Many people tonight appreciated Rachel's explanation of what is happening within the ailing nuclear reactors in Japan. I've taken what Rachel said tonight and adapted it a little for blog format for those of you who want to share it or read through it at your own pace.
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The nuclear fuel rods in a reactor like the ones that are in trouble in Japan are about 12 feet long -- and they're skinny. Calling them rods isn't exactly right because they're not solid. They're straws. They're hollow.
The straws themselves are made of a metal called zirconium, and inside that metal straw is uranium.
When the reactor is working, the uranium pellets inside the fuel rods are creating fission. They're creating a nuclear reaction in order to generate heat.
The whole point of nuclear power is that you create an environment in which fission happens -- a nuclear chain reaction happens, but it's controlled so it doesn't produce an explosion. It generates heat in a controllable way instead. You use that heat to boil water. The boiling water makes steam, the steam spins a turbine, and that makes electricity. That's the basic idea behind these forty-year-old reactors in Japan that are in so much trouble now.
When a reactor is shut off, either in the normal course of events, or because of something like an earthquake, the nuclear reaction is stopped. To do that, a bunch of control rods are moved in among the fuel rods. The control rods stop the nuclear reaction from happening, in an orderly way.
Did you ever have the chance to develop a photo in a real darkroom? You put the photo in a developer solution until the image comes in the way you want it, and then once it's the way you want it, you put it in a different chemical bath to stop the developing. That's like the control rods. They stop the nuclear chain reaction.
But those fuel rods, those pellets of uranium inside the metal straws, even when the reactor is turned off, are still wicked hot. And so even though the reactor is off and it's not being used to boil water to make steam to spin turbines to make electricity anymore, the fuel rods still have to stay underwater. Because otherwise they're just too hot to keep it together -- to maintain their integrity. They'll melt.
The first thing that happens is the metal on the long metal tubes oxidizes -- it essentially just rusts really, really fast. And as you know from what happens in normal life when something rusts, it breaks down. It bubbles, cracks, splits. Damage to those fuel rods is a partial meltdown.
As the water level drops and the fuel rods are exposed to the air and the metal straws of the fuel rods oxidize, one of the gases produced is hydrogen, which can be explosive.
Authorities believe that a hydrogen explosion is what happened in two of the reactors at the Fukushima Daiichi plant. When we were told this weekend after the first explosion at the Daiichi nuclear plant, that authorities had detected radioactive iodine and cesium in the atmosphere, what did that mean? Why were they detecting those radioactive elements in the atmosphere? Those detections were an indication that the fuel rods had been damaged, which let some of the radioactive elements in that nuclear fuel, get released.
That is not good. That is a partial nuclear meltdown.
That is also not the same as a total nuclear meltdown, which they're still working to stave off.
The explosions that happened at two reactors at the Daiichi nuclear plant in Fukushima on Saturday and on Monday Japan time are not nuclear explosions. They're explosions caused by the inability to keep those fuel rods underwater and cool. The radioactivity released so far has been a sign that fuel rods were damaged. The steam that's being vented -- that's being let out into the atmosphere to avoid the pressure building up too high around the reactor -- that's mildly-radioactively-contaminated steam, contaminated by the fuel rods being at least partially compromised.
They have kept up efforts to submerge the fuel rods in seawater even after they knew they were damaged -- in order to prevent any further damage. As I said -- what they think they've got, is a partial meltdown. They're trying to avoid an uncontrolled total meltdown, in which the fuel rods break down totally -- and the uranium slumps down into the bottom of the reactor in what is essentially like radioactive lava -- burning (I think) at several thousand degrees Fahrenheit.
If that happens, that pile of hot radioactive goo will burn through most everything around it, and we'll be hoping that these last-line-of-defense containment structures are actually capable of containing that melted fuel and keeping it from the outside world and from the Earth. Because if they're not, that would entail a much larger release of radioactivity.
Tonight, just hours ago, we got word that a third explosion had been heard onsite at the Fukushima plant.
There are three reactors there they were worried about at Daiichi. Two of them had hydrogen explosions on Saturday and early today Japan time. Now it appears that the third reactor has suffered an explosion as well. The first two reactor explosions, authorities say, did not result in an unconstrained large radioactive release -- containment vessels had survived the blast.
