What happened and what do we face in fukushima?

Dr Saputo,<br><br> My name is Jack Gamble and I'm a nuclear engineer. I found several of the opinions you expressed in your piece at The Canadian to be troubling and I would like to open a dialogue on the subject were you interested.<br><br> I have a hard time believing the aftermath of the 9.0 earthquake and 45' tsunami at the Fukushima Daiichi nuclear power plant qualifies as the worst industrial accident of all time, especially in the context of the Banqiou dam failure and the Bhopal disaster which each killed hundreds of thousands of people instantly (it is now four months since the Daiichi meltdown and the equivalent of a sunburb to the legs on a three employees is the extent of harm caused to humans by radiation from those meltdowns). Also, given the cumulative affects of climate change, and tens of thousands who die every year in North American due to respiratory illness caused by fossil fuel emissions, I would think the Fukushima meltdown pale in comparison.<br><br> Based on what I've read, you'll likely not agree with most of what I have to say, but of course discussion never hurt anyone.<br><br> Please if you ever have any questions, free to contact me.<br><br> Thank you,<br><br> Jack Gamble<br> Editor<br> Nuclearfissionary.com

Hi Jack...<br><br> Thanks so much for the comments. I understand and appreciate what you're saying.<br><br> I would completely agree with you that the damage caused by the earthquake and tsunami do not measure up to that of other major events where loss of life has been much greater. At least, not up to this point in time. However, how much damage would you predict will result from the meltdown and leakage into the environment of these nuclear reactors that will continue for many decades. How much damage will occur to sea life and its health effects on the rest of the planet? <br><br> Chernobyl caused far more than a few sunburns...and at a severe price for the 500,000 people who suffered from participating in the cleanup there and for the unknown numbers of people who suffered from the effects of low dose radiation poisoning...we'll never know this answer. There isn't even a plan to clean up the Fukushima mess that has resulted...no one can even get near the disaster sites. Leakage into the environment will go on for centuries... <br><br> You make very good points that there are many other disasters that exist in the world today that are based on damage to the environment. And I agree that we should be dealing with them as soon as possible as we have polluted our planet and ourselves in the process in a very major way. <br><br> The message of the video was to wake up the world to the fact that we've not acted responsibly when we made the decision to use nuclear power for energy...what happened in Japan could occur in many other locations through acts of nature that are beyond our control. We simply cannot continue to take the risks that are inherent in creating nuclear plants for our energy needs. <br><br> Lastly, I'm wondering if you explain how the fail safe mechanisms that led to the meltdowns failed to protect against a meltdown. There's much to contemplate on this...until we know the answer to this fully and transparently, we'll have to use our imagination. <br><br> I'm interested in your response...and again, thanks for starting the dialogue!<br><br> Warm regards,<br> Len

Dear Jack and all,<br><br>I respect your opinion and viewpoint and I appreciate the mature manner in which you voiced your disagreement. None of us has all the answers but if we all bring together our knowledge and professional experience we learn more about ourselves and the world we live in and on. And if our discussion is in public many people will surely learn as well.<br><br>Respectfully,<br>Harry

Hello all and thank you very much for the responses. I was pleasantly surprised to see the activity. I don't mind if you use any of this material for the blog, please feel free. If it's not too much trouble, a link to my own blog somewhere would be appreciated (pardon the shameless self-promotion). It's http://nuclearfissionary.com<br> <br>Now to the meat and potatoes (I apologize for the length):<br> <br>--------------------------------------------------<br> <br>As to the sequence of events at Fukushima, please take everything with a grain of salt as the information coming out of Japan has been inconsistent and incomplete. As far as I can tell, all 6 of the reactors at Fukushima Daiichi were shutdown within 3 seconds of the earthquake with little to no damage. There is speculation that the Unit 4 structure took some damage from the quake and it has since been reinforced.<br> <br>After the initial shock, all control rods were quickly sent into the reactor in what is known as a SCRAM (an acronym going back to the 30's that stands for Safety Cut Rope Ax Man). With the reactor shutdown (no more fission) you have decay heat to deal with. One of the unique properties of nuclear power is that our fuel continues to generate heat after the reactor is shut down (about 6% of normal power initially and it drops over time). <br> <br>With the reactor shutdown, you still need electrical power to drive pumps that cool the reactor. The earthquake took down the grid which is the normal source, so backup diesel generators atomically start to supply that power. Given that Fukushima Daiichi is a six reactor site, I would speculate that there were about a dozen of these generators which are similar to a train locomotive engine.