When you think of nuclear disasters, the first thing that probably comes to mind
is Chernobyl. However, this was not the first nuclear disaster, nor was it the
last. It seems that several nuclear tragedies have been either overlooked or intentionally
left out of history books for various reasons. Nuclear power can be a great source of energy,
but it can also lead to catastrophe. You are about to find out about the most deadly nuclear
accidents of all time, and the crazy part is you probably haven’t heard of most of them.
Many consider an accident at Chalk River Laboratories in the 1950s to be one of the
first nuclear accidents that ever occurred. Chalk River Laboratories is located just over 100 miles
northwest of Ottawa, Canada. In the 1950s, it was a state-of-the-art facility where scientists,
engineers, and researchers worked on developing future nuclear technology. But
with new technology comes risk, and when dealing with nuclear energy, these risks can be huge.
On December 12, 1952, the National Research Experimental reactor at
Chalk River encountered a power flow issue that resulted in a runaway
fission reaction. The temperature in the coolant tank began to rise slowly at first,
but as researchers tried to get it under control, things went from bad to worse.
Sirens started to blare as the temperatures in the reactor core rose to dangerous levels.
The engineers tried to lower the control rods into the coolant tank, but they jammed,
and the chain reactions continued. Suddenly three of the rods began to lift out of the
coolant tank unexpectedly. The engineers panicked as the rods continued to rise and
overheat. In the next instant, the core went into meltdown. Hydrogen explosions
rocked the building. The reactor seal blew off its hinges and dumped 1.2
million gallons of radioactive waste into the basement of the Chalk River facility.
The scientists and researchers knew that the radioactive water was dangerous, but proper waste
disposal procedures had not yet been put in place. The engineers at Chalk River dug ditches only
5,000 feet away from the Ottawa River where they dumped the water from the reactor. Unsurprisingly,
some of the radioactive waste leached into the Ottawa River system and the surrounding
area. The radiation spread throughout the region and flowed towards the United States.
Interestingly, future president Jimmy Carter was stationed as a Naval officer in Schenectady,
New York at the time where he and 26 other men helped clean up the Chalk
River nuclear accident. It’s unknown how many people were affected by this disaster,
but the insane part is that the facility reopened two years later
with very few modifications made to the its procedures and mechanisms. Therefore,
it wasn’t surprising that in 1958, Chalk River Laboratories suffered another nuclear accident.
The National Research Universal reactor was housed in a separate building than the first reactor,
but a similar set of circumstances led to problems with this reactor as well.
The fuel rods began to overheat just like at the National Research Experimental reactor
from years before. The scientists realized they were headed towards a second meltdown
and used a robotic crane to lift one of the metallic uranium rods out of the reactor.
However, as the crane moved the rod away from the reactor, the uranium caught fire and fell
into the core below. The entire facility was doused with radiation, and the surrounding
area became contaminated once again. Even worse, the valves for the facility’s ventilation system
were left wide open, resulting in large amounts of radioactive steam being released into the air.
The researchers and engineers scrambled to extinguish the fire before the rest of
the reactor rods went into meltdown. They dumped buckets of wet sand into
the hole in the reactor's containment vessel. The fire was eventually put out,
but large amounts of radiation had already leaked from the reactor core. Military
personnel had to be brought in to aid with the clean-up of all the radioactive waste.
It’s hard to tell just how many people suffered due to the radiation leaks at
Chalk River Laboratories in the 1950s. The people who worked there and those who helped with the
clean-up were both exposed to unhealthy levels of radiation. No reports indicate that anyone
immediately died from radiation exposure, but as time went on, medical issues began to arise,
such as higher rates of cancer and other illnesses connected to radiation poisoning
in people who worked at or lived near the Chalk River nuclear research facility.
We may never know the extent to which the Chalk River Laboratories accidents
affected the people and environment. We will also probably never know if the radiation
leaked into the nearby river systems and ended up affecting people living downstream. Either way,
these two nuclear accidents were some of the first to occur but most certainly wouldn’t be the last.
Between the two nuclear accidents at Chalk River in the 50s, a much worse
disaster occurred in the Soviet Union in 1957. After World War II, the Soviet Union
began constructing nuclear facilities like crazy. They needed to outdo the Americans,
or at least keep up with them if they were going to remain a dominant power in the world.