Tonight, reports from Japan indicate that the third blast may be more serious -- that it may have resulted in a breach of the internal containment vessel. For the first time.
An explosion is not the same as a meltdown. An explosion at a nuclear reactor is not the same as a nuclear explosion. What's happened is that the inability to keep enough water circulating over those fuel rods to keep them cool has resulted in damaged nuclear fuel rods. And that's caused three explosions so far.
And that has provided us with the only conceivable thing that could make the whole world look at the horrible devastation in Japan and think we're as-yet worried about something else, about what might happen next.
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Thanks so much for this explanation! I think for the first time in my life I actually understand how nuclear power works!
Of course I wish I had learned this under different circumstances.
But as it is.... Rachel if this TV Gig doesn't work out... you may have a second calling as a teacher!
Thanks again... Sending all good thoughts to the Japanese people.
I'm kinda disappointed you invited on all the anti-nuclear biased scientists to play the alarmist tune... I know the rest of the media is doing it but it doesn't have to be you as well. It's especially bad when you consider that the UCS supported legislation that OUTLAWS the reprocessing of spent nuclear fuel. The Nuclear Waste problem in the US exists SOLELY because it is illegal to reprocess USEFUL leftovers into usable fuel. So, just a little hint... the UCS are incredibly biased against Nuclear power.
As a liberal and a physicist I'm often frustrated by the constant misunderstanding and misinformation that is spread by other liberals who are biased against nuclear power. Chernobyl is the energy generation equivilent of politic's "Nazi". Seriously. Nuclear power now-a-days is at least a thousand times safer than Chernobyl and what is going on now in Japan is actually an amazing testament to how unbelievably well designed and SAFE those plants are.
Here are some links to get you educated:
I understand hysteria and alarmism gets the media more viewers... but I think that you, Rachel, and your team at the Rachel Maddow Show are some of the few people who are likely to go a bit futher and do a bit more research and rise past the base fear mongering of most every other media outlet.
I don't think she engaged in any sort of alarmism.
I think the point is that no matter how safe we design a nuclear power plant. We can run into disasters like this one that show we're not as smart as we think we are.
I say this shows the natural danger of creating electricity in this manner.
I agree that today's show was pretty damn good, but to be fair if you are going to show the 'dangers of creating electricity in this manner' rather than just limiting yourself to explaining the current crisis, you should explain that nuclear is orders of magnitude safer than coal burning, even from a radiation viewpoint.
If you could replace every coal plant in america with a nuclear one tomorrow you would save 20-30 thousand lives a year, even allowing for these events.
I like Rachel's 'explain the problem in Japan' take without getting too much into the energy debate. This isn't the time for it.
I think your comment that this is a testament to how well designed the nuclear plants are is a bit early. It remains to be seen YET how this pans out. If there is any reason to be "alarmist" well, I'd say this is it.
How many people will die in surrounding countries from contamination of the air, soil, water, fish, ect.
The real question is whether the U.S. should monitor/restrict sea food from Japan for the next few months until we know our risks.
Reactor 2 is not holding pressure and it is likely the heat exchanger has cracks. That is bad because this let out the water that was cooling the fuel while neutrons dissipate. Exposed fuel rods will crack. Tokyo Electric is circulating sea water through a part of the system never intended to hold sea water, so it is likely that some fuel is leaking into the ocean.
Seriously? Our government wont' even truthfully monitor the seafood from the Gulf regarding the oil spill. If we trust the government on what you put in your mouth, we only have ourselves to blame. DON'T EAT IT is the only safe way.
And apparently my links didn't go through?
Copy and Paste these, then.
There is a large difference between the BWR design and the PWR.
The PWR uses a tube boiler (steam generator) that is inside the reactor containment structure. The basic tube boiler design goes back more than a 100 years, and form the basis of fossil fuel boilers in particular the very high pressures possible, and also of a dry turbine cycle. The fossil plant has efficiency of 40%, but the key always is the strength of steel at the temperature maximizing the efficiency and the design where diameters are minimized. Compare the inside /outside diameter of the individual tubes. This small diameter and high pressure and high temperature cannot be transferred to a nuclear plant, except using the PWR steam generator design, but the primary nuclear boiler is just big pot. Making a large pressure vessel to hold a pressure that is anywhere near those seen in fossil boiler at anywhere near the temperature of the fossil boiler is not possible. The result is much a lower temperature and pressure, so low that the steam is delivered wet, a condition not seen in fossil plants, but complicate nuclear plant design.
