Splitting the Atom
by Jason GodeskyI’ve recently been evaluating the alternatives to our current energy economy. In “Do you believe in magic?” I argued that biofuels, and most renewable energy sources in general, run into the basic problem that we only get so much energy from the sun every day. “The Other Fossil Fuel” took a look at coal, and why it’s an unlikely (and undesirable) replacement for our current energy usage. So, what about the new hot button energy source, touted by environmentalists from James Lovelock to Patrick Moore and Stewart Brand: nuclear?
Three Mile Island
Three Mile Island nuclear power plant near Harrisburg, Pennsylvania, is by far the United States’ most famous, because of an accident to its number 2 reactor on 28 March 1979, that proceeded to unfold over the next five days. The health effects from the Three Mile Island incident continue to be studied,1, 2, 3, 4 but most consider it mostly a “near miss.” Because of its proximity, I’ve seen 3MI personally several times, but it never ceases to be a surreal experience.
The near-catastrophe at the plant, perched on an island in the Susquehanna River near Harrisburg, Penn., effectively halted any expansion in the U.S. nuclear energy industry, which generates about 20 percent of the nation’s electricity.
The resulting cancellation of dozens of planned nuclear plants forced utilities to rely on decades-old nuclear and coal-burning plants for growing electric power demands.
For the last decade, utilities have looked almost exclusively to natural gas plants to fill the gap, which has exacerbated the nation’s shortage of that clean-burning fuel.
And two years ago, massive corrosion found at an Ohio nuclear plant points to lingering safety questions.5
Seven years later, the Chernobyl disaster showed the world just how devastating a full nuclear meltdown could be. I had two friends in college, Ukrainians who migrated to the United States as children, who both lived in Kiev in 1986. One of them told me a story of a parade scheduled that day. The government let it go on. He credited his own well-being to a friend of his mother’s, who worked in the government, and called them to warn them only to stay inside. Only when nuclear material began wafting over the Swedish border, did the disaster come to light—the USSR was content to keep it quiet as long as possible.
The Benefits
Nuclear power has made strange bedfellows of environmentalists and the Bush administration, and their reasons are certainly worth consideration. If, as Lovelock argues, global warming is the most pressing crisis we face, then nuclear power’s lack of carbon emissions make it a clear preference. Because nuclear power plants are built with such protections in mind, while coal plants are not, people living near coal plants are actually subjected to higher levels of radiation than those living near nuclear power plants, simply from the uranium impurities in the coal.6 Even more impressive is the immense amount of energy that can be obtained even from a small amount of uranium. Those same uranium impurities in coal can produce more energy in a nuclear reactor, than the coal produces in combustion.7
The past two decades have seen significant improvements in the safety of nuclear power plants, as well. Despite the number of nuclear power plants in the world—more than 4408—Three Mile Island, Chernobyl, and Tokaimura9, 10, 11 remain the only notable failures. An industry group brags:
The excellent safety record of U.S. nuclear power plants attests to the high quality of engineering, construction and operation of these plants. No member of the American public has been harmed by nuclear power plant operation.12
As seen above, the former claim is an exaggeration, at best, but it remains quite clear that the threat of a nuclear meltdown at any particular plant is quite low. This is good, considering the enormous implications for when that low probability occurs, as seen at Chernobyl. Nuclear power may be relatively safe, but it is by no means foolproof, and the absolutely catastrophic implications of any failure make the expected value of a gamble on nuclear power unclear, at best.
Nuclear waste
Of course, the greatest concern for nuclear power plants is not meltdown, but nuclear waste. Nuclear waste could be greatly reduced by recycling spent fuel—a measure outlawed by Jimmy Carter in 197713 for fear of nuclear terrorism.
The spent fuel rods from a nuclear reactor are the most radioactive of all nuclear wastes. When all the radiation given off by nuclear waste is tallied, the fuel rods give off 99% of it, in spite of having relatively small volume. There is, as of now, no permanent storage site of spent fuel rods. Temporary storage is being used while a permanent site is searched for and prepared.
When the spent fuel rods are removed from the reactor core, they are extremely hot and must be cooled down. Most nuclear power plants have a temporary storage pool next to the reactor. The spent rods are placed in the pool, where they can cool down. The pool is not filled with ordinary water but with boric acid, which helps to absorb some of the radiation given off by the radioactive nuclei inside the spent rods. The spent fuel rods are supposed to stay in the pool for only about 6 months, but, because there is no permanent storage site, they often stay there for years. Many power plants have had to enlarge their pools to make room for more rods. As pools fill, there are major problems. If the rods are placed too close together, the remaining nuclear fuel could go critical, starting a nuclear chain reaction. Thus, the rods must be monitored and it is very important that the pools do not become too crowded. Also, as an additional safety measure, neutron-absorbing materials similar to those used in control rods are placed amongst the fuel rods. Permanent disposal of the spent fuel is becoming more important as the pools become more and more crowded.14
Nuclear waste can be devastating for the environment. While it may be true that “for every ounce of nuclear waste, a traditional power generating station will produce tons of poisons and toxins,”15 it is also true that it does not take very much nuclear waste to seep into ground water or contaminate top soil, and poison an entire ecosystem. The Hanford Site in Washington state is the largest nuclear waste storage site in the United States, and it has been described as, “one of the worst environmental disasters of the 20th century.”15 Nuclear weapon storage facilities have evidenced the very same problems.16, 17
Uranium supply
As promising as recycling spent fuel in safer nuclear power plants may be, there are even deeper problems with nuclear power than the relatively simple question of finding something to do with “spent fuel.” Nuclear power is incredibly efficient, requiring only ounces of uranium to produce the energy output of tons of coal. This, too, is fortunate, given that uranium is a generally rare element in the universe, and not particularly abundant on earth. A summary of uranium resources published jointly by the Nuclear Energy Agency of the OECD and the UN’s International Atomic Energy Agency concluded that at current price levels, there is only a 50 year supply of uranium on the planet. Nuclear power currently provides 20% of the human population’s electricity demand,18 and this level of use can be sustained for 50 more years. Basic arithmetic tells us that if we were to increase nuclear power to 100% of our current electricity usage, our uranium supply would be sufficient for only 10 years. Of course, one may object that nuclear cannont—and should not—be expected to provide all of our electricity, but if we expect it to replace fossil fuels, we will need it to account for nearly that much, so that our other energy sources can provide for the continuing growth our current civilization is predicated on: we will need more electricity next year than we do this year, after all (electricity usage is predicted to double between 2002 and 203019)
More importantly, oil is not the only fuel that peaks.20 What the Hubbert curve essentially describes is a problem of diminishing returns. Uranium mining, too, is subject to the same trend.
