Just the facts! Japanese Nuke Plants

Added note 03/15/11 05:50PST.. As you know, this is here because we DIYers are fascinated by all power sources, most of us are by no means experts, but due to our curious nature, we generally know more about these plants than the average fast food server.

I think there’s some notable lessons here that we can apply to our own off grid (non nuke:-) designs and I have written about some of them before. It goes right back to KISS. One Nuke plant expert was critical of this 40 year old GE plant design because it was borrowed from a submarine, very compact  and he thought it was not all that well suited for stationary use. I didn’t get his message at first, but as this plant failure unfolds I understand his criticism better. 

I like thermal  siphon cooling tanks for listers, it’s bulky, but when properly designed, you don’t need a water pump, if it’s not part of the design, it doesn’t fail!

Apparently.. the nuke designers believe in KISS as much as we do, newer nuclear power plants have been optimized for shore duty, and when the moderator rods are inserted, and the core shut down, there’s a thermal siphon cooling loop that will dissipate all of the heat load from a shut down core, no pumps, no electricity required! Even at this hour, we have no clue if this reactor in Japan is producing higher radiation levels from hydrogen gas emissions OR from a far more serious source… an exposed core. 

Those who want every Nuclear Reactor in the World shut down likely have no idea of the impact… so we’ll see together how humanity sorts this out.      

       

 

 

We’ve learned you can’t count on the Meda for the facts, we also know we can count on the rabid anti-nuke crowd to insert their BS. Following is a post made by “BI Nuke Expert” on insider business comment page. I’m confident this person has the facts, and understands this vantage of reactor very well.

Media has not disappointed me in hyping the story to attract viewers or readership, it’s what they do for a living.

I’m still betting that the Nukes pose the greater fear, but… best to focus on the more critical elements.. getting people out of the rubble piles, medical attention, food, water, and sanitation. This is not Hati, but disease can spread rapidly, especially in areas with high population densities. 

Added note 3/14/2011 2154 hrs PST.  I haven’t seen any fall out shelters for sale here  yet, but some of the Anti nuke, anti everything people want to shut off all our reactors already. These explosions really make for good TV! That hydrogen is nasty stuff, especially when you have a good fuel air ratio and an ignition source.. BOOM! But what radioactive elements are in these gasses, and how long before they decay into nothing?  The really bad stuff is inside that vessel, and many experts say it’s likely it’ll stay there. 

Meanwhile, people are cold, hungry, without food or sanitation. As we know, these are the things that can kill a lot of people quickly. God help Japan..   

BI Nuclear Expert on Mar 13, 3:44 PM said:

I repeat, there was and will *not* be any significant release of radioactivity.

By “significant” I mean a level of radiation of more than what you would receive on – say – a long distance flight, or drinking a glass of beer that comes from certain areas with high levels of natural background radiation.

I have been reading every news release on the incident since the earthquake. There has not been one single report that was accurate and free of errors (and part of that problem is also a weakness in the Japanese crisis communication). By “not free of errors” I do not refer to tendentious anti-nuclear journalism – that is quite normal these days. By “not free of errors” I mean blatant errors regarding physics and natural law, as well as gross misinterpretation of facts, due to an obvious lack of fundamental and basic understanding of the way nuclear reactors are build and operated. I have read a 3 page report on CNN where every single paragraph contained an error.

We will have to cover some fundamentals, before we get into what is going on.

The plants at Fukushima are so called Boiling Water Reactors, or BWR for short. Boiling Water Reactors are similar to a pressure cooker. The nuclear fuel heats water, the water boils and creates steam, the steam then drives turbines that create the electricity, and the steam is then cooled and condensed back to water, and the water send back to be heated by the nuclear fuel. The pressure cooker operates at about 250 °C.

The nuclear fuel is uranium oxide. Uranium oxide is a ceramic with a very high melting point of about 3000 °C. The fuel is manufactured in pellets (think little cylinders the size of Lego bricks). Those pieces are then put into a long tube made of Zircaloy with a melting point of 2200 °C, and sealed tight. The assembly is called a fuel rod. These fuel rods are then put together to form larger packages, and a number of these packages are then put into the reactor. All these packages together are referred to as “the core”.