<br> <br>The diesels started, and the plants stabilized themselves immediately. Everything was functioning when the 45' tsunami came along. The plant has a 30' seawall built around it to protect it from what was at the time considered the worst case tsunami (they were wrong obviously). The water knocked out all of the diesel generators which left only DC batteries with an 8 hour life to power the cooling systems.<br> <br>During that 8 hours, communications were difficult as the wave had knocked out roads, towers, phone lines, and generally chaos ensued. But during those 8 hours, there should have been time to bring things like portable generators or gasoline powered pumps online to pump seawater into the reactor. What I believe happened next (speculation on my part) was that the operators of the plant asked for permission from their CEO to pump in seawater and vent pressure to make it easier to pump water in. I believe that this decision actually reached the Prime Minister's office and was delayed while those crucial first hours ran off the clock. <br> <br>At an American plant (I can't speak for the Canadians) control room operators have absolute authority over the operation of the plant. A company executive or politician would be thrown in jail by the NRC for attempting to prevent an operator from pumping sea water into the reactor or venting pressure. Unfortunately, this is not the case in Japan.<br> <br>When the batteries died, the cooling stopped and the remaining water in the reactor was boiled off until the fuel became uncovered. When that happens the fuel quickly heats up and at just over 2,000 degrees Fahrenheit, the zirconium alloy fuel cladding begins to react with the water around it and this produces hydrogen as the fuel melts.<br> <br>Even at this point, the operators could have recovered as they did at Three Mile Island. Unfortunately, they didn't vent the hydrogen and pressure continued to build. It is believed that by the time the decision to vent was made, the valves on the hardened vent system had failed and were stuck closed. The pressure would have been vented to atmosphere if the vents hadn't failed. Eventually pressure built up until a pipe or other component leaked hydrogen into the surrounding building (secondary containment) instead of outside. From there it was just a matter of time until a spark ignited the hydrogen and that was what you saw on CNN. Hydrogen burns happened at Units 1, 2, and 3 and a partial one happened at Unit 4 that I believe was caused by Unit 3 hydrogen traveling though a common pipe to unit 4 (there was no fuel to melt in the Unit 4 reactor and we have since learned that the fuel pool at unit 4 survived the event).<br> <br>When that happened, all of the pumps and connecting equipment were destroyed such that when power was restored, there was nothing to connect to. Hence more portable pumps and equipment then had to brought in, further delaying the response.<br> <br>It's worth noting that primary containment appears to have held. When venting finally did happen, the gas contained radioactive isotopes like Iodine-131 and Cesium-137 that are normally contained within the fuel. It remains to be seen what condition the reactor and primary containment are in. Engineers were surprised to learn when Three Mile Island Unit 2 was opened after the meltdown that the molten fuel had only melted a fraction on an inch into the 7 inch thick reactor vessel. I certainly hope such a surprise awaits us at Fukushima.<br> <br>I don't believe Fukushima will ever be anywhere near as bad as Chernobyl did. We're now several months after the accident without a single radiation-related fatality where some 30 workers had died only a few days after working on the Chernobyl reactor.<br> <br>To this day it blows my mind to ponder what the Chernobyl people were thinking from the design phase of the RBMK reactor all the way through to moments before the accident and even the handling of the aftermath.<br> <br>Without going into too much reactor physics, the Chernobyl reactor had no containment dome, only a thin aluminum roof. The reactor internals were such that the accident was made possible and the aftermath much worse. You can read more about those specifics here: http://nuclearfissionary.com/2010/03/03/what-happened-at-chernobyl/<br> <br>It's also worth noting that at Chernobyl, the reactor literally blew it's lid and the entire core was belched into the atmosphere by a steam explosion (Chernobyl wasn't a meltdown, it was a steam explosion). The majority of the core and most of the radioactivity never left the Fukushima containment domes.