Radiation disasters
When there is a large forest fire, it often makes national
news. A small local brush fire seldom
does. If there is public exposure to
radiation, no matter how large or small, it is an event worthy of national
attention. Most radiation disasters
we’ll cover are accidental, but not all of them. It is worth noting that if you add up all the radiation induced morbidity and mortality documented from these disasters, it is a small fraction of the annual carnage on American highways.
The Nevada tests
In 1951, at the height of the Cold War, the United states
began testing nuclear weapons in Nevada.
About 100 bombs were exploded above ground over the next seven
years. These tests were conducted under
the supervision of the Atomic Energy Commission (AEC). Nuclear devices produce fallout, radioactive
airborn dust which eventually settles somewhere. Much of this dust goes up into the earth’s
atmosphere and gets distributed around the world. Often, by the time it settles, much of the
radioactivity has already decayed away.
Some of the fallout stays closer to the ground, and is carried by the
local prevailing winds, often hundreds of miles. Clearly, people in Nevada and Utah received
some radiation from these tests. The
whole world did. The question is how
much, and with what effect.
At the time of the tests the AEC did only minimal monitoring
of areas which might receive the fallout,
and they denied there was any potential for harm. Only years later, when it was too late to
accurately assess where the radioactivity actually deposited, did the AEC own
up to their mistakes. The people in some
of the areas which might have received fallout believe strongly they have had
adverse effects, such as clusters of leukemia and cancer. Loss of livestock has also been blamed on the
tests. However, epidemiological studies
of these areas have not shown any definitive consequences, and the “clusters”
are not conclusive.
Clusters of cancer and leukemia, or any disease for that
matter, draw attention. When for example
a cluster of cases of leukemia occurs in a small town, the victims and their
families naturally ask, “Why me? Why here? Why so many?” The next thing they do is look for a manmade
cause, because as we discussed earlier, people do not expect to get sick from
natural causes anymore. When the cluster
is near a chemical waste dump or a facility associated with radiation, you can
guess the first suspect. The problem is
that clusters are normal. Natural
disease is a random event. We can say
the average number of cases per thousand people, but we cannot predict which
people. Random events cluster because
they are random. If they didn’t cluster,
they would be regular events, not random.
When you toss a coin 100 times you don’t get heads every other
time. Occasionally that will happen, but
more often you will get clusters of heads ranging from 2 to 6, and the same for
tails.
What about the rest of the US? Scientists and the National Cancer institute
have tried to estimate the number of cases of leukemia and thyroid cancer which
might be attributed to above ground nuclear tests by both the US and
Russia. From 1945 to 1992 there were
around 1000 such detonations (obviously madness, but this is what we did). These numbers have so much estimation
involved that they can be manipulated to show both very little or very great
effects, due primarily to the poor monitoring at the time of the tests. However, given the large doses released, some assume that at least some of the leukemia and thyroid cancer in the US is
related to these tests.
However, there has been no measurable increase in the global
rate of these cancers since the testing.
If 1,000 nuclear explosions have not measurably changed our cancer rate,
how can anti-nuclear activists like Helen Caldicot claim a single nuclear power
plant accident in Japan will generate "millions of new cases of cancer in
the Northern Hemisphere."? We'll
talk more about this in another page on greenies.
The other big casualty of these tests was trust. The government misled and deceived people
about the actual events and the potential for harm, and they did such a poor
job monitoring the tests that small affects, which might have occurred, cannot
be detected by current methods.
Fortunately, the “civilized” countries in the world have stopped such
testing.
Hanford and other weapons related plants
Building nuclear bombs requires highly purified radioactive
elements, particularly uranium. Building
thousands of nuclear weapons requires lots of purified uranium. As part of the Manhattan Project which
created the first atom bomb, a uranium purification plant was established in
Richland, Washington, the Hanford Plant.
This plant expanded greatly during the cold war, and like the Nevada
tests, those in charge restricted information the public should have known with
regards to radiation release and exposure.
Those living around Hanford, especially those living downwind from the
plant in the prevailing winds ("downwinders") feel they have been physically
harmed by their exposure.
Although not made public at the time, it is now known that
the Hanford plant released radioactive byproducts into the air and water around
them. These releases were documented at
the time, and the majority of the releases took place between 1944 and
1971. Between 1987 and 1995 a large
project under the auspices of the Center for Disease Control was undertaken to
try and calculate the actual amount or dose of radiation in the various regions
surrounding Hanford. The total area is
about 75,000 square miles and includes the Columbia River. It was called the Hanford Dose Reconstruction
(HEDR) Project, and it was concluded in the late 90s.
