THIRTY YEAR ANNIVERSARY OF CHERNOBYL
There were four reactors at Chernobyl. In 1982
reactor #1 had a meltdown but was fixed. In 1986 reactor #4 exploded in “The
Chernobyl Disaster” and was permanently shut down. In 1991 reactor #2 caught
fire, the roof collapsed and it was permanently shut down. In 1996 reactor #1 was permanently shut down. In the year 2000
reactor #3 was permanently shut down. The government of Ukraine hopes to have
cleanup of the site finished by the year 2065...
What happened on April 26, 1986...
A safety inspector at the Kursk Nuclear Reactor wrote
a report entitled “The accident in Block 4 of the Chernobyl power station and
nuclear safety in RBMK type reactors” which blamed the Chernobyl explosion on
design flaws. This was very brave-to speak the truth in the USSR! Even today it
is thought that DESIGN flaws created an atmosphere in which Chernobyl exploded.
It wasn’t lazy human operators.
In fact the human operators were trying to test the
speed at which reactor could heat up/cool down to set up a safety system which
would solve a glaring problem with the reactor. You, cold water is flowed over
the reactor to cool it down. If the water flows too fast it doesn’t soak up
enough heat, which causes the reactor to overheat and turn all the water into
steam which blows up the reactor. If you flow the water too slowly the water
gets too hot, turns into steam and blows up the reactor. If the water is at the
wrong flow rate for somewhere around 435-60 seconds it’ll vaporize and blow up
the reactor. Great: just set the water flow rate at the proper speed, right?
Well, here’s the problem: the water pump runs on
electricity so if there is a problem with the reactor you can’t run the water
pump…KABOOM! So the geniuses (not sarcastic) at Chernobyl set up a
generator/water pump that ran on diesel fuel. The reactor has a problem: the
diesel generators/fuel pump would kick in and keep the water flowing/flowing at
the proper rate so the reactor wouldn’t completely explode. If there was a
total loss of power and the control rods were all sent down and all the main
reactor nuclear interactions were stopped there would still be a 7% output of heat for a time. Now, that doesn’t sound
like much, but the reactor took 7,400 gallons per hour of cooling water. So you
think, okay you’d only have to pump around 500 gallons of water per hour and be
okay? Not quite since any voids in the cooling channels allow the water to turn
to steam and blow up the reactor. Also, that would be too slow a flow rate and
the water would heat up way faster than normal and explode.
So no matter what you want the water to keep flowing
at its normal rate through the reactor. Thus, they put in the emergency diesel
generators to keep the water flowing. The problem? The diesel generator takes a full
60 seconds to kick in and start the water pumps. For TWO YEARS the people at
Chernobyl operated the reactor knowing that any slight problem and they would have
no backup! Amazingly, almost three decades later the Fukushima reactor had a
similar problem: they too had diesel generators/water pumps...but there was an
earthquake and a tidal wave washed away their diesel generators. KABOOM!
So, the Chernobyl scientists decided that it was time
fix this problem. They came up with a really neat solution that was similar to
regenerative braking systems in hybrid cars. When the reactor lost enough power
it would begin the 60 second start up process of the diesel backup generators.
In the meantime the steam engines powered by the reactor would turn slower and
slower as they ground to a halt BUT they would
still be spinning, and it was theorized that these steam engines would still
produce a lot of energy as they spun slower and slower-enough to power the
water system/generators for around 35 seconds. So, instead of having the
reactor un-cooled for 60 seconds it’d be more like 25 seconds or less. Really a
super simple and super neat idea!
Like good scientists they wanted to know their
baselines: how long did it take for the reactor to lose enough power that the
water flow would be affected? What was the exact power output of the steam
turbines as they lost energy and moved slower and slower, but were still
producing energy that could be tapped like regenerative brake systems?
Basically that wanted to test all the components of their system for: how hot?
How much energy? How quick? They tested this dying steam engine theory twice
before and failed, but they made changes and were going for a third test.