<br> <br>After the accident at Chernobyl, no sirens went off and no actions were taken in nearby Pripyat for several hours. There was no evacuation plan in place and no protective measures were taken for the residents nearby. The people who lived near the plant were unknowingly inhaling Iodine-131 and other radioactive materials. Most of these materials leave the body before they can do much harm, but I-131 is unique in that it collects and remains in the thyroid gland for long periods of time. As of 2005, some 6,000 cases of thyroid cancer have been directly attributed to the Chernobyl disaster by the World Health Organization (WHO), a large amount of them in children. However, thyroid cancer has a very high survival rate and only 15 of those 6,000 cases proved fatal. It is also believed that the increased monitoring of thyroids after the disaster skewed those statistics as a thyroid cancer is sometimes known to go undetected otherwise. It's believed that the simple act of telling people not drink milk in the area after the disaster could have prevented 90% of those cancer cases. The only other statistically identifiable health impact from Chernobyl is a roughly doubled incidence of leukemia among those workers who were sent to the plant after the accident (not the general population).<br> <br>As of last year, WHO puts the total number of dead from Chernobyl to date at 56 and says that as many as 4,000 people may eventually "die sooner." However when a worker from Chernobyl dies 25 years later from cardiac arrest at the age of 70, it's difficult to say weather Chernobyl played a roll in that death, hence the 56 to 4,000 range. There are some studies out there that I refer to as politically-motivated that attempt to assign dramatic numbers like 1 million. Time after time these works don't hold up under the scrutiny or legitimate scientific bodies. At times there are some powerful images of deformed babies on TV and the internet. While heart wrenching, there is just no sound science that says these terrible conditions are any more or less frequent than they are anywhere else before or after the Chernobyl disaster.<br> <br>In Japan, the evacuation took place soon after the meltdowns and Potassium Iodide (KI) pills were distributed. These pills are NOT anti-radiation pills as some believe, but are known as thyroid blocking agents. They saturate the thyroid gland with normal iodine such that any Iodine-131 that is ingested will pass through the body in a day or two instead of concentrating in the body for months.<br> <br>So based on our experienced from Chernobyl and the improved response form the Japanese, I would say that there is a very good chance that no one will die from the radiation at Fukushima. If any do, it will likely be workers at the plant and not local residents. Of course time can only tell, and I am no health physicist.<br> <br>But a very large dose of Iodine-131 did save my life 7 months ago when a radiologist treated my over active thyroid gland that would otherwise have given me a heart attack. After that treatment, I was so radioactive that I couldn't get INTO the nuclear plant where I work for more than 50 days because I would set off the radiation monitors if I tried to walk in. I did however walk right out the front door of the hospital 5 minutes after swallowing the pill. Considering that standing next to me for 5 minutes back in January would have given you a larger dose of radiation than living a few miles away from Fukushima, I can say with a reasonable certainty that those residents are safe. The dose I received is likely more than many of the workers at Fukushima have received, so I certainly do hope I'm right as my life is literally riding on it (so far so good).<br> <br>Between nuclear medicine, nuclear power, cold war data from careless weapons testing, and disasters like Chernobyl, we are learning that radiation is not nearly as dangerous as we once thought. It should be understood and respected, not feared.<br> <br>-- <br>Jack Gamble

Dear Jack,<br><br>I am sad to hear about your medical condition and I sincerely hope that all is well now. Thank you for the detailed assessment of the Fukushima accident, including numbers putting things in perspective. Your account was valuable in that it shows that there is a technical and a moral component to nuclear technology. It would help to separate the two.<br><br>Technical view: nuclear technology has proven effective in generating electricity and building bombs of vast destructive potential while physically small in size and weight. The fuel cycle problem of what to do with the large amounts of highly radioactive spent fuel was solved to a large extent in the 1970s with the development of the breeder reactor design. However, because it breeds large amounts of weapon-grade plutonium it was deemed unacceptable for fear of terrorism. That left us with a situation where globally we use only approximately 5% of the energy content of the reactor fuel and produce 20x more spent fuel for which there is no viable way of assuring safe disposal for hundreds or thousands of years, the minimum time necessary to render the fuel benign in case of leaking containers.