Many epidemiologic studies have been done on the regions
included in HEDR, and none have shown a significant increase in cancer
rates. The most conclusive, The Hanford
Birth Cohort study, compared long term health of downwinders born from 1945
through 1951 (when releases were highest) with those of similar Washington
state residents remote from Hanford.
There was a slight increase in Hashimotos thyroiditis among the men in
the Hanford group, but no other significant effect. Most authorities suspect this is probably due
to the Iodine 131 these men ingested via fresh milk from locally grazing cows.
Here again the biggest victim is trust. Had people been aware of the facts, they
could have made a decision for themselves. Stay or leave.
Drink local milk or don't drink it. In the absence of choice, certainty and trust,
our perception of risks is completely different. For the downwinders the other major
consequence is stress, with the subsequent development of stress related
psychosomatic illness. The downwinders
have not shown any measurable differences in their incidence of cancer, stroke,
heart disease or other major killers in the US, but those who do get sick or
have sick family members constantly worry their disease was preventable. Those who are healthy fear they may get a
preventable disease. It is a vicious
circle: unrealistic fear of radiation induced somatic disease leads to
increasing psychosomatic disease, which leads to increasing fear……..
Three Mile Island
A nuclear power plant uses a controlled nuclear reaction to
produce heat, which produces steam to power electric generators. The core of the reactor is comprised of
bundles of tubes, some of which contain 2 to 4% radioactive Uranium(U235), and
others which contain inert elements which absorb neutrons. When the neutrons released from the U235
react with other U235 atoms, energy is released and heat is generated. By varying the positions of the two types of
tubes, the amount of reaction and heat produced can be carefully
controlled. The entire core is
surrounded and cooled by water. This
constantly flowing water allows the generated heat to be used (as steam) and
prevents the tubes in the core from overheating and melting, thereby losing
control of the reaction. This is the
reactor. In the US all reactors are
completely surrounded by a second building, the containment building, in case
there is ever a problem with the reactor.
Around 4 am on March 28, 1979, some water pumps at Three
Mile Island Unit 2 nuclear power plant near Middletown, PA failed. As you can imagine, if the cooling water
isn't pumped, there is no coolant. As
things began to heat up in the reactor, it automatically shut down. The pressure in the water around the core
began to rise, and a relief valve opened as it should. When the pressure dropped, the relief valve malfunctioned,
it did not close as it should, and coolant water flowed out through the stuck
valve unbeknownst to the reactor operators.
Eventually, the core overheated and about one half of the core melted. By the evening, the core was again cooled and
the reactor was stabilized. There
continued to be some pressure buildup in the cooling systems and on March 30
there was a controlled release of contaminated gas. The plant was closed, the radioactive
material removed and over the next 15 years the site was cleaned up.
There were no injuries to plant workers. There was no significant exposure to anyone
in the area. The two million people in the area received an average of 1 mRem
from the event, while the average natural dose of radiation in the US is 300 mRem
per year. The maximum dose for anyone
around the site was 100 mRem, still only a fraction of the dose we all get
every year from background radiation. In
summary, the reactor system failed, but the safety features incorporated in the
design worked, and no one was hurt. The
public reaction was more dramatic.
The movie China Syndrome was playing throughout the country,
and said specifically that a core meltdown had the potential to contaminate an
area “the size of Pennsylvania.” Thousands of residents in the area fled the
state amid rumors of an imminent “China Syndrome”. Federal and state governments, having never dealt
with a similar emergency in the past, responded in a very chaotic pattern. Dick Thornburgh, the governor of Pennsylvania
at the time, took charge of the situation locally, but had to deal with
constant miscommunications and errors between the people on site, and
regulators in Washington DC who were trying to manage the situation from a
distance. One such error prompted the
premature calling for the emergency evacuation of 200,000 people from the
region. Such an evacuation would have
been far more dangerous than the actual event, had not the governor rescinded
the call. One anonymously sourced story
released by the news said “URGENT….The NRC now says the gas bubble atop the
nuclear reactor at Three Mile Island shows signs of becoming potentially
explosive.” Even Jimmy Buffett says “don’t
want to go to no Three Mile Island.
Don’t want to see my skin aglow.”
Anti-nuclear organizations to this day refer to it as a “terrible
disaster” with “massive amounts of radioactive contaminants released in to the
environment.” It was an environmental
disaster, but not because of the small amount of radiation released.
TMI had both negative and positive results. On the positive side, the American public
became aware of their need to be informed about government and business
decisions which may influence the environment.
