But even at a reactor that does not fare as well in a large earthquake and is not immune to the loss of off-site power, there is "essentially zero risk of early fatalities," according to the NRC worst-case modeling. Even when a release of radioactive material reaches the environment, "it's small enough and takes so long to reach the community that people have already been evacuated or otherwise protected," NRC's Burnell argues. "The public avoids any short-term dose large enough to kill." And that is exactly what happened at Fukushima.
The dangers of spent fuel
The multiple explosions at Fukushima Daiichi revealed another safety risk, one that is, if anything, of more concern in the U.S. The explosions tore open reactor buildings, damaging the 12-meter-deep pools where used nuclear fuel is kept cool, potentially setting off another meltdown in the fuel there as the surrounding water drained away or boiled off. Densely packed spent fuel without water can heat enough to burst its zirconium cladding and, ultimately, set the cladding ablaze. Without walls, which had been blown out by previous explosions, there was nothing left to keep the cesium 137 and other radioisotopes in the nuclear fuel from escaping in such an event at the Fukushima reactors.
In fact, the plume of contamination spreading to the northwest of the stricken nuclear power plant may have come from such spent fuel. Despite having been shut down for refueling, Unit 4 also suffered an explosion and what remains identified by Japanese authorities as a "lube oil fire." (NRC experts, though, disagreed, at least at the time: "We know it wasn't a lube oil fire," argued Larry Camper, director of the NRC's Division of Waste Management and Environmental Protection, on March 20, 2011, according to the transcripts.) The fire, whatever kind it was, appears to have carried radioactive particles into the surrounding countryside to the northwest as it coincided in time with the wind blowing in that direction.
In the U.S., because of a lack of a long-term plan for dealing with such nuclear waste, spent-fuel pools are even more densely packed, making it easier for a meltdown to occur in the event of a loss of water. Such pools at the nation's 104 nuclear reactors hold more than 45,000 metric tons of the nation's approximately 65,000 metric tons of such used nuclear fuel. That said, the nuclear industry's FLEX approach, would also include additional pumps and hoses to get water to the spent-fuel pools, as well as instruments to monitor their condition.
Ironically, the loss of walls and roofs may have been the key to preventing a worse accident at Fukushima. By ripping off the walls and roofs, the explosions enabled emergency workers to spray cooling water into the pools directly—if inefficiently—via water cannons and other devices. "What would have happened had those explosions not occurred?" asks nuclear engineer David Lochbaum of the Union of Concerned Scientists. "The radiation levels in the buildings were too high to allow access, even if workers had equipment with which to add water to the pools." In that case, the spent nuclear fuel likely would have begun melting down and there would have been few ways of restoring cooling water.
In fact, throughout the first week of the Fukushima crisis, emergency workers tried to figure out a way to open up a larger hole in the Unit 2 reactor building, which had not suffered an explosion, to allow better access to inject cooling water without creating the kind of spark that might cause another hydrogen blast.
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18 Comments
Add CommentThe MIT report on Fukushima and "lessons learned" is at http://mitnse.files.wordpress.com/2011/08/fukushima-lessons-learned-mit-nsp-025_rev1.pdf
Reply | Report Abuse | Link to thisThere is one event that I have not seen discussed in any of these analyses. A solar superstorm (see Aug 2008 Sciam) has the potential to disrupt the entire electrical grid and damage control electronics. Multiple reactors could be simultaneously deprived of power and authorities would have to deal with multiple events at reactors without passive cooling mechanisms.
Reply | Report Abuse | Link to thisHow come when wind or solar energy is discussed, commenters come out of the woodworks to discuss how Nuclear is the way to go, and to mock all the liberals who worry about the larger saftey concerns... but here there is silence?
Reply | Report Abuse | Link to thisAlso I understand from the article the discussions about how there is time to evacuate people so it isn't as much of a danger, but it seems to me that irradiating large swaths of land and rendering it uninhabitable for years, while perhaps not the same as killing a bunch of people right away, is still a horrible enough outcome that it should be considered a total failure of the technology if it happens (like it has already).
It just doesn't seem that nuclear can be cost effective when the full costs are added in... accidents happen, always will. Even the newer plants that solve some of these issues are still vulernable to others that may happen, and given human failures and Murphy's law, will happen somewhere at some point in time.