Uranium is widely distributed in the earth’s crust but only in minute quantities, with the exception of a few places where it has accumulated in concentrations rich enough to be uses as an ore. The main deposits of ore, in order of size, are in Australia, Kazakhstan, Canada, South Africa, Namibia, Brazil, the Russian Federation, the USA, and Uzbekistan. There are some very rich ores; concentrations as high as 1 percent have been found, but 0.1 percent (one part per thousand) or less is usual. Most of the usable “soft” (sandstone) uranium ore has a concentration in the range between 0.2 and 0.01 percent; in the case of “hard” (granite) ore, the usable lower limit is 0.02 percent. The mines are usually open-cast pits which may be up to 250m deep. The deeper deposits require underground workings and some uranium is mined by “in situ leaching”, where hundreds of tonnes of sulphuric acid, nitric acid, ammonia and other chemicals are injected into the strata and then pumped up again after some 5- 25 years, yielding about a quarter of the uranium from the treated rocks and depositing unquantifiable amounts of radioactive and toxic metals into the local environment and aquifers.21
Notice the same trend with uranium as we have with oil: we mine the highest quality ores first, leaving lower quality ores (in this case, less uranium in the ore). Because we use so much fossil fuel in mining uranium ore, this can ultimately defeat many of nuclear power’s advantages over fossil fuels.
When the leaner ores are used - that is, ores consisting of less than 0.01 percent (for soft rocks such as sandstone) and 0.02 percent (for hard rocks such as granite), so much energy is required by the milling process that the total quantity of fossil fuels needed for nuclear fission is greater than would be needed if those fuels were used directly to generate electricity. In other words, when it is forced to use ore of around this quality or worse, nuclear power begins to slip into a negative energy balance: more energy goes in than comes out, and more carbon dioxide is produced by nuclear power than by the fossil-fuel alternatives.
There is doubtless some rich uranium ore still to be discovered, and yet exhaustive worldwide exploration has been done, and the evaluation by Storm van Leeuwen and Smith of the energy balances at every stage of the nuclear cycle has given us a summary. There is enough usable uranium ore in the ground to sustain the present trivial rate of consumption - a mere 2 1/2 percent of all the world’s final energy demand—and to fulfil its waste-management obligations, for around 45 years. However, to make a difference—to make a real contribution to postponing or mitigating the coming energy winter—nuclear energy would have to supply the energy needed for (say) the whole of the world’s electricity supply. It could do so - but there are deep uncertainties as to how long this could be sustained. The best estimate (pretending for a moment that all the needed nuclear power stations could be built at the same time and without delay) is that the global demand for electricity could be supplied from nuclear power for about six years, with margins for error of about two years either way. Or perhaps it could be more ambitious than that: it could supply all the energy needed for an entire (hydrogen-fuelled) transport system. It could keep this up for some three years (with the same margin for error) before it ran out of rich ore and the energy balance turned negative. …
The implication of this is that nuclear power is caught in a depletion trap—the depletion of rich uranium ore - at least as imminent as that of oil and gas.22
Hidden costs
Mining ore is not the only element of nuclear power that requires fossil fuels. We typically consider only the fuel input, in the case of nuclear power, uranium. But for nuclear power, there are significant startup and decomissioning costs that must be examined.
From the outset the basic attraction of nuclear energy has been its low fuel costs compared with coal, oil and gas fired plants. Uranium, however, has to be processed, enriched and fabricated into fuel elements, and about two thirds of the cost is due to enrichment and fabrication. Allowances must also be made for the management of radioactive spent fuel and the ultimate disposal of this spent fuel or the wastes separated from it. …
The cost of nuclear power generation has been dropping over the last decade. This is because declining fuel (including enrichment), operating and maintenance costs, while the plant concerned has been paid for, or at least is being paid off. In general the construction costs of nuclear power plants are significantly higher than for coal- or gas-fired plants because of the need to use special materials, and to incorporate sophisticated safety features and back-up control equipment. These contribute much of the nuclear generation cost, but once the plant is built the variables are minor.
In the past, long construction periods have pushed up financing costs. In Asia construction times have tended to be shorter, for instance the new-generation 1300 MWe Japanese reactors which began operating in 1996 and 1997 were built in a little over four years.23
So, the low cost of nuclear power we see today is largely a result of the freeze on construction that followed the Three Mile Island incident, allowing the greater initial investment of nuclear power plants compared to other plants to be paid off. To begin constructing new plants would cause the price of nuclear power to rise significantly.
