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Can't an operational fusion reactor breed tritium? If so we just need enough tritium to start one.

by api 4y ago

ceejayoz 4y ago
The article covers that. > Tritium breeding was originally going to be tested as part of ITER, but as costs ballooned from an initial $6 billion to more than $25 billion it was quietly dropped. Willms’ job at ITER is to manage smaller-scale tests. Instead of a full blanket of lithium surrounding the fusion reaction, ITER will use suitcase-sized samples of differently presented lithium inserted into “ports” around the tokamak: ceramic pebble beds, liquid lithium, lead lithium. > Even Willms admits that this technology is a long way from being ready to use, however, and a full-scale test of tritium breeding will have to wait until the next generation of reactors, which some argue might be too late. “After 2035 we have to construct a new machine that will take another 20 or 30 years for testing a crucial task like how to produce the tritium, so how are we going to block and stop global warming with fusion reactors if we will not be ready until the end of this century?” says Mazzucato.
- api 4y ago
  Oops missed that. ITER is not necessarily the best approach to fusion, although it's the best funded. In any case if we can't breed tritium than we either need to shoot for higher energy D-D fusion or some other reaction or fusion will never be cost-competitive.
  - GuB-42 4y ago
    Is there any other approach to fusion than ITER? I mean fusion capable of practical power generation. D-T fusion is the easiest, and yet super hard. Tokamaks are the only design that we know how to build in order to meet the goal, with maybe stellerators in second position. Inertial fusion work for scientific and military experiments, but are far from being a usable power source. Things like fusors and its derivative are great hobby projects with a few limited practical applications, but we are not even sure if it is physically possible to produce more energy than we put in. As for LENR (aka. cold fusion) we are essentially at the "thought experiment" stage, when it is not a scam. One other idea that may work with current tech is to dig a large cave, line it with really thick material and detonate hydrogen bombs inside it, extracting energy from the heat of the explosion. I don't think I need to tell you that even if we can do that (unsure), we certainly shouldn't (absolutely sure). Or, take, advantage of that really big fusion reactor we already have and makes us go around in circles.
    - DennisP 4y ago
      Most conservatively, there are tokamaks that use more modern superconductors, able to support much stronger magnetic fields. Tokamak output scales with the fourth power of the magnetic field, so that allows the same output as ITER from a much smaller, cheaper reactor. The MIT spinoff CFS is doing this, along with Tokamak Energy in the UK. CFS is shooting for a net power attempt in 2025. There are also various alternative designs, like Zap Energy's z-pinch, General Fusion's magnetized target fusion, and Helion's field-reversed configuration. Helion is attempting hybrid D-D/D-He3 fusion, the other two are D-T.
      - pfdietz 4y ago
        All the DT approaches suffer from poor volumetric power density, for fundamental reasons independent of the details of magnetic fields or confinement schemes. For that reason I feel Helion's approach is the least dubious.
- cpuguy83 4y ago
  $25 billion... thinking about how much money we've dedicated for active warfare in the last 2 months alone... clearly we have our priorities.
  - gwright 4y ago
    I struggle to understand this type of comment. You can't respond to the bad guys with a plea for them to stop what they are doing because you would rather spend the money on something else. That isn't to say that battles should not be picked carefully, just that sometimes you don't have a choice and have to deal with a situation and spend lots of $$$ and sometimes blood in order to avoid a worse situation. Even in the context of "last 2 months alone" it isn't clear what specific action is being referenced so the comment is just too abstract, IMHO. In some cases it makes sense to engage, in others it doesn't. There is no single correct answer unless you want to enter into a discussion of pacifism.
    - prox 4y ago
      That is not what that comment says. It clearly means money can be spent when we go to war, or when we need pandemic money, but a measly 25billion in comparison suddenly is “a lot”. If we want fusion, we have to invest.
    - jessaustin 4y ago
      We do have a choice about Ukraine, just as we had a choice about Syria, Libya, Iraq, Yemen, Afghanistan, Vietnam, Honduras, Guatemala, El Salvador, etc. We are making the wrong choice now, just as we made the wrong choices before. Although we kill lots of people, many of them innocent rather than "bad", we never actually "avoid" worse situations. In cases like Libya our intervention has worsened human life by every measure. In other cases we might have delayed inevitable events somewhat (e.g. Vietnam couldn't go to war with China until it finished beating us). The "specific action" in every case is spending public funds, which is the purpose of the USA military, intelligence services, diplomatic corps, and news media, and has been since the Korean War. Insofar as they affect security at all, our military efforts usually reduce it.
  - 4y ago
- BurningFrog 4y ago
  I'm very unimpressed by the "we must only consider short term solutions to global warming" idea. We don't know the future, and we keep being surprised by it!
  - adgjlsfhk1 4y ago
    if we want to significantly curb global warming, long term solutions aren't where we need to focus effort
    - DennisP 4y ago
      Then it's a good thing we're not focusing effort on long-term solutions. We're spending a lot more money on rolling out renewables than we are on fusion research. That doesn't mean we should cut out long-term solutions entirely. If we want to fund more renewables than we are now, then the place to cut back is the many fossil fuel projects that we're still investing in. Until we've done that, I think any positive effort deserves applause instead of complaints about focus.