I'm for increasing nuclear power plants because we have little choice. We must increase domestically fuel energy used in everything. But I can say that unfortunately this means a certain risk because it is not possible to totally ensure cooling of existing or any currently practical nuclear power plants. The best we can do, as the article states, is provide 3 days of cooling without power. It seems we'll have to mange that somehow.
Reply | Report Abuse | Link to thisThere is a far safer nuclear reactor technology that does not depend on a constant supply of high-pressure water to prevent core meltdown from decay heat after fission is shut down. That is the molten salt reactor designed and successfully operated by Oak Ridge National Laboratory in the 1960s, using fluoride fuel in molten salt. In the event of total power loss, as happened at Fukishima, a freeze plug would melt, allowing the molten salt to drain into a tank where it is passively cooled. The Liquid Fluoride Thorium Reactor technology is superior to conventional solid-fuel reactor technology in many ways. It is far more efficient, consuming virtually all of the thorium fuel, generating very little waste, and thorium does not have to be isotopically enriched.
Reply | Report Abuse | Link to this"using fluoride fuel in molten salt"
Reply | Report Abuse | Link to thisI meant thorium fuel dissolved in fluoride salt.
Thorium is a strategic material. China holds a good part of the World reserve and intends to use it as a national resource. They will not export.
Reply | Report Abuse | Link to thisThe USN would never operate reactors so prone to circumstantial conditions on their submarines. It is more than technology, it is a mind set. The USN safety record speaks for itself.
I would personally favor Naval type reactors in farms than one giant power plant with multiple reactors.
"...Thorium is a strategic material..."
Reply | Report Abuse | Link to thisNo it ain't. There is loads of the stuff, the US Gov't buried 100's of tons of the metal because they didn't know what to do with it. It is a byproduct of Rare Earth Mining, and they have to PAY to get rid of it, they would happily give it away for free.
For the truth, and not this propaganda, go to fairewinds.com/updates.
Reply | Report Abuse | Link to this"The NRC’s refusal to thoroughly examine these flaws is reminiscent of the Atomic Energy Commission’s refusal in 1972 to thoroughly examine the innate flaws in the GE Mark 1 containment systems that failed at Fukushima. The AP1000 Oversight Group is demanding that these design flaws be remedied prior to design certification, lest history repeat itself."
"Arnie Gundersen testifies to the NRC Petition Review Board detailing why the 23 BWR Mark 1 nuclear power plants should be shut down following the accidents at Fukushima."
"three nuclear safety problems uncovered during the Fukushima accident that nuclear regulators and the nuclear industry wish they could ignore."
"claims that Fukushima was caused because Japanese regulators did not properly oversee Tokyo Electric. Fairewinds shows that in the United States, the same cozy relationship exists between the NRC and the nuclear industry [and this propaganda rag]. Proper regulation of nuclear power has been coopted worldwide by industry refusal to implement the cost to assure nuclear safety [and the mass media's blind eye]"
"...numerous concerns with the Bellefonte Unit 1 nuclear project. First designed with slide rules back in 1968, Bellefonte Unit 1 is America's oldest nuclear power plant that has yet to generate any electricity. TVA began construction in 1974, mothballed the plant in 1988, and cannibalized the plant for scrap metal between 2006 and 2008. Alarmingly, the Nuclear Regulatory Commission recently allowed construction of Bellefonte Unit 1 by TVA to start again with its 1968 design and its 40-year old weakened foundation and containment... seven areas of substantial risk"
"... a more insidious danger lurks... the US regulators and regulatory process have left Americans unprotected. ...points of vulnerability in American plants... unaddressed by the NRC for three decades. Finally, they concluded that an accident with the consequences of Fukushima could happen in the US....With more radioactive Cesium in the Pilgrim Nuclear Plant's spent fuel pool than was released by Fukushima, Chernobyl, and all nuclear bomb testing combined. Gundersen and Lockbaum ask why there is not a single procedure in place to deal with a crisis in the fuel pool?"
There are many more and some very good educational videos on nuclear and its alternatives from nuclear engineers that, in effect, support nuclear energy, done safely.
tharriss @3
Reply | Report Abuse | Link to this"How come........... here there is silence?