Because of such overlooked costs, some have estimated that the cost of a new nuclear plant may be underestimated by as much as a factor of three.24
An alternative to fossil fuels?
As David Fleming argues,25 the amount of fossil fuel used in the creation of nuclear power—from the construction of nuclear power plants, to the mining of uranium ore, to the expensive decommissioning and cleanup of nuclear power sites, makes it impossible to use nuclear power as an alternative to fossil fuels. At best, nuclear can be used as an adjunct to fossil fuels that may go some way to reducing our carbon emissions—or, may not. In return, we get smaller amounts of much more dangerous waste, with no clear plan to dispose of it. Even in this context, as we’ve seen above, the current uranium supply is insufficient to provide more than a few more decades of nuclear power, even under current conditions. Fleming discusses more experimental possibilities, such as thorium and fast breeder reactors, in detail, and finds that they, too, are highly questionable.
Nuclear can never be the “magic bullet” so many environmentalists have hoped it could be. It cannot be separated from a larger, fossil fuel based, industrial economy. It’s difficult to judge whether it is even objectively “cleaner,” or if we’re simply trading one kind of devastation for another. Ultimately, however, we must face the fact that nuclear power is no more an answer to Peak Oil than biofuels or coal. The sooner we recognize that there is no magic bullet, and that vast simplifications of our society will be required, the sooner we can focus on that necessary task without being distracted by such will o’ wisps, promising to allow us to continue on the civilized path of destruction.
Wow, I’d known that nuclear power was a wash in terms of environmental impact, but I didn’t realize how little we had left to power the world. There goes another pipe dream.
Comment by ChandraShakti — 10 July 2006 @ 8:21 PM
Just curious as to whether or not you’ve looked into the newfangled pebble-bed reactors, as a response to the issues of safety.
My understanding is that they can be designed such that critical failures are a near-impossibility due to inherent physical limitations.
Certainly though, that doesn’t address any of the other concerns with nuclear power.
Comment by dagnabit — 10 July 2006 @ 10:11 PM
Our over-consumption, high-energy per capita lifesyles–again cannot be supported for a very long period. All the unintended consequences of our search for the “magic” technological complexity that will keep the system going seems to be where civilization hangs it hopes. Although so few people actually research any of the “alternative” tech’s that having conversations with many of the folks ends in “the dailogue of the deaf”.
Barring Nano-technology my research for the past ten years, came up with Zero sustainable/scalable technologies that could sustain the current size/population of civilization–not even considering the very real possibility of increasing population/energy consumption.
Unless Nano-technology can be perfected to turn our garbage into oil etc, its best to prepare for a much simpler/localized system–which in itself will prove a challenge to many ecosystems & social systems, since the logic of sustainable living has quickly been lost to most within a couple generations.
Comment by Bubba — 11 July 2006 @ 9:27 AM
Right, nanotech. I was wondering what my next big article might be.
Comment by Jason Godesky — 11 July 2006 @ 9:31 AM
Glad to help out. The fact that I found Nanotechnology the only feasible alternative for civilization to maintain itself in some manner, doesn’t mean its not “magic” or extreme wishful thinking. From my readings, we are a long way off from making functional nano-bots that can re-structure the atoms of common materials into fossil fuels and the like.
But for the wishful thinking crowd, its the “magic” that would conceivably have a chance to succeed where switchgrass/ethanol/nuclear will most definitely not provide the abundand energy required to keep things going in their current form.
Nano-tech is a level of complexity, if its even possible to perfect, that most certainly would carry with it scary prospects (grey goo—increased domination etc) Plus, who would program these things, we have enough problems with complex software and bugs and the like as it is…
Oh well, better off learning to make cat-tail bread, IMHO
Comment by Bubba — 11 July 2006 @ 11:56 AM
I was suprised to see no mention of thorium, at least to dismiss it as a currently viable option. There certainly is some buzz about it and although it appears that commercially viable thorium reactors are some years off it does appear, mostly because of thorium’s abundance, as something of a light on the horizon.
Comment by cassandra — 11 July 2006 @ 5:53 PM
Especially since I did mention thorium.
It’s a little long, and tangential, for the main article, but here’s Fleming’s whole section on thorium, since you brought it up:
Before anyone asks, the link has a similar section on fast breeder reactors, too.
Comment by Jason Godesky — 11 July 2006 @ 6:01 PM
ta Jason,
miswishful reading on my part?
Comment by cassandra — 11 July 2006 @ 6:26 PM
do you know anything about waste water from power plants? from what i know, most power plants are located near water, so they can extract water from it. and then they heat that water up (mixed with uranium) in a reactor REALLY hot to spin the turbine. after the water has served its purpose, it’s put back in the river while it’s still very hot and kills any life in that area.
apparently, this is why oklahoma didnt want any nuclear plants in the state…because it would be increidbly expensive to build water coolant areas.
my friend was telling me all this…so i dont know how true this is..
Comment by Scott — 11 July 2006 @ 11:14 PM
Thanks very much, Jason. Your essay, like David Fleming’s (at http://www.feasta.org/documents/energy/nuclear_power.htm; or one can simply Google on the eleven-word string David Fleming Why Nuclear Power Cannot Be a Major Energy Source) makes the anti-nuclear case very clearly indeed.
I believe the world leader in grid wind turbine installations, Germany, has formally committed itself to decommissioning all its grid-connected nuclear plants and to building no new ones.
