Nuclear Energy, Yes or No?

[Lauren Hynde]

Approximately twenty percent of electricity generated in the United States is by Nuclear Power Plants. Although a new plant has not been built in over thirty years.

Some European nations use Nuclear to a greater degree than the US, some approaching fifty percent.

Just to correct that information, only seven European Union members have nuclear energy production plants. Of those, only two generate a higher percentage of energy than the US: France (37%) and Sweden (30%). Of the seven, three (Sweden, Germany, Belgium) have introduced phase-out programs. Finland is currently the only EU member that is expanding its conventional nuclear capacity.

The overall European policy, in trying to fulfil its Kyoto Protocol requirements, is to reduce carbon-based emissions, and so nuclear power could remain an important part of the European energy production plan, but only if it proves to be absolutely indispensable, and not a second after it outlives that absolute necessity.

In the mean time, the EU is firmly decided to move forward with the construction of the International Thermonuclear Experimental Reactor in France, which will deal primarily with nuclear fusion research.

 

[Weird Harold]

Hydrogen would be great, but hydrogen doesn't occur naturally, and it takes more energy to manufacture hydrogen that you get from burning it. In other words you still have to burn coal or oil to make hydrogen.

Hydrogen (H2) does occur naturally and can be collected and liquified through multi-stage refrigeration. On a cosmic scale, hydrogen is the most common element in the universe and the majority is free hydrogen.

Hydrogen does NOT have to be produced by electrolysis of water. Numerous chemical reactions produce Hydrogen as a byproduct and many of those chemical reactions also produce nothing but "non-polluting" compounds -- eg there are no toxic results.

It is currently technically possible to produce large quantities of Hydrogen with out resorting to fossil fuel powered electricity. Colly mentioned Solar and Wind generated power, but you can add hydro power to the list.

If the entire output of Hoover Dam were redirected to electrolizing the waters of Lake Mead the amount of power delivered to the drive wheels of vehicles would be much less than the electricity currently delivered through the power grid -- about an 80% reduction in the useable power Hoover Dam produces.

However, the loss of absolute power available from Hoover Dam would have some environmental benefits.

There would be no need for the thousands of miles of high-tension power distribution wires that are accused of causing health problems for those living near them and cost Billions of dollars to maintain. Thousands of acres of land required for those power line right of ways could be returned to wilderness or developed as appropriate.

The other by-product of Electrolizing water into Hydrogen -- pure Oxygen -- would offset the loss of oxygen prodution caused by the dstruction of rainforests.

Small Hydrogen fueled electrical generation systems could eventually replace large centralized fossil fuel power plants because Hydrogen fueled generating stations wouldn't pollute and could be more acceptable within city boundaries.

The idea of diverting existing Hydro and other electrical generating systems isn't really practical as a first step, though. The need is to provide more power, not use what we have less efficiently -- no matter how much better it would be for the environment.

I think that existing Solar and Wind power technologies could easily be placed in the middle of the Pacific on floating Hydrogen generating rafts. Experimental power generating technologies -- like using the temprature differential at different depths of the ocean or a variationon Tidal Generators that uses the energy of the waves -- could be added to the mix.

Compressed or liquified hydrogen could be transported by hydrogen filled and powered blimps to whereever it's needed and the deflated blimps returned to the hydrogen platforms by hydrogen or nuclear powered ships.

The power lost in producing and transporting the hydrogen would be irrelevant because mid-ocean solar radiation and ocean winds can't be tapped by any other way and delivered to where it's needed -- all of that potential power is lost completely now. Tapping into those vast potential resources and getting ANY additional power to land is a net gain in the available power.

Large mid-ocean platforms would naturally lend themselves to producing more than hydrogen for fuel -- Electrolizing large amounts of sea-water would tend to also extract the minerals dissolved in that seawater; almost every element and compound required to expand the hydrogen generation platforms is dissolved in seawater along with thousands of other elements and compounds that could offset some of the operating costs; if not pay for them completely.

Storms would not be a problem for hydrogen production -- they'd be peak output times for a properly designed system -- although they'd be a problem for the distribution system.