The nuclear power industry and the regulatory agencies involved did a
massive review of safety and design in the plants, making the plants even
better. On the negative side the
development of nuclear power in America stopped. While some might say this was a victory for
the environment, I disagree. Nuclear
power carries a very small potential for harm, but pouring millions of tons of
pollutants into the air and water every day from coal, oil and gas powered
generators is doing very real harm, not
potential harm. It will be great
when we can get all our power from renewable sources like solar, wind and water
generation, but we could have been using cleaner nuclear power until such a
time comes.
Chernobyl
The April 1986 event at the nuclear reactor in Chernobyl, Ukraine
was a real disaster. The RBMK reactor at
Chernobyl was not just a power plant; it was also designed to produce Plutonium
for nuclear weapons. Because of the need
for frequent removal of the fuel rods by crane, the reactor does not have a
surrounding containment building. No one
else in the world has reactors like this.
The design is inherently unsafe.
The containment building is a major safety component of reactor design,
and there was not one at Chernobyl.
The plant operators were conducting an experiment with the
reactor, and disabled the reactor safety features. Had they not done this, the plant would have
shut down and the incident avoided. A
lot of people have asked why anyone would disable the safety features of a
nuclear power plant. There is no good
reason, but that is what they did. The
experiment they were conducting allowed an enourmous increase in the nuclear
reactions taking place in the core, which increased the heat and steam to the
point where it exploded, blowing the top off the reactor. The reaction probably stopped then, but the
heat and oxygen caused the core to catch fire, burning for nine days. This allowed the reactor contents and
radioactivity to spread as a smoke cloud for nine days. Thirty-two people died in the accident and
fire fight. In the following months thirty-eight more people, mostly fire fighters
who got very high radiation doses, died of acute radiation sickness.
As the contaminated smoke spread over northern Europe, there
was a large scale public outcry for government reaction. Because the Soviet Union was not forthcoming
with information about what was actually happening, the level of public fear
was escalated. While no one outside the
local area of the event received any serious dose of radiation, there was a
detectable amount of radiation in the air, and on crops and grazing land
throughout much of Western Europe.
“Detectable” is the key word here, and worth a comment or two.
We have gotten very good at detecting exceedingly small
quantities of radiation. We can measure
doses below 1 microRem (1 mRem = 1000 micro Rem). Natural back ground radiation ranges from 100
to 2000 mRem annually. This is relavent
because while there was “detectable” radiation in Western Europe, the doses to
the population never exceeded the normal background range. Poland carried out the largest, fastest
emergency response in the history of medicine, administering a single dose of
stable oral iodine to 18.5 million people in just 3 days to block the
absorption of Iodine 131 released from Chernobyl. They spent millions of dollars protecting people
from a small but “detectable” dose to the thyroid, when previous studies of
people treated intentionally with radioactive Iodine 131 had shown no cancer
increase at doses 100 to 1000 times higher.
Around the world there was an urgency to respond, to
act. Various standards for acceptable
levels of contamination in food, meat, water were enacted, often with little
review of the potential costs or the real need for action. According to Zbigniew Jaworowski, former
chairman of the United Nations Scientific Committee on the Effects of Atomic
Radiation, in a 2004 paper, these limits “varied by a factor up to 50,000. The basis of these limits was not science,
but reflected the emotional state of the decision makers, and also political
and mercantile factors. For example,
Sweden allowed for 30 times more activity in imported vegetables than in the
domestic ones, and Israel imposed lower limits for radioactivity in food
imported from Eastern than from Western Europe.” He states further “The most nonsensical action, however, was the
evacuation of 336,000 people from the regions of the Soviet Union, where during
the years 1986 – 1995 the Chernobyl fallout increased the average radiation
natural radiation dose (about 250 mRem) by 80 to 140 mRem per year, i.e. by
about 30 to 50%. The evacuation was
based on radiation limits recommended by the International Commission for Radiological
Protection (ICRP) for “the event of major radiation accidents” and on
recommendations for protection of the general population, which were tens to
hundreds times lower than natural doses in many countries. “ Here again is a consequence of the Linear No
Threshold philosophy: no detectable dose is safe. The cost of these reactions totals in the
hundreds of billions of dollars.
In America, on the other side of the world from Chernobyl,
the outcry was equally loud, and equally emotional. Goldman, et al used the LNT to calculate a
fifty year total cancer death toll from Chernobyl of 53,000 people . They took the dose from Chernobyl to the
average US citizen, 0.46 mRem, introduced the data from the Hiroshima survivors, and
applied it to the entire population of the Northern hemisphere. This number, 53,000 cancer deaths from
Chernobyl, is often cited by radiation phobic people and organizations. We could do a similar calculation for a round
trip flight from New York to San Francisco.