The Zircaloy casing is the first containment. It separates the radioactive fuel from the rest of the world.

The core is then placed in the “pressure vessels”. That is the pressure cooker we talked about before. The pressure vessels is the second containment. This is one sturdy piece of a pot, designed to safely contain the core for temperatures several hundred °C. That covers the scenarios where cooling can be restored at some point.

The entire “hardware” of the nuclear reactor – the pressure vessel and all pipes, pumps, coolant (water) reserves, are then encased in the third containment. The third containment is a hermetically (air tight) sealed, very thick bubble of the strongest steel. The third containment is designed, built and tested for one single purpose: To contain, indefinitely, a complete core meltdown. For that purpose, a large and thick concrete basin is cast under the pressure vessel (the second containment), which is filled with graphite, all inside the third containment. This is the so-called “core catcher”. If the core melts and the pressure vessel bursts (and eventually melts), it will catch the molten fuel and everything else. It is built in such a way that the nuclear fuel will be spread out, so it can cool down.

This third containment is then surrounded by 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 explosion, but more to that later).

Fundamentals of nuclear reactions:

The uranium fuel generates heat by nuclear fission. Big uranium atoms are split into smaller atoms. That generates heat plus neutrons (one of the particles that forms an atom). When the neutron hits another uranium atom, that splits, generating more neutrons and so on. That is called the nuclear chain reaction.

Now, just packing a lot of fuel rods next to each other would quickly lead to overheating and after about 45 minutes to a melting of the fuel rods. It is worth mentioning at this point that the nuclear fuel in a reactor can *never* cause a nuclear explosion the type of a nuclear bomb. Building a nuclear bomb is actually quite difficult (ask Iran). In Chernobyl, the explosion was caused by excessive pressure buildup, hydrogen explosion and rupture of all containments, propelling molten core material into the environment (a “dirty bomb”). Why that did not and will not happen in Japan, further below.

In order to control the nuclear chain reaction, the reactor operators use so-called “moderator rods”. The moderator rods absorb the neutrons and kill the chain reaction instantaneously. A nuclear reactor is built in such a way, that when operating normally, you take out all the moderator rods. The coolant water then takes away the heat (and converts it into steam and electricity) at the same rate as the core produces it. And you have a lot of leeway around the standard operating point of 250°C.

The challenge is that after inserting the rods and stopping the chain reaction, the core still keeps producing heat. The uranium “stopped” the chain reaction. But a number of intermediate radioactive elements are created by the uranium during its fission process, most notably Cesium and Iodine isotopes, i.e. radioactive versions of these elements that will eventually split up into smaller atoms and not be radioactive anymore. Those elements keep decaying and producing heat. Because they are not regenerated any longer from the uranium (the uranium stopped decaying after the moderator rods were put in), they get less and less, and so the core cools down over a matter of days, until those intermediate radioactive elements are used up.

This residual heat is causing the headaches right now.

So the first “type” of radioactive material is the uranium in the fuel rods, plus the intermediate radioactive elements that the uranium splits into, also inside the fuel rod (Cesium and Iodine).

There is a second type of radioactive material created, outside the fuel rods. The big main difference up front: Those radioactive materials have a very short half-life, that means that they decay very fast and split into non-radioactive materials. By fast I mean seconds. So if these radioactive materials are released into the environment, yes, radioactivity was released, but no, it is not dangerous, at all. Why? By the time you spelled “R-A-D-I-O-N-U-C-L-I-D-E”, they will be harmless, because they will have split up into non radioactive elements. Those radioactive elements are N-16, the radioactive isotope (or version) of nitrogen (air). The others are noble gases such as Xenon. But where do they come from? When the uranium splits, it generates a neutron (see above). Most of these neutrons will hit other uranium atoms and keep the nuclear chain reaction going. But some will leave the fuel rod and hit the water molecules, or the air that is in the water. Then, a non-radioactive element can “capture” the neutron. It becomes radioactive. As described above, it will quickly (seconds) get rid again of the neutron to return to its former beautiful self.

This second “type” of radiation is very important when we talk about the radioactivity being released into the environment later on.

