Follow Slashdot stories on Twitter

 



Forgot your password?
typodupeerror
×

Comment Re:Solution! (Score 1) 151

The problem, is that there aren't enough of them. ;) More seriously, that is basically what geothermal does, and it is useful where available. Exploration and drilling are expensive though, and suitable sites are limited. Interestingly, while the environmental effects are minimal compared to fossil fuels, they are still not as benign as with nuclear. Drilling releases greenhouse gasses trapped deep in the earth, among other things including radon. (Hence both geothermal and fracking put out more radioactivity than nuclear plants, though still nothing to panic over.) Fundamentally though, geothermal is merely indirect nuclear, taking advantage of the decay of thorium and uranium within the earth itself.

Comment Re:Solution! (Score 1) 151

That coal should be left in the ground, and not foolishly burned for energy. It is criminal to turn such a valuable concentrated carbon resource into ash, particulate, and CO2 and disperse it into our environment. Incidentally, there is more than 10 times the energy recoverable from the traces of uranium and thorium within the coal, than from combusting the coal itself. Of course, that isn't available if we mix the ash into sidewalks and roads, and such. (and it still contains some of the other nasties which didn't make it into our air or water already.)

The point is that there will never be "enough" coal if we continue using it as an energy source. It might last for a while, but conservation is still not sustainable. Conservation will only drive up prices for energy and preclude using it for energy intensive processes like recycling. Even producing the steel, concrete, and rare earths necessary for renewables is highly energy intensive and entirely dependent upon heat from fossil fuels today. Those renewables are also exposed to the elements and need to be recycled every decade or two. We are already reverting to burning trees, and it is only going to get worse until more people accept that nuclear power.

Anyway the crucial point is that nuclear provides reliable energy 24/7 through severe weather or natural disasters and with a minimal environmental footprint. They are among the most robust structures in existence, and molten salt reactors would be even more resistant to damage. (Granted, the transmission infrastructure is still vulnerable, and that is another reason why it should be minimized.) Even coal and natural gas plants can be taken off line by severe weather. During the recent polar vortex, it was nuclear which kept the lights on in New England.

Comment Re:Solution! (Score 5, Informative) 151

With an abundance of sustainable and reliable energy, survivability of an event such as a volcanic winter would be drastically increased. Energy is the only limiting factor in producing a 100% self-sufficient and self-contained living environment, not only in space, but on earth as well. Energy availability would be instrumental in facing such a disaster, and with adequate preparation we could manage quite comfortably.

However, if the green dream of a world powered exclusively by renewables were realized, humanity would have no hope whatsoever. The lights would go out indefinitely, and any sort of civilization would promptly collapse, with only a handful surviving in miserable conditions. Renewables are not reliable, and are incapable of sustaining civilization through such a crisis.

While efficiency is a laudable goal (to which most engineers already aspire), eking by with extreme conservation is highly anti-productive, and exacerbates environmental and societal problems. Energy is not a disease to be eradicated, but a resource essential for enabling greater levels of recycling and reuse, and ultimately a sustainable high quality of life with minimal environmental footprint. With prosperity, population also tends to level off, solving that problem as well.

Energy is only a problem when it is derived in an environmentally destructive manner, as with mining and extraction of fossil resources, or the vast and inefficient collection, storage, and distribution infrastructure for wind and solar. These sources also require extensive mining for the raw materials comprising the infrastructure, and the fuels required for transportation in both cases.

Owing to a far superior energy density, nuclear energy necessitates very little mining and supporting infrastructure. Molten salt reactors like LFTR use nuclear fuel roughly 200 times more efficiently than todays LWRs, and with passive safety and no need for water cooling, they can be sited virtually anywhere. For perspective, a 1GWe LFTR plant would be roughly the size of a Walmart. Incidentally, there are upward of 10,000 Walmarts, which would accommodate 10TW of LFTR power production--enough to provide for 10 billion people at US per capita power consumption.