Readers interested in learning still more about the high cost and poor reliability of nuclear plants could do a Google search for the sorry story of the Pickering facility here in Ontario. Pickering is a cluster of reactors using the CANDU heavy water moderator technology, twenty or so kilometres downwind from Toronto’s central business district, and feeding some gigawatts into a provincial grid from which around a dozen million Ontarians draw around 25 gigawatts. There has been no end of trouble at Pickering, with cost overruns and engineering failures. In the 2003 blackout, we in Toronto were in a state of electricity famine for some days, with our part of the provincial grid too fragile to support the subway system, in large part because Pickering could not be brought up quickly from its unplanned shutdown.
I believe that the CANDU technology was what Canada sold to 1960s or 1970s India, in Canada’s biggest-ever foreign-affairs disaster: thanks in part to the Canadian technology deal with its concomitant transfer of expertise and apparatus, 1970s India assembled enough U-235 for its first nuclear weapon. The Indian nuclear detonation in turn spurred Pakistan to acquire the bomb, and in more recent years a rogue Pakistani physicist (Khan?) has for his part been in communication with unpleasant military people in the Middle East. Evidently we have not come to the end of this sorry CANDU tale, already at least three decades in the telling.
Nuclear stories seem to take a long, long time to work themselves out, to humanity’s ultimate grief. Lick our dust, Euripides.
Sincerely,
Toomas (Tom) Karmo
http://www.metascientia.com
Comment by verbum@interlog.com — 12 July 2006 @ 1:10 AM
As seen above, the former claim is an exaggeration, at best, but it remains quite clear that the threat of a nuclear meltdown at any particular plant is quite low.
For what it’s worth, Stan Goff seems to think they’re a disaster waiting to happen. Can’t remember if I read that in Full Spectrum Disorder or on his blog. Oh, hell, I guess I’m not that lazy…here’s a link.
Comment by Eddie — 12 July 2006 @ 1:14 AM
Hey Scott –
It doesn’t happen much, but I remember a section in Paul Hawken’s The Ecology of Commerce talking about a power plant in Europe — Germany I think — where they set up a system to sell thier ‘waste water’ to local industries in need of lots of hot water… so that both the power plant AND the other industries were benefiting, while preventing ecological damage from the waste water AND the increased energy usage to heat water at the other plants.
There are all kinds of possibilities like that, unfortunately, system thinking is still VERY SLOW to occur in this age of mega corps.
Janene
Comment by Janene — 12 July 2006 @ 11:39 AM
Thanks, Eddie, for the link to Stan Goff. Mr Goff in essence invites the following question: How do the temperature and fluid pressure of a water-cooled reactor vessel evolve when the reactor loses its auxiliary power supply?
That’s the supply normally brought in from outside the reactor site by the grid, and in case of a grid failure supplied by diesel generators. Mr Goff has some statistics on vulnerability of those diesels to failures, for instance through overheating after prolonged summer running.
So, to reiterate: if the grid goes down, as it did for the Pickering nukes on 2003-08-14, and the emergency diesel generators themselves fail (as I presume did not occur in Pickering on 2003-08-14), what, speaking quantitatively, goes on in the core?
Mr Goff makes allusions to Chernobyl while neglecting to remark that North American nukes use water as a moderator, not Chernobyl-style graphite. But his basic question is a good one.
Since we are now in the business of accumulating links on this blog, let me offer another one: engineer James Aach’s properly researched techno-thriller “Rad Decision”, at http://raddecision.blogspot.com/.
Mr Aach has himself served in the nuclear industry. I’ll try to contact him by e-mail. Mr Aach: If you are reading this blog thread, would you perhaps care to give us your thoughts on Mr Goff’s query? How high **DO** temperatures and pressures rise when the safety systems lose power? Have you some numbers for us, perhaps with explicit, albeit gross, uncertainties in the style “plus-minus 30 percent”? Can you address both a USA (pressurized light-water) and a Pickering (heavy-water) scenario?
I may later try bringing this tthread to the attention of our Pickering overseers (with whom I have no affiliation beyond this, that my taxes pay their salaries).
Sincerely,
Toomas (Tom) Karmo
verbum at interlog.com
http://www.metascientia.com
Comment by Toomas (Tom) Karmo — 12 July 2006 @ 12:19 PM
The problem isn’t whether nuclear power is a viable alternative to fossil fuel. The last thing humans need is a cheap and limitless supply of clean energy. So armed, human biomass would continue, even step up, it’s war against all other biomass.
What we need is to reduce our wants, not increase our means, or continue our fruitless hunt for Utopia.
Comment by Modred — 13 July 2006 @ 7:50 AM
That is the ultimate point. This series is meant to disarm the pointless day-dreaming that continues to distract so many people from the reality that they can no longer afford to be enslaved, and continue to pin their hopes on this or that technology to continue their imprisonment as long as possible.
Comment by Jason Godesky — 13 July 2006 @ 9:55 AM
Janene,
Trigen, of oklahoma city, does that very same thing. they even provide “waste steam” for condesation and air cooling. hence, the name TRIgen, energy, steam, and hot water, all from one plant.
Comment by Tony — 13 July 2006 @ 8:05 PM
I should add, using the same energy inputs and capturing previous waste.
http://trigen.com/
Lest we forget the BENEFITS of nuclear energy, like it’s ability to clear humans out of the wilderness for hundreds of miles when it all goes wrong, and showing us jsut how adaptable nautre really is…
http://news.nationalgeographic.com/news/2006/04/0426_060426_chernobyl.html
Comment by Tony — 13 July 2006 @ 8:12 PM
Thanks to Mr. Karmo for the nice comments about my book Rad Decision. I would agree with some of the correspondence that conservation should be the first, second and third priority of any energy policy, before we start talking about the miracles of oil shales, fusion, or moose on treadmills. Ultimately, the cheapest, safest energy is that which you don’t use.
