Is Nuclear Fusion The Answer To Clean Energy?

[Wombat + 1,028]

On 9/15/2020 at 3:46 AM, Dan Clemmensen said:

Note also that, while your assertions are basically true, there are caveats. First, By convention we call p+B11==>3He4 "fusion" but it's actually fission. We call it fusion because we lump it in with other relatively clean light-element nuclear reactions instead of lumping it with heavy-element nuclear reactions that have nasty decay products.

Next, it's still radioactive, just not very radioactive. For example it's a lot less radioactive (curies per MWh) than, say, coal fly ash, but it's still radioactive. First, there are a few low-probability side reaction that generate neutrons, and these will ultimately create radioactive isotopes in the reactor shielding. Next, a fair amount of the energy will result in hard x-rays generated by bremsstrahlung, right? This energy must be captured in the shielding, which will convert it into heat which in turn can be used to generate electricity. The x-rays don't produce radioactive isotopes, but this still means you need a fair amount of shielding mass, say a 10 cm thickness of lead all the way around, so even the smallest reactor will weigh at least 500 Kg.

Thorium reactors are very safe and produce little waste, but that is the whole problem. The USA only ever produced one reactor but abandoned it because it didn't produce plutonium. That is the only reason nuclear reactors are built in most places.

[Wombat + 1,028]

On 9/17/2020 at 9:34 AM, Meredith Poor said:

Sapphire project:

What they're saying here is that they already have fusion, and they also have elemental transmutation, particularly transmutation capable of converting radioactive waste to harmless elements. Their efforts from here are focused on scaling up and commercialization.

You are so gullible. Either that, or deaf. They did not say they got 14 times more power out than they put in, they said 14 times more THAN EXPECTED! They achieved a temperature of 113 degrees celsius, WOOHOO! Hot enough to boil water. Just because some serious institutions are backing the technology does not mean they will be any more successful than ITER when it comes to getting more energy out than in. Very interesting, but about as useful as a fusor. They MIGHT win a govt contract to treat some high level radio-active waste, very doubtful, and they MIGHT be able one day to produce rare earths more cheaply than mining and chemistry, even more doubtful, but if you believe they will be producing electricity, then go ahead and put some cash in. If you were smart, you would watch the video above that Dan Warnick provided, and listen a little more carefully.

[Rob Plant + 2,617]

On 9/15/2020 at 8:39 PM, Dan Clemmensen said:

Sorry, but Gamma rays and the somewhat less energetic X rays are ionizing radiation. They are very dangerous in high doses and somewhat dangerous in lower doses.

Yeah look what happened to the Hulk!!

[Rob Plant + 2,617]

You guys need to go to the Iter.org web site

billions being spent on fusion projects globally but this one is by far the biggest

[Wombat + 1,028]

On 9/16/2020 at 5:39 AM, Dan Clemmensen said:

Sorry, but Gamma rays and the somewhat less energetic X rays are ionizing radiation. They are very dangerous in high doses and somewhat dangerous in lower doses. This is why the x-ray room in a hospital is heavily shielded to protect the technicians.  1 cm of lead cuts this radiation in half, 2 cm cuts in by fours, and 10 cm (about 4 in) cuts it by 1024. your "inch of lead" cuts it by a factor of about 6. This stuff is nasty. See

https://en.wikipedia.org/wiki/Acute_radiation_syndrome

lead is roughly ten times the density of your body. A path of length ten inches through your body will interpose about the same mass as a path of 1 inch in lead, and will therefore stop about 5/6 of the gamma rays. Every stopped gamma ray is stopped by either the photoelectric effect or the Compton effect and produces an energetic electron that tears up the tissue around it. Gamma radiation is what the general public is usually talking about when the term "radiation" is used. Alpha and beta are less penetrating. Neutrons are a different story.