As a fuel, Hydrogen is significantly less efficient than gasoline or even diesel, but it's also much more plentiful and is totally non-polluting in terms of greenhouse gasses and toxic byproducts. If we accept and adapt to the inherent inefficiencies in production, distribution and use, the potential increase in total energy availble to the public in a conversion to a Hydrogen Fueled tecnology is well worth the inefficient use of energy we can't tap any other way.

 

[TheEarl]

This is going to be an absolute first - I disagree with Harold.

I've come over all faint.

H2 does occur naturally, but not in commercially viable amounts on the Earth. Free hydrogen may abound in the universe, but it'll be a long time before we can harvest that.

Harold's idea of a flotilla of power stations in the Pacific isn't necessarily a bad one, but brings some major problems. Mid-ocean mechanics of any kind are costly and notoriously fragile. You say a storm would be peak time for a properly designed system, but we're a long way from designing that system. Atm anything which gets put mid-ocean gets munched very quickly. Plus we cannot underestimate the problems with distributing hydrogen. If you have the power generator on the rafts, then it adds to the risk of losing machinery and makes it almost impossible to transport. However if you transport pure H2, then you'd better have an all non-smoking crew. One tiny spark and the entire thing's sky-high. That's why the Hindenberg burned.

Hydrogen's a beautiful idea and I agree wholeheartedly with the developments of the hydrogen cell and the experiments to create H2 efficiently. However it is nowhere near a viable alternative atm. Can you see any power company investing in a flotilla of wind barges, with a risk of losing 40% every year to produce energy of which 80% is wasted to produce hydrogen that could explode and destroy the supply lines? Hope for the future, but not for today.

The Earl

 

[dr_mabeuse]

Hydrogen (H2) does occur naturally and can be collected and liquified through multi-stage refrigeration. On a cosmic scale, hydrogen is the most common element in the universe and the majority is free hydrogen.

Hydrogen does NOT have to be produced by electrolysis of water. Numerous chemical reactions produce Hydrogen as a byproduct and many of those chemical reactions also produce nothing but "non-polluting" compounds -- eg there are no toxic results.

I'm unaware of any terrestrial sources of hydrogen gas, though I suppose there may be some bubbles atop natural oil fields. And yes, hydrogen is the most abundant element in the universe, but that's because it's also the simplest element and the main component of stars.

As far as chemical reactions that produce hydrogen, I've been in chemistry for a long time, and the only feasible non-electrolytic method of production I'm aware of involves treating a metal with a strong mineral acid, which is a very expensive way to go. There's still some hope of being able to generate hydrogen by using sunlight and synthetic biocatalysts like chlorophyll (that's what plants do), but that's way in the future.

The other problem with hydrogen is in transporting it. Hydrogen boils at -253 deg. C, only 20 degrees above absolute zero, so liquifying it isn't trivial. On the other hand, hydrogen can be soaked up by certain metals like water in a sponge and then released by gentle heating. That's the good news. The bad news is that those metals are palladium and platinum, which aren't cheap.

I'm all in favor of hydrogen as a fuel, but I think there are some really difficult problems to be faced regarding its use.

---dr.M.

P.S. A quick Google showed that scientists working at Argonne National Laboratory (my old alma mater) have recently come up with a copper-chlorine catalyst that can produce hydrogen at a temperature of 500 degrees C. with 40% efficiency. That's a temperature that can be produced in modern powerplants. http://www.sciscoop.com/story/2003/4/22/73111/2009

There might be light at the end of the hydrogen tunnel yet.

 

[china-doll]

dbl post.

 

[china-doll]

Several years ago I worked for the power company. We had over a dozen power stations of various sizes, most were coal, some were oil and a couple were gas. 2 of them were nukes. I worked in one of the coal plants. At the time I worked there, the coal plant was, I believe the 3rd largest fossil fuel plant east of the Mississippi (but probablly not any more). Something on the order of about 1600 megawatts.

The smallest of the nukes genereated about twice that at full power. So obviously the power potential from these monsters is huge. And in a maner of speaking it is clean power, meaning that there are no greenhouse gasses.

But there are several major problems associated with nukes.

THe first, and most obvious, is the potential for catastrpohy. The plants are designed to be foolproof, with multiple backups for just about everything, automated emergency systems, general overdesigs etc. But history has shown us that no system, no matter how well designed, is foolproof. THere is always the potential for some unforseen disaster, a one in a million shot the no one saw comming.