What happened at Fukushima

I will try to summarize the main facts. The earthquake that hit Japan was 7 times more powerful than the worst earthquake the nuclear power plant was built for (the Richter scale works logarithmically; the difference between the 8.2 that the plants were built for and the 8.9 that happened is 7 times, not 0.7). So the first hooray for Japanese engineering, everything held up.

When the earthquake hit with 8.9, the nuclear reactors all went into automatic shutdown. Within seconds after the earthquake started, the moderator rods had been inserted into the core and nuclear chain reaction of the uranium stopped. Now, the cooling system has to carry away the residual heat. The residual heat load is about 3% of the heat load under normal operating conditions.

The earthquake destroyed the external power supply of the nuclear reactor. That is one of the most serious accidents for a nuclear power plant, and accordingly, a “plant black out” receives a lot of attention when designing backup systems. The power is needed to keep the coolant pumps working. Since the power plant had been shut down, it cannot produce any electricity by itself any more.

Things were going well for an hour. One set of multiple sets of emergency Diesel power generators kicked in and provided the electricity that was needed. Then the Tsunami came, much bigger than people had expected when building the power plant (see above, factor 7). The tsunami took out all multiple sets of backup Diesel generators.

When designing a nuclear power plant, engineers follow a philosophy called “Defense of Depth”. That means that you first build everything to withstand the worst catastrophe you can imagine, and then design the plant in such a way that it can still handle one system failure (that you thought could never happen) after the other. A tsunami taking out all backup power in one swift strike is such a scenario. The last line of defense is putting everything into the third containment (see above), that will keep everything, whatever the mess, moderator rods in our out, core molten or not, inside the reactor.

When the diesel generators were gone, the reactor operators switched to emergency battery power. The batteries were designed as one of the backups to the backups, to provide power for cooling the core for 8 hours. And they did.

Within the 8 hours, another power source had to be found and connected to the power plant. The power grid was down due to the earthquake. The diesel generators were destroyed by the tsunami. So mobile diesel generators were trucked in.

This is where things started to go seriously wrong. The external power generators could not be connected to the power plant (the plugs did not fit). So after the batteries ran out, the residual heat could not be carried away any more.

At this point the plant operators begin to follow emergency procedures that are in place for a “loss of cooling event”. It is again a step along the “Depth of Defense” lines. The power to the cooling systems should never have failed completely, but it did, so they “retreat” to the next line of defense. All of this, however shocking it seems to us, is part of the day-to-day training you go through as an operator, right through to managing a core meltdown.

It was at this stage that people started to talk about core meltdown. Because at the end of the day, if cooling cannot be restored, the core will eventually melt (after hours or days), and the last line of defense, the core catcher and third containment, would come into play.

But the goal at this stage was to manage the core while it was heating up, and ensure that the first containment (the Zircaloy tubes that contains the nuclear fuel), as well as the second containment (our pressure cooker) remain intact and operational for as long as possible, to give the engineers time to fix the cooling systems.

Because cooling the core is such a big deal, the reactor has a number of cooling systems, each in multiple versions (the reactor water cleanup system, the decay heat removal, the reactor core isolating cooling, the standby liquid cooling system, and the emergency core cooling system). Which one failed when or did not fail is not clear at this point in time.

So imagine our pressure cooker on the stove, heat on low, but on. The operators use whatever cooling system capacity they have to get rid of as much heat as possible, but the pressure starts building up. The priority now is to maintain integrity of the first containment (keep temperature of the fuel rods below 2200°C), as well as the second containment, the pressure cooker. In order to maintain integrity of the pressure cooker (the second containment), the pressure has to be released from time to time. Because the ability to do that in an emergency is so important, the reactor has 11 pressure release valves. The operators now started venting steam from time to time to control the pressure. The temperature at this stage was about 550°C.

This is when the reports about “radiation leakage” starting coming in. I believe I explained above why venting the steam is theoretically the same as releasing radiation into the environment, but why it was and is not dangerous. The radioactive nitrogen as well as the noble gases do not pose a threat to human health.