I afraid I don’t have time right now to read and reflect on the referenced literature, so I’ll go right to basic question being asked of me : “How do pressures and temperatures in the core of a water-moderated nuke evolve in a hypothetical scenario in which the nuke loses the external power that energizes its safety systems?” The scenario presented is one in which first the grid fails, in summer heat, and in which the summer heat then causes an improperly cooled onsite auxiliary diesel generator to fail.
I can answer this in part, at least, though perhaps not with the precision you might like. My primary expertise is in Boiling Water Reactors (BWRs) of the type found in the US, Japan and western Europe. Even these plants have a lot of design differences between them. I know a lot less about the Pressurized Water Reactors (PWRs) used in the West, and next to nothing about light-water reactors. I suspect that much of Rad Decision applies to all three, however, in its discussion of general plant operation and the social and health aspects of splitting the atom.
The simple, snarky answer to the question of core temperature changes after a loss of offsite and onsite AC power is that core temperatures will actually start going down. That’s because you’ll have an automatic reactor shutdown and nicely cooled-off fuel thanks to some other safety systems. You’ve got to add in a whole other group of failures to get core temperature to go up.
So let’s look further at the proposed scenario: First, when talking about this sort of thing, it’s really important to note just how unlikely it is. As the scenario notes, in case of a power grid failure (which we know can happen), nuclear plants have onsite AC power supplies such as diesel generators. Generally, there will be multiple and independent onsite AC generators (not just one). In addition, if all offsite and onsite AC power is in fact lost, western plant designs generally will have multiple, independent emergency methods for core cooling and water replacement that rely only on DC power (batteries) and steam provided by the shutdown reactor itself. (My fictional plant in Rad Decision has two of these systems). These emergency core cooling systems must then also fail to work in order to reach the problem state you propose - a reactor core with no cooling. So, in short, even if all the power lines leading into a plant go down, there must be additional, multiple failures both of (several) independent AC onsite power generators, and of (several) cooling systems not dependant on any AC power. That redundancy substantially lowers the odds of getting to a state with no core cooling - and those very, very low odds are important to keep in mind when discussing what may happen if you actually do get there.
Now, let’s say we’ve gotten to the point where a western nuclear reactor has indeed been cut off from a fresh cooling water supply.
1) It’s not the absolute temperature and pressure values that matter, but how these values correspond to the maximum values the fuel can handle before leaking and ultimately rupturing and then how much the reactor vessel and primary cooling system can handle before rupturing. After all, a BWR runs with water at 500F and 1000 psig under normal conditions, which wouldn’t be pleasant to be in the middle of in any case.
2) The scenario you envision is discussed in my book for a fictional light-water Boiling Water Reactor (BWR) used in the US. First, when offsite power is lost, control rods are automatically inserted to shut down the nuclear reaction via a system that is not dependent on AC power (from either power lines or onsite diesel generators). For the time being, pressure in the reactor will also be controlled via a system not dependent on AC power. (The DC/steam-powered emergency core cooling systems would also have tried to start and, apparently, they have failed.) The fuel rods do continue to give off some heat even with the nuclear chain reaction turned off, however, and the core temperature then rises over time due to the lack of introduction of fresh cooling water. (If enough control rods don’t go in to shut off the reaction, temperatures will go higher, faster, of course. But now you’re piling on even more failures, and I don’t think that’s a reasonable assumption even for a rational worst case scenario planner.) Eventually, in a shutdown reactor with no cooling, fuel temperatures reach a point where fuel damage begins to occur. Based on the data I had from various simulations, I estimated a little more than an hour before any fuel damage would occur at my fictional reactor. (I can’t be super quantitative about it - there’s a lot of variables.) The general progress of such an event would be similar for other BWRs but the time frame could vary quite a bit depending upon reactor sizing and fuel design.
I always try not to address in detail any subjects I’m not familiar with. While I suspect Pressurized Water Reactors (PWRs), as used in the US, would have a similar answer to my fictional scenario, as I’ve noted above I don’t have expertise in these, and I have no background at all in heavy water reactors. It’s quite possible that the information you’re looking for, in general cases, can be found in text books and government publications available to the public.
Also, note that an hour is only the start of the fuel damage process and western plants are built to withstand some pretty significant core damage before the public starts seeing seriously bad radiation doses. TMI (a PWR) had part of its core turn to rubble under somewhat different circumstances, and the actual public radiation doses weren’t horrible - even if the communications and the ensuing panic left something to be desired from a public health perspective. (What constitutes “seriously bad radiation dose” is another topic my book addresses.)
I hope the above somewhat answers your questions. I would strongly encourage those interested in the nuclear issue to read Rad Decision. I spent a long time putting it together to provide an entertaining lay person’s guide to nuclear energy A - Z, from alpha particles through Chernobyl, TMI to the blue glow of reactor fuel. Without that type of real-world background, general discussions on nuclear safety can lose a lot of their practical value for understanding and solving problems (however much they may still influence the public and body politic).
In short, I’ve tried to say what I felt needed to be said in Rad Decision, in careful, detailed, and often nuanced language - - so I always point to it as the place to go for answers. The full text is currently online at no cost, along with additional commentary. See http://RadDecision.blogspot.com.
JA
Comment by James Aach — 13 July 2006 @ 10:38 PM
Mr Aach:
Thanks so much for your thorough reply. Over the next few days, I expect to be rereading and digesting what you have to say, as I hope will some appropriate desk at Ontario Hydro. (I have now alerted Ontario Hydro, via appropriate Hydro public-relations e-mail addresses, to the existence of this discussion thread. Ontario Hydro is the entity that runs our troubled deuterium-moderated Pickering reactors.)
