All Episodes
Previous Next
Plain Text
Jan. 14, 2014 - Skeptoid
17:43
Skeptoid #397: Fukushima vs Chernobyl vs Three Mile Island

Years after the disaster, some claim that Fukushima radiation is still going to cause widespread death. Learn about your ad choices: dovetail.prx.org/ad-choices

Transcriber: nvidia/parakeet-tdt-0.6b-v2, sat-12l-sm, and large-v3-turbo
|

Time Text
Nuclear Energy Misconceptions 00:07:01
When the Fukushima nuclear plant was largely destroyed by the Japanese tsunami of 2011, it reignited a worldwide firestorm of anti-nuclear sentiment, causing many to hold up Chernobyl and Three Mile Island as two more examples, proving that nuclear energy is too dangerous to be used.
Today, we're going to put that assertion to the test.
That's coming up now on Skeptoid.
A quick reminder for everyone, you're listening to Skeptoid, revealing the true science and true history behind urban legends every week since 2006.
With over a thousand episodes, we're celebrating 20 years of keeping it focused and keeping it brief.
And we couldn't have done it without your curiosity leading the way.
And now we're even offering a little bit more.
If you become a premium member, supporting the show with a monthly micropayment of as little as $5, you get more Skeptoid.
The premium version of the show is not only ad-free, it has extended content.
These episodes are a few minutes longer.
We get rid of the ads and we'll replace them with more Skeptoid.
The extended premium show available now.
Come to skeptoid.com and click Go Premium.
You're listening to Skeptoid.
I'm Brian Dunning from Skeptoid.com.
Fukushima versus Chernobyl versus Three Mile Island.
In March of 2011, an undersea earthquake sent tsunamis thundering across Japan, killing nearly 20,000 people and creating the most expensive natural disaster in history.
Among the casualties was the Fukushima Daiichi nuclear power plant, which was almost completely submerged by the tsunamis, an unprecedented event.
Power was lost, obviously.
Cooling systems stopped, and the net result was a complete meltdown of three of the plant's reactor cores.
It was a perfect storm of worst-case scenarios.
And now, even years afterward, some are calling it a worldwide radiation disaster.
Worse than even Chernobyl, it will produce a staggering death count for decades or even centuries.
Today, we're going to evaluate these assertions and see if we can separate fact from fiction.
With the shocking end-of-the-world scenario headlines, such as your days of eating Pacific Ocean Fish Are Over, and 28 signs at the West Coast is being absolutely fried with nuclear radiation from Fukushima, either Fukushima was the worst environmental disaster ever, or some of the worst misinformation ever is being trumpeted.
To find out which, we'll put it into context with the two other best-known nuclear disasters.
The 1986 explosion of a reactor at the Chernobyl plant in the Ukraine and the 1979 partial meltdown of a reactor at the Three Mile Island plant in Pennsylvania.
The most important technical point to understand about various reactor kinds is the moderator.
The moderator is a substance that slows down the fast neutrons being shed by the radioactive uranium fuel, converts their kinetic energy into thermal energy, and turns them into slow thermal neutrons.
A thermal neutron is much more likely to strike another uranium nucleus.
This allows a chain reaction, in which the fuel produces enough heat to power a conventional steam generator.
Most nuclear reactors use water as the moderator.
Put uranium fuel rods into water in the proper configuration, and you'll get a chain reaction.
Chernobyl, however, was a very different type of machine.
It was what we call an atomic pile, the devices first designed during World War II to produce plutonium for atomic weapons.
The atomic pile is literally a pile of graphite blocks, half a meter long and a quarter meter square, with a hole bored through the long axis.
These graphite blocks were used as the moderator.
The problem with building a reactor out of graphite blocks is that graphite burns.
Contain burning graphite within a concrete structure, and it explodes.
This is exactly what happened at Chernobyl, and it's exactly why nobody would ever build a graphite-moderated reactor today.
The whole reactor core was literally a bomb waiting to go off.
Three Mile Island and Fukushima were both water-moderated reactors.
This was one of the most significant safety improvements of the early 1950s.
Fukushima's basic design is one of the earliest, called a boiling water reactor.
The moderating water, which is also the cooling water, is directly boiled and drives a steam generator.
The reason the Fukushima accident happened is that all sources of power were destroyed by the tsunami, including backups, backups, and their backups.
And without the pumps to keep the system circulating, the cooling water boiled completely away.