The idea was to run the reactor (but at a reduced
rate of power) and shut off the water (steam) flow to the steam engines. The
water would flow over the reactor and cool it like normal. It would get hot and
turn to steam like normal. Instead of then going to turn the steam engine to
produce electricity it would be piped off elsewhere. This would allow the
scientists to see just how long it would take for the steam engine to slow down
after losing steam. This would also let them see how much energy the steam
engine would still produce as it was slowing down-and thus if it was enough to
power up the emergency systems for at least part of the 60 second delay until
the diesel generators were going full blast.
They reduced the power of the reactor and something
horrible happened. Normally when the reactor is running it produces Xenon.
Xenon slows down the reactor, but because the reactor is running at full power
it burns the Xenon-135 and turns it into Iodine. Great, but at the reduced
power during the test the reactor wasn’t making enough power to burn up the
Xenon. More and more Xenon kept accumulating in the core which kept slowing the
reactor down more and more. Suddenly, the scenario of “what if we lose power
and can’t keep the water cooling pumps running” became a real situation!
At that same time an engineer accidentally inserted
some control rods too far. As the reactor was slowing down from too much Xenon,
he slowed it down even more by hitting the brakes (inserting the control rods).
In a reactor there are many control rods. These rods “soak
up” excess radioactivity and slow down the reaction. Pull the rods up and you
get more radioactivity, heat, steam and electricity. Push the rods down inside
the reactor and they slow down/shut off the reactor. They’re like the brakes in
a normal (non-hybrid) automobile: press soft to slow down, press harder to slow
faster, press really hard to stop.
At this time the flow rate of the coolant was
erratic. The steam pressure and flow were not normal because they were
bypassing the steam engine for the test. Everything was going crazy. Luckily
they reversed course and took out some fuel rods. This let the reactor start
producing more (stable) energy. They dodged a big bullet. So what did they do
know? They kept fiddling with the reactor so they could get to their experiment!
They turned on a few extra water pumps. This immediately
dropped the water pressure of the coolant and everything started overheating
because even though more water pumps
were on the water pressure was split among them and dropped creating voids and
thus premature steam and heat. While it is true that this design is called a "boiling reactor" if it runs at less than 20% power the bubbles in the water become a problem because the effect of the high temperature that reduced neutron flux goes away. The reactor becomes unstable and can experience uncontrollable power surges. No problem, just increase the flow rate! They
did and the reactor got too much flow and lost power again. So they decided to
take out even more control rods to increase the reactor power again! Out of 211
rods they removed 193. In this reactor, even during full loss of power they
were supposed to remove at most 183
rods. Clearly it was a touchy situation. They were veering from too much steam
to too much power to too little power to run the cooling systems. What should
they do? Why, they decided that now
was the perfect time to finally START THEIR EXPERIMENT!
They shut down the steam engine. This cut off energy
to the water flow. The steam engine kept spinning slower and slower, so during
their experiment the water flow became slower and slower and this lead to
overheating. They turned on the diesel generators. It was estimated that in 39
seconds the diesel generators would be fully running.
The beginning of the end...
Sadly, at 36 seconds someone
(not the automatic systems but a human) hit a special button. In the literature
this is called the EPS-5/AZ-5 button. There are photos of this button online.
It does something that sounds really good and safe: it inserts all the control
rods and slows the reactor down. The problem? Almost all the control rods were
taken out, so they all started dropping into the extremely overheated water in
the reactor. Sounds good no? The control rods were made of a moderator called
Boron. Check my previous posts and/or click on the keyword “Boron” to see the
cool uses I’ve had it for in my own experiments.
However, these control rods were tipped with
graphite. When all of these graphite tips hit the coolant water at the same
time a weird thing happened. They displaced the cooling water by a smidge. The 193
graphite rod ends pushing out desperately needed coolant water was enough to
allow a HUGE rise in core temperature and the coolant water flashed over to
steam. This shattered a bunch of the control rods! Then everything got worse
and the people who were there are mostly dead, but the main thing is the
reactor exploded.
It reminds me of when people overheat water in a
microwave: if you use a smooth coffee mug you can actually overheat the water
and when you stick you a stirring spoon into the water it literally explodes
and showers you with hot water! People have been seriously injured this way.
Too cool too fast actually overheated things.
The structure of Chernobyl reactor #4 was mounted to
the underside of a steel plate that weighed 4 million pounds. Yes! FOUR MILLION
POUNDS! What happened to this top plate? It went flying through the roof of the
reactor and into the sky.