It's only worthwhile engaging in debate with people who have respect for the truth, facts, the laws of nature and simple arithmetic. And are concerned about the environment, global warming and energy dependence.
I've yet to come across one anti-nuker who meets all these criteria, and most fail on several.
It's best to engage on sites where people are called out on their allegations, and banned if they can't back them up.
Try, for example:
http://bravenewclimate.com/
When building a new, water-cooled reactor, start by digging a hole, open at the top, large enough to house the entire reactor building. Then erect the reactor building inside the hole.
Reply | Report Abuse | Link to thisPut control rooms outside the hole, at normal ground level.
If all other cooling systems fail, let water in from the nearby river or lake, so that it floods the hole and drowns the reactor building. This provides an efficient cooling system that will work regardless what happens.
Even if an extreme earthquake turns everything into rubble, or if a solar storm of a surprising and never-expected magnitude fries a large part of the technology on which our societies depend, still the reactor will be cooled for any length of time that may be needed. And with reliable cooling, contamination is negligible.
Why is everyone so paranoid and scared of nuclear power?
Reply | Report Abuse | Link to thisThat should be this articles headline!
Ok so Fukushima had a ‘disaster’ due to a tsunami.
Ask yourself; how many people were irradiated, died or are dying from the effects of the power stations radioactive fallout?
Then ask yourself, how many people died from the tsunami?
Why is it that when ever nuclear power is mentioned all the ’It goes bang and your hair falls out’ brigade start up?
Fire burns but we use it, water drowns people but we use it, cars kill but we drive them!
And what is this nonsense about the cost and the clean up from Nuclear power?
Do you realize you are worrying about consequences from nuclear power over thousands of years but no one is worried about the next one or two hundred years!
Will we even be here in a thousand years?
With all the climate change deniers sacrificing their offspring’s futures for the want of needful things and to hell with tomorrow, ‘How safe are US Nuclear Reactors?’ is an illogical argument.
Do you really think that if a French, German, Russian or Chinese reactor went rabid, the fallout would stop at their borders?
Wind, water or solar power is NOT and will NOT be a cure for our ever increasing power needs. You have to accept that fact.
When I discuss a problem I like to put my two pennyworth of a solution, otherwise it is pointless. So here it is:
What is needed is international agreement on nuclear power station standards, training and safety measures; conformity and standards in building the safest type.
REmember: Life is full of risks. It is how we manage them that counts, not screaming about banning fire just because a house burns down!
Cuger Brant : The cost of the Fukushima disaster is such that Tepco will have to be nationalised. Some japanese claim that food grown around the plant does not absorb cesium and so may be safely eaten. So why are they taking off the topsoil in the contaminated zone? Uranium ore deposits will have run out within 30 years, but radioactive waste buried 600 meters underground in scandinavia is subject to very rapid isostacy due to glaciations, so could be uncovered long before attaining even the first half-life mark! Let's be honest, nuclear power was only part of obtaining stocks of plutonium for making h-bombs. All that for just 6% of world electricity production.
Reply | Report Abuse | Link to thisFukushima had backup diesel generators for cooling. Had they worked, there wouldn't be a crisis. Unfortunately, these generators were at the basement below sea level. The tsunami flooded the basement and disabled the generators. The tsunami wall was not high enough to protect the plant.
Reply | Report Abuse | Link to thisHad the Japanese put the reactors underground below sea level, the tsunami would have flooded them and provide water cooling even without power. The sea is a source of unlimited water supply for cooling if only the plant was properly designed.
US nuclear plants of similar design are just as safe or unsafe as Fukushima.
James Lovelock, the world's foremost environmentalist:
Reply | Report Abuse | Link to this"...Windfarms won't cut it at all," he said. "It's better than doing nothing, but it's absurd, just gestures. Time is of the essence..."