With a fossil fuel plant, a failure could be a disaster. A boiler explosion in a big coal fired plant could level several square miles, something that most people dont know and are probablly better off not knowing.

But a failure at a nuke is a all together different animal. As others have noted, a meltdown not only destroys the surounding area, but also contaminates millions of square miles downwind with radiation. When Chernobyl had it's disaster, the fallout was recorded as far away as the northwester US. That contamination will still be there 100 generations from now. Stop and really think about how long that is for a second.

Next is the disposal of the spent fuel rods. THe US is still persuing Yucca mountain in Nevada. It has been persuing this for 20 years and is only marginally closer to putting it in service than it was 10 years ago. The lawsuits will take decades to sort out. So that leaves us with the current system where all of the spent fuel is stored on site at the reactors. I forget the numbers, but I believe it is something on the orger of 75% of all plants are up to capacity and can store no more.

The third problem is heat. THis affects all powerplants and nukes most of all. THey generate a tremendous amouth of heat that must be balanced. Also the steam created to turn the turbines must be cooled and recondensed to run the system again. This is usually done with cooling towers wich are not very efficient or by taking in huge amounts of river or ocean water. Taking in these huge amounts of water and then discharging them back into the ocean or river has the effect of raising the temp of the surrounding river/bay whatever which can have adverse effects on the plants and fish.

The last problem is the nuke beaureacy which is huge. Becaus of the safety issues the plants are almost policied and regulated to death. Changing a lightbulb takes 15 forms and 23 people and 6 weeks. This only gets worse every year and will probablly be the death toll of the nukes. THeis drives the costs thru the roof. In the minds of the power industry, if they cant make power cheaper than coal/oil/wind whatever, then why build them?

 

[Bandit1]

I remember sitting in on a discussion while I was in college about alternative energy sources.

There was one very vocal idiot who had shouted objections to everything.

When someone suggested putting thousands of solar panels out in the mojave desert, he wailed that would mean less sunlight for everyone else and that we would all freeze to death. And plants would wither and die from lack of sunlight etc.

When someone suggested wind power, he raised objections claiming that harnessing the wind would mean interfering with the free flow of the air and that would mean massive climate changes worldwide.

After the first outburst it was generally decided that he was stoned out of his gourd.
After the second outburst, we were sure of it and he was escorted from the room before the discussion went on.

 

[Weird Harold]

This is going to be an absolute first - I disagree with Harold.

I've come over all faint.

H2 does occur naturally, but not in commercially viable amounts on the Earth. Free hydrogen may abound in the universe, but it'll be a long time before we can harvest that.

You can go down to an industrial supply house and buy a tank of Hydrogen -- that Hydrogen did NOT came from electrolysis it's produced as a byproduct of producing LOX and most of the Hydrogen produced that way is simply disposed of.

Collecting Hydrogen from the Earth's atmoshpere is possible in "commercial" amounts through Multi-Stage Refrigeration. But you're correct that there isn't enough free hydrogen in the atmoshpere to creae a hydrogen based power infrastructure on. Collecting free hydrogen from Space and returning it to Earth is even less practical.

However, the start of a hydrogen fueled economy will start with the "waste" hydrogen collected by multi-stage refigeration plants that exist to produce LOX and gaseous O2 for many different industries

Harold's idea of a flotilla of power stations in the Pacific isn't necessarily a bad one, but brings some major problems. Mid-ocean mechanics of any kind are costly and notoriously fragile. You say a storm would be peak time for a properly designed system, but we're a long way from designing that system. Atm anything which gets put mid-ocean gets munched very quickly.

But Oil Companies still spend billions to put exploration and production platforms in mid ocean and fewer every year are destroyed or even damaged by storms.

The knowldge and technology developed for those oil platforms can easily be applied and improved upon for other purposes.

Plus we cannot underestimate the problems with distributing hydrogen. If you have the power generator on the rafts, then it adds to the risk of losing machinery and makes it almost impossible to transport. However if you transport pure H2, then you'd better have an all non-smoking crew. One tiny spark and the entire thing's sky-high. That's why the Hindenberg burned.