The system to insert control rods to stop the reaction wouldn't operate, and the fuel melted.
For months, fire hoses sprayed water into the open reactors to prevent open flames from pumping radioactive smoke into the atmosphere.
This contaminated water was barely containable.
It leaked into the ocean and was stored in anything that could be used as a tank.
Three Mile Island's design was a step newer, called a pressurized water reactor, and it's of the same basic type as most existing plants.
The main incremental safety feature here is that the core is kept pressurized to prevent the water from being able to boil.
And as water's temperature goes up, its ability to moderate neutrons goes down.
Thus, the system is self-regulating.
If the core gets too hot, it stops working efficiently, so it cools back down.
But like any system, this one was prone to breakdowns and human error.
A broken valve allowed coolant water out of the core, and a confusingly designed instrument panel fooled operators into thinking the opposite was happening, who then let out more.
By the time they figured it out, enough damage had been done that radioactive water had been able to mix with the separate water that runs through the steam generators.
That radioactive steam was then released through the plant's filtration system, which removed nearly all the dangerous contaminants.
Fortunately, at Three Mile Island, only a tiny amount of radiation was released.
It was an expensive cleanup and repair, but it was effectively contained.
None of the containment structures were breached.
Radiation Risks Explained 00:08:28
There were no injuries, nobody within 16 kilometers received more than a chest x-ray's worth of radiation, and epidemiological studies predicted zero eventual deaths.
At the opposite end of the spectrum was Chernobyl.
Since the plant openly exploded, a huge amount of very dangerous radioactive debris was spread over a large area.
Two people were killed outright by the explosion, and a few dozen first responders were dead of acute radiation poisoning within three months.
Estimates of eventual deaths vary wildly, with the most extreme coming from anti-nuclear activists, but the best epidemiological studies predict about 4,000 eventual cancer deaths in the region.
Reactors produce a lot of radioactive elements, but the two we care most about are iodine-131 and cesium-137.
Iodine-131 is very dangerous, but fortunately it has a very short half-life of eight days.
After 10 half-lives, or about 80 days, it's basically gone and no longer a threat.
Three Mile Island produced about 560 gigaberels of iodine-131.
Chernobyl produced about 3 million times as much.
About 1,760 peta becquerels.
In a world that can feel overwhelming, spreading thoughtful, evidence-based content is one of the best ways to make a positive impact.
Ask your local public radio station to air the Skeptoid Files, a 30-minute radio-friendly version of Skeptoid that pairs two related episodes promoting real science, true history, and critical thinking.
And in these challenging times for public media, we're offering these broadcasts for free to radio stations, available on the PRX Exchange or directly from Skeptoid Media.
It's an easy ask.
Just send a quick message to your station's programming director.
By helping to bring the Skeptoid files to the airwaves, you'll help promote the essential skills we all need to tell fact from fiction.
Just go to your local station's website, find the programming director's email address, or just their general email address.
You can even use the telephone.
I know that might sound crazy.
It's an old legacy device that allows real-time voice communication.
I know that's weird, but hey, it's an option.
The world can feel chaotic, but you're not powerless.
When you promote critical thinking, you can help your community tell fact from fiction.
And that's how we shape a better future.
In uncertain times, spreading good ideas can make you feel helpful, not helpless.
Let's stand up for reason, truth, and understanding together.
Get them to air the Skeptoid files from Skeptoid Media, available on the PRX Exchange, and they'll know what that is.
Where does Fukushima fit between these two?
At the high end, about 500 peta becquerels.
That's about a million times more than Three Mile Island and about a third of Chernobyl.
But things were done very differently.
The area around Fukushima was very quickly evacuated, and prophylactic iodine was distributed just as fast.
Neither of these things were done at Chernobyl.
The result was that in those first few weeks, when the iodine-131 presented a risk, lots of people near Chernobyl were exposed, and almost nobody was exposed at Fukushima.
Then there's the cesium-137, which is the long-term threat about which bloggers and reporters expressed so much fear in the years following Fukushima.
No significant amount was released at Three Mile Island because it was filtered out.
But at Chernobyl, 85 peta becquerels were scattered over the surrounding area.
It has a half-life of 30 years, which is a really long time, and it's why we're probably going to have to wait for a few more 30-year half-lives to go by before the area around Chernobyl will be safe to move back in.
At Fukushima, cesium-137 was in the smoke from the burning fuel and was in the cooling water sprayed into the damaged cores.