Nuclear facilities at this time were used to conduct research and develop weapons. The
Mayak nuclear fuel processing plant was located in the town of Ozyorsk in southwestern Russia.
On September 29th, the cooling system at the facility failed. The core began to overheat
as workers tried to get the chain reaction under control. Unfortunately, they failed.
The reactor exploded, sending a massive cloud of radioactive particles into the air. Unlike
the Chalk River disaster that was somewhat contained, these particles swept across
the Russian landscape, contaminating entire towns as wind currents carried them across
the country. The deadly particles spread over 300 square miles. The Soviet government waited
an entire week before declaring a state of emergency and evacuating the 10,000 residents
who had been in the path of the radioactive cloud, but at that point, it was too late.
The Mayak facility was highly classified, and the Soviet government did not want word to spread of
its existence. The evacuated citizens were given no clear reason as to why they were being moved or
that they should be concerned about radiation. The Soviet people were eventually resettled,
but as time went on, the population started to develop some mysterious ailments.
People’s skin began to redden and die. Entire portions of their skin and muscles fell off the
bone as a result of high radiation exposure. It was now clear what had happened in the region
and what the Soviet government was trying to hide. In order to cover their tracks,
Soviet leaders created the East-Ural Nature Reserve,
which encompassed the contaminated area. This was done solely to prohibit access to the region.
It wasn’t until two decades later that a Russian biologist named Zhores Medvedev blew
the whistle on his own government and exposed what had happened at the Mayak facility. It’s
estimated that 200 people died from cancer as a direct result of radiation exposure
from the Mayak nuclear accident. However, it’s highly likely that thousands more were exposed
to dangerous levels of radiation and suffered from illnesses caused by the nuclear accident.
This incident has come to be known as the Kyshtym disaster because, until recently,
Ozyorsk did not appear on any official maps. The Soviet government did their best to suppress
any information about the facility or the disaster that occurred there. This is why
the nuclear accident was named after Kyshtym, the next closest town that appeared on maps.
The same year as the Kyshtym disaster in the Soviet Union, Great Britain had their own
nuclear mishap. On October 10, 1957, Britain's first nuclear reactor, known as Windscale,
was working to create more materials for their nuclear weapons program. The facility had been
running since the 1940s without any problems, but on this day, things went terribly wrong.
Workers at the facility were running routine maintenance on the reactor when they noticed
temperatures began to rise. The temperatures were still within reasonable levels, but they
didn’t seem to be leveling off. The workers tried circulating fresh coolant to keep the temperatures
down, yet nothing seemed to work. It quickly became apparent that something was very wrong.
One of the scientists realized that the uranium-filled graphite core
within the reactor had caught fire. But this wasn’t a new development;
the fire had been burning within the core for at least two days prior. Since the moment the
core had caught fire, it had been releasing radioactive contaminants into the air.
At this point, there was nothing that could be done about the radiation already spewed
into the atmosphere. The engineers at Windscale needed to keep the core from
completely melting down to stop any further contamination. They brought in cooling fans,
compressed carbon dioxide, and cold water to drop the core's temperature. After days of work, the
staff at Windscale smothered the fire and brought the core's temperature back to safe levels.
It was now October 12th, and a radioactive cloud was drifting across the United Kingdom
and into Europe. There was no way to evacuate the enormous area that was being covered by
radioactive particles. One set of precautions taken at the time was to pull all of the milk
and dairy products from the shelves of stores for a month. Even still, it’s estimated that
the Windscale disaster caused around 250 cases of cancer, but this is probably a lowball assessment.
Upon inspection of the Windscale disaster, it was found that the accident could have
been avoided. The fire that began in the core should never have happened, and the fact it was
allowed to burn for several days put the lives of countless people at risk. Like with the Kyshtym
incident in the Soviet Union, Windscale was hidden from the public for several decades.
This was likely because Britain didn’t want its own nuclear weapons program hindered by
restrictions and red tape. At the time, nuclear war seemed almost inevitable, and to many,
the importance of developing nuclear weapons far outweighed the risks.
Not all nuclear accidents occurred on land, however. Deep in the North
Atlantic, a nuclear-powered submarine almost sunk as a result of a deadly accident.