The Hindenburg was 1920's technology and paintd with an aluminum paint that was as explosive as TNT! It's also widely believed, but unproveable that it was destroyed by sabotage rather than by accident.

Transporting pure hydrogen is inherently dangerous, but we routinely transport many substances that are more dangerous than Hydrogen with relatively few mishaps -- Gasoline and crude oil for example.

How much environmentl damage would have been caused if the Exxon Valdez were loaded with liguified Hydrogen instead of crude oil?

Hydrogen's a beautiful idea and I agree wholeheartedly with the developments of the hydrogen cell and the experiments to create H2 efficiently. However it is nowhere near a viable alternative atm. Can you see any power company investing in a flotilla of wind barges, with a risk of losing 40% every year to produce energy of which 80% is wasted to produce hydrogen that could explode and destroy the supply lines? Hope for the future, but not for today.

If a market for hydrogen can be created, then I can certainly see a power company investing less than would be required for the oil drilling and production platforms they already spend billions on.

However, it's a Catch-22 situation at the moment -- You could be driving your current car powered by Hydrogen next week but won't do so because there is no Hydrogen distribution system for you to refuel from reliably.

Relatively inexpensive conversion kits are available to convert any internal combustion engine to Hydrogen, Natural Gas, Propane, or any other gaseous fuel. Hydrogen conversions can be to gaseous Hydrogen or Liquid Hydrogen fuel storage.

The problem that prevents wide-spread conversion to fuels other than gasoline and diesel is there are very few places to refuel and those that do exist are too widely separated to permit long distance traveling -- the distance between refueling points is further than the range of most gaseous fuel conversions except for propane/LPG conversions.

I can see somplace like the State of California subsidizing a "proof of concept" hydrogen generation raft to fuel a proof of concept hydrogen powered electrical generation station and a small scale hydrogen fuel distribution system in a "test area" where they ban any fuel except Hydrogen.

Except for a few dedicated environmentalists converting their personal vehicles to Hydrogen power, it's NOT a concept that is going to happen in the next year or two, but it's a transition that might begin in the next decade.

One of the first steps in the conversion is killing the impression the Hindenburg is the inevitable result of using Hydrogen for transportation -- whether as a lifting gas or as a fuel. The Hindenburg was a very graphic disaster and is remembered for the compelling imagery and commentary, but it was NOT as big a disaster as it's legend makes it.

from: http://www.pilotfriend.com/century-of-flight/Aviation history/coming of age/Hindenburg.htm

Of the ninety-seven aboard, thirty-six died, including thirteen “civilian” (paying) passengers, the first passengers of this kind killed in a dirigible accident. (Past fatalities had been crew members and military personnel, never paying passengers.) Captain Pruss was saved, but Captain Lehmann staggered out of the fire only to die in the hospital a few hours later. Before he died, however, he was interviewed by one of the investigators sent hastily to Lakehurst to determine what had happened—none other than Charles Rosendahl. As Lehmann lay dying, he muttered to Rosendahl that the explosion must have been caused by an incendiary bullet shot from the ground. Lehmann’s dying words, “It must have been an infernal machine,” were often quoted, though no one was quite sure what he meant. ...

Hydrogen lifted airship disasters are much less disastrous than a single jet aircraft crash. But then I'm not advocating using hydrogen lifted blimps for passenger service, just freight service with maximum automation and minimum crew.

Fleets of Blimps could deliver Hydrogen anywhere in the world, but they wouldn't necssarily need to -- they could just as easily deliver their loads to castal distribution centers where it could be transported by conventionl truck, rail and/or pipelines that would present less danger to the public and environment than the transportation of Gasoline by those same methods today does.

 

[TheEarl]

You can go down to an industrial supply house and buy a tank of Hydrogen -- that Hydrogen did NOT came from electrolysis it's produced as a byproduct of producing LOX and most of the Hydrogen produced that way is simply disposed of.

However, the start of a hydrogen fueled economy will start with the "waste" hydrogen collected by multi-stage refigeration plants that exist to produce LOX and gaseous O2 for many different industries

The waste H2 produced in those industries would be a start, but any and all methods of creating hydrogen available nowadays are far too inefficient to supply any large-scale market. With luck research will allow easier splitting of H+ ions in the future, but the technology's not there yet.