At some stage during this venting, the explosion occurred. The explosion took place outside of the third containment (our “last line of defense”), and the reactor building. Remember that the reactor building has no function in keeping the radioactivity contained. It is not entirely clear yet what has happened, but this is the likely scenario: The operators decided to vent the steam from the pressure vessel not directly into the environment, but into the space between the third containment and the reactor building (to give the radioactivity in the steam more time to subside). The problem is that at the high temperatures that the core had reached at this stage, water molecules can “disassociate” into oxygen and hydrogen – an explosive mixture. And it did explode, outside the third containment, damaging the reactor building around. It was that sort of explosion, but inside the pressure vessel (because it was badly designed and not managed properly by the operators) that lead to the explosion of Chernobyl. This was never a risk at Fukushima. The problem of hydrogen-oxygen formation is one of the biggies when you design a power plant (if you are not Soviet, that is), so the reactor is build and operated in a way it cannot happen inside the containment. It happened outside, which was not intended but a possible scenario and OK, because it did not pose a risk for the containment.

So the pressure was under control, as steam was vented. Now, if you keep boiling your pot, the problem is that the water level will keep falling and falling. The core is covered by several meters of water in order to allow for some time to pass (hours, days) before it gets exposed. Once the rods start to be exposed at the top, the exposed parts will reach the critical temperature of 2200 °C after about 45 minutes. This is when the first containment, the Zircaloy tube, would fail.

And this started to happen. The cooling could not be restored before there was some (very limited, but still) damage to the casing of some of the fuel. The nuclear material itself was still intact, but the surrounding Zircaloy shell had started melting. What happened now is that some of the byproducts of the uranium decay – radioactive Cesium and Iodine – started to mix with the steam. The big problem, uranium, was still under control, because the uranium oxide rods were good until 3000 °C. It is confirmed that a very small amount of Cesium and Iodine was measured in the steam that was released into the atmosphere.

It seems this was the “go signal” for a major plan B. The small amounts of Cesium that were measured told the operators that the first containment on one of the rods somewhere was about to give. The Plan A had been to restore one of the regular cooling systems to the core. Why that failed is unclear. One plausible explanation is that the tsunami also took away / polluted all the clean water needed for the regular cooling systems.

The water used in the cooling system is very clean, demineralized (like distilled) water. The reason to use pure water is the above mentioned activation by the neutrons from the Uranium: Pure water does not get activated much, so stays practically radioactive-free. Dirt or salt in the water will absorb the neutrons quicker, becoming more radioactive. This has no effect whatsoever on the core – it does not care what it is cooled by. But it makes life more difficult for the operators and mechanics when they have to deal with activated (i.e. slightly radioactive) water.

But Plan A had failed – cooling systems down or additional clean water unavailable – so Plan B came into effect. This is what it looks like happened:

In order to prevent a core meltdown, the operators started to use sea water to cool the core. I am not quite sure if they flooded our pressure cooker with it (the second containment), or if they flooded the third containment, immersing the pressure cooker. But that is not relevant for us.

The point is that the nuclear fuel has now been cooled down. Because the chain reaction has been stopped a long time ago, there is only very little residual heat being produced now. The large amount of cooling water that has been used is sufficient to take up that heat. Because it is a lot of water, the core does not produce sufficient heat any more to produce any significant pressure. Also, boric acid has been added to the seawater. Boric acid is “liquid control rod”. Whatever decay is still going on, the Boron will capture the neutrons and further speed up the cooling down of the core.

The plant came close to a core meltdown. Here is the worst-case scenario that was avoided: If the seawater could not have been used for treatment, the operators would have continued to vent the water steam to avoid pressure buildup. The third containment would then have been completely sealed to allow the core meltdown to happen without releasing radioactive material. After the meltdown, there would have been a waiting period for the intermediate radioactive materials to decay inside the reactor, and all radioactive particles to settle on a surface inside the containment. The cooling system would have been restored eventually, and the molten core cooled to a manageable temperature. The containment would have been cleaned up on the inside. Then a messy job of removing the molten core from the containment would have begun, packing the (now solid again) fuel bit by bit into transportation containers to be shipped to processing plants. Depending on the damage, the block of the plant would then either be repaired or dismantled.