Jason G, and readers overall:
Mr Aach’s comments raise a more GENERAL question, which Jason or his colleagues may some day care to address in a book or essay. Suppose the electricity grid goes down and stays down, for many days or many weeks. Then (this is today’s more general question) what parts of our infrastructure get damaged beyond easy repair, forcing outright writeoffs in capital investment? Many devices - street lamps, elevator motors, radio transmitters - can be turned back on when power returns after a long shutdown, but not all can be. A former Soviet engineer, I think once active in Soviet Ukraine, has asserted to me that when subway-tunnel pumps failed in the Leningrad of his day, it was found cheaper to drill a new tunnel than to pump out the old flooded one. I believe that some cabling under Manhattan relies for its integrity on the maintenance of pressure inside the cable sleeve from a constant flow of dry nitrogen, with that flow ultimately dependent on an external electricity supply. Can that flow safely be stopped, then restarted? Or is the cable ruined, say by twisting of some torqued conductors inside it, once its sleeve pressure falls below a certain level?
Mr Aach is for his part surely now inducing some of us to consider, whether in what he explicitly writes or through an imaginative process of extrapolation, the possibility that a reactor core could be similarly ruined. The idea some of us are surely now having is that once enough supporting systems go down, we face a reactor failure in the manner of Three Mile Island - not a rupture of the containment vessel, releasing a Chernobyl dose of radioactivity, but a failure ruining the reactor core.That would be a failure forcing the writeoff of an investment conceivably exceeding a thousand million US dollars.
Maybe, for all I know, the critical number of supporting-system failures, I mean a number large enough to destroy a reactor core, could be reached in a sufficiently prolonged grid blackout. I’m imagining here the diesel, for instance, for the backup generators, eventually just running out, once Petro-Canada ceases to be able to run its pumps at the filling station, or once the upstream pumping stations in the Trans-Canada Pipeline cease working.
Here I do envisage Petro-Canada running its diesel pumps on lead-acid batteries that store only a finite number of ampere-hours. But is someone at Petro-Canada thinking ahead now, and already now connecting the battery banks to solar-cell chargers? What government supervision exists on this potential chokepoint?
At least some of our urban infrastructure is already known to be weak. Toronto was unable to pump water for its water towers and elevated reservoirs on 2003-08-14, since the pumping gear was too greedy to be run off portable emergency diesel generators. Sewage could be pumped in that way, on that blackout day, but mains freshwater - needed for, among other things, fighting fires - could not be. The blackout date of 2003-08-14 was a Thursday. I think the federal government in Ottawa was analyzing the crisis that evening, or was analyzing it over the next few days, in the awe-struck realization that Toronto had until Tuesday before its water mains ran dry. It was our good luck to have the grid back, although in fragile form, quickly enough to run those too-big pumps.
In the best of all possible worlds, we would have some graduate students in departments of engineering or of physical geography write dissertations analyzing infrastructure vulnerabilities and in particular analyzing the consequences of an extended grid failure. Public funding, through scholarships or prizes, for such dissertation projects would be an appropriate undertaking for FEMA in the USA or analogous entities in other jurisdictions.
More generally, we would in the best of all possible worlds have a formal discipline of infrastructure vulnerability, with open debates in subject-specialized professionally refereed journals, in a loose analogy with the formal discipline of computer security that we have already.
Ultimately we want to be able to assign metrics to cities, measuring the infrastructure robustness of Toronto against, say, the infrastructure robustness of Cleveland, even as the old 1990s Polycenter Security Compliance Manager used to assign security metrics to individual DEC OpenVMS and Unix computers. The exercise might show that cities which grow beyond a certain size, or more generally which exceed some formaly defined threshold in engineering complexity, CANNOT afford adequately robust infrastructure.
Sincerely,
thanking Mr Aach, Jason G,
and everyone for this good thread,
Toomas (Tom) Karmo
http://www.metascientia.com
verbum at interlog.com
PS: Yes, Cleveland: they actually DID have their public water supply stop on 2003-08-13. In their case, special trucks were able to deliver water for people to drink.
Comment by Toomas (Tom) Karmo — 14 July 2006 @ 4:58 PM
Sorry for clerical errors in the posting above: “formally”, not “formaly”, and in the “PS” section 2003-08-14, not 2003-08-13.
Comment by Toomas (Tom) Karmo — 15 July 2006 @ 3:35 PM
This is an interesting and informative essay. Though I was aware of all the points you raise, this brings them all together well.
What may be the best “energy source” in the future may be conservation. I read most of the factual information years ago, so I’m not sure of exact statistics. But my impression is that more efficient appliances, a bit less speed in our lives and slightly less energy using habits could “produce” far more energy than such sources as nuclear with very little reduction in lifestyle.
Comment by Dave Gordon — 26 July 2006 @ 10:51 PM
Ultimately, there is no magic bullet–there is no one alternative fuel, nor even a combination of alternative fuels, that can replace our current consumption. We’ll need to learn to live with less. Even simple efficiency runs into the problem of Jevons Paradox: a technology that makes more efficient use of a fuel will result in that fuel being consumed more quickly, not less. So, ultimately, even simple conservation is unlikely to help much. We need to start getting used to the fact that we’re going to have to live our lives with much less energy, and stop living beyond our means.
Comment by Jason Godesky — 27 July 2006 @ 8:54 AM
Yeah, nuclear energy is definitely not worth it. And people for it blame environmentalists for stopping it. Like they won anything else. They just can’t see that nuclear energy isn’t good. I believe there could have been some kind of alternative now that I think about the electric car powered with coal. It seems to me that the elites didn’t want this society to continue much longer either. Because they did nothing to prevent getting to this point.