<br><br>Moral view: A relatively small number of experts make decisions that may have potentially devastating effects on the world population. They set exposure limits and safety standards they deem sufficient according to present knowledge and then proceed in the development of a technology that produces vast amounts of materials that were previously non-existent on this planet (no significant amounts of trans-uranium elements exist naturally) and have half-lifes of thousands of years or more. The experts implicitly assume the consent of the world population and hundreds of future generations to proceed on a one-way street where certain incidents produce irreversible effects. The experts also assume that the safe operation of a great number of nuclear facilities can be assured for many generations to come.<br><br>Some hypothetical numbers: Let's look at just one important element, plutonium. It is used in bombs and in some nuclear reactors. It was used in the MOX (mixed oxide) fuel used in Fukushima reactor 3. A minimum of approximately 10kg is needed for a bomb but much more exists in reactors. Here is a Time article giving us some numbers:<br>http://ecocentric.blogs.time.com/2011/03/17/mox-the-fukushima-word-of-the-day-and-why-its-bad-news/<br>Assuming one reactor load being 300 tons of MOX with 6% of it being plutonium yields 18 tons or 18,000kg. Consider this article mentioning the plutonium toxicity:<br>http://en.wikipedia.org/wiki/Plutonium<br>It quotes "math shows that one pound of plutonium could kill no more than 2 million people by inhalation", down from Ralph Nader's estimate of 8 billion people killed from one pound of plutonium dust (to me the language of "no more than 2 million people" indicates a troubling attitude toward fellow men). By this account one Fukushima 4 reactor load could hypothetically kill 36,000lbs x 2 million people = 72 billion people. Fortunately this is only a hypothetical calculation but to me it raises a question about the wisdom of using nuclear processes to boil water.<br><br>Over the next few days I will calculate an estimate of how long it would take to evaporate the water in the reactor core absent of cooling at 36MW of idle power in a shut down 600MW reactor (6% of nominal power).<br><br>Harry

Thanks Harry, I'm feeling much better now. I can actually climb a flight of stairs without taking a knee and at rest you can no longer hear my heart pounding from across the room, a big improvement over a year ago.<br> <br>You're referring to the Carter Administration ending the fuel reprocessing program. At the time, he was correct in that Plutonium once separated from the highly radioactive material could become a proliferation risk, although the French have succeeded in preventing that, the risk was always there.<br> <br>However, a few years ago when the A.Q. Kahn network was discovered, the nuclear genie was forever out of the bottle I'm afraid and there is no way to be rid of that knowledge. Kahn was the single largest proliferation network since the cold was and he is known as "The Father of the Islamic Bomb" because he alone gave nuclear weapons programs to some extent to Iran, Iraq Lybia (lucky for humanity Ghadafi gave up his program before the recent civil war broke out), Pakistan, and North Korea.<br> <br>Because of AQ Kahn, it is now VERY easy to make nuclear weapons simply by digging up Uranium Ore, which is very common, and enriching it in a centrifuge. Before that, the only way to make a bomb was to convert Uranium-238 into Plutonium-239 in a breeder reactor (like at our own Hanford and Savannah River military sites). Or to use a highly energy intensive process called gaseous diffusion to enrich Uranium. Now, using a reactor to make Plutonium or by stealing it from the US or France is by far the HARDEST way to make a bomb.<br> <br>This is why the Iranians have built an enrichment plant full of centrifuges under a mountain at Qom. Many in the press are concerned with the power reactor the Iranians built on the surface, hence the stories about them fueling the reactor, but the intelligence community isn't concerned with the reactor, but rather the centrifuges. I believe the reactor is either a publicity stunt (so they can claim peaceful intent) or an economic goal so they can burn less oil for electricity and sell it to the west for more money. If the reactor were really the weapons program, like in Syria and Iraq a few decades ago, then the Israeli's would have destroyed it by now as they did the Syrian and Iraqi reactors. But the Iranian facility is so deep underground it would take a nuclear strike to eliminate, obviously not an option. Instead we're hearing about things like the stuxnet worm which set them back years, and assassinations/defections of certainIranian nuclear scientists. Short of starting a war, this has been the only way to delay or stop the Iranian centrifuge program which is making 80% enriched uranium (cannot possibly be used in a power reactor which uses 4% enriched).<br> <br>Centrifuges creating highly enriched Uranium is the means by which every nation to obtain nuclear weapons since the end of the cold war has done so, not using Plutonium.<br> <br>On the flip side, the US signed a treaty with the Russians to dispose of leftover weapons grade plutonium by making it into MOX fuel. We are building such a facility at Savannah River, where we once made bombs. In total, 64 tons of weapons grade plutonium, enough to make thousands of warheads, are being disposed of this way.