I’d like to thank this guy for the time to make this post.. Ask yourself… what has man every built that has performed so far above the design criteria? Consider your car… this is like having a 100 MPH head on collision and finding your seat belt and air bag allowed you to walk away from the scene under your own power. What’s amazing, is this is a 40 year old plant, and the new designs are far better!
GB 

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25 Responses to Just the facts! Japanese Nuke Plants

  1. R S Johnson says:

    SIRS: Thank you most kindly for the post; send it to CNN and the Japanese News Net Works. They may use it, thus causing our news shows to not want to be upstaged and also passing this information on. Free people need to understand what is occurring rather just being offered the next commercial time slot.

    This document is the first well drafted and accurate presentation of the episode at the BWR type plant, a GE design. I will be forwarding this to friends who ask me what is occurring.

    These events must not stop the US from moving forward with Nuke power. Our energy costs need to become the lowest in the world so we can enjoy the benefits, (such as being able to pay off, not just make interest payments on) our outstanding National debt. RJ, USN ret

    • George B. says:

      RJ,
      There are plenty who think high priced energy is good for us. We know millions will die in the thrid world if energy rises in price. Some would say that would be a good thing.. on the other hand, they say a single life lost to a nuke accident is way too many. Their agenda is likely quite different than what they tell us.

  2. Bill knighton says:

    Nuclear energy is a good deal and it should be used. But it sounds like this person is engaged in some of what he is complaining about, only on the positive side. But it might be hard for me to know since the only information I can get comes from the news people and the Internet. One thing, he stated that the fuel used was uranium. But from what I read, and again this might be wrong, it’s mixed oxide fuel. It’s made up of both uranium and plutonium. I’m not saying that’s a bad thing but a main point of the piece was that some news in the last few days has contained at least an error per paragraph. Btw I like mixed oxides. The USA uses them. According to the “megatons to megawatt” project 50 percent of USA nuclear fuel is made from plutonium taken from decommissioned soviet weapons. Since the USA gets 20 percent of it’s energy from nuclear power then it means 10 percent of our electricity used to live in soviet weapons. How neat is that?
    The article also said that any nucleotides released would break down to non-radioactive products before you can spell it. I don’t think this is true.
    Still I’m glad someone is sticking up for nuclear power. But the message is diluted when it stretches the facts.

  3. George B. says:

    Bill, I thought he mentioned the oxides.. whatever the case, this is far the best article I’ve read, and likely far more accurate and a better risk acessment than what I hear on the main media channels.. We need remind ourselves, this is also a 40 year old plant.. no doubts in my mind, we have even safer designs..

    Maybe we’ll see a thermal loop with no power needed to cool the core on shut down?

  4. Bill knighton says:

    I wrote something that was wrong. The fuel from the “megatons to megawatts” program is uranium. It is not mixed with plutonium like I wrote.

  5. Bill knighton says:

    I thought I read 20 years ago about an experimental fuel rod where thermal expansion alone would be enough to moderate the reaction. It’s too bad there is so much resistance to new nuclear technology or even old ideas . There is an idea of having a variety of reactors each taking the waste from the type above it as a fuel source.

  6. George B. says:

    Seems to me the reaction is plenty moderated if only 3% of the cooling is necessary after shut down. We know the Tsunami took out the backup diesel power. The fact that it was diesel means it’s heavy and costly to locate higher in the structure. In the Navy, we used 1250 KW Jet Turbines (and smaller) as a source of power when we went to GQ. The Navy used these because of their low mass and they could be placed high in the super structure without mods. This could be a mod for this reactor IF it can be restarted at some point, put backup power higher

  7. Dave H. says:

    “We know the Tsunami took out the backup diesel power.”
    You would figure all of those smart people would consider “earthquake” =
    Tsunami! Not much runs well on saltwater. A containment building with a snorkle could keep it alive on site.

  8. George B. says:

    Allow me to ramble a bit…(what’s new you say)..

    The reactor was designed for earthquake+tsunami.
    That wave can be full of heavy stuff, and I would imagine it could shear through the side of a building with ease. If this reactor is ever restarted, I would imagine they’ll have a break water out front. It will be interesting to see what the experts come up with as a probability for an event like this again during our lifetimes.
    I think about ‘fly by wire’ aircraft, with three levels of redundancy, odds of failure are considered to be in the billions to one. This is considered to be a very large number by all save the idiots we elected to manage out national debt. Anyone worried that this reactor could experience a quake followed by a Tsunami of this magnitude again in the next 100 years should NEVER fly in a modern aircraft.