But Oil Companies still spend billions to put exploration and production platforms in mid ocean and fewer every year are destroyed or even damaged by storms.

The knowldge and technology developed for those oil platforms can easily be applied and improved upon for other purposes.

Oil drilling in the mid-ocean (especially Atlantic) is generally marked as commerically unviable. Close to the coast or in the N.Sea definitely. Out in the middle, the attrition rate is terrible. The price of oil is the only thing which forces them anywhere near there and, barring a major (and I mean major) power shortage, hydrogen barges just aren't going to get the necessary returns.

The Hindenburg was 1920's technology and paintd with an aluminum paint that was as explosive as TNT! It's also widely believed, but unproveable that it was destroyed by sabotage rather than by accident.

Mentioning the Hindenberg was a bit cheeky I'll admit. Poor debating on my part there.

Transporting pure hydrogen is inherently dangerous, but we routinely transport many substances that are more dangerous than Hydrogen with relatively few mishaps -- Gasoline and crude oil for example.

How much environmentl damage would have been caused if the Exxon Valdez were loaded with liguified Hydrogen instead of crude oil?

Good point.


Hydrogen's definitely a fuel of the future, but until more research is put into creating H+, it won't be viable and the research won't be funded until the oil panic starts. Pity.

The Earl

 

[gauchecritic]

Somebody please disabuse me of my hopefully wild imaginings, which are:

Nuclear power plants produce the raw elements for weapons grade plutonium. (If true then my theory about the reasons for nuclear power are a little more sinister than a clean energy source.)

Nuclear power, actual usable electricity from nuclear reactions, is too small to be commercially viable. Thus the main commmercial use (other than a military weapon) of nuclear power is to boil water to turn turbines.

Nuts and sledgehammers spring to mind. (along with ulterior motives)

If either of the above are true then nuclear power stations should be closed as soon as possible.

Naa, close them anyway, and while I'm at it make CRT's illegal too because of the x-rays they produce, which are a significant factor in the rise of various cancers in non-smokers. Oh and air pollution from cars.

 

[Colleen Thomas]

Somebody please disabuse me of my hopefully wild imaginings, which are:

Nuclear power plants produce the raw elements for weapons grade plutonium. (If true then my theory about the reasons for nuclear power are a little more sinister than a clean energy source.)

Nuclear power, actual usable electricity from nuclear reactions, is too small to be commercially viable. Thus the main commmercial use (other than a military weapon) of nuclear power is to boil water to turn turbines.

Nuts and sledgehammers spring to mind. (along with ulterior motives)

If either of the above are true then nuclear power stations should be closed as soon as possible.

Naa, close them anyway, and while I'm at it make CRT's illegal too because of the x-rays they produce, which are a significant factor in the rise of various cancers in non-smokers. Oh and air pollution from cars.

Breeder reactors do produce weapons grade fissionables, but not all reactors are breeder reactors.

Nuclear power produces plenty of electricity, although it suffers from the same peak time problems as fossil fuel reactors.

The vast majority of nuclear waste is not weapons grade, but it could be used to make a "dirty" bomb, ie it could be wrapped around conventional explosives.

With nuclear you make a choice, you are betting it will be safely run and the energy you get is safer than the pollution of fossil fuel plants. In the average to best case scenarios, it's wonderful, clean, abundant electricty and relatively cheap. In the worst case, it's horrible almost beyond imagining. That's the trade off you make with nuclear.

-Colly

 

[Lauren Hynde]

In the average to best case scenarios, it's wonderful, clean, abundant electricty and relatively cheap. In the worst case, it's horrible almost beyond imagining. That's the trade off you make with nuclear.

That's what is so great with the Thermonuclear (Fusion) Experimental Reactor. If it works, it's the end of the world's energy problem forever. If it doesn't work, it's the greatest blackhole of money in the history of humanity. If it works and something goes wrong with the containment fields, we won't even have time to worry about it.

 

[china-doll]

That's what is so great with the Thermonuclear (Fusion) Experimental Reactor. If it works, it's the end of the world's energy problem forever. If it doesn't work, it's the greatest blackhole of money in the history of humanity. If it works and something goes wrong with the containment fields, we won't even have time to worry about it.