Everyone on the plane gets about 5 mRem from the decreased atmospheric
absorption of cosmic radiation from space at normal jet altitudes. Why don’t professional pilots have a dramatic
lifetime increase in cancer? What about
those poor Brazilians, where background levels approach 4,000 mRem per year on
some beaches? I guess that is why the
women on Brazilian beaches look so bad.
Like TMI, there have been both good and bad outcomes from
Chernobyl. The economic drain probably
contributed to the collapse of the Soviet Union, and perhaps an end to the
Nuclear arms race between them and the US.
Nuclear scientists and engineers from outside the USSR have been allowed
to participate in the cleanup plans and safety improvements at other Soviet
reactors. On the negative side, there has been
an increase in the number of childhood thyroid cancers. Intense surveillance of children in the area
has shown an increase in the number of cancers found. The data is debated though, because the
incidence of occult thyroid cancer can be very high in some parts of the world,
and no one knows what the incidence in the Ukraine was before the event. Fortunately, it is rarely a fatal disease,
with only 9 reported deaths from thyroid cancer so far among the millions of
“exposed “.
These childhood deaths from thyroid cancer are often exaggerated
and inflamed by anti-nuclear organizations and websites. They blame nuclear power and radiation for
the deaths and cancers. But, is this
really the cause? Suppose a railroad
bridge failed, and the government responsible for the bridge decided not to
tell anyone, out of fear of embarrassment.
When a train load of children ran off the bridge and died in the crash,
where is the real problem? This is
exactly what happened in Chernobyl. When
the reactor failed, the Soviet government refused to acknowledge the problem,
and did not inform the people living in the area of Chernobyl what simple
precautions to take. Had they cautioned
people not to drink the local milk for 2 or 3 months, or better still, given
the people a couple of inexpensive iodine tablets, none of the thyroid disease
would have developed. The radioactive
iodine, like the bridge, was the instrument of harm. Politics was the cause.
In their 20 year follow-up report on Chernobyl the World
Health Organization agrees that initial estimates of morbidity and mortality
from the event were way too high. They
seem to agree with Professor Jaworowski’s earlier assessment: “The Chernobyl accident was a radiation event
unique in human history, but not in the history of the biosphere. There is evidence of a number of episodes of
greater radiation levels during the evolution of life on earth, e.g. due to
supernovae. In terms of human losses it
was a minor event as compared with many other manmade catastrophes but, in
political, economic, social and psychological terms, its impact was enormous.” Again to quote Dr. Jaworowski, “The
psychosomatic disorders observed in 15 million people in Belarus, Ukraine, and
Russia who were affected by the April 1986 Chernobyl accident are probably the
accident’s most important effect on public health. These disorders could not be attributed to
the ionizing radiation, but were assumed to be linked to the popular belief
that any amount of man-made radiation—even minuscule, close to zero doses—can
cause harm…”
The Chernobyl event was a true disaster. Most authorities agree it is as bad as it can
get. The reactor was poorly designed,
with no containment building and inadequate safety systems. The operators were poorly trained, and
actually turned off the key safety systems in place. The government denied what was going on and
did not warn people in a timely manner.
Around 75 people lost their lives during and after the event ( an
average day for American highway fatalities).
There was a massive evacuation (mostly unnecessary) from the surrounding
area with subsequent enormous social, emotional, and economic costs. Radiation phobia is expensive, both in economic
costs and human suffering.
The Fukushima Accident 2011
On Mar 11, 2011 the Great East Japan Earthquake of 9.0 magnitude occurred, moving Japan a few meters to the east. The subsequent tsunami it created inundated over 560 square kilometers, killing over 19,000 people. The waves also flooded a number of Japanese nuclear power plants. The tsunami was up to 23 meters high. The japanese plants were built in the 70s, based on the standards at the time. This tsunami was much higher than the design allowed, and flooded not only several reactors, but their back-up power generators as well.
Detailed analysis of the plant failure
When the earthquake occcured, all of Japan's reactors shut down immediately, as designed. The fuel rods are automatically retracted from the core, the reaction stops, and then the entire core is cooled to remove excess heat while the core cools down to what is termed cold shut down. With loss of the back-up generators, the water circulating pumps ceased to operate and the cores could not be adequately cooled. At three reactors this resulted in a meltdown of the core withing 3 days after the quake. With meltdown, the fuel rods melt and fall into the bottom of the reaction chamber, making normal control of the fuel and movement of the rods by remote control impossible.