    It’s highly likely there will be no health issues due to radiation release, the reactors experienced an event seven times greater than they were designed for! What examples of engineering have performed so well?
    What about all the other things that caused loss of life here? What will the new standards be? History might be the best teacher.

  9. George B. says:

    We are now learning a lot more about the Japanese plants and the complications, one being all the spent fuel rods stored near the complex, and the need to cool them. So many things to address, and far more to concentrate on than one reactor core in trouble… very sad.

  10. Bill knighton says:

    I don’t want to overly criticize centralization because it works and a lot of people depend on it and economy of scale and all that, but I wonder what the world would look like if we had decentralized nuclear power. Home or neighbor hood scale. Is it possible that there could be made a cylinder that’s just hot all the time. Something that could heat our water and air and make steam. Some space probes have used radioiostope thermoelectric generators that produced hundreds of watts for decades. I think the thermocouples they use to turn that heat into electricity are terrible as in only a few percent efficient. Meaning that the nuclear power sources in these space craft are letting out a lot of heat and if we had this technology on a home scale it would be potent. Maybe the economics of it makes it impossible and it’s not wasted potential. But maybe it’s yet another thing we could have had, like small diesel cars, that regulation and hysteria have kept from us.

  11. Bill knighton says:

    Interesting. Russia has used radioisotope thermoelectric generators for decades to power light houses. There’s a picture of some decrepit looking ones on Wikipedia. They seem to be put in a cage that looks like a 300 gallon tote. According to another critical article, some have not been monitored for a decade and are running past their design life. I wonder if the strontium they run is something that can be mined out of the ground at an energy profit, or if this is just a means of storing energy.

    • George B. says:

      Bill,

      Sounds like a very primitive device, but reliable, and that was likely the Russian goal. I have seen pictures of kerosene lamps used to power a pile of thermocouples to charge a battery for radio communications, telco has long used thermocouples and propane heaters as a source of power for mountain top repeaters in very remote locations. No worries about efficiency, as reliable operation is the number one goal. Nowadays with the worry than some nut would gain entry and use radioactive materials for a dirty bomb, I’d imagine you’d need to bury a small power source like the Russian one in 300 yards of concrete and rebar to satisfy a portion of the powers that be. The new peltier junctions you can find on ebay and elsewhere would allow you to build an array and one popular source of heat would be the wood stove. Another device I expect to see some day are modified turbo chargers that directly drive small generators. The compressor side is removed, and a PMG is driven directly at shaft speed. The effort to size the turbo and the PMG needs to be addressed, or the results would likely be poor, but there is the potential to harvest maybe 20% of the shaft shaft horsepower at full load with the same amount of fuel.

      • bill knighton says:

        I was looking some more at the efficiency of thermoelectric devices and I came across this. http://bit.ly/gCP3l0
        They are about 5 miles from where I live. They believe their nano engineered thermoelectrics will pass %30 efficiency. I’m going to not hold my breath. But I hope it turns out better than eestor’s 52 kwhr ultra capacitors.

  12. Dave H. says:

    Why re invent the wheel ………. use thermo siphon to cool in a power outage…KISS! Maybe a bit to simple but a proven technolgy.

    • George B. says:

      Dave,
      A friend sent me a link regarding the standard features of the thrid generation plants, it appears to address every problem they had with this reactor, andthe system DOES thermal siphon cool once the moderator rods are inserted!

      Seems to me one could use the same technology to assure cooling of spent fuel rods too.
      too.. We won’t know the truth as to what all went wrong, but I heard there were valves they couldn’t operate right aways because they didn’t have compressed air! We of course think about air tanks and regulators for standby.. a very sad situation, but I’ll bet plant operators were not empowered to make decisions and to take early action. Seems Americans are more likely to train at that depth, and have those expectations, likely Brits, Germans, too, but I only muze here. We need keep in mind what kind of rubble was on the plant floor, it could have been a jungle you couldn’t have walked through!

      No doubt in my mind, you could build a nuke plant that could take a direct hit with an automic weapon and keep running! it’s all a matter of money..