Dan, Alpha particles are the most highly ionising, but are only capable of penetrating a couple of mm through skin. As I say, it is ingestion or inhilation that causes the problem. Having said that, peoples fear of radiation is far greater than the actual threat. Thought you might be interested in this:

https://www.radioactivity.eu.com/site/pages/Chernobyl_Caesium.htm

[Wombat + 1,028]

37 minutes ago, Wombat said:

Dan, Alpha particles are the most highly ionising, but are only capable of penetrating a couple of mm through skin. As I say, it is ingestion or inhilation that causes the problem. Having said that, peoples fear of radiation is far greater than the actual threat. Thought you might be interested in this:

https://www.radioactivity.eu.com/site/pages/Chernobyl_Caesium.htm

Having said that, disposal of radio-active waste is still a problem:

https://ieer.org/resource/books/high-level-dollars-low-level-sense/

About 20 years ago, Australia developed a product called "SYNROCK" (Synthetic rock) to dispose of high-level waste but it has recently been found that it would only work for about 1500 years, as opposed to the 200,000 years necessary. Still, 1500 years should be good enough if used in conjunction with sub sea-bed disposal. Shouldn't be hard to shove spherical balls of the stuff down old offshore oil platforms?

[Dan Clemmensen + 1,011]

4 hours ago, Wombat said:

Dan, Alpha particles are the most highly ionising, but are only capable of penetrating a couple of mm through skin. As I say, it is ingestion or inhilation that causes the problem. Having said that, peoples fear of radiation is far greater than the actual threat. Thought you might be interested in this:

https://www.radioactivity.eu.com/site/pages/Chernobyl_Caesium.htm

your citation is about radioactive fallout (nuclear accident or nuclear war), where the ingested or inhaled in the most dangerous. Gamma radiation is still important in the early phases when (for two weeks after a war) the fallout on the ground is still emitting lots of it. The situation for a nuclear generator in much different. Here, the radioactive material is well characterized and localized, and ideally no radioactive atoms are escaping at all from the innermost container. Alpha and beta will not escape either, so you only need to worry about neutrons and gamma. The problem is that the gamma needs at least 10 cm of lead or equivalent for a factor of 1000 reduction, and the neutrons will radioactivate some of the atoms in your structure, including the shielding.

Note that I am mostly going from memory  here from a looong time ago. I went to Oak Ridge High school. My dad was the civil defense director (fallout shelters, etc.) My father-in-law was a reactor shielding expert. But I have tried to keep informed.

Edited October 3, 2020 by Dan Clemmensen
sp

[Dan Clemmensen + 1,011]

3 hours ago, Wombat said:

Having said that, disposal of radio-active waste is still a problem:

https://ieer.org/resource/books/high-level-dollars-low-level-sense/

About 20 years ago, Australia developed a product called "SYNROCK" (Synthetic rock) to dispose of high-level waste but it has recently been found that it would only work for about 1500 years, as opposed to the 200,000 years necessary. Still, 1500 years should be good enough if used in conjunction with sub sea-bed disposal. Shouldn't be hard to shove spherical balls of the stuff down old offshore oil platforms?

Encapsulation has been studied for at least 60 years. Encapsulation in borosilicate glass is simple and fairly effective and was already being evaluated in 1970. 200,000 years is a fairly silly number, probably the number needed to reduce the radioactivity to the equivalent of background level for the average natural mineral. But the resulting non-radioactive decay products are heavy metals and will poison you non-radioactively in far smaller amounts than would be required by the radioactivity. Because of the way half-life works, the stuff is safe to handle without protection after about 600 years unless you eat it. If civilization has not survived and developed a way to deal with this stuff in 100 years, we have far larger problems to worry about.

[Meredith Poor + 883]

11 hours ago, Wombat said:

You are so gullible. Either that, or deaf. They did not say they got 14 times more power out than they put in, they said 14 times more THAN EXPECTED! They achieved a temperature of 113 degrees celsius, WOOHOO! Hot enough to boil water. Just because some serious institutions are backing the technology does not mean they will be any more successful than ITER when it comes to getting more energy out than in. Very interesting, but about as useful as a fusor. They MIGHT win a govt contract to treat some high level radio-active waste, very doubtful, and they MIGHT be able one day to produce rare earths more cheaply than mining and chemistry, even more doubtful, but if you believe they will be producing electricity, then go ahead and put some cash in. If you were smart, you would watch the video above that Dan Warnick provided, and listen a little more carefully.