The PWR and its steam generator are in separate vessels in the same building where as the BWR has effectively taken the steam generator into the reactor vessel, greatly complicating the internal design. Designing a PWR reactor is similar enough as far as the reactor core looks to a BWR. But the PWR is not subject to the violence of boiling because its pressure is double that of BWR. To accommodate all the added equipment into the reactor vessel the BWR vessel is twice as large but half the pressure. One look at all the equipment inside a BWR and a second look at the original safety systems and a third look at all the add-ons since the original design tells us that the BWR is much more complicated design. This cannot be overlooked in any comparison of making an overall safe design, the more parts, the more complicated, the more complicated the more likely that some part will fail or become useless. The impact of this design difference does not just end with one level of complexity, but goes on to impact other aspects. The doubling of the size of the reactor means that the domed cylinder design containment building of the PWR is not feasible for the BWR. Every time the details the design comes down to the strength of steel and concrete facing high pressure, and high volumes of steam the number of design alternatives explodes. An experienced modeler would be attracted to a whole collection of the BWR containment designs, designs that result from trying to handle more and more steam. On one sense the PWR can be made safer sooner that the BWR ever could be, if the steam volume is minimized, (or compartmentalized). Not the least is the fact that steam for the turbine in the PWR does not pass through the reactor becoming radioactive, this means that entire turbine-generator build has to have additional shielding protection adding to its mass, and even reduced the work space to premium.
The simple fact that venting hydrogen created from the uncovered core of the BWR is not isolated to the reactor, but throughout the steam suppression system is dauntingly unsafe. Exploding buildings is not a design safety feature is long term failure to redress the complexity of the BWR design, a design that possible should have never been attempted, should not exist, and should phased out.
The fact that tsunami caused the multiple failures of the backup emergency power systems, is little comfort, as we now can say without any doubt that these backup power system are as vital as any other safety measures, for days weeks and mouths after an accident. More so we should look at the PWR system and upgrade their reactor designs to fully implement separate dual turbine buildings making redundant design part of every system. These failures show that the goal of nuclear power cannot be reached is we compromise simplistic design goals, with ever more elaborate and examples after the fact safety systems.
Again exploding building might suggests another addon like passive hydrogen re-combiners but should suggests not making the explosive conditions in the first place.
Keep your reactor cool forever.
Many, many thanks to you, Rachel, and your staff, for presenting an informative and excellent program tonight! To be informed helps - even if the information is uncomfortable to hear. The old saying that the "unknown can be scarier than the known", is so true.
I continue to be so proud of a graduate of my old high school - CV - and how far you have gone with your life. Not to mention how much your wisdom and hard work has helped further the truth that we need to hear in these trying times. Be safe and God bless.
Kindest regards. Kathy
So isn't this a good time to go Solar? There is a big nuclear power plant in the sky, and there is no waste or risks of accidents. Don't get me wrong I believe in safe nuclear energy...but I am starting to wonder if now is the time to leap forward towards a solar powered future. Grow the petroleum products we still need with hemp or corn or soy or biomass of your choice and save the family farms. The rest can be solar. No more reliance on the Middle East for our energy needs. Call me a dreamer, but I'm not the only one.
If you drive down I-80 through Nebraska and Iowa you will see many new wind turbine generators.
We are on our way to something safer.
-- Gabrielle Giffords, address to the Solar Economic Forum, 10 September 2009
So let's change our perception.
Thank you Gelsamel. My husband, previously worked in nuclear industry, has been very frustrated with the bad information coming from media sources that have good reputations, such as NYT. note fourth paragraph here
Thanks for the great explanation. I am also concerned about the anti nuclear bias in the news. As far as all the toxins released by the nuclear reactors, it is minuscule in comparison to all the toxins released by a coal fired plant. It is imperative that we develop more nuclear power plants so we can shut down the truly dangerous coal plants.
Gelsamel
Actually, the 'alarmists', as you call them, are more likely to be correct this time.