We'll all have a front row seat for the Solar Systems newest bright spot.

 

[Colleen Thomas]

That's what is so great with the Thermonuclear (Fusion) Experimental Reactor. If it works, it's the end of the world's energy problem forever. If it doesn't work, it's the greatest blackhole of money in the history of humanity. If it works and something goes wrong with the containment fields, we won't even have time to worry about it.

The idea of cold fusion has been around a long time. It's sort of the energy panacea, will fix everything. Of course you areplaying with the same reaction that occurs at the heart of a star.

Unless I misundertand how it works, a failure in the containment fields won't be that catastrophic. The reaction only occurs naturally undr massive gravitational forces. But I am no expert. If the frech blow up europe with it and you survive, I've got a spare bedroom

 

[Lauren Hynde]

Unless I misundertand how it works, a failure in the containment fields won't be that catastrophic. The reaction only occurs naturally undr massive gravitational forces. But I am no expert. If the frech blow up europe with it and you survive, I've got a spare bedroom

Yes, the reaction only occurs naturally under massive gravitational forces which we don't have, so we have to compensate by forcing a reaction at temperatures several times higher than the sun's. Or so I heard.

 

[Colleen Thomas]

Yes, the reaction only occurs naturally under massive gravitational forces which we don't have, so we have to compensate by forcing a reaction at temperatures several times higher than the sun's. Or so I heard.

I'll ship you some SPF agillion

 

[china-doll]

The idea of cold fusion has been around a long time. It's sort of the energy panacea, will fix everything. Of course you areplaying with the same reaction that occurs at the heart of a star.

Unless I misundertand how it works, a failure in the containment fields won't be that catastrophic. The reaction only occurs naturally undr massive gravitational forces. But I am no expert. If the frech blow up europe with it and you survive, I've got a spare bedroom

I'm not sure if I'm right here so someone feel free to correct me if I'm not...

But it was my understanding that what was required to start a fusion reaction was intense pressure and heat. But once the reactionwas started it was selfsustaining as long as it has material to feed on. Meaning that if the magnetic containment field failed and the reaction was allowed to contact the vessel walls they would be consumed as well, then the surounding area and so on until... poof... new Sun.

The idea of a runaway fusion reaction has been played around with in many sci-fi books over the years, but that doesn't mean it's real science.

Anyone know for sure?

 

[Weird Harold]

The waste H2 produced in those industries would be a start, but any and all methods of creating hydrogen available nowadays are far too inefficient to supply any large-scale market. With luck research will allow easier splitting of H+ ions in the future, but the technology's not there yet.

There is a lot of ineffeciency in the energy industries already. Hydrogen production would be just a bit more inefficient than what we already put up with -- using current technologies.

But in spite of the ineffeiency in absolute terms, Mid-ocean hydrogen production is possible with current off-the-shelf technology for the most part and has the potential to completely replace all of the energy we derive from fossil fuels and then some.

The price of oil is the only thing which forces them anywhere near there and, barring a major (and I mean major) power shortage, hydrogen barges just aren't going to get the necessary returns.

I'm not thinking in terms of "barges" -- barges are just too small. I'm thinking in terms of several hundred acres of solar panels floating on the surface at a minimum.

Without a market for the hydrogen, there wouldn't be the finacial returns so mid-ocean hydrogen production would have to be subsidized by governements to break the catch-22 of no supply because there's no market and no market becuse there's no supply

Mentioning the Hindenberg was a bit cheeky I'll admit. Poor debating on my part there.

Not really. The Hindenburg disaster and the fear of "Hydrogen Bombs" are a large part of the resistance to deveoping hydrogen as a fuel. Until those misunderstandings are addressed and overcome, Hydrogen is going to be seen as "too dangerous" in spite of the fact that natural gas pipelines into homes are far more dangerous than Hydrogen would ever be.

Somebody please disabuse me of my hopefully wild imaginings, which are:

...

Nuclear power, actual usable electricity from nuclear reactions, is too small to be commercially viable. Thus the main commmercial use (other than a military weapon) of nuclear power is to boil water to turn turbines.