Then what happened? Another explosion
that was even worse!!! This sent
hunks of molten core pieces flying around onto the roofs of surrounding
buildings. The roofs of the surrounding buildings were water-proofed using
bitumen which promptly burst into flames. The roof of reactor #3 (which was
still running) also caught fire and was threatening to explode. What is bitumen?
It’s basically asphalt, which is kind of like coal mixed with gasoline;
although to be fair it is relatively
non-flammable. Still though: why not metal roofing? Heck, why not concrete?
The Nuclear Energy Agency put out a great report that includes an in depth explanation of each step of the accident. It's title is, "CHERNOBYL: Assessment of Radiological and Health Impacts. Update of Chernobyl: Ten Years On" which is available free online as a
PDF.
Soviet Design: the bitumen roofs were
prohibited by the buildings codes and never should have been there in the first
place. The whole reactor should have been in a containment building, but it was
in a shoddy Soviet building with bitumen smeared roofs.
The graphite tips of the control rods?
They caused a huge spike when used at a different reactor nearly 3 years
earlier! Graphite was also used as a lining inside the core. Much is made of
this graphite igniting when it was thrown into the air during the explosions.
It’s simple: the graphite was red hot in the water-filled core. The core
exploded and the red hot graphite flew onto the bitumen covered roofs of the
nearby buildings. Red hot and no longer covered with water and now exposed to
the air they simply caught fire. It was this fire which gathered up the
radioactive materials and put it into the air, spreading it all over the world.
Much like volcanic ash.
Button EPS-5/AZ-5: there are two
scenarios that play out with the safety button that dropped all the control
rods. One says that everything was fine and mellow and they decided to shut
down the reactor after all the craziness of the moments before. The other says
that things got even worse and someone hit the safety button. Either way it
made things worse.
The reactor was a type RBMK. This type of reactor was
refused a patent in the Soviet Union
because of design flaws when it was proposed in 1967! Victor Bobrv who was
acting Head of State Laboratory Registry of Inventions has stated that he sent
back the first application for a the RBMK to be registered…but then a month later
in the Soviet run newspaper Pravda it was announced that the problem of nuclear
reactor design efficiency had been solved. Then from 1971 to 1975 the RBMK type
reactor made up two-thirds of the Soviet planned nuclear capacity. Alla
Yaroshinkskaya wrote a book titled “Chernobyl: The Forbidden Truth” which
delves into this briefly.
The design was around 30% efficient and there were
other problems: it used graphite and regular water (instead of heavy water) to
control runaway nuclear reactions. Regular water turns to steam and thus you
lose part of your moderation. A cheap but difficult way to run a reactor if
things go wrong and you get too much steam. Steam creates a void. The void is
empty and doesn’t help slow the nuclear reaction: leading to more heat and more
steam leading to more nuclear reactions, and on and on until it explodes.
Alla Yaroshinkskaya’s book titled “Chernobyl: The Forbidden
Truth” centers more on what was happening at the time: the people, the
scientists, the propaganda, town hall meetings that grew heated, etc. It’s a
bit hard to follow the book in parts, but I suppose that in itself reflects the
mood at the time (and for years afterwards). She even lists some of the previously secret documents uncovered after the fall of the Soviet Union.
The cover up is worse than the crime!
Although I don’t
consider what the operators did foolish or criminal-the cover up which started
that very day of what happened and what the dangers to the public from
radioactivity were!
After reactor #4 exploded the roof of reactor #3
caught fire. The staff wanted to shut down #3 and get to safety but were told
to keep working like nothing had happened. After about three and a half hours
they couldn’t take it, disobeyed orders and shut down #3. Most of the #3
workers then were able to leave, some stayed behind to control the shut down
and cooling off of their still intact reactor. Stay in a burning building
surrounded by the worst release of radioactivity in human history. An American
would say, “I’d get another job!” but in the old Soviet Ukraine “the job gets
you!” The local government office would assign you a job. They would allocate
your food allowance.
