Why Chernobyl disaster happened?

There was a safety drill at the plant. It supposed to be done at day time when more senior engineers are present at duty time. But it was postponed to night when the electricity demand from the plant is the lowest. But at that time only junior engineers are present at No4 reactor.
Is the accident was operator flaw or reactor design.

Uranium rods are used to produce heat in the reactor core. Control rods are inserted to regulate the amount of energy produced by uranium. As water pass over the reactor core it turned into steam. Just like conventional power plants, the steam turns turbine and turbine powers generator. It produces electricity. Chernobyl runs on the very electricity that it produces. That’s why the safety test was run on night so that if something failed should not affect Chernobyl’s electronic industry.

1hr 90 minutes before the explosion:
Reactor is powered down. But power level dropped too much too soon.

52 minutes before the blast:
Operator has to raise power level. He did it by taking out control rods. It worked, power levels are back.

21 minutes:
Another operator starts the safety drill by altering the water flow around the reactor core. The idea is the main pump which ideally runs the water flow will be stopped during the simulated power failure. There is a backup. So by this operator can make sure there is an alternative water supply. For that he uses 2 auxiliary pumps which divert extra water from the other parts of the power station to reactor 4. When he turns on the extra pumps he allowed too much water to the reactor core in too fast.

The rate of the water flow over the reactor is crucial. Because the faster the flow of water the lesser the steam is produced by the reactor.

After 15 minutes of pumping extra water into the system, there is not enough steam to keep the turbine running.

5 minutes:
Operator know that he has to increase the flow of steam to the turbine. He decided to pumping water into steam drum. The steam drum is the central chamber where both steam and water level kept in checked. But the operator allowed too much cold water into the drum. So the excess water enters into the reactor core. And now too little steam is produced.

The test is not started yet. So this is the situation before the test.

To increase the flow of steam first operator decided to reduce number of control rods in the core. The operating guideline specifies a minimum of 26 control rods. The operator removed all the rods except 6.

But at this critical stage the night shift continues the test.

With less control rods the only thing that keeps from over heating the reactor the flow of water. The smallest drop in water level is critical. There was no communication between the 2 operators.

3 minutes:
Second operator realized that too much water is flowing to the steam drum. He cuts the excess flow. But it also affected the water flow to the over heated reactor core. He has no idea that the first operator removed all the control rods expect 6.

1.5 minutes:
Without enough control rods to keep the temperature in checked, the reactor core seriously over heated.

56 seconds before the blast:
The turbine operator gets the order to do the safety test. He shuts down the turbine. Suddenly the dials in control room showed energy level of the reactor souring dangerously high.

Now there is no time left. The fuel rods ruptured because of the extreme heat. The blast generates a huge force of pressure against the reactor’s 2000 ton lid. 8 tons of highly radioactive debris explodes. Investigators calculated that it shoot 1km above the sky.

The explosion is less dangerous. The much bigger crisis is there compared to other industrial disasters. Radioactivity. Radioactivity not just spread through air. The reactor core can melt into the water table underneath. It will contaminate drinking water. So they have to place a missive concrete slab underneath. There is a 200 tons of radioactive lava remains inside the reactor wreckage.

They decided to place huge concrete tomb around the entire reactor. The radiation from the debris is causing lethal doses of radiation into the air. The debris must be cleared away. Its a job to the army. The soldier are ordered to shovel the radioactive debris back to the destroyed core. Solider did this task wearing a lead clothing weighing 30 kg. Each man is allowed to work for 3 minutes. But it is long enough to receive a life time of radiation. Many thousands will die as a consequence of this.

Construction of shelter continues with the cleanup operation. In a fight against time, it completed in 206 days.

Cause Systemic poor management.

Access is restricted 30 km of no-man’s land around the reactor.
Ukrainian govt calculates that around 8000 people died because of the explosion. Thyroid cancer in children and teenagers increased 100 times.

Today 200 tons of uranium and a ton of deadly plutonium remains inside the destroyed reactor. In 1997 a group of 28 nations to fund a work on a 10 year plan for a long time solution to Chernobyl. A 20,000 steel arch will completely enclose the reactor 4.

– from Seconds From Disaster by National Geographic Channel

The work that started in 1997 till now did not completed, just like new nuclear plant construction. An estimate done on 2006 says that its costs $1.2 billion dollars.

Do you want this kind of dangerous technology just to boil water. I think its not. There are plenty of other solutions available. Some we know for more than 2000 years. Remember Archimedes used solar power to burn Roman ships. Why we missing the point?

Stop Jaitapur nuclear power plant project in Ratnagiri

Don’t Buy the Big Nuclear Lie

Don’t Pay for a Mistake

Nuclear power – just about the most ridiculous, dangerous, costly and wasteful way to boil water* ever undertaken.

* There may be a confusion when we say nuclear power plant. “Keep Uranium on clay dish, then connect 2 electrodes, now electricity will flow through the electrodes”. Mainstream media in India is selling this kind of thoughts. Actually its not like that. Atomic reaction will release intense amount of energy in the form of gamma rays, ultraviolet, infrared, x rays etc. In these only infrared, which is heat, is used in power plant to boil water. Boiled water releases steam. That steam is used in turbine to convert its pressure energy to electricity as the same way as coal based thermal power plant. But in nuclear plant things are costly and dangerous.