Each year, a 1GWe reactor would only consume about a ton of thorium, and produce about a ton of fission products. All of the fuel required to power the world for a year could be mined at a site not much larger than a Walmart itself. However, it could instead be recovered from the tailings of rare earth or other mining already in progress. (For reference, a metric ton of thorium fits in a sphere 55cm (or 1.8ft) in diameter.) A plant could easily have decades worth of thorium on hand.

Of course, the picture wouldn't be complete without considering the waste. A single GWe of generating capacity is enough to power a sizable city, producing 1t (metric ton) of fission products per year. One might worry that these are going to accumulate and produce an intractable problem, but in reality the radioactivity is constantly disappearing, and will reach a steady state when the creation balances the decay. As 83% of the fission products of a LFTR are stable after a decade, and the rest no more radioactive than ore in 300 years, the sum total of waste produced for one GWe of power, will gradually build up to, yet never exceed 59t after 300 years. This is a trivial amount, which is still overstated as many of the fission products have uses. (radioisotope thermal generators, sources for medicine or food irradiation, etc.) Even if politics prevents doing something useful with it, it could still be safely stored in a small room on site.

Comment Reactor grade plutonium is useless for bombs... (Score 1) 104

Reactor grade plutonium is useless for bombs, and parroting the lie doesn't change that. See Dr. Helen Caldicott: Toilet Paper & Plutonium at 5:50. (The other Caldicott videos by Thorium Remix also offer further insight into a prototypical leader of the anti-nuclear movement. The source of this story, "The Bulletin of the Atomic Scientists" belongs in the same class and deserves similar scorn for their rampant intellectual dishonesty.)

However, the article refers to unexposed MOX fuel, which is not the same thing, and the isotopically pure plutonium-239 can be separated in that case. The problem is that when Japan halted all of their reactors, the MOX fuel never made it into a reactor; had it been exposed in a reactor, there would be no issue. The safest place for fissile is in the core of a reactor, where it is rendered useless for weapons while producing vast amounts of energy. Molten salt reactors do an even better job and can thoroughly destroy all of the remaining spent fuel as well, which releases roughly 20 times more energy yet.

Comment Re:Wait until those lamers find out... (Score 1) 385

Hanford was a weapons production site, which has nothing to do with nuclear power. Arguments against nuclear power on the basis of waste all fall flat, because the actual byproducts are short-lived and the quantity is a total non-issue. Hence, dishonest ideologues resort to conflating it with weapons waste, or using vastly inflated numbers which do not account for reprocessing. Even those numbers amount to nothing next to alternatives though, including highly resource inefficient wind and solar.

Once a modern reactor converts the remaining 99% of energy contained within spent fuel and depleted uranium into energy, there is virtually no waste at all. About 83% of fission products would be stable within 10 years, and the remainder in a few centuries. However, nearly all of it have uses and value if separated. Nuclear "waste" is a fictional problem created by people who insist on wasting valuable nuclear material, rather than putting it to good use.

Comment Re:Another misconception bites the dust (Score 1) 365

Some of it may be scrubbed, but there are still significant losses. Even a small fraction of a percent escaping results in substantial pollution when burning billions of tons of coal a year. Have a look at the contents, and that isn't even considering the contribution of CO2 to ocean acidification.

Germany should reverse course, as they are not on a path which will eliminate or even mitigate coal pollution. Current policy is driving prices up and creating a permanent dependence on fossil fuels to compensate for unreliable energy from wind and solar. A $100B spent on nuclear instead would have been a much wiser investment.

Comment Ammonia is not an energy source... (Score 1) 380

Producing ammonia today consumes more than 1% of all man-made power, and natural gas is used as a source of hydrogen. Like hydrogen, it is an energy carrier and not a energy source. That considered, ammonia produced with nuclear heat would be an excellent carbon neutral liquid fuel, and is expected to cost significantly less than gasoline.