"...Nuclear Power is the only green solution..."
www.ecolo.org/lovelock/lovelock-wind-power.html
James Lovelock calls Nuclear Energy "The Natural Energy of the Universe":
www.youtube.com/watch?v=OOaDY13bI84&feature=player_embedded
Prominent Environmentalist George Monbiot, on "...How the Fukushima disaster taught me to stop worrying and embrace nuclear power..."
www.monbiot.com/2011/03/21/going-critical/
George Monbiot says: "...On every measure (climate change, mining impact, local pollution, industrial injury and death, even radioactive discharges) coal is 100 times worse than nuclear power... Nuclear kills when it goes wrong, coal kills when it goes right..."
World's #1 Climatologist Jim Hansen warns gullible, religious greenies like Eco-Steve to not drink the Renewable Energy Kool-aid:
www.columbia.edu/~jeh1/mailings/2011/20110729_BabyLauren.pdf
"...it is much less than worthless. If you drink the kool-aid...you are a big part of the problem...The problem is that, by drinking the kool-aid, you are also pouring it down the throats of my dear grandchildren and yours. The tragedy in doing so is much greater than that of Jim Jones' gullible followers, who forced their children to drink his kool-aid. All life will bear the consequences..."
"...Victor and Yanosek discuss ineffectual U.S. policies to promote green energies and green jobs ... They conclude that the policies do not promote technologies that can compete with fossil fuels without subsidies...suggest incentives for innovative technologies, including advanced nuclear power. Bill Gates is so distressed by the irrational pusillanimous U.S. energy policy that he is investing a piece of his personal fortune to help develop a specific 4th generation nuclear technology..."
"...The lobby...Union of Concerned Scientists...broadcast a request to all citizens to write...congress...to demand improved nuclear power safety. Huh? The number of people who have died from nuclear power in the U.S. is zero. How to improve on that? The safety record of the nuclear industry is the best of all major industries in the U.S..."
"...No people died at Fukushima...When a plane crashes and kills 100 people do we choose to terminate the airline industry? No, we take steps to make planes safer...nuclear has the best safety record of any energy...new nuclear have great improvements..."
Americans simply don't have the political consensus necessary to continue with nuclear power. It is crazy to let the spent fuel sit in ponds beside every reactor simply because we are unable to agree on moving the stuff to a patently safer site like Yucca Mountain. The political gridlock shows no sign of resolution, and meanwhile our reactors are nearly all beyond their original 40-year design lives, operating on "extensions". The oldest and most threatening ones should be closed down quickly, if only to sharpen the need for more realistic political debate.
Reply | Report Abuse | Link to thisI thought that reactors were fitted with control rods(boron?)to absorb neutrons and stop fission, and not just use water to keep things cool. Have things changed?
Reply | Report Abuse | Link to thisI imagine most USA plants are no safer than Japan.
Reply | Report Abuse | Link to thisMany US,Russian,French etc.Companies are developing much better Plants. The Russians using there Liquid Metal cooled reactors from there military as a starting point will have a small demonstration plant going by 2017.Small simple reactors that eliminate most of the problems with existing reactors. Most of these new ideas result in far less nuclear waste, can use waste from existing plants as fuel etc. and operate at low pressure and are simple. [Idiot proof.] At the moment though most of the really simple but advanced designs are still more or less in development or being built. Possibly the Chinese now will take the lead in this area - they have the need. In 2008 China working with Russian Companies built what the IAEA called the safest plant in the World at the time. I note they are talking to Bill Gates and looking at new ideas also to build safer plants. The Russians obviously took the Chernobyl disaster to heart also. The simple fact is Nuclear in its first 3 generations has proved to be 6-7 times safer than coal. The deaths with coal just happen slower and are not as spectacular. My prediction is we will see ever increasing Nuclear power starting soon and in the next 5 years it will really take off as the new designs are proven up etc. It is the only alternate for many countries and the world if they are to lift themselves out of poverty etc. and we are to reduce CO2 emissions. [Until Fusion becomes available.] They are just not quite there yet with cheap reliable Nuclear Power Stations. Now as people realise a major accident in an old relatively unsafe plant did not kill thousands, nuclear will take off again shortly. The resultant death's etc. from Chernobyl have been very low and all the Medical experts that have followed it up say the biggest problems are Psychological. All the idiots who predicted 10,000 to 100,000 deaths based on "myth" and the reporters who gave these idiots airtime etc. are probably guilty of causing more deaths and ruined lives than the disaster itself. All published by real experts - both Nuclear and Medical.