5 ms·

In my opinion funding should rather go to Thorium and breeder fission reactors. If something has been tried for decades without a clear breakthrough, it's defin

In my opinion funding should rather go to Thorium and breeder fission reactors. If something has been tried for decades without a clear breakthrough, it's definitely time to try some other promising avenue.

tormeh 12y ago
Well, then kill off some fusion reactors and divert funding to Thorium and breeder, but let's not cut out fusion completely.
- anigbrowl 12y ago
  MIT's continuance came at the expense of cuts to another project: The international fusion project, meanwhile, was funded at $200 million, $25 million less than the administration had originally requested.
  - waps 12y ago
    But ITER is the worst possible fusion project. I mean no offence, but ITER makes nuclear reactors look cheap and small. (well, granted, the actual reactors are small, but I'm talking about the support infrastructure too) Frankly, if ITER has the scaling laws of Tokamaks right, there won't ever be a working Tokamak smaller than a 10 story building, or producing less than about 1.5 GW. And q values can go up to maybe 10, not counting generator losses. To be honest : we don't want that. Getting this refunded basically means that more money is going to various other fusion ideas, and that's much better than having all our eggs in one hugely expensive, massively unwieldy and "just 10 more years" project (just 10 more years for about 40 years now). Frankly, ITER is one of those huge failed projects that just won't admit failure for mostly political reasons. We all know about lots of them. Either it will fail directly because physics somehow prevents Tokamaks from being cost effective, or it will fail because it won't succeed by the time we need it to succeed. So far, the net result of the project is that a 6 story Tokamak can't work, due to plasma instabilities. So they're building a 10 story one. The project itself has stupendous accomplishments. It has demonstrated almost unprecedented international scientific collaboration. The amount of money freely given to fund ITER is ridiculous. The amount of companies collaborating with academics on it is in the hundreds. It has so many governments invested in it ... It has so many committees and university boards invested in it it's hard to find a decent physics department that isn't invested in it ... but all of these are political achievements. The physics side of the project is finding physics not all that cooperative. You should think about what ITER is trying to do as a way to apply massive force to reality until it bends to our will. It's not smart at all (of course the details of doing this are very intricate. There's a difference. Smart is finding a way to beat the calculation speed of a huge datacenter with a 1990's pentium when it comes to calculating digits of pi [1]. Intricate is building a huge datacenter. Both are great accomplishments, of course). The problem with most of the other projects are facing is that they violate "holy cows" of physics in some way. Polywell physics require a very low-pressure non-thermalized gas, which has been demonstrated but violates thermodynamics theory. It's never going to get past more than one or two physics boards. Z-pinch is one of those tricks that's just too good to be true if it works (it does work to some extent of course). Like polywells, it's a huge risk, so getting physics professors to bet their careers on it is a non-starter. Laser fusion (and other forms of inertial confinement fusion) has similar "WTF" parts that will prevent their widespread acceptance. Because most of these things have multiple projects running, in practice this is about 12 projects. All fusion projects, with 2 exceptions (one of which is strongly suspected to be a fraud), are happening inside America, funded by either the DoD or DoE. Each of them has a much