Comment by planetwarming — 2 August 2006 @ 12:10 AM
I don’t know what you argued about renewable energy. But we get a ridiculous amount of energy from the sun everyday. It’s just that it cannot be harnessed efficiently.
Comment by planetwarming — 2 August 2006 @ 12:33 AM
We do get quite a bit of energy from the sun—energy that also needs to be shared out amongst all the other life on the planet. We’re already taking up 40% of it just for agriculture. As I pointed out in “Do you believe in magic?” while we do get a lot of energy from the sun every day, we use even more energy in fossil fuels every day.
Comment by Jason Godesky — 2 August 2006 @ 4:06 PM
Jason,
You may want to check that factoid.
The earth receives about 215 BTU/sq ft/hr from the sun (assuming about a 50% loss due to reflection) With a cross sectional radius of 3950 miles that gives about 2.93 x 10^17 BTU/hour
According to the site I found (http://www.eia.doe.gov/neic/brochure/infocard01.htm) world energy usage for 2003 was 4.2 x 10^17 BTUs
Which is a little under 2 hours worth of sunlight.
Comment by JimFive — 2 August 2006 @ 4:23 PM
Hmmm.
I was mostly concerned with biofuels, which I suppose would suffer from the inefficiency of photosynthesis…
I remember a debate on this some time ago with Engineer Poet, and he threw around a lot of facts and figures that seemed very suspect to me.
That was the other figure I’d been missing, though, Jim; thank you for that. I’ll be going back to my drawing board now, and in a week or so you can expect a shiny new article on solar power.
Comment by Jason Godesky — 2 August 2006 @ 4:34 PM
“The earth receives about 215 BTU/sq ft/hr from the sun (assuming about a 50% loss due to reflection) With a cross sectional radius of 3950 miles that gives about 2.93 x 10^17 BTU/hour”
thats theoretical, you will never ever get even close to that with any kind of solar power. also the fraction you do get will be eaten up by the costs of any system you make TO harness it.
Comment by truekaiser — 9 August 2006 @ 6:30 PM
“thats theoretical”
Not exactly, that is the total amount of energy the earth receives from the sun. I wasn’t talking about solar electricity, and neither was Jason or he wouldn’t have mentioned sharing that energy with all the other life on the planet.
Comment by JimFive — 10 August 2006 @ 10:27 AM
The solar thermal panels on my roof are capable of collecting 1000’s of btu/sq ft/day…
http://www.aetsolar.com/images/AE-40.jpg
Comment by JCamasto — 10 August 2006 @ 1:36 PM
so what are you talking about?
btu is used to gauge both solar pannels and solar heating?
Comment by truekaiser — 12 August 2006 @ 3:13 AM
href=”http://en.wikipedia.org/wiki/Btu”>BTU is a unit of energy, mostly used for heat. Hence, using BTU for solar thermal panels and solar heat.
Comment by William Carrington — 13 August 2006 @ 1:41 PM
Could we put in a gentle plea for SI units, please, as is proper in physics, when Jason writes his solar-power essay? That means joules for energy (rather than BTUs), watts for power, and watts per square metre (rather than watts per square foot) for energy flux in incoming sunlight. The use of non SI-units looks reasonable in the USA, but very odd in all other jurisdictions. SI is designed to make it as painless as possible to check numbers in an argument.
Sincerely,
Toomas (Tom) Karmo
http://www.metascientia.com
Comment by Toomas (Tom) Karmo — 14 August 2006 @ 12:46 AM
What I missed was any discussion of the relative risk of different energy sources.
How many life-years are lost per Gigawatt of coal-generated electricity as opposed to fission-generated electricity?
What is the relative risk to the environment?
etc.
These are the questions to ask.
Comment by copeland@pt.lu — 16 August 2006 @ 3:44 PM
I haven’t crunched numbers, but remember to factor in expected value. Probability of a meltdown, multiplied by the global devastation it would entail. Now compare that to a coal-fired plant; I’m guessing there’s not much difference.
Comment by Jason Godesky — 16 August 2006 @ 3:56 PM
Interesting to note no one (that I could find…) responded to dagnabit’s early comment on Pebble-bed reactors. Though hardly ‘new-fangled’, this design has a much higher degree of inherent safety than BWR/PWR designs, as well as a higher fuel effiency.
But ultimately you are spot on with your post of July 27th and Jevons paradox…
Comment by popeye — 18 August 2006 @ 11:14 AM
Here’s what I was able to pull up on pebble-bed reactors without too much research:
Comment by Jason Godesky — 18 August 2006 @ 11:27 AM
What a bunch of lies.
First of all, the probability of a meltdown with a PWR or BWR is miniscule compared to the obsolete MBKR design used by the soviet union. And that miniscule probability is gigantic compared to the much lower probability that will come from the EPR (European Pressurized Reactor).
Second of all, the main result of the Chernobyl accident was the death of 50-60 people fighting the fire, a few cases of thyroid cancer from children who were infants at the time (everyone else is pretty much immune), and the creation of a vast new thriving nature preserve. THIS is what we’re supposed to be afraid of? Oh yeah, I guess you count the mass hysteria since you seem to be inverting “the only thing we have to fear is fear itself” to conclude that we SHOULD fear fear.
Third of all, nice use of CANDU for fear-mongering. In point of fact, CANDU is probably the worst of all modern designs and certainly the worst-managed by far. Canada’s reactors are shit. But so what? When you calculate the cost of a new thermal plant, you don’t look at the one that was burned to the ground for insurance fraud, do you?