When the rods fall into the chamber, they are submerged in cooling water. This generates steam, and this steam must be vented to keep the entire plant from exploding. Because of the direct contact between the steam and the material, the steam contains some radioative material, primarily radioactive forms of Cesium and Iodine. This vented material is responsible for the subsequent contamination around the plant, and to some extent the adjacent ocean.
In addition to the vented steam, large amounts of contaminated cooling water was produced. Efforts to control this water were not completely successful, and contaminated water leaked into the ocean. This leakage was very high in the initial week after the event, but was gradually controlled. This resulted in a significant release of Cesium and Iodine into the Pacific Ocean.
Woods Hole Oceanographic symposium on the effects of the spill on the ocean. Very good presentations in video or pdf.
The Japanese government ordered the immediate evacuation of a 20km radius around the plant. In April this area became a no-go area, and residents were not allowed to return until clean-up was adequate. In 2012 residents were allowed access to most of the restricted area.
It is interesting to consider the coverage of this disaster in the US media. The wave killed 20,000 people, and left millions homeless. No one died from the nuclear power events. And yet the coverage in the US media was far and away concentrated on the nuclear events. Radiation phobia sells. I will be devoting a seperate page to this issue shortly.
Here is a link to two articles about the actual radiation levels in the land around the reactors and the potential effects on the inhabitants of the area and the plant workers by Dr. Jacquelyn Yanch at MIT.
MIT articles
Since the event it has been learned that there had been recommendations to increase the protection of the generators at these plants becuse of the risk of higher tsunamis based on analysis of prior tsunamis. This was not done. Like Chernobyl, some or part of this event might have been avoided. Also like Chernobyl, the psycologic trauma from this event due to radiation phobia is going to far outweigh the actual morbidity and mortality from radiation hundres or thousands fold.
The Fukushima Accident 2011
On Mar 11, 2011 the Great East Japan Earthquake of 9.0 magnitude occurred, moving Japan a few meters to the east. The subsequent tsunami it created inundated over 560 square kilometers, killing over 19,000 people. The waves also flooded a number of Japanese nuclear power plants. The tsunami was up to 23 meters high. The japanese plants were built in the 70s, based on the standards at the time. This tsunami was much higher than the design allowed, and flooded not only several reactors, but their back-up power generators as well.
Detailed analysis of the plant failure
When the earthquake occcured, all of Japan's reactors shut down immediately, as designed. The fuel rods are automatically retracted from the core, the reaction stops, and then the entire core is cooled to remove excess heat while the core cools down to what is termed cold shut down. With loss of the back-up generators, the water circulating pumps ceased to operate and the cores could not be adequately cooled. At three reactors this resulted in a meltdown of the core withing 3 days after the quake. With meltdown, the fuel rods melt and fall into the bottom of the reaction chamber, making normal control of the fuel and movement of the rods by remote control impossible.
When the rods fall into the chamber, they are submerged in cooling water. This generates steam, and this steam must be vented to keep the entire plant from exploding. Because of the direct contact between the steam and the material, the steam contains some radioative material, primarily radioactive forms of Cesium and Iodine. This vented material is responsible for the subsequent contamination around the plant, and to some extent the adjacent ocean.
In addition to the vented steam, large amounts of contaminated cooling water was produced. Efforts to control this water were not completely successful, and contaminated water leaked into the ocean. This leakage was very high in the initial week after the event, but was gradually controlled. This resulted in a significant release of Cesium and Iodine into the Pacific Ocean.
Woods Hole Oceanographic symposium on the effects of the spill on the ocean. Very good presentations in video or pdf.
The Japanese government ordered the immediate evacuation of a 20km radius around the plant. In April this area became a no-go area, and residents were not allowed to return until clean-up was adequate. In 2012 residents were allowed access to most of the restricted area.
It is interesting to consider the coverage of this disaster in the US media. The wave killed 20,000 people, and left millions homeless. No one died from the nuclear power events. And yet the coverage in the US media was far and away concentrated on the nuclear events. Radiation phobia sells. I will be devoting a seperate page to this issue shortly.
Here is a link to two articles about the actual radiation levels in the land around the reactors and the potential effects on the inhabitants of the area and the plant workers by Dr. Jacquelyn Yanch at MIT.
MIT articles
Since the event it has been learned that there had been recommendations to increase the protection of the generators at these plants becuse of the risk of higher tsunamis based on analysis of prior tsunamis. This was not done. Like Chernobyl, some or part of this event might have been avoided. Also like Chernobyl, the psycologic trauma from this event due to radiation phobia is going to far outweigh the actual morbidity and mortality from radiation hundres or thousands fold.
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