Maximum of 15 peta becquerels, just over a sixth as much as Chernobyl, was released into the environment.
How much cesium-137 does it take to produce 15 peta becquerels of radiation?
About 4.7 kilograms.
That's a lump a little smaller than a tennis ball.
Now, don't think that sounds like an absurdly small amount.
4.7 kilograms is a lot of atoms.
If spread into an atomically thin pancake, it could easily cover the entire world.
As with all dangerous radioactive elements, we've done a lot of study on the health effects of cesium-137.
Although it has a radioactive half-life of 30 years, It has a biological half-life of 70 days.
70 days is the amount of time it takes animals like us to get half of it out of our system.
That can be accelerated to just 30 days with treatment.
From animal testing done in the 1970s, we know that 140 mega becquerels per kilogram of body weight is a lethal dose.
So with a little algebra, we know that Fukushima's 4.7 kilograms was enough cesium-137 to kill 1.5 million people.
So here's the big butt.
Almost none of it will ever find its way into anyone's body.
The Fukushima contamination is detectable all over the world, and it's probably in the bodies of everyone living on the planet.
That's the nature of entropy.
There's a lot of it in the water stored in the tanks at the Daiichi power plant and in the soil in the evacuated zone, but the rest of it has been carried by water and atmospheric currents everywhere.
Our oceans contain 1.5 billion cubic kilometers of water.
Dilute Fukushima's 4.7 kilograms into that, and every cubic kilometer of water would contain less than 1,000th of a lethal dose.
In other words, to die from Fukushima's radiation, you will need to drink 1,000 cubic kilometers of seawater and somehow manage to absorb every atom of cesium-137 from it.
But if you're looking only to eventually get cancer, then you might be able to do so on only a few hundred cubic kilometers of the Pacific.
But if you tried to do that, you would already die 1 million times over from just the primordial radioactive elements that exist naturally in our oceans.
More than 15 zetta becquerels, a million petabecquerels, of naturally occurring potassium-40, rubidium-87, uranium-238, and so on.
This is the central thesis of science reporters who have been desperately trying to respond to scientifically illiterate fearmongers printing headlines like, your days of eating Pacific Ocean fish are over, and 28 signs that the west coast is being absolutely fried with nuclear radiation from Fukushima.
Our planet's entropy has, long ago, already rid itself of any credible threat from the Fukushima radiation, outside of the immediate evacuation zone.
Fishing has long been suspended from Daiichi's vicinity, so there's no way that eating illegally caught fish can give you any significant Fukushima radiation.
The Fukushima disaster will probably end up being the most expensive industrial accident and cleanup in history, but it has certainly not been among the most dangerous, thanks largely to Japan's prompt action.
The newest World Health Organization assessment concludes, No discernible increase in health risks from the Fukushima event is expected outside Japan.
With respect to Japan, this assessment estimates that the lifetime risk for some cancers may be somewhat elevated above baseline rates in certain age and sex groups that were in the areas most affected.
Support Skeptoid Today 00:02:09
Clearly, it wasn't good.
But if you want to be able to develop proper response plans, you have to understand the correct facts about the situation.
Absurdly exaggerated and sensationalized reports do not help anyone.
Rather, they increase confusion and decrease our ability to respond to such events appropriately.
Like every weekly program, Skeptoid takes time and money to produce.
Skeptoid Media is funded entirely by listeners.
99 cents an episode is all I ask, the same as anything else on iTunes.
Come to skeptoid.com and spend 30 seconds setting up your automated recurring micropayment.
And that's what it takes to make the show possible.
Please join me today.
You're listening to Skeptoid.
I'm Brian Dunning from Skeptoid.com.
Hello, everyone.
This is Adrienne Hill from Skookum Studios in Calgary, Canada, the land of maple syrup and mousse.
And I'm here to ask you to consider becoming a premium member of Skeptoid for as little as $5 per month.
And that's only the cost of a couple of Tim Horton's double-doubles.
And that's Canadian for coffee with double cream and sugar.
Why support Skeptoid?
If you are like me and don't like ads, but like extended versions of each episode, Premium is for you.
If you want to support a worthwhile nonprofit that combats pseudoscience, promotes critical thinking, and provides free access to teachers to use the podcast in the classroom via the teacher's toolkit, then sign up today.
Remember that skepticism is the best medicine.
Next to giggling, of course.
Until next time, this is Adrienne Hill.
From PRX.
Export Selection