K-19 was a Hotel-class Soviet submarine. This was the classification that NATO intelligence
gave nuclear-powered ballistic missile submarines. On July 4,
1961, K-19 was traveling in the frigid waters of the North Atlantic when its nuclear engine
began to overheat. There was a malfunction in the coolant system, and there was no backup.
So the sub’s crew did the only thing they could: they figured out a way to fix the coolant leak.
The reactor started to become alarmingly hot. If the crew didn’t find a way to redirect
coolant to the nuclear core, it would explode and release an enormous amount of radiation
throughout the submarine and into the ocean. Brave engineers and other crew members locked
themselves in the engine room and worked on fixing the reactor as radiation ripped
through their bodies. These men knew they would receive a lethal dose of radiation,
but that didn’t matter. They would do whatever it took to save their crewmates.
Eventually, they were able to jerry-rig the coolant system to divert the necessary cold
water to the core and bring the temperature down. The submarine couldn’t travel back to
the Soviet Union on its own, but at least the core wouldn’t explode and destroy the
sub. A rescue mission was launched to bring K-19 back to port. Another sub towed K-19
across the Atlantic and returned it to the shores of the Soviet Union.
When the crew disembarked K-19, the men working on fixing the core were found to
have been bombarded by radiation. In the coming months, many would become seriously
ill and die as a result of their heroic actions. Other members of the K-19 who were
not exposed to as much radiation survived for many more years. However, all of the
men aboard K-19 would eventually succumb to diseases associated with radiation exposure.
But this is not where this particular disaster ends. Although the submarine did not explode
and the crew members were able to live for a few years after the accident, other tragedies occurred
as a result of the K-19 accident. The sub that towed K-19 back to base also became contaminated
by the radiation. Many of the men aboard the rescue sub also became ill due to the radiation.
Even after K-19 was docked to be repaired, the nuclear core continued to release radiation. The
people on the naval base and the workers who fixed the sub all became contaminated. Although we will
never know how many people died as a direct result of the radiation leak aboard K-19, it would seem
anyone who came into contact with the sub received enough radiation to alter their health. It’s
possible that dozens or even hundreds of people were affected by the nuclear accident aboard K-19.
In 1979 the United States would experience its own nuclear disaster. This would be one
of the worst accidents at a nuclear power plant in the world. Up until this point,
most nuclear accidents were a result of nuclear material being created for weapons
or to power vessels of war. However, the accident at Three Mile Island would cause
controversy around nuclear energy and the dangers that come with it. To this day,
the events at Three Mile Island have eroded the public's confidence in nuclear energy.
On March 28, 1979, a pressure valve at the Three Mile Island Nuclear Power Plant near Harrisburg,
Pennsylvania, failed to close. The nuclear plant was supposed to be state-of-the-art
and promised to bring the United States an efficient, affordable energy source.
When the pressure valve in one of the reactors failed, it caused cooling water contaminated
with radiation to flow through different parts of the facility. The workers in the control room
realized what was happening and desperately tried to redirect the contaminated water.
But in the chaos, the workers made a series of errors that made matters worse. The irradiated
water continued to spread. They diverted water all night, but by the following morning, the core had
reached over 4,000 degrees. If the temperature increased to 5,000 degrees, it would melt down,
leading to a catastrophic explosion that would send radioactive debris across the country.
The power plant was spewing radioactive steam into the air, but things could get much worse.
The owners of the powerplant downplayed the critical nature of the situation. First,
they claimed that the meltdown was under control when it was not,
and then they said no radiation was leaking out of the power plant. However,
within days radiation was detected in four different counties around Three Mile Island.
The governor of Pennsylvania immediately issued an order for pregnant women and small children to
be evacuated from the area since they would be the most vulnerable to the radiation.
As this was happening, the cooling system at the nuclear power plant was still not working
properly. People fled their homes and headed to safety. On March 31, the emergency teams finally
got the valves back online and were able to cool the core before it exploded. No direct deaths
or injuries were recorded during this time at Three Mile Island, but the fact that radioactive
particles were released into the atmosphere and dispersed across the state cannot be overlooked.
