Tuesday, 26 June 2018

CHERNOBYL DISASTER. THE BACKGROUND STORY

3rd - 4th June 2018
The ex-Number 4 reactor under its shiny new steel carapace.

Chernobyl (or Чернобыль, or often transcribed as Chornobyl) is a small town about 80 miles north of Kiev situated in flat densely forested countryside near the river Pripyat, a tributary of the river Dnipro (Dneiper). There was a large nuclear power facility 5 miles to the north of the town next to the river.

Why go there? Well lets get the old joke out of the way "don't go there or Chernobyl fall off". I went, as many tourists do, out of curiosity.

A reminder of what happened. At 1.26am on 26th April 1986 the #4 reactor at the nuclear facility blew up. (lots of 6's there....666, the sign of the devil)
Four reactors were operating at the time with two more under construction and a further four planned. It was to be an enormous source of electric power. The Soviets had constructed a 'model town', Pripyat, about a couple of miles north of the facility, by the river, to house all the scientists, engineers, technicians and labour force, and their families, who worked at the site. It had a population of 48,000 and boasted facilities which were considered very luxurious by Soviet standards. An ideal situation for all concerned. The Soviet government insisted, to allay public concern, that these nuclear reactors were 100% safe. So safe, the Minister for Industry declared, that he would be happy to have one built on Red Square. So safe that it was considered unnecessary to issue any special (nuclear) emergency equipment or protective clothing to anyone in the area, including the local fire service based in the town of Chernobyl. Indeed, if they had issued such equipment it would imply that the facility was not 100% safe. Good Soviet logic.

On the evening of 25th April 1986, when the #4 reactor was being shut down for routine maintenance, it was decided to do some tests on the ability of the grid to power the reactor core cooling systems, and the emergency cooling system was shut off. This was not a good decision. Due in part to human error and in part to design flaws and not following procedures, this caused a power surge, a steam explosion followed by a full blown nuclear explosion. Oh dear! The reactor blew off its 500 tonne top and spewed tonnes of radio-active material over the surrounding area and a vast radio-active cloud which eventually covered most of Europe and Scandinavia. For two days the Soviets denied that there had been a serious incident....just a small fire which would be dealt with quickly. It was only when the nuclear cloud wafted over Sweden that their scientists alerted the world.

Strangely enough only one person was killed in the initial explosion. His remains were never found. Another technician died the next day in hospital from severe radiation burns. 28 firemen were deployed from Chernobyl to fight the fire and stop it spreading to the rest of the site. As mentioned, they had no special protective clothing or equipment and must have known the danger into which they were placing themselves. They succeeded in containing the blaze. Within a month all 28 had died of radiation poisoning. They were brave men. So, a total of 30 were acknowledged killed as a direct result of the explosion. 

In the follow up containment and clearance operation of the site it was estimated that about 600,000 personnel were involved, mostly military, working in very short (1 minute) periods at the reactor itself to clear away contaminated debris. There is no record of how many suffered or died as a result. The personnel involved in the clear-up operation were termed (in official guidese) as 'liquidators'; an unfortunate term I feel.

Its a strange thing, I have gathered, being exposed to severe nuclear radiation. It has unpredictable consequences. There is a factual account of a Japanese man working for the Mitsubishi company in Hiroshima in 1945. On his way to work he was caught in the open a mile from where the atomic bomb exploded. He was blown to the ground, knocked unconscious and suffered severe radiation burns. On regaining consciousness he managed to stagger home. He and his wife (unharmed) were thoughtfully evacuated to a family home in Nagasaki. Three days later, still very injured and ill, possibly while sipping a recuperative cup of tea in the garden, the second atomic bomb fell on Nagasaki. He was caught in the open again, resulting in further radiation injuries. What a bummer! 'Out of the frying pan into the fire' you might say. To cut a long story short, he recovered, went on to father two perfectly normal daughters and died of old age at 89. I am told it is all to do with the effect radiation has on your DNA and cells, and DNA can repair itself.
However, long term exposure to radiation does not, presumably, allow the DNA to regenerate. Or, perhaps, if you ingest radio-active material this will cause long term problems.
Another example; a young photo-journalist called Igor Costyn flew over the site in a helicopter on the morning of the explosion. It was still burning and spewing out radio-active gases. He got some great photos which were mostly wrecked by exposure to radiation. He, seemingly, totally unprotected, did not suffer any residual effects. He died in a car crash in his 70s. I do not profess to being very knowledgeable about nuclear radiation, but am much more so now than before this visit. I now know my Sieverts!

The residents of nearby Pripyat, mostly asleep at the time I presume, were not informed of anything (didn't they hear the bang?) until later that day when they were told there had been a fire at the site. Two days later they were told that the town was to be evacuated as a precaution, but only for a few days after which they would return. A thousand buses were assembled and the Pripyat folk were told to leave everything behind, including pets, other than overnight essentials. They would soon be back. They never returned. It is now a ghost town, of which much more later.

Interestingly, the other reactors went on working after the explosion. The power had to come from somewhere. The #3 reactor, which was next door, abutting the wrecked #4, was the last to be decommissioned and went on operating until the year 2000!

There is now a 30km outer exclusion zone, containing many long-deserted villages, around the site, with a stricter inner 10km one. Having said that, there are still about 2000 personnel working at the site carrying out decommissioning work and goodness knows what else. They have barrack-like accommodation in Chernobyl town.

Well, thats the background info folks, which should put my visit, and the following photos in the next blog, into context.

Left: The #4 reactor soon after the explosion. Numbers 1, 2, and 3 to the left of it.
Right: #4 reactor after the initial carapace was put over it. #3 to the left of it was still working until 2000.
More to come, I'm afraid, when I get around to it.


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