Radiation levels around the Fukushima plant are currently eight times in one hour what is considered the safe level for a whole year. The way the Japanese deal with transparency over nuclear matters requires one to necessarily take a pessimistic view of matters, unfortunately.
Also, many people have warned of the added dangers of using Mox fuel in reactors (from reprocessing, often of decommissioned nuclear warheads) and I fear they will be proven correct with the way Fukushima is proving harder to contain than a lot of experts hoped.
Thanks for the links, Gelsamel. Although Rachel's coverage lacked many details, I didn't particularly find it to be "alarmist" or "fear mongering." The unconfirmed reports of damage to containment units were not even mentioned in the links you provided. In fact, the one page even says, "UPDATE: It is now the case that there are issues at a couple of the power reactors, and the above is not strictly accurate."
This is obviously a developing story, and I really appreciate Rachel's even-handed approach to important issues like this.
Nuclear radiation cannot be seen, felt, tasted, or smelled, but it does cause cancer. When there is a melt-down and radiation escapes into the atmosphere, people can easily die from it over the next ten years or so, but they do not know what has killed them – they just have cancer and die. That is how the nuclear industry apologists are able to say that no one died from radiation at 3 Mile Island. That was also how they were able to minimize the number of radiation deaths from Chernobyl. A Ukrainian minister of health later said the deaths there were actually in the hundreds of thousands, but that received virtually no publicity in this country. By the way, you may recall that the radiation cloud from Chernobyl spread around the world (in 1986). Who knows how many cancer deaths in the U.S. were caused by that.
Plutonium 239, one of the most dangerous components of spent fuel rods, has a half life of 24,000 years. (See the U.S. Govt. Nuclear Regulatory commission website at )
Fuel rods contain hot, volatile radioactive material and they have to be cooled for thousands and thousands of years after they are used. When they are not cooled, you can have meltdowns and massive releases of radiation. That's why the spent fuel rods are perhaps the most dangerous aspect of nuclear power.
Spent fuel rods are being kept in cooling pools all over this country, generally next to the nuclear power plants where they were used. In Japan, apparently they are keeping the spent fuel rods from the Fukushima reactors in the same building as Reactor #4. This is one of the reactors that is on fire now (as of March 14, 2011).
This is grim stuff.
The story that is not being talked about is the inherent design flaw in pressurized water reactors. The cladding that wraps the fuel rods has another function other than keeping fission products out of the cooling water system - it has to keep water off the fuel rods else a violent chemical reaction will occur, highly accelerated oxidation of a exotic metal whose byproduct is copious amounts of Hydrogen, the same element that gave the Hindenburg its lift, and later is fiery drop. And since the temperature of this localized environment is extremely hot, this reaction will be even more accelerated - it's a nightmare scenario for Nukes (nuclear operators).
So when the cooling water is applied to a reactor with compromised fuel-cladding as a last resort to prevent meltdown, especially seawater in this case, it is known that there will be a huge amount of Hydrogen formed very quickly. This chemical consequence is inherent in the design of a pressurized water reactor.
It is not as well known but there is another way of providing electricity from fission than using really expensive pressurized water reactor: gas-cooled reactor. A GCR has limitations compared to a PWR such as less power per cubic foot, they are smaller and have to be built in clusters. Yet on top of being somewhat safer (no water, no Hydrogen bubbles ready to Hindenburg) they are much cheaper to build because they coolant systems operate at a much lower system pressure.
I'm not an expert but having worked on pressurized reactors in the Navy, I chose not to enter the Civilian Nuclear Industry because that design always bothered me - the fuel and the water do not mix safely. I'd love to hear the discussion on energy policy address gas-cooled reactors if we must have nuclear power in this country and a comparative study on the associated costs of the different designs as well as safety issues. I mean it would be nice if there was a situation where emergency cooling was required and the roof didn't blow off the building(s).
Billy, the plants in Japan that are in trouble are BWRs, not PWRs. Maybe you should revisit your textbooks.
Also, the hydrogen comes from a chemical reaction between water and zirconium in the fuel cladding, not water and fuel itself. (Zr + 2H2O = ZrO2 + 2H2)
There were NO restrictions on imports of foods from Europe to Australia after Chernobyl.....I stopped buying ANY tinned products from Europe and people thought I was silly....
One thing that nobody has considered is a tax deduction, federal subsidy, and mandate to use photovoltaic roof shingles during construction and re-roofing.
