chernobyl tragedy
of 17
/17
CHERNOBYL TRAGEDY THE WORST NUCLEAR POWER ACCIDENT IN THE HISTORY.
Embed Size (px)
TRANSCRIPT
- 1. CHERNOBYL TRAGEDY THE WORST NUCLEAR POWER ACCIDENT IN THE HISTORY.
- 2. WHAT??
- On April 1986,reactor number 4of the Chernobyl plantexplodedreleasing plumes of highly radioactive fallout into the atmosphere and over an extensive geographical area.
- WorstNUCLEAR POWER plantdisaster everand the onlylevel 7instance on the INTERNATIONAL NUCLEAR EVENT SCALE.
- Fallout400 times than that had been in Hiroshima .
- Statistics reveal56 direct deaths , and about4000 extra cancer deathsamong about6,00,000 contaminated ones .
- Resulted inevacuation and resettlement of over 4 lakh people .
- With estimatedcost of 200 billion USD . It iscostliest tragedyin modern history.
- 3. WHERE??
- Chernobyl at the time of accident was under former USSR.
- Now its in Ukraine. Located to north of Kiev and near town of Pipriyat.
- Ukraine and Belarus were the most affected countries by the explosion.
- 4.
- Station had4 RBMK 1000 plant . With first one commissioned in 1977, and fourth in 1983.
- Each produced1 GW of electricitycontributed 10% of Ukraines power supply.
- Plants 5 & 6 were under construction.
- On April 26, 1986.Plant 4 was running at low power . As it neared its end of fuel cycle. Was to be shut down for maintenance.
- ATest was proposed to check performance of generator , which supplied when main power will be off. Called Power blackout experiment.
- Reactors design was unstable at low power , and operators werereckless about safety precautions.
- Animportant safety device was avoidedduring station building due to financial reasons. Plant worked2 years without it . Operatorsdesperateto carry out the test
- Experiment wasperformed at the most dangerous point in reactor cycle .
- 5. The REACTOR
- Uranium Rods: by fission produced 3200 MW thermal energy.
- Heat SteamRun Turbineelectricity.
- Control Rods. And Graphite rods. Moderate the reactn.
- Unusual accumulation of steam around Uranium rods may lead to uncontrollable fission.
- 6. Exactly What Happened
- Inexperienced crew.
- Blackout operation started.
- Reactor unstable below 700MW.
- Operator mistake or system failure lead reactor power suddenly drop to 30MW.
- Shocked crew took out whole control rod, violating safety procedures.
- Regained to 200MW. Manual taking over of cooling systems.
- Shut down warning systems to continue the test.
- Steam started forming near rods. Operators Unaware.
- 7. Exactly What Happened
- Operators continue test.
- Steam continue to build up inside reactor core. Increasing Power
- 700MW900 MW2000MW OUT OF CONTROL.
- Following safety shutdown procedure, control rods fully inserted.
- But graphite tips increased the fission. Power now 10000MW. 100 times more.
- BOOM, power lids blown off by steam from bottom of reactor.
- Air entered the core, mixed up with the reactants. IInd bigger explosion
- BOOM.
- 8. CRISIS
- Radiation level hit off to5000r per second.
- Theconditions were overlooked , operators and fire fighters continued to put off fire without any masks, not being aware.Many of them died within a week.
- To reduce emissions, the teambombarded the reactor with 5,000 metric tons of shielding materialconsisting of lead, boron, sand, and clay. It took 3 weeks.
- Emissions included Cs-17, I-131, Sr-90 and other radio nucleotides.
- Wind carried this to other geographic regions.
- 2 died and 52 hospitalized within 24 hours. High radioactive presence in air remains a concern.
- 9. CRISIS
- Chernobyl and Pipriyat were immediately evacuated.
- Evacuation of Belarus and other parts carried out in stages.
- About4 lakh peoplehad to be resettled.
- Estimated100 died within 3 months .
- Secretive USSR tried to cover up the facts, and show the world everything was normal.
- Chernobyl was completely sealed.
- 10. The SARCOPHAGUS
- Aconcrete containment buildingor a protective box called sarcophagus was placed over the wrecked reactor.
- This was toprevent the additional radioactive materials from escaping .
- 200 tones of radioactive material lie deep within it.
- The plant after isolating from the 4 threactor continued to work due to insufficient power generation.
- But by intervention of IAEA and G-7 countries,the plant was shut down by 2000 .
- However after this much years, the outside of sarcophagus is appearing to be degrading.
- Anew sarcophagusor NSCwill be installed around the reactor by 2011 , which will be thelargest movable structure ever built.
- 11. VICTIMS NOT SURVIVORS LIVING WITH THE RADIATIONS. One described.. experience of the radiation as"tasting like metal",andfeeling a sensation similar to pins and needles all over his face. At leastone type of cancerattributed to Chernobyl. Thyroid Cancer increasedfour foldsfrom 1986, with children the most affected.
- 12. AFTERMATH
- Evidence of leakage was first found by Sweden, and then so on. Lastly USSR had toadmit.
- Pipriyatriver badly affected . Pine forest covering the area turned brown and died. It was then calledRed Forest
- 20% farmlands of Belarus completely removed from production.
- MadeUSSR less secretive . Became more open society.
- Luckily thecontamination were not genetic and the next generation were not affected.
- Evacuated area: ahaven for wildlife . New species found due to absence of humans.
- 13. GHOST TOWN OF PIPRIYAT Boards showing signs of now extinct towns ANOTHER MEMORIAL
- 14. 20 YEARS HENCE
- 15. On Soviet
- Potentially unstable reactor design. + Incompetent operators + Irresponsible management .
- Resulted into that horrific explosion On that April night of 1986.
- A book by Gregory MedvedevThe truth about Chernobyltells aboutsecretive, authoritarianSoviet bureaucracy.
- Chose cheapness over safety. Promoted Incompetent personals.
- Soviets policy engineered the tragedy.
- 16. LAST WORDS
- GREAT POWER COMES WITH GREAT RESPONSIBILITIES.
- Power should be used for Human Development than Economic Development.
- Nuclear Energy although produces large amount of electricity, it is a high risk substance.
- Hence it should be dealt by highly responsible people.
- Judicious and specific use.