If people are getting sick or dying as a result of
radiation levels rising past the ‘safe’ background level-just raise what is
considered the ‘safe’ background level! In a classified communication (Secret Protocol
#9, May 8th, 1986) the Ministry of Health of the USSR changed the acceptable minimum radiation
levels. It said, “…in certain cases these levels can e multiplied by 50…” If
people are dying in a flood because the water has risen 25 feet above flood
surge, just recalculate ground level to minus 25 feet: then there is no flood
and nobody has died because of it.
Because the Soviet Union was so poor and because they
didn’t evacuate most of the people who should have been evacuated: the farmers
near Chernobyl / Kiev kept farming! The Soviet Minister of Health put out
another order (Secret Appendix to paragraph 10 of Protocol #32 August 22nd,
1986) which decided that they would USE THE RADIOACTIVE FOOD produced near
Chernobyl but “distribute the contaminated meat as widely as possible
throughout the USSR.”
A Soviet man came up with a name for this trading of
bad food for good: “Equilization”. The people forced to live in the radioactive
area would be given clean food, their bad food would be shipped all over the
rest of the USSR and given to normal people (without their knowledge). This would
spread out the radiation all over. Soviet thinking: if everyone is just a little sick-then nobody is sick and
everyone is healthy. If all the contaminated food is spread out, then less people would get sick from eating smaller portions of it...or something like that. I re-read it over and over and couldn't figure out why they'd feed poison to their own people.
Why would the people stand for this? It was a secret. Also, it was the Soviet Union. You couldn’t just go out and
buy un-irradiated food. Go out? “Let’s see your travel papers comrade!” Buy
some food? “Let’s see your voucher for food allowance of this particular item….sorry,
but: DENIED COMRADE!” Go eat some glowing potatoes.
Also, the government set
production targets for food growth. Remember, the Soviet government owns
everything-even the food you produce is theirs. They didn’t lower the farm
production targets in affected areas. In one instance they actually increased the target of blood donations…from
people living in an irradiated area!
The Deputy Prosecutor General of the Soviet Union,
Victor Andreyev stated that between “-89 47,500 tonnes of meat and 2 million tones
of milk over the permitted level of pollution were produced…a large part of
these products were sent out of the contaminated zones of Ukraine, Byelorussia
and Russia…” and consumed by other Soviet citizens. Other officials are on
record as having allowed contaminated products to be consumed.
The Socialist government did try to help. They built
brand new houses for the workers at the other reactors at Chernobyl to live in…right
near the old radioactive ones. Right in the still to this day radioactive part
of town! Soldiers came and killed everyone’s pet cats and dogs and pulled up
the floorboards of some houses and carried away the dirt that was under the
floorboards. They built a new school building in the death zone and then later
came back and dug up a few inches of the soil around the outside of it and carried
the dirt away. They collected the radioactive food still being farmed there and
gave it to unknowing victims all over the Soviet Union to ‘equalize’ the
radiation. Of course there was rumor early on that the radioactive food should
come nowhere near Moscow.
There were three sets of information in those times:
the lies given to the people, the half-truths given to Socialist ally countries
directly affected by the radiation plume, and finally the truth! The “truth”
was that tests were being done on
thousands of people, but the results of those tests were never shared with the
patients, or their doctors. The lab sent them straight to Moscow, who then
churned out feel good, happy stories. One in particular was about birds singing
in the night air above Pripyat (the town north of Chernobyl). While radioactive
garbage was raining down from the sky the Soviet government decided to go ahead
with the Soviet May Day Parades! All those people exposed with no knowledge!
Cesium in the form of radioactive iodine has a half life of 8 days. Take iodine pills for 8 days and you don’t
die of thyroid cancer. Did they do that? No, they held a parade on day 6! Keep
in mind that the radiation reached Norway after passing through these people
first. To be fair, one communiqué relates the desire to shorten the festivities
from 4 to 2 hours. And that was just the Cesium! It has been said that the
reactor belched out, “the entire Periodic Table!”
Western nations sent experts in. The experts went
home and said everything was terrible; but the Soviet controlled newspapers and
TV said, “the visiting experts say everything is great. Don’t worry-be happy!”
The mere presence of honest experts from the west provided a photo-op that was
used to disseminate lies. Look up ‘useful idiot’ in relation to propaganda. When
the government controls the media, they can make anyone seem to say anything.