Photovoltaics produce about 10 watt/ft^2 so a 1,000 square foot home could produce up to 10KW at noon if fully roofed with solar shingles.
This kind of power has is on the verge of being cost competitive and government policy would drive a major change.
WOW!!!!!
it is really, really important to NOT assume that authorities in japan don't know what they are talking about or have something to hide just because they are speaking Japanese which of course, American reporters can't understand. The reporter that Rachel had on Monday's show from Tokyo seemed to come dangerously close to that attitude
i normally applaud rachel's research but unfortunately with chernobyl she has gotten it all wrong. as reported in the sunday times reporting on a recent report on the accident by the u.n. the total number dead that can be directly attributed to exposure to radiation is 56 people. that's it. it's unfortunate that that many died but it is a far cry from the irrational anti-radiation people who know nothing of the science/physics invovled. question why are the places in this country where cancer rates are the lowest have the highest levels of background radiation? some people try to say there's a difference between background radiation and radiation from nuclear power plants but radiation is radiation doesn't matter if it occurs naturally or is from something man made. scientific evidence is indicating that exposure to less than 500millirems is not only not bad for you but might actually be good for you. i have spent hundreds of hours researching this and learning nuclear physics. knowledge is power. there's a bbc program called horizons and they did a special a few years ago on the 20th anniversary of chernobyl called new nuclear nightmares that cuts through all the propaganda perpetrated by the anti-nuclear activists. let the flaming begin...hehehe.
I'd like to hear your explanation for the sudden spike in infant mortality rates in the ares surrounding 3mile island.
none of it has been directly attributable to radiation exposure. also other indirect indicators of radiation exposure are not present like increased cancers etc. you show me scientific evidence published in peer reviewed journals that directly attribute those imr's to radiation and i'll stand corrected but i doubt you will because i have looked.
@kellen just an fyi imr's in the united states are the second highest in the modern world at 6.06 deaths/1000 live births (2011). so sorry please site your evidence so that i can fact check. my evidence comes from here:
the world factbook
and here
articlesdotcnndotcom2006-05-08/health/mothers.index_1_mortality-rate-death-rate-world-s-mothers?_s=PM:HEALTH
two reputable sources that are accepted and are high on the hierarchy of evidence pyramid.
sorry can't post links so i did the best that i could. however if you do a simple google search they both rate highly on that search.
There was a Frontline report with interviews from residents of the area stating that the big studies were trimmed down after they began. There have been studies of the rise in infant mortality rates and childhood cancer in the region. They are above the national average.
I have many friends that lived in Harrisburg and noticed an increase in cancer in their immediate families (meaning all my friends had at least one immediate family member with cancer). They've not been included in any study. I also know that many are just now developing thyroid conditions.
I think the long-term studies just aren't being done.
there's a big difference between civilians complaining and actual scientific evidence. the facts are there have been no cancers tied to the civilians in and around 3 mile island, even rachel maddow reported this fact. it's because of peoples irrational fears of radiation that causes them to assume that any illness they get is because of the radiation exposure which btw if there were going to be any cancers they would have already happened. hard cancers appear 20 - 25 yrs after exposure and we're well outside that timeline at this point. score another point to science. and btw your evidence based on your own immediate experience is called anecdotal evidence and is on the lowest rung of the hierarchy of evidence right next to heresy. and while people may be developing thyroid conditions it is not from 3 mi island because that is a hard cancer and they show up within 20 - 25 years and we're over 30 years out from that accident. soft cancers like leukemia show up within 10 years...this is all non controversial and can easily be googled.
none of it has been directly attributable to radiation exposure. also other indirect indicators of radiation exposure are not present like increased cancers etc. you show me scientific evidence published in peer reviewed journals that directly attribute those imr's to radiation and i'll stand corrected but i doubt you will because i have looked.
