Caveat: It seems I have to put a warning sign on this post. I am not a nuclear physicist and the opinions on this post are personal and are not professional, scientific advice on radiation or its effects.
I’ve had a crash course in nuclear physics this week. I took basic Physics in university, but my major was History, so I never really got into it. This interconnected world sure makes it easy to learn informally though.
From Twitter, I was led to an excellent overview of how the Fukushima Daiichi reactor works at Why I am not worried … which is now being hosted by MIT’s Nuclear Information Hub:
The solid fuel pellet (a ceramic oxide matrix) is the first barrier that retains many of the radioactive fission products produced by the fission process. The Zircaloy casing is the second barrier to release that separates the radioactive fuel from the rest of the reactor.
The core is then placed in the pressure vessel. The pressure vessel is a thick steel vessel that operates at a pressure of about 7 MPa (~1000 psi), and is designed to withstand the high pressures that may occur during an accident. The pressure vessel is the third barrier to radioactive material release.
The entire primary loop of the nuclear reactor – the pressure vessel, pipes, and pumps that contain the coolant (water) – are housed in the containment structure. This structure is the fourth barrier to radioactive material release. The containment structure is a hermetically (air tight) sealed, very thick structure made of steel and concrete. This structure is designed, built and tested for one single purpose: To contain, indefinitely, a complete core meltdown. To aid in this purpose, a large, thick concrete structure is poured around the containment structure and is referred to as the secondary containment.
Both the main containment structure and the secondary containment structure are housed in the reactor building. The reactor building is an outer shell that is supposed to keep the weather out, but nothing in. (this is the part that was damaged in the explosions, but more to that later).
Then I read today on the MIT site that, “Radiation levels on the edge of the plant compound briefly spiked at 8217 microsieverts per hour but later fell to about a third that.” What’s a microsievert, I asked myself, and how dangerous are 8217 of them? I was able to find out via Wikipedia that:
1 Sv = 1000 mSv (millisieverts) = 1,000,000 µSv (microsieverts) = 100 rem = 100,000 mrem (millirem)
And I further read that at 250,000 µSv “Some people feel nausea” and at 1,000,000 µSv there is “Mild to severe nausea”. Makes 8,217 µSv look pretty small to me.
The mainstream media reports tell a different story. Here’s one from the Canadian Broadcasting Corporation:
Most of the attention in the past three days has been focused on Daiichi units 1 and 3. A complete meltdown — the melting of the radioactive core — could release radioactive contaminants into the environment and pose major, widespread health risks.
There is no mention of radiation levels, or what would happen in the event of a core meltdown [containment], in this story and in many others by the CBC and other mainstream media/entertainment sources.
Update: A more detailed explanation of the factors at play, via Twitter:
There are some characteristics of a nuclear fission reactor that will be common to every nuclear fission reactor. They will always have to contend with decay heat. They will always have to produce heat at high temperatures to generate electricity. But they do not have to use coolant fluids like water that must operate at high pressures in order to achieve high temperatures. Other fluids like fluoride salts can operate at high temperatures yet at the same pressures as the outside. Fluoride salts are impervious to radiation damage, unlike water, and don’t evolve hydrogen gas which can lead to an explosion. Solid nuclear fuel like that used at Fukushima-Daiichi can melt and release radioactive materials if not cooled consistently during shutdown. Fluoride salts can carry fuel in chemically-stable forms that can be passively cooled without pumps driven by emergency power generation. There are solutions to the extreme situation that was encountered at Fukushima-Daiichi, and it may be in our best interest to pursue them.
This is why it’s so important to be a self-directed learner. Who stands to benefit by the stuff that’s being Pushed to you? Advertisers? Whether it’s news or education, we have the networks that can help us figure things out. It just takes a little effort.
It’s not just the media, either. This weekend I came across an article in The Atlantic, Lies, Damn Lies and Medical Science that showed that “as much as 90 percent of the published medical information that doctors rely on is flawed”. We need to think for ourselves.
Update 16 March: The CSMonitor (almost mainstream media!) is providing some good in-depth reporting:
Meltdown 101: What are spent fuels and why are they a threat?
Opinion: Japan’s Nuclear Crisis: 6 reasons why we should – and shouldn’t – worry
Good coverage by The Guardian – Japan Nuclear Crisis Live Updates
I must say that the mainstream press are stepping up on this.
18 March: From a science journalist: Nuclear power won’t kill you
Sorry, you don’t seem to understand the time dosage problem with radiation. In a nutshell, do you think you have the same radiation effects from a single x-ray and you do with an x-ray every day for 2 years?
The numbers you quote are a time dosage – “8217 microsieverts per hour ” You then talk about “And I further read that at 250,000 µSv ”Some people feel nausea” and at 1,000,000 µSv there is “Mild to severe nausea”. Makes 8,217 µSv look pretty small to me.”