Comment Re:time to die... (Score 2) 204

Worse yet, all of those round trips are done synchronously. If the goal is network transparency, X is awful no matter how you slice it.

It is desirable to minimize the display to input path for interactive applications, and I'd love for the ability to use tablets as a custom interactive input panel for desktop applications. There will always be a delay in the event processing loop of an application, but I believe that this is the one which should be minimized, allowing truly interactive multitouch or pen based controls to be created. Then, for remote applications, one can move the control surfaces to the local display.

It isn't clear that this needs to be baked into the protocol, and may work fine as an API on top of a minimal system like wayland. Putting this logic into the display server may not be flexible enough, as one could imagine a whole spectrum of uses. At one extreme, the whole application could be running local (on your remote display). Then, perhaps only the filesystem, network, or other OS services could be proxied, and so forth. Creating a truly universal protocol is a daunting if not impossible task.

Comment Re:what a waste (Score 1) 187

It is probably more since wikipedia was last updated, and plant operators will continue to pay into it for decades in some cases. Two things to consider: decommissioning plants early reduces such funding, and as more are decommissioned, the cost should fall.

Virtually all of the costs associated with nuclear are artificial, wether the endless litigation and permitting barriers, or the industrial base and technology development which has stagnated for decades. These problems are solvable, and nuclear could easily be the most cost effective and environmentally friendly form of energy given a serious commitment to pursue it.

Comment Re:what a waste (Score 1) 187

The details of the chemistry control need to be worked out, but the reprocessing in a LFTR is very straightforward. The most common and problematic fission products are gaseous and just bubble out of the liquid fuel, which by the way is 750C, not several thousand degrees C. Some plate out, and others may even remain dissolved in the salt for the lifetime of the reactor.

If you are concerned about human error, then there is no safer place for radionuclides than fluoride salts. Poor chemistry control may damage the reactor, but the fuel and non-volatile fission products are going nowhere, even if the reactor vessel is cracked open. At worst, some of the fission products in the off gas system could escape, but they pose no long term health concern--the ones that do remain safely locked away in the salt, which will eventually freeze solid.

The reactor you describe is a fantasy, and wasteful besides. Ironically, unless it were a molten salt reactor, it could never burn through 100% of the fuel, producing a long-term radiological hazard that should not be left in the ground. An MSR burns virtually 100% of the fuel, is walk away safe, and requires no complex or safety critical control systems. It essentially runs itself, following the load; you add fuel and remove heat, that is all. Sure, some maintenance is required, and a lot of engineering, but nothing else holds half so much promise.

Comment Re:The real cost of nuclear is the long tail of wa (Score 2) 187

The $25bn put aside from nuclear waste storage is still only a fraction of the subsidy that nuclear has received. The free government backed insurance is literally priceless, as no commercial insurer would ever offer it.

So should we kill the airline industry as well? Limited liability is not exclusive to nuclear, nor has it been a burden in practice with reasonable limits. Rather than calling it priceless, why don't you be honest about what that "free government backed insurance" has cost to date. I believe the word for that you are looking for is "zero". It may not remain zero, but per unit of energy produced, and relative to the alternatives, it will continue to be extremely small. Subsidies for renewables and fossil fuels on that basis have a very real cost, and are quite high.

At any rate, insurance figures will be meaningless as long as regulatory limits on radiation are so absurdly far below safe limits. When nuclear plants can not even be permitted in many places due to perfectly benign background radiation levels exceeding said absurd limits, there is clearly a problem.

Nice attitude, by the way. Raving and foaming at the mouth really adds credibility and weight to your well reasoned argument.

Your comments empty of any constructive ideas are no better. Given the endless "raving and foaming at the mouth" of anti-nuclear ideologues, the colorful language is understandable and more easily forgiven.

