Chernobyl

@@by 6:30 am

1986

• other 3 reactors are shut down
• most fires are extinguished
• core of reactor 4 remains burning

after 4/28

1986

• about 530,000- 600,000 recovery workers would work on the Chernobyl site
• Drained 20,000 tons of radioactive water from underneath the core, buried contaminated topsoil, killed what they believed were contaminated pets/livestock
• The explosion resulted in the death of 2 workers -28 firemen/workers died 3 months after the explosion from acute radiation sickness

@@1:28 am

1986

• firefighters arrive
• no knowledge of the radiation, no protective clothing
• begin putting fires out and moving debris not knowing they're radioactive

@1:23 am

1986

• test officially begins -sudden surge of power
• emergency shutoff button is pushed which releases all control rods into the core to slow rate of nuclear reactions
• control rods jam
• exposes design flaw: control rods made of boron which reduces activity but have graphite tips which increases reaction rate
• big surge in reactivity

@1:24 am

1986

• output of reactor is 10x the power it should be
• explosion at reactor 4
• smaller 2nd explosion followed
• reactors lid (10,000 tons) is blown off/ goes through the roof
• bits of radioactive material and fuel are sent everywhere
• dozens of fires break out
• air is filled with dust, radioactive material is flung far distances; radiation filling the atmosphere

@@2:14 am

1986

• local officials arrive on scene
• miscommunication/misinformation due to confusion and Chernobyl workers unable to communicate bc of acute radiation effects and injuries (vomiting, burned, ect.)
• police officers are ordered to put up roadblocks to stop traffic coming in and out of Pripyat, a nearby city

@12:30 am

1986

• night shift arrives (less personnel/less experience)
• power of reactor falls below normal limits
• operators remove majority of control rods (which absorb neutrons, preventing further fissions) to raise power

@intro

1986

• nuclear power plant supplying power since 1977
• located in modern day Ukraine
• 1986: test too see if during a power failure the still spinning turbines could produce enough energy to keep the coolant pumps running

@day before

Apr 25, 1986

• operators reduce power
• emergency core cooling system disabled so it wont interfere with the test
• test delayed due to power outage in nearby town

@@2pm 4/27

Apr 27, 1986

• Nearby residents not informed of accident begin to get sick
• officials begin evacuations 36 hours after accident
• about 115,000 are evacuated from Pripyat and other nearby towns
• residents told it was a temporary evacuations

@@10 am 4/27

Apr 27, 1986

• Committee led by Valery Legasov is formed
• Main focus was to put out core fire as radiation will be carried by the wind to far distances
• helicopters start dumping clay, boron, lead, etc into the fire to slow/stop radioactive emissions

@@4/28

Apr 28, 1986

• Officials try to keep situation out of public/international view
• Sweden detects large amounts of radiation in atmosphere via air monitors traced to Chernobyl
• News spreads fast and internationaly
• later that evening news officially breaks on Russian TV. State the situation is under control

-study

1987

One study states average effective doses:
- 120 mSv for 530,000 recovery operation workers
- 30 mSv for 115,000 evacuated persons Its estimated that Chernobyl workers received doses of appoximately 0.8 - 16 Gy and that the 530,000 recovery workes may have receive between 0.02 Gy and 0.5 Gy between 1986-1990

-later

1987

• Victims were buried in zinc or concreate coffins bc it was believed that their bodies were radioactive
• In 2006 WHO estimated that 9,000 cancer deaths where due to Chernobyl
• approximately 346,00 people were relocated from Pripyat and other surrounding areas
• Some scientists estimate that the area around Chernobyl will be habitable in 20,000 years
• There were at least 1800 documented cases of thyroid cancer in children who were 0-14 years old at the time of the accident