You need to multiply the 8217 /hour X the number of hours of exposure. It takes a day to get to your “mild nausea.” About a week to get to severe nausea. Where does the nausea come from? The fast-growing lining of the stomach sloughing.
I’ve had two parents undergo chemo and I promise you, it is umm, unpleasant. To think of everyone within 17 miles of a Japanese reactor going through that is inhumane but in your blog, you dismiss it.
I am very much with you about learning – but I guess there is a little more to nuclear physics than Wikipedia.
# Lowest clearly carcinogenic level: 100 mSv/year[3]
# Criterion for relocation after Chernobyl disaster: 350 mSv/lifetime
And if the numbers are hard to follow – think of sunburn and sunlight. 10 minutes in direct sun, love it. 1000 minutes and I have a bad sunburn. Same idea here.
Please, don’t spread this wrong thinking around. It doesn’t matter in many things but when it comes to our health and thinking about our risks, misinformation and misunderstanding matter a great deal.
Thanks for the information, Rick. I’m not spreading misinformation, just trying to figure things out with so many media outlets not doing good journalism. It doesn’t seem that a meltdown will be followed by catastrophic leakage and there is little information about radiation levels at a distance. Where does the 17 mile radius that you note come from? Is it important? I agree there’s more to nuclear physics than wikipedia and the MIT information site, which is why people with specialized knowledge should not only be sharing their knowledge but making it understandable. It’s what I try to do in my own small way. My son spent last summer working at a nuclear facility and he’s been helping me learn too :)
Do you have a blog where you explain this better? Can you recommend some good resources to understand this complex field? Help us learn here, Rick.
The average person doesn’t care about how much exposure nor do they want a physics lesson. I was in Kyiv Ukraine when the Chernobyl disaster took place and I can tell you a week before the news told us there was a disaster the information had made its way door to door (before Twitter, the Internet or texting). We heard of Iodine pills, red wine and the fact that kids can’t take any exposure – hence all the children suffering from thyroid cancer in the years since ( I believe the official record is something like 4,000). When the Soviet government told us to stay inside, get rid of our clothes, cover our heads if we were going outside – it lasted for three days. You can’t see radiation but you need food, you need to work and for many people they wanted to get out of the City. It was unbearably hot and with no air conditioning (which you couldn’t use since you were supposed to keep your windows closed) you could choose to suffocate indoors or spend your last days enjoying the sunshine. By June there was no children left in the City of two million as everyone was frantic to get their children somewhere safe – thus for weeks you couldn’t get anywhere close to the train, bus or air port to buy a ticket. You relied on your “social network” to help you out. I was lucky as I was Canadian and my student visa was done on June 19, 1986 so I flew home. The people in Japan are likely in the same state – hoping fate is on their side.
Pat; my understanding from reading the linked resources is that Chernobyl was quite different, in that graphite was used as a coolant, instead of water, plus many other safety systems were not in place. What I don’t appreciate is when the media use Chernobyl as a direct comparison.
It looks to me like 8217 microsieverts per hour is about 21,000X greater than our average exposure (360 rem/year). It’s very possible I am looking at it wrong too but what I know is there is reason to trust the evacuation orders from the true experts rather than relying on what I can gather from Wikipedia. I use Wikipedia for information. This kind of thing requires education.
Rick; thanks for your information & links via Twitter. I have concluded at this time that the risk of an explosion and a major radiation burst is quite small. My key questions, to which I’ll try to find some answers are:
How severe are the radiation leaks at the reactor?
What is the half-life of this material?
How far does this radiation spread and what will affect its spread?
What will affect the increase/decrease of these leaks?
I’m also noting that anti-nuke organizations are taking advantage of these incidents to influence policy in other countries.
Courtesy a buddy on facebook, Gizmodo has good coverage here: http://goo.gl/x4I7e
Also, Casey Research does a good job of comparing this incident with Chernobyl and Three Mile here: http://goo.gl/UwXX2
I think this post is a terrific example of both the benefits and dangers of social media as a form of informal learning. We’re pointed to a headline called “Why I am not worried about Japan’s nuclear reactors.” This headline has gone viral. Pop it into Google, with quotes, and see 79,200 hits.
As with any viral blog, we need to treat it with caution, especially since it’s already highly politicized. This is part of the new media cycle. We have lots of traditional media, lots of partisan media and then lots of social media that feeds into both (but especially the latter). I honestly don’t know if this helps or hurts the truth-seeking process. I suppose it doesn’t really matter, however, since it’s just the way things are these days.
As for this particular story, there’s only an edited version placed with a caveat at Mitnse: “Note that the title of the original blog does not reflect the views of the authors of the site.” It also eliminates statements such as, “The plant is safe now and will stay safe.”