lower chance of success than ITER, I would agree with that, but if they do succeed, the payoff will be much greater. If polywells work, for example, we should be able to build a 100 megawatt or so fusion reactor the size of a 60s TV set, that could operate in a building that needn't be bigger than a big house. You know, easily small and efficient enough to install on even medium sized ships. Hell, you could probably power planes with it. None of the projects even approach the size and inefficiency of ITER (meaning 10 stories, maximum achievable q value of 10 or lower). ITER should be shelved as "not good enough" and people should go back to the cafe napkin stage. [1] http://bellard.org/pi/ http://bellard.org/pi/
    - deleted 12y ago
      [deleted]
    - waps 12y ago
      > Also, you can't make small scale fusion power plants. If the reactor was the size of a light bulb and produced 40w of power you would still need several feet of shielding to avoid killing anyone in the area and that shielding would vary quickly become extremely radioactive. Fission is low energy in comparison. http://en.wikipedia.org/wiki/List_of_coal_power_stations http://en.wikipedia.org/wiki/List_of_coal_power_stations over 5+ GW of thermal power. Google "aneutronic fusion". Granted, ITER will never support it, but that's just another reason to try other things. ITER makes everything radioactive, but aside from that being the easiest reaction there is no good reason for doing that. As for the size of fusion reactors, go to your nearest (big) hospital. They have a football-sized one in the radiology department. The box it's in is fridge-sized. A Farnsworth-Hirsh fusor to be exact. It will be shielded, because it's using DT fusion. If you really knew what you were doing you could get it to fuse p+B11 and it would produce electrons, but it would defeat the point for the hospital, as it's neutron radiation is exactly why they have it. Now granted this reactor has a q value of 0.02 or so. But if there were a smart way to get it to a q of 100 or so that would almost be your lightbulb example. Get it to work on p-B11 and ...
      - Retric 12y ago
        There is no such thing as neurotic fusion. Best case neutrons carry 1% of the total released energy, but if a 100w light bulb produced 1w of unshielded 2.5MeV neutrons it would quickly give everyone in a fairly large room a lethal radiation dose. Edit: For the morbidly curious 1w / (3 x 10 -13)j/electron = 3.3e+12 electrons. 10M from the device you have a sphere with a surface area of 1256m^2. http://miscpartsmanuals3.tpub.com/TM-55-315/TM-55-3150021.htm http://miscpartsmanuals3.tpub.com/TM-55-315/TM-55-3150021.ht... 1 rem (neutrons/cm2) from 2.5 MeV neutrons = 3* 10^6 neutrons / cm^2. 100 rem received over a short time period are likely to cause acute radiation syndrome (ARS), possibly leading to death within weeks if left untreated. So, 3 * 10^6 * 100 * 100^2 * 1256 = ~4 * 10^ 15 electrons would kill ~1/2 the people standing within 30 feet in ~10 minutes. And far less time than that to start handing out cancers left and right. And at 10 feet that's ~60 seconds. (Assuming I did not mess up...) PS: It's far safer to spread the same dose over longer periods of time. But, if your working near a useful fusion device it needs to be heavily shielded.
adrianN 12y ago
A while ago, some fusion researchers answered questions on Slashdot. They posted this graph of fusion funding: https://i.imgur.com/sjH5r.jpg https://i.imgur.com/sjH5r.jpg They said that fusion is not a certain number of years away, but around 80 billion dollars global funding away. Here is the full QA http://hardware.slashdot.org/story/12/04/11/0435231/mit-fusion-researchers-answer-your-questions http://hardware.slashdot.org/story/12/04/11/0435231/mit-fusi...
- nitrogen 12y ago
  Only $80bil? Why hasn't Apple gotten right on that? Our cars won't be powered by Mr. Fusion, they'll be powered by iColliders.