Can't an operational fusion reactor breed tritium? If so we just need enough tritium to start one.

by api 4y ago

Can't an operational fusion reactor breed tritium? If so we just need enough tritium to start one.

The article covers that. > Tritium breeding was originally going to be tested as part of ITER, but as costs ballooned from an initial $6 billion to more than $25 billion it was quietly dropped. Willms’ job at ITER is to manage smaller-scale tests. Instead of a full blanket of lithium surrounding the fusion reaction, ITER will use suitcase-sized samples of differently presented lithium inserted into “ports” around the tokamak: ceramic pebble beds, liquid lithium, lead lithium. > Even Willms admits that this technology is a long way from being ready to use, however, and a full-scale test of tritium breeding will have to wait until the next generation of reactors, which some argue might be too late. “After 2035 we have to construct a new machine that will take another 20 or 30 years for testing a crucial task like how to produce the tritium, so how are we going to block and stop global warming with fusion reactors if we will not be ready until the end of this century?” says Mazzucato.

api 4y ago
Oops missed that. ITER is not necessarily the best approach to fusion, although it's the best funded. In any case if we can't breed tritium than we either need to shoot for higher energy D-D fusion or some other reaction or fusion will never be cost-competitive.
- GuB-42 4y ago
  Is there any other approach to fusion than ITER? I mean fusion capable of practical power generation. D-T fusion is the easiest, and yet super hard. Tokamaks are the only design that we know how to build in order to meet the goal, with maybe stellerators in second position. Inertial fusion work for scientific and military experiments, but are far from being a usable power source. Things like fusors and its derivative are great hobby projects with a few limited practical applications, but we are not even sure if it is physically possible to produce more energy than we put in. As for LENR (aka. cold fusion) we are essentially at the "thought experiment" stage, when it is not a scam. One other idea that may work with current tech is to dig a large cave, line it with really thick material and detonate hydrogen bombs inside it, extracting energy from the heat of the explosion. I don't think I need to tell you that even if we can do that (unsure), we certainly shouldn't (absolutely sure). Or, take, advantage of that really big fusion reactor we already have and makes us go around in circles.
  - DennisP 4y ago
    Most conservatively, there are tokamaks that use more modern superconductors, able to support much stronger magnetic fields. Tokamak output scales with the fourth power of the magnetic field, so that allows the same output as ITER from a much smaller, cheaper reactor. The MIT spinoff CFS is doing this, along with Tokamak Energy in the UK. CFS is shooting for a net power attempt in 2025. There are also various alternative designs, like Zap Energy's z-pinch, General Fusion's magnetized target fusion, and Helion's field-reversed configuration. Helion is attempting hybrid D-D/D-He3 fusion, the other two are D-T.
    - pfdietz 4y ago
      All the DT approaches suffer from poor volumetric power density, for fundamental reasons independent of the details of magnetic fields or confinement schemes. For that reason I feel Helion's approach is the least dubious.
cpuguy83 4y ago
$25 billion... thinking about how much money we've dedicated for active warfare in the last 2 months alone... clearly we have our priorities.
- gwright 4y ago
  I struggle to understand this type of comment. You can't respond to the bad guys with a plea for them to stop what they are doing because you would rather spend the money on something else. That isn't to say that battles should not be picked carefully, just that sometimes you don't have a choice and have to deal with a situation and spend lots of $$$ and sometimes blood in order to avoid a worse situation. Even in the context of "last 2 months alone" it isn't clear what specific action is being referenced so the comment is just too abstract, IMHO. In some cases it makes sense to engage, in others it doesn't. There is no single correct answer unless you want to enter into a discussion of pacifism.
  - prox 4y ago
    That is not what that comment says. It clearly means money can be spent when we go to war, or when we need pandemic money, but a measly 25billion in comparison suddenly is “a lot”. If we want fusion, we have to invest.
  - jessaustin 4y ago
    We do have a choice about Ukraine, just as we had a choice about Syria, Libya, Iraq, Yemen, Afghanistan, Vietnam, Honduras, Guatemala, El Salvador, etc. We are making the wrong choice now, just as we made the wrong choices before. Although we kill lots of people, many of them innocent rather than "bad", we never actually "avoid" worse situations. In cases like Libya our intervention has worsened human life by every measure. In other cases we might have delayed inevitable events somewhat (e.g. Vietnam couldn't go to war with China until it finished beating us). The "specific action" in every case is spending public funds, which is the purpose of the USA military, intelligence services, diplomatic corps, and news media, and has been since the Korean War. Insofar as they affect security at all, our military efforts usually reduce it.
- 4y ago
BurningFrog 4y ago
I'm very unimpressed by the "we must only consider short term solutions to global warming" idea. We don't know the future, and we keep being surprised by it!
- adgjlsfhk1 4y ago
  if we want to significantly curb global warming, long term solutions aren't where we need to focus effort
  - DennisP 4y ago
    Then it's a good thing we're not focusing effort on long-term solutions. We're spending a lot more money on rolling out renewables than we are on fusion research. That doesn't mean we should cut out long-term solutions entirely. If we want to fund more renewables than we are now, then the place to cut back is the many fossil fuel projects that we're still investing in. Until we've done that, I think any positive effort deserves applause instead of complaints about focus.