In the end, yes, a viral blog can serve as a jumping off point for learning. And the author here might even be right “not to worry.” Time will tell. I personally think the public is served by such blogs but we should keep in mind just how difficult it can be to separate fact from opinion in the age of social media, especially with complex technical issues where the facts on the ground are in flux. This represents part of the danger of trying to learn from social media.
It’s a danger worth living with, in my opinion, but we should put aside all Utopian thoughts. Learning this way can be tricky, messy, and time-consuming. There ain’t no free lunch when it comes to knowledge.
The only real advantage is that there can be a sort of “self-correction” mechanism for the truly open minded. But my sense is that people who come at these issues with a real desire to learn (as opposed to a desire to prove their own point of view) are few and far between.
“Learning this way can be tricky, messy, and time-consuming. There ain’t no free lunch when it comes to knowledge.”
I agree completely, Mark.
Is being informed learning? Is being misinformed learning?
Interesting how we can get a false sense of security or danger from a few articles.
Formal vs Informal is not the issue anymore. How to we develop a litteracy around trust, security and privacy? And I would add that we have to create a litteracy around learning and fallacies of logical thinking.
Am not against nuclear or pro nuclear but this was one scary article to read.
Now that so much information is available only a click away, it becomes very important for good science to get out of the ivory tower and become accessible. Not in some paid academic journal that 20 people read, but for the world, like wikipedia (which has its own issues). Better literacies are needed but so too do we need more knowledgeable people to engage. For too long institutions have marginalized the importance of the web. Now they have to catch up or themselves be marginalized. When disaster strikes, people turn to the web.
Harold (and others),
This has been interesting. You seem to have settled into a meme about scientists choosing an all too private way to discuss science with the general public. After I write this, you might back away from it but you seem to believe that scientists choose to keep to themselves.
I know that isn’t true. Sure, some scientists prefer “alone” time in the lab but plenty are as social as they come. The difficulty interacting with the public can’t be explained by personality types or quirks.
It can be explained by the often challenging type of knowledge chased by scientists. It occurs by speculating, followed by time (often years) chasing the truth in the speculation. You say we write to a journal read by 20 but that part of the process is necessary – we have to share our speculations, then our data in support or against the speculations and it has to be done in great detail to allow colleagues to tear it down. That process of tearing down is not about opinion, or it is limited to those with highly informed opinions. This has to be done to an audience that has intense interest. Sorry that’s only 20 readers.
And while I am at it, I am also sorry that learning some of these things can take years if not longer. There are, at least, 20 factors that come into play on the subject of safety of nuclear reactors in Japan. To make a really knowledgeable assessment of safety, it would take years of experience. What was wrong about your take on the matter was that you honestly believed you could learn enough from a Wikipedia article and your life experience.
It’s truly not that way with most of science. Again, sorry and I wish it were easy. If it were, we would not be suffering the shortage of scientists and engineers we now see coming.
There are some things, many things in certain fields of study, that cannot be learned in an hour, a day, a year. When in grad school, I literally devoted 10-20 hours a day for
oops, hit a key by accident. I’ll just continue.
…10-20 hours a day for 5 years studying my subject. It’s not mastered easily. It was necessary and it was worth it.
I am happy to try and discuss scientific issues with the “general public.” I quite enjoy it, after all, I am a teacher first. I work at a public university so I am literally on call to the people of my state and my country. I am but a phone call away, and that is true for every scientist working at a US public university. I believe it is the same in Canada. I get calls all the time and I spend the time to answer questions. Again, I am sorry I am not called and asked more questions. (Let’s admit it, I am a very sorry guy.) So let me ask you? Did you call an expert? Did you invest the time to understand what you can know and not know? Or was it easier to go to Wikipedia and claim knowledge and understanding?
Communication is two way. IMO, I don’t think most of the public wants to hear from scientists nearly as much as we read about on blogs.
I think there are many people who do want to hear from experts, myself included. Scientists do need to communicate better and the peer review process is flawed, as the link to Daniel Lemire’s (a scientist) on my next blog post shows. I’m also finding better information on nuclear radiation from two mainstream media outlets, The Guardian & the the CS Monitor, who are bringing science to the masses.
I’d like to be clear on my use of wikipedia. I used it to confirm a unit of measurement. The article that was re-published by MIT was what influenced my understanding of the situation. Further articles have clarified my understanding, like commentary from A Man with a PhD blog.
I have spent twenty years in my own field but I have to justify my work with each new client, as I’m self-employed. That means I have to simplify things for common understanding. I don’t expect my clients to deeply understand human cognition or the myriad of social media platforms.
I think it’s difficult for the average person to just pick up the phone and call a stranger for advice, though. But thanks for reaching out, Rick, and through the wonders of social media I now have a contact if I want to explore chemical reactivity or better understand scientific research. All in all, this has been a learning experience for me and that’s been the objective of my blogging here for the past seven years.