Fourth, uranium is not in short supply. The hump you see in that stupid graph is caused by working through overstocking.
Fifth, fast breeders were deemed uneconomical because of an increase in cost of fuel by a factor of 3 or so. Considering what a small part of costs fuel accounts for, it can easily triple in price without affecting electricity prices any. This can’t be said for any of the fossil fuels.
Sixth, if we can power civilization for the next century with uranium, we’ll have more than enough time to fix the problems with thorium.
Seventh, the oil inputs to uranium mining are largely fuel. Electric vehicles and electrified rails (for transport) would take over from the ICE (Internal Combustion Engine).
Comment by Richard Kulisz — 13 November 2006 @ 9:45 PM
From the sources you cite, it’s clear that David Fleming is a big fat liar and totally unreliable.
Oh and permanent storage of nuclear waste is more than planned. The reason it hasn’t happened already is because we could AFFORD to wait 40 years. This isn’t the case with any other energy source.
As for the lack of plans in the fucked up USA, well that’s just a result of having all these rabidly anti-nuclear environmentalists. The same anti-nuclear environmentalists that created the global warming crisis with their preference for oil power plants over nuclear power.
Because what it all comes down to is that people like civilization and they want more of it. The very last thing they want is your fucked up “power down” tribal agrarian society.
Comment by Richard Kulisz — 13 November 2006 @ 9:58 PM
What a bunch of misinformation.
(1) Which is something I actually mentioned in the article: “it remains quite clear that the threat of a nuclear meltdown at any particular plant is quite low.” But as I want on to say, a very low probability of catastrophe can still give you a very poor expected value—the probability may be mercifully low, but the consequences of any failure are catastrophic. And of course, for any non-zero probability, the chances increase the more you use it.
(2) You’re vastly downplaying the effects of Chernobyl. I’ve known people who were there. The full toll of Chernobyl is difficult to gauge; between Soviet authorities and modern pro-nuclear lobbies, there’s consistently been very powerful groups quite interested in keeping a lid on all the information. No thorough assessment has ever been done. If it hadn’t started spilling over into Sweden, the USSR would’ve been perfectly content to pretend it’d never happened at all. But given the spread of the radiation, the true health effects are probably staggering. Not that we’ll ever be allowed to know.
(3) I didn’t mention CANDU, that was someone in the comments.
(4) The graph certainly shows how uranium production has fallen off in a classic Hubbert-style peak, but the short supply is shown more by the Nuclear Energy Agency of the OECD and the UN’s International Atomic Energy Agency, whose report said that we had only 50 years of uranium left just for current levels of use—or are they a bunch of fear-mongers, too?
(5) Well that, and, nobody’s sure if fast breeders will even work.
(6) Assuming that the problems with thorium are fixable. If we have another century of civilization, that doesn’t mean we’ll have another century of the same. Innovation is subject to diminishing returns. Our inventions are increasingly costly and increasingly modest. We’re approaching an asymptote—making thorium work may not be possible, or if it is possible, it may lie beyond our asymptote of innovation. Since you’re obviously unfamiliar with the rest of the site, you may want to read thesis #14 and thesis #16, which go into great detail on why this argument is utter bullshit.
(7) I believe I mentioned that this is primarily a question of fuel, but fuel is absolutely a critical point to consider. If we’re going to replace this all with electrified rail, we need to lay that electrified rail first. That’s a very high up-front cost (particularly since our uranium mines aren’t always in the easiest neighborhoods to get to). And now you need to mine uranium even faster, because its EROEI is dropping now that you’re paying for the investments out of the nuclear budget rather than fossil fuels. And that still doesn’t answer all the other critical roles fossil fuels play in the mining process: drilling, pumping, etc.
David Fleming is a respected writer and authority on energy. You’re a well-known internet troll. I’m going to go out on a limb and say that there might well be one of you that’s “a big fat liar and totally unreliable,” but I’m betting it isn’t Fleming.
I’m guessing you must be referring to the Yucca Mountain plan, where the U.S. intends to dump all of its nuclear waste. Except the facility hasn’t been properly planned, and even though it’s been desperately needed for years now precisely because we can’t afford to wait so long with such dangerous materials (the impacts waiting this long has already had are discussed in links provided in the original article), it’ll have to wait longer anyway precisely because it’s not ready yet.
I thought you just said it was planned—”more than planned,” in fact. So which one is it? Is it “more than planned” or do we have a “lack of plans”? You contradict yourself from one sentence to the next!
Really? What’s your favorite part about civilization? War? Disease? I hear stress-related heart disease is big with the kids these days. Oh, how about starvation? Alienation, maybe? I mean, who doesn’t love being treated like a cog? Oh, I know, cancer! It’s cancer, isn’t it? Don’t you just love cancer?
You’re right, longer, healthier lives in commuities that appreciate you as a person are just so out of style, man. Who would want that? Give me mass extinction and a slow, painful, wasting disease any day of the week!
Comment by Jason Godesky — 14 November 2006 @ 11:33 AM
Yeah, we sure do love our agriculture here…
Comment by Giulianna Lamanna — 14 November 2006 @ 12:30 PM
As for problems with HTGR’s, I still cannot see the picture of the faulty fuel pebble ( I have asked the site administrator of tmia.com at least two times for this picture). Be that as it may, what do you guys think of the concept of a solar-powered fusion torch to get rid of old MOX fuel rods?
(yes, I know there is no practical fusion torch in existence yet).
Also, does everyone here dismiss the Linear non-threshold model of radiation exposure/harm?
Comment by Steve Z — 1 February 2007 @ 11:58 PM