I grew up in a town with a nuke plant. Not a nuclear power plant an actual bomb making nuke plant. THERE IS NOTHING good about having one in your back yard. They leak, they never tell you the truth when there is a leak, they contaminate everything around them and then some. There used to be tritium leaks, and they would say oh its not harmful or it's only harmful if it rained that day, which it did at times. They finally closed down, and payed the city alot of cash. Filled in the swimming pool with dirt and grass because of the contamination, explained the local park was contaminted, but OK if you didn't eat any dirt and they closed it permanently, They built a skate park over the old pool to make it seem all better. They found plutonium in my relatives creek several miles away, and said oh its ok, and began building business over the contaminated land. Some people that work there still have to be checked for radiation exposure, but hey the rents cheap. All they did was fill all the big holes in with dirt and left the plutonium there to seep into the ground over the next thousand years, because there is no way of destroying it. There is an incredibly high risk and high numbers of cancer incidents in the town. I am a victim of those statistics or I guess we can't really prove it, but they can't seem to deny it either.
again it all depends on the rate of exposure. here's some facts that should put things into perspective.
20 ciggs a day leads to 6 years lost
15% overweight leads to a loss of 2 yrs of life
all accidents leads to a loss of 207 days of life
exposure to 300mrem/year leads to a loss of 15 days of life
exposure to 1rem/year leads to a loss of 51 days of life.
so based on the facts i'm much more worried about my weight and the fact that i smoke ciggarettes than i am about being exposed to radiation. just put things in more focus chernobyl high estimates are around 500mrem of radiation average exposure. so if you want to be an ostrich go for it i will rely on logic and reason and the science that it's founded on.
Well I'm going to assume that you never lived in a town with a nuke plants so your credibility to the results of such a life are null and void. All your statistics are self inflicted nuke plants are just buit even when you don't want them and you are forced to just live with that or move when you oh ya your home value drops and the health damages are already done. Also your losing 6yrs off your I'm assuming 72yr life span or 2yrs is no comparison to dying within days of cancer and a lifetime of wondering if you beat when it will come back. So I'm relying on logic, reason, life experience, common sense, and the medical science that I have been shown.
um actually you logic is completely nonsensical. just because i haven't lived somewhere doesn't mean i don't anything. so just because i don't live in the gulf states i can't say anything about the gulf spill? silly and ignorant. again i rely on scientific evidence. all that stuff i posted above are from the scientists and can be found on the nrc site, doe site, and numerous university physics sites. just like i don't believe in god i don't believe in anecdotal evidence that has no basis in fact ie your anecdotal conclusions. again if radiation is so bad for you we'd be dead because we're constantly being bombarded by radiation. also the areas of this country with the highest levels of radiation have the lowest cancer rates. so you go off and be an ostrich totally afraid of the silliest things i will continue to move through relying on science, logic and facts.
Will, FYI, nuclear fuel does not 'burn,' if you meant as in actual flaming/burning/fire, such as what was seen at Chernobyl. What burned at Chernobyl was actually the graphite from the control rods, which the Japanese reactors do not have.
I suggest we be as calm and logical about this as possible. I am not exactly "cool" with what's happening there, but I am also hardly in a panic, either. Right now, the Japanese really do have the situation as close to under control as you can get, remember that Chernobyl went from emergency to full nuclear meltdown in just a few hours, and that the real catastrophe there was the lack of an external containment facility, which the Japanese reactors have.
Gelsamel- can you please share the links or outlets from which we can do some proper research? I'm very interested.
Thank you.
I did so in my 2nd post. For some reason my initial post did not keep them in there when I sent the message. For those who have responded to my previous post I'd ask you read some of the info there.
You explanation about the nuclear accident in Japan is the best I have seen so far. I give you "B" ... you missed the fact that the closer the uranium is together the greater the chain reaction and thus the greater the temperature ... an the melting of the rods basically brings more uranium closer together making it hotter and thus melting more rods. You also missed how the increased temperature increases the pressure and makes it more difficult to inject cooling water.
You should try asking President Carter for an explanation. He was trained as a Nuclear Engineer and was the Captain of a Nuclear Submarine.
There is one aspect of this story I've heard nothing about from any station. I have heard no one ask about imports. The USS Ronald Reagan traveled through a radio active cloud yeasterday. They had to reroute the ship and scrub for radioactivity.
While Chernobyl was terrible, we import little from that part of the world. The same can not be stated for Japan and Asia. Who is monitoring shipments coming into the USA for radioactivity and will anyone be sending back shipments that are contaminated?
I love my Ipod and TV as much as the next American but I don't want a radioactive one and the last thing I want to do is give a child a cancer causing teddy bear.