, Michael S. "9/8/86 ''WE ARE STILL NOT SATISFIED''" Breaking News, Analysis, Politics, Blogs, News Photos,
Video, Tech Reviews -TIME.com. 1996. Web. 16 Apr. 2011.
<http://www.time.com/time/daily/chernobyl/860908.convention.html>.

Celeste Raphael, Matt Dahlgren and Drew Short
• Health in Chernobyl
• The Worldwide effects
• Progress of the clean up
• Precautions with nuclear energy
• The pro’s and con’s of nuclear energy

 The Spread of Radiation
 Nordic Countries
 Europe
 The Rest of the World

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 Teams of Doctors Help Out
 No Government Support for Returnees

 Richard Balmforth Reuters 10:27 a.m. CDT, April 19, 2011 sns-rt-international-us-uktre73i10e-20110419
“KIEV (Reuters) -World powers, spurred by the nuclear crisis in Japan, on Tuesday pledged 550 million euros ($780 million) to help build a new containment shell at the site of the 1986 Chernobyl accident.”

 Melody Thomas, Physics and Human Affairs Instructor
NWACC Science and Mathematics/EMPACTS
 Dr. Art Hobson, Professor Emeritus, U of A Physics Dept.
Author: “Physics, Concepts and Connections.”
 C. Dianne Phillips, NWACC EAST/EMPACTS Facilitator