Nuts and sledgehammers spring to mind. (along with ulterior motives)

Colly addressed the breeder reactor distinction, so I won't bother.

All modern power generating plants (save hydro electric) use steam turbines to convert Heat to Elecricity. Nuclear Power just uses a "clean" source of heat to produce the steam. The amount of "waste" per giga-watt of power is actually miniscule compare to the "waste" fossil fuel fired plants produce.

The only thing that produces less "waste" is geothermal power generation which, like Hydro Electric, is seldom practical where the power is actually needed.

 

[Lauren Hynde]

Anyone know for sure?

That is what I heard on TV last week when they were talking about the ITER. Magnetic fields containing the reaction that will have to be several times hotter than the sun.

 

[Colleen Thomas]

I'm not sure if I'm right here so someone feel free to correct me if I'm not...

But it was my understanding that what was required to start a fusion reaction was intense pressure and heat. But once the reactionwas started it was selfsustaining as long as it has material to feed on. Meaning that if the magnetic containment field failed and the reaction was allowed to contact the vessel walls they would be consumed as well, then the surounding area and so on until... poof... new Sun.

The idea of a runaway fusion reaction has been played around with in many sci-fi books over the years, but that doesn't mean it's real science.

Anyone know for sure?

Stars burn out and it isn't because they are out of things to react, if so there wouldn't be red dwarfs, or brown dwarfs. A star dies when it reaches the point of creating a certain element with the reaction, I want to say Iron, but I am not positive. From all I have read, if a star's mass goes beneath a certain level, then the gravitational pressure is no longer enough to sustain the reaction.

It would seem logical that if you started such a reaction, it would continue only so long as there was sufficient heat/pressure to sustain it. Once it broke the containment feild, it would seem that it would end, as it no longer had the requisite heat/pressure to sustain it.

Haven't read Hawking in quite a while, so I may be off base.

 

[Bandit1]

I'm not sure if I'm right here so someone feel free to correct me if I'm not...

But it was my understanding that what was required to start a fusion reaction was intense pressure and heat. But once the reactionwas started it was selfsustaining as long as it has material to feed on. Meaning that if the magnetic containment field failed and the reaction was allowed to contact the vessel walls they would be consumed as well, then the surounding area and so on until... poof... new Sun.

The idea of a runaway fusion reaction has been played around with in many sci-fi books over the years, but that doesn't mean it's real science.

Anyone know for sure?

Fusion reactions are self sustaining only under certain conditions such as those found in the sun and inside magnetic fields produced for that purpose. i.e. untense heat and tremendous pressures.
Otherwise we would have several new suns sitting where Hydrogen bombs have gone been detonated.
Once free of the magnetic confinement, the fusion reaction would quickly exhaust the available fuel and die out.
Yes there would be considerable damage to the facility, but nothing like there would be if a fusion weapon had been detonated.
The main trouble at present isn't in containing a steady fusion reaction, it is in producing a stable fusion reaction in the first place.
However once that bug has been ironed out, then fusion power could be developed into a viable energy source.

 

[Lauren Hynde]

Once it broke the containment feild, it would seem that it would end, as it no longer had the requisite heat/pressure to sustain it.

That's what I think also, and what makes more sense, but how fast can the "thing" cool down? Even if the reaction stop immediately, you'd still be left with matter hotter than the sun and capable of melting the entire planet.

 

[Colleen Thomas]

That's what I think also, and what makes more sense, but how fast can the "thing" cool down? Even if the reaction stop immediately, you'd still be left with matter hotter than the sun and capable of melting the entire planet.

It will cool tremendously fast. Once exposed to the atmosphere the heat will dissipate quickly. The heat from an H-bomb is split second at the level of fusion, then relatively quickly falls off as the area around it absorbs the heat and passes it outward from the event.

 

[Lauren Hynde]

It will cool tremendously fast. Once exposed to the atmosphere the heat will dissipate quickly. The heat from an H-bomb is split second at the level of fusion, then relatively quickly falls off as the area around it absorbs the heat and passes it outward from the event.

So, worst-case-scenario, France.

 

[Bandit1]

So, worst-case-scenario, France.

Or would that be best case?