<br> <br>We're also disposing of Uranium warheads with the Russians under a treaty called Megatons to Megawatts, where we have destroyed 15,000 Russian warheads by making them into fuel since 1993. This is the source of 50% of all US Uranium. Considering that nuclear power makes 20% of US electric, that means 10% of all electricity in the US is powering our cities with the bombs built to destroy them. Hopefully, when we're done with the Russian bombs, we can get rid of a few thousand of our own.<br> <br>Basically, the decision on weather or not to make nuclear weapons is now independent of nuclear fuel as it is much easier to build a bomb without it. Considering the obvious benefits of recycling that waste to reduce to volume of the really nasty stuff (only 4% of a fuel rod) and obtain the rest of that energy without further mining. Another benefit of reprocessing is called vitrification, where the 4% highly radioactive waste is converted from gasses inside the fuel rods into glass which is much easier to contain. The French do this and store every ounce of their highly radioactive waste under the floor in a room the size of a basketball court at La Hague. Logistically, it makes more sense to do this than to store it in dry casks at 104 locations around the US (still safe, just a waste of resources).<br><br>I won't argue the toxicity of Plutonium, Argonne National Labs did a study that says for every 5,000 Pu particles you inhale your chance of developing lung cancer at some point in your life increases by 1%. That's how Marie Curie was killed as she handled the stuff in her bare hands for years (her notebooks are still radioactive). But I would add that the toxicity of Plutonium is nothing compared to the I-131 and Cesium-137 that leaked along with it. I think there is a concerted effort to demonize Plutonium and MOX fuel because those are the keys to answering the favorite political talking point of the activists: "what do you do with the waste."<br> <br>As to the one pound killing millions thing, a pound of pure arsenic or cyanide could do the same, although the chances of one pound being eaten evenly, and then the 1% risk actually coming to fruition and causing cancer, and then that cancer being 100% fatal, are a series of probabilities, some very low, some not, all lining up perfectly in the worst case scenario. I can make those stats also say that one pound could NOT kill those people if none of the 1% risk ever occurred, which is not reasonable of course, but far more likely than ALL of the 1% happening. But phrases like 1 pound killing millions certainly sounds profound even if it is statistically just shy of impossible.<br> <br>It's also worth noting that ALL reactors have plutonium in them, not just the MOX fuel bundles.but even in regular fuel bundles (U-238 is constantly made into Pu in a Light Water Reactor). It makes me wonder why the activists are focusing on 3% of the fuel rods in one reactor that contain about 7% plutonium, when the other 97% in that reactor, and 100% of the fuel in the other 3 reactors contain about 2% Plutonium. There is several orders of magnitude more Pu in the non-mox bundles combined, so why are people talking so much about a much smaller quantity? It makes much more sense when you consider the political value of demonizing MOX fuel.<br> <br>Again, sorry for the length. But in short, nuclear power is the easiest way to dispose of bombs, and unfortunately now the hardest way to make them. Plutonium can certainly be dangerous, but the benefits shouldn't be ignored, the danger needs to be kept in perspective and the political motives of the ones pushing the fear on television should be considered. And to be fair, my own motives should be considered so please feel free to fact check me.<br>Thanks again,<br> <br>-- <br>Jack Gamble<br>nuclearfissionary.com

Hi Jack,<br><br>I am glad to hear that you are doing better and I hope that you will regain all of your previous health. Thank you for the information and data in your last email, it helps to get a more realistic picture of the Fukushima situation.<br><br>The human component of the nuclear industry, civil as well as military, is a wild card, as you well pointed out in the case of the A.Q. Kahns of the world. This is an unpredictable aspect of the nuclear issue and can only be controlled by constant vigilance and does not instill much confidence in me, sadly. Therefore, for the moment I'd like to focus on the technical aspect, which is more calculable and predictable. <br><br>Searching the internet for some numbers I found this link to a GE document entitled "BWR/6 General Description of a Boiling Water Reactor". Could you please comment on its authenticity? In case the link becomes inaccessible I also attached the pdf to this email. The document describes a handful of safety systems, most of which apparently failed in several of the Fukushima reactors, which is puzzling to me and a subject all in itself. For the moment I'd like to focus on the time to partial meltdown once all cooling is lost. For this I must know how much water has to evaporate before the fuel rods are exposed and partial meltdown can begin. I could not find good numbers in the document, could you give me an estimate what water volume is above the upper level of the fuel elements?<br><br>Thanks in advance,<br>Harry