Some studies suggest that there might be a correlation between increased cancer and
infant mortality rates in the region and the release of radiation from the nuclear
power plant. If this is true, then the Three Mile Island incident not
only caused the American people to become wary of nuclear energy but also may have led to the
early deaths of many citizens, making it the deadliest nuclear accident on American soil.
Faulty parts caused some nuclear accidents; others were caused by carelessness. This was
the case with a nuclear contamination event in Goiania, Brazil, in 1987.
A radiotherapy institution within the city decided to relocate and leave some of their
old equipment behind. However, they did not follow the proper waste disposal protocols
when disposing of the equipment, especially those containing radioactive material. On
September 13, two scavengers entered the abandoned building and removed one of the
teletherapy units that still contained highly radioactive cesium chloride.
The two men carried the radioactive unit to a junkyard in a wheelbarrow,
where they sold it to the junkyard owner. The problem was that the teletherapy device
was spewing radiation the entire trip from the abandoned building to the junkyard. When the
junkyard owner saw that his newly acquired device contained glowing blue material,
he invited friends and family over to see it. The scavengers, junkyard owner, and everyone who
came in contact with the device had no idea they were being exposed to high amounts of radiation.
After the incident, hundreds of people began to show signs of radiation sickness.
This nuclear accident wasn’t due to a core meltdown or nuclear weapons but leftover
medical equipment. It’s estimated that 245 people were exposed to the radiation. This
led to high rates of cancer in Goiania at the time, something that could have been
prevented by just eliminating the negligence around disposing of radioactive materials.
This brings us to the worst nuclear disaster that has ever occurred. It was 1:00 AM on April 25,
1986, at the Chornobyl nuclear power plant when operators began reducing
power on reactor number 4 for routine maintenance and a safety test. The
safety test was being conducted to identify if the still spinning turbines could create
enough power to keep the coolant pumps running if the plant was to lose power
At 2:00 PM on April 25, reactor number 4’s cooling system was shut down so that it didn’t
interfere with the test. Everything seemed to be going according to plan. There was a
change in personnel around 11:00 PM when the night shift took over the test. They
were less experienced and never received proper instructions on how to carry out the test safely.
April 26, 1:23 AM, the test officially began. As soon as it started, a sudden power surge
occurred. An operator pressed the emergency shutdown button, but the control rods jammed
as they entered the core and exploded. The blast caused the 1,000-ton roof to be blown off of the
nuclear power plant. A fireball erupted into the sky. Radiation spewed out of the core,
and irradiated particles filled the sky. Fires broke out across the Chornobyl power
station as workers tried desperately to get the nuclear reactor to stabilize.
In order to get control of the situation, the Soviet government blockaded the nearby town
without informing the police or anyone involved of the potential risks of radiation poisoning. By
6:35 AM, all fires were extinguished, and the rest of the reactors were shut down,
but radiation continued to pour out of reactor 4. The firefighters and workers
believed that the radiation was under control, but they were misinformed. When
it became clear that the nuclear reactor was still expelling massive amounts of
radiation, the government ordered the evacuation of the surrounding areas.
On April 28, Sweedish air monitors detected large amounts of radiation coming from the
Soviet Union. The USSR informs the world that there has been a nuclear accident at
Chornobyl. Over the next several days, 800,000 workers were brought in to help
with the cleanup. They pumped liquid nitrogen underneath the power plant to
try and cool the core. Mounds of sand were dumped into the reactor from helicopters.
It wasn’t until May 6 that radioactive emissions began to decline as the fire in the core burned
itself out. The emergency workers began constructing a concrete structure around
the core to contain the radioactive fallout. Official records claim that only 31 people
died as a result of the Chornobyl accident, but the number is likely much higher due to
the number of workers involved and the amount of radiation they were exposed to. Many people
likely died years later from cancers caused by the radiation from the Chornobyl explosion,
while countless acres of land became uninhabitable due to radioactivity.
As technology advanced and we created safer reactors, nuclear accidents have decreased.
There are around 440 nuclear reactors in the world today. The last one to melt down was the Fukushima
Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. This disaster was the result of a tsunami
and earthquake that decimated the northeastern part of the country. The meltdown resulted in the
deaths of two workers but leaked radioactive waste into water supplies and the surrounding area.
Now watch “What If North Korea Launched a Nuclear
Bomb (Minute by Minute).” Or check out “What Happens To Nuclear Waste?”