tormeh 12y ago

Well, then kill off some fusion reactors and divert funding to Thorium and breeder, but let's not cut out fusion completely.

anigbrowl 12y ago
MIT's continuance came at the expense of cuts to another project: The international fusion project, meanwhile, was funded at $200 million, $25 million less than the administration had originally requested.
- waps 12y ago
  But ITER is the worst possible fusion project. I mean no offence, but ITER makes nuclear reactors look cheap and small. (well, granted, the actual reactors are small, but I'm talking about the support infrastructure too) Frankly, if ITER has the scaling laws of Tokamaks right, there won't ever be a working Tokamak smaller than a 10 story building, or producing less than about 1.5 GW. And q values can go up to maybe 10, not counting generator losses. To be honest : we don't want that. Getting this refunded basically means that more money is going to various other fusion ideas, and that's much better than having all our eggs in one hugely expensive, massively unwieldy and "just 10 more years" project (just 10 more years for about 40 years now). Frankly, ITER is one of those huge failed projects that just won't admit failure for mostly political reasons. We all know about lots of them. Either it will fail directly because physics somehow prevents Tokamaks from being cost effective, or it will fail because it won't succeed by the time we need it to succeed. So far, the net result of the project is that a 6 story Tokamak can't work, due to plasma instabilities. So they're building a 10 story one. The project itself has stupendous accomplishments. It has demonstrated almost unprecedented international scientific collaboration. The amount of money freely given to fund ITER is ridiculous. The amount of companies collaborating with academics on it is in the hundreds. It has so many governments invested in it ... It has so many committees and university boards invested in it it's hard to find a decent physics department that isn't invested in it ... but all of these are political achievements. The physics side of the project is finding physics not all that cooperative. You should think about what ITER is trying to do as a way to apply massive force to reality until it bends to our will. It's not smart at all (of course the details of doing this are very intricate. There's a difference. Smart is finding a way to beat the calculation speed of a huge datacenter with a 1990's pentium when it comes to calculating digits of pi [1]. Intricate is building a huge datacenter. Both are great accomplishments, of course). The problem with most of the other projects are facing is that they violate "holy cows" of physics in some way. Polywell physics require a very low-pressure non-thermalized gas, which has been demonstrated but violates thermodynamics theory. It's never going to get past more than one or two physics boards. Z-pinch is one of those tricks that's just too good to be true if it works (it does work to some extent of course). Like polywells, it's a huge risk, so getting physics professors to bet their careers on it is a non-starter. Laser fusion (and other forms of inertial confinement fusion) has similar "WTF" parts that will prevent their widespread acceptance. Because most of these things have multiple projects running, in practice this is about 12 projects. All fusion projects, with 2 exceptions (one of which is strongly suspected to be a fraud), are happening inside America, funded by either the DoD or DoE. Each of them has a much lower chance of success than ITER, I would agree with that, but if they do succeed, the payoff will be much greater. If polywells work, for example, we should be able to build a 100 megawatt or so fusion reactor the size of a 60s TV set, that could operate in a building that needn't be bigger than a big house. You know, easily small and efficient enough to install on even medium sized ships. Hell, you could probably power planes with it. None of the projects even approach the size and inefficiency of ITER (meaning 10 stories, maximum achievable q value of 10 or lower). ITER should be shelved as "not good enough" and people should go back to the cafe napkin stage. [1] http://bellard.org/pi/ http://bellard.org/pi/
  - deleted 12y ago
    [deleted]
  - waps 12y ago
    > Also, you can't make small scale fusion power plants. If the reactor was the size of a light bulb and produced 40w of power you would still need several feet of shielding to avoid killing anyone in the area and that shielding would vary quickly become extremely radioactive. Fission is low energy in comparison. http://en.wikipedia.org/wiki/List_of_coal_power_stations http://en.wikipedia.org/wiki/List_of_coal_power_stations over 5+ GW of thermal power. Google "aneutronic fusion". Granted, ITER will never support it, but that's just another reason to try other things. ITER makes everything radioactive, but aside from that being the easiest reaction there is no good reason for doing that. As for the size of fusion reactors, go to your nearest (big) hospital. They have a football-sized one in the radiology department. The box it's in is fridge-sized. A Farnsworth-Hirsh fusor to be exact. It will be shielded, because it's using DT fusion. If you really knew what you were doing you could get it to fuse p+B11 and it would produce electrons, but it would defeat the point for the hospital, as it's neutron radiation is exactly why they have it. Now granted this reactor has a q value of 0.02 or so. But if there were a smart way to get it to a q of 100 or so that would almost be your lightbulb example. Get it to work on p-B11 and ...
    - Retric 12y ago
      There is no such thing as neurotic fusion. Best case neutrons carry 1% of the total released energy, but if a 100w light bulb produced 1w of unshielded 2.5MeV neutrons it would quickly give everyone in a fairly large room a lethal radiation dose. Edit: For the morbidly curious 1w / (3 x 10 -13)j/electron = 3.3e+12 electrons. 10M from the device you have a sphere with a surface area of 1256m^2. http://miscpartsmanuals3.tpub.com/TM-55-315/TM-55-3150021.htm http://miscpartsmanuals3.tpub.com/TM-55-315/TM-55-3150021.ht... 1 rem (neutrons/cm2) from 2.5 MeV neutrons = 3* 10^6 neutrons / cm^2. 100 rem received over a short time period are likely to cause acute radiation syndrome (ARS), possibly leading to death within weeks if left untreated. So, 3 * 10^6 * 100 * 100^2 * 1256 = ~4 * 10^ 15 electrons would kill ~1/2 the people standing within 30 feet in ~10 minutes. And far less time than that to start handing out cancers left and right. And at 10 feet that's ~60 seconds. (Assuming I did not mess up...) PS: It's far safer to spread the same dose over longer periods of time. But, if your working near a useful fusion device it needs to be heavily shielded.

adrianN 12y ago

A while ago, some fusion researchers answered questions on Slashdot. They posted this graph of fusion funding: https://i.imgur.com/sjH5r.jpg https://i.imgur.com/sjH5r.jpg They said that fusion is not a certain number of years away, but around 80 billion dollars global funding away. Here is the full QA http://hardware.slashdot.org/story/12/04/11/0435231/mit-fusion-researchers-answer-your-questions http://hardware.slashdot.org/story/12/04/11/0435231/mit-fusi...

nitrogen 12y ago
Only $80bil? Why hasn't Apple gotten right on that? Our cars won't be powered by Mr. Fusion, they'll be powered by iColliders.