Ryan Evans

1
High Integrity Systems Nuclear Power Plant

• Ryan Evans Nick Shepherd

2
How a Power Plant works
Uranium is the principle element used in nuclear
reactors
Nuclear fission is the process of splitting atoms.
The free neutrons can be captured by other atoms
such as boron, which can be used to control the
reactions.
E mc2
3
The Power plant
4
Events Leading Up To The Accident

• 25th April 1986 experiment
• Requirements for test
• Backup generator takes 40 seconds to work
  effectively
• Turbines used between power failure and backup
  generators working
• Test to take place at 20 - 30

5

• Problem 1 Too many control rods raised power
  output dropped to 7

6

• Problem 2 Automatic shutdown disabled more
  rods pulled out beyond safe limit

7

• Problem 3 Test started below the minimum level

8

• Problem 4 Emergency procedure short circuited by
  operators

9
(No Transcript)
10
Statistics

• Between 600,000 and 1 Million liquidators
• Reached Level 7 on International Nuclear Events
  Scale
• Still feel the effects of the disaster in 100,000
  years time
• Unofficially 60,000 of liquidators have died
  either from Acute Radiation Poisoning or other
  related illness
• Between 10 and 50 tons of nuclear fuel
  unaccounted for

11
Level 2 Conditions

• Operators under extra pressure because tests were
  planned prior to routine maintenance. If the
  testing was not completed now, then it would have
  to be done in a years time.
• Of all of the RBMK plants, the Chernobyl was run
  the best, and the crew knew it, they became
  overconfident.
• Test was perceived as an electrical test and had
  been conducted uneventfully before. Thus the
  operators did not think carefully when performing
  tasks upon the reactor.
• Positive Coefficient of the Reactor makes it very
  difficult to control, safety being dependent on
  control.
• Used RBMK instead of PWR.

12
Level Three Conditions

• Much debate including
• Flawed Operators Theory
• Flawed Design Theory

13
Extensions and Additions

• Adding a roof to cover the sarcophagus. A French
  company building a stadium-like building that
  will house the whole of the former reactor 4
  building.
• 300 liquidators and 600,000 further employed.
  Real figures need to be guessed at because of the
  Soviets
• Soviets built RBMK plants instead of the safer
  PWR design, they built the RBMK because they
  decided they would produce Plutonium and
  electricity from a single reactor, rather than in
  two separate reactors like the PWR. They also
  didnt have the funding that most countries that
  use the PWR system.

14
Preventions

• Better training for all employees
• (general nuclear physics knowledge)
• Better control of safety protocols
• Make it so they cant be disabled / short
  circuited
• More respect for equipment and technology
• The disaster at Chernobyl released 300 times more
  radioactive pollution than Hiroshima

15
Further Reading

• http//news.bbc.co.uk/1/hi/in_depth/europe/2006/ch
  ernobyl/default.stm
• http//en.wikipedia.org/wiki/Chernobyl_disaster
• Google Video
• BBC Horizon Nuclear Nightmares