  13. homealone777 says:

    As earthquake prone as that country is, and as prepared as they thought they were; Hey, it just caught them off guard; WAY OFF GUARD! I pray for them. It may be a very long time recovering from this. I personally don’t think we or they, have seen just how serieous this is going to turn out to be; Or how far reaching.

  14. James W says:

    This is a well written article on a great site I just found yesterday. Kudos! FWIW, I used to build control systems for nuke power plants. We tested parts and systems for earthquake survival. Not being a nuclear engineer, I cannot speak to the nature of the radiation emissions. What I can tell you is a Western (non Soviet era) nuke plant is one of the best built devices known to man. Period.

    Just two other points of interest: Admiral Rickover NEVER preferred the Boiling Water Reactor (BWR) design for naval vessels. All USN nuclear reactors (submarines, aircraft carriers and cruisers) use a Pressurized Water Reactor (PWR) design. This Wikipedia article (please forgive me for the way the URLs appear): http://en.wikipedia.org/wiki/Hyman_G._Rickover#Naval_Reactors_and_the_Atomic_Energy_Commission bears this out, as does http://users.owt.com/smsrpm/nksafe/fifties.html and http://www.abc.net.au/rn/scienceshow/stories/2009/2629053.htm to cite a few. The only exception was an experimental liquid sodium cooled reactor installed in USS Seawolf (SSN-575) that was replaced by a PWR in 1959. Please see http://en.wikipedia.org/wiki/USS_Seawolf_%28SSN-575%29 and http://www.history.navy.mil/danfs/s9/seawolf-ii.htm.

    Given point 1, it appears point 2, that the BWR design used by GE in the Japanese plants was borrowed from a submarine, was a mistake on someone’s part.

    I look forward to exploring this site. Lots of interesting stuff to explore here…

    • George B. says:

      James, welcome to utterpower, we are students here, most of us that haunt this place will be students of most things on our death beds, it’s continious learning that makes life the joy that it is. Anyone who would like to contribute an article should do so, just let me know, I am so thankful for the articles contributed on wood burning here. A fantastic physics lesson in itself done by John L.

    • George B. says:

      James, we discuss stationary engines here, and they can be VERY different than the portable ones, reduced size and mass are not all that much of an advantage in their design. and seldom do they become the highest priority of the designers. We can spread stuff out. for Instance… we can assure that no component is mounted on the engine frame that can be mounted remote where vibration doesn’t affect it’s life. It appears this is the other possible error in using a marine reactor, there was some consideration to the size and mass of the package, and this normally means size and weight become higher priorities in the design than necessary on land. There are other possible differences, the realtionship between the reactor and a source of aux or emergency cooling water and more.. I think we need start with a clean board and new piece of chalk IF we are to design the safest possible land based reactor. Of course the Russians did it worst, but no one in Russia would build a reactor designed like this Japanese reactor. a late 1940s design? It still performed very well in a diaster far worse than it was ever designed to experience. Kinda reminds me of AMONIX, they claim they are the leaders in efficient solar panels. Who needs efficiency when you’re land based and building on cheap desert land? Only members of the Gang green Party and politicians would buy that nonsense.. Efficient panels ARE requirments in space vehicles :-)

  15. George B. says:

    James, happy to see your post, and the additional links you supply us.

    Most of the folks who are anti nuke have no grasp of the energy we need now and in the future. As I mentioned earlier… they claim they’re worried about more radiation deaths, but they seem to totally ignore the fact that millions woudl likely die IF we turned off all the commercial nuke reators tomorrow.

    Please drop in and help us sort out what is real, and what is not as it pretains to practical alternative energy solutions.

    George B.

  16. Pingback: An Important Study of America’s Greenest Practical Energy Source | UtterPower.com

  17. George B. says:

    It’s now just a year later, we’ve had time to reflect..
    Is it possible the biggest losses (created by this reactor scare) will be seen in Germany? I may be wrong, they may wake up and see that Nukes are Green, but it may be that Germany allows fear to make critical decisions about their future. They have spent a fortune on solar energy…all in one of the poorer areas on the planet for such an investment. And of course you know they want to shut down their reactors. Who’d a thought they’d screw themselves this way? Time tells all…

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