Comment Re:what a waste (Score 1) 187

Decommissioning a LFTR poses no special difficulty, and all of the salt can be recycled for use in a new plant. If anything, the liquid fuel simplifies the process. The fission products are continuously removed so that they do not build up, and can be stored safely. The bulk of them (87%) stabilize within ten years, and the remaining require storage for only a few hundred years. Starting with thorium, very few long lived actinides are produced, and those are continuously recycled into the fuel salt. Only a tiny amount of even that is lost to the waste stream due to reprocessing inefficiencies.

As the storage requirements for LFTR waste are vastly simplified, it makes little sense to insist on building yet another a huge and expensive facility dedicated to storing spent LWR fuel in the interim. Dry casks at plant sites are perfectly adequate for the time being. Even with much increased global energy demands supplied exclusively by nuclear, the waste produced still reaches steady-state at a minuscule quantity. All the waste on earth would fit on a plot of land roughly the size of a wal-mart, though there is no need to geographically concentrate such an insignificant quantity.

China is investing in molten salt reactors because the technology has been proven, and the commercial risks are small. Without the obscene regulatory burden and uncertainty introduced by the dysfunctional permitting process in the west, there would be no shortage of investors. India was pursuing thorium in solid fueled reactors in the past which offers little benefit, though even they have now turned their attention to molten salt reactors. There are many promising efforts and significant interest around the world from those who are actually serious about facing our energy crisis.

Comment Re:what a waste (Score 4, Insightful) 187

It would not be a subsidy. The Nuclear Waste Fund has accumulated a balance of $25 billion dollars, paid in fees over the years by nuclear plant operators. The parent is only suggesting that it be spent on developing the technology which has the greatest potential for managing the "waste", rather than waiting it out. In the end, those are the only two options: fission it, or bury it.

Nuclear "waste" and "spent fuel" are misnomers, as conventional reactors extract less than 1% of the energy from mined uranium. It is insane to treat it as waste, when the technology exists to completely transform the remainder into energy, while eliminating virtually all of the long term radioactivity. The technology was proven decades ago, and the remaining development and commercialization could be completed using a small fraction of the available fund.

Molten salt reactors like LFTR would not only produce enormous amounts of electricity from that "waste", but also valuable medical isotopes, radioisotopic fuel for space probes, and rare earths. As a high temperature reactor, even the rejected "waste" heat has many potential uses, including desalination and producing ammonia or other synthetic liquid fuels. Another interesting application is carbon neutral cement.

Discouraging development of nuclear not only prevents safer designs and a solution for the waste issue, but also assures continuing dependence on fossil fuels in the many cases for which renewables are not suitable. (Including the production of more renewables, which require a whole lot of steel and concrete. Or to provide energy while the wind and sun are unavailable.)

Comment Re:Money is irrelevant... (Score 1) 411

That requires energy, which fossil fuels will be incapable of providing in the future no matter the cost.

Those other things don't make that comment less false.

Even coal is a finite resource and it will run out in the future. It is assumed that we will stop mining before reaching an EROEI approaching 1 at infinite cost. In practical terms, I still don't see how that statement can be false. The point is that access to energy is of primary importance, and the welfare of humanity ought to be placed above the business interests of the fossil fuel industry.

Everyone benefits from affordable sustainable energy, and preventing the deployment of nuclear power maintains an artificial scarcity which only benefits the fossil fuel industry. Those in control, appear determined to bring society to the brink of destruction in order to exploit that scarcity, and people who entertain the fantasy of a world powered exclusively by the sun and wind are only helping them.

Comment Re:Keystone XL (Score 1) 411

Expensive, yet still far less so than wind and solar. With nuclear, most of the cost is not inherent in the technology, but arises from the endless litigation and delays, along with the atrophied supply chain and construction industry. Beyond that, the costs of nuclear will be dramatically reduced once molten salt reactors are commercialized.

Deployment of nuclear faces difficult, yet addressable problems. On the other hand, the economics of renewables are limited by the laws of nature, and those are not mutable.

Slashdot Top Deals

For God's sake, stop researching for a while and begin to think!

Working...