At this point, I'm not much concerned with whether this group in particular can get to a sufficient yield to generate useful amounts of power. I'm paying more attention to the number of actors in the fusion space, and the collection of different approaches they are all following. Solar and wind are 'a lot of little improvements in a lot of little ways'. Fusion may turn out to be the same story - vast amounts of cross fertilization leading to some 'big picture' painted by a lot of contributors. In any case, working fusion would simply be icing on the cake, since a lot of other technologies are commercially viable and are growing exponentially. If it turns out to be sufficient simply to transmute particularly noxious radioactive waste into harmless elements, it would be enough.

[Wombat + 1,028]

3 hours ago, Meredith Poor said:

At this point, I'm not much concerned with whether this group in particular can get to a sufficient yield to generate useful amounts of power. I'm paying more attention to the number of actors in the fusion space, and the collection of different approaches they are all following. Solar and wind are 'a lot of little improvements in a lot of little ways'. Fusion may turn out to be the same story - vast amounts of cross fertilization leading to some 'big picture' painted by a lot of contributors. In any case, working fusion would simply be icing on the cake, since a lot of other technologies are commercially viable and are growing exponentially. If it turns out to be sufficient simply to transmute particularly noxious radioactive waste into harmless elements, it would be enough.

I agree that if it were possible to cheaply process radioactive waste, that would be a big plus for the nuclear fission industry, but still not enough so to make the nuclear industry viable in many countries that have good solar and wind resources.

[Dan Clemmensen + 1,011]

1 hour ago, Wombat said:

I agree that if it were possible to cheaply process radioactive waste, that would be a big plus for the nuclear fission industry, but still not enough so to make the nuclear industry viable in many countries that have good solar and wind resources.

It has been technically feasible to process nuclear waste pretty much since the beginning of the nuclear age, using breeder reactors and deep ocean dumping. The problems have been an irrational fear of trace contamination, and a very rational fear of proliferation of nuclear weapons.

[Wombat + 1,028]

6 hours ago, Dan Clemmensen said:

It has been technically feasible to process nuclear waste pretty much since the beginning of the nuclear age, using breeder reactors and deep ocean dumping. The problems have been an irrational fear of trace contamination, and a very rational fear of proliferation of nuclear weapons.

They are also more expensive than traditional reactors, despite the fuel cost savings.

[Wombat + 1,028]

On 9/11/2020 at 12:31 AM, Meredith Poor said:

Every time posts like this show up, I invite people to keyword search 'Hydrogen Boron 11 Fusion'. This is definitely nuclear fusion - however it is not 'large', expensive, or radioactive.

Meredith, this is speculation:

https://paintbrushsage.blogspot.com/2012/08/ice-cube-and-gravity-wave-telescopes.html

And this is science:

https://link.aps.org/accepted/10.1103/PhysRevLett.106.221101

Spot the difference?

Although the first article sounds very alluring, it is not backed mathematically or experimentally. You may have noticed that the author specifically rules out the frame dragging effect (x-axis), whilst the second article confirms it, as well as the geodesic effect, (y and z-axis). Note that the author of the first article believes in the possibility of cold fusion and has a design for something similar to the saphire reactor, but the kinds of scientists that did the Gravity Probe B experiment or that are building the ITER, do not believe in cold fusion. Just as "oils ain't oils", there is high-quality science and low quality science. That is what I am trying to teach you Meredith. Show me the math! I was blessed to be taught by two of the worlds top cosmologists at my supposedly 2nd-rate University, and I can assure you that they would have laughed at the first paper. Still, I enjoyed reading it as it threw up some interesting questions that I had not considered before so thankyou for starting this thread and getting me into action

[Gerry Maddoux + 3,627]

Ah, but Charles Frederick Lawson is much more fun to read. And he's says he's not a math guy.

You have to admit, the guy has a million ideas. Some of them are possibly right. I agree: fun to read.

😀

[Dan Clemmensen + 1,011]

4 hours ago, Wombat said:

They are also more expensive than traditional reactors, despite the fuel cost savings.

Breeders are more expensive because the tech was not pursued commercially for 60 years like non-breeders, so the costs have not come down. Also, the costs of the radioactive waste products are externalized. The breeder can consume wastes instead of generating them and dealing with the waste is where our discussion started. If you pay the breeder to consume waste, it might change the equation.