3 ms·

How much damage can a few grams of gas do to a massive reactor vessel?

by adrianN 3y ago

ben_w 3y ago
Gas? Not much. 14 grams of D-D fusion byproduct plasma? This much damage: https://www.youtube.com/shorts/wqKn_3iJOP4 https://www.youtube.com/shorts/wqKn_3iJOP4 (I chose 14 grams to make it the same). While it's ridiculously difficult for fusion to go off like that, even spreading that same energy over 2.488 hours (for a nice 1 GW-thermal reactor) leaves you with the problem that it is in the form of high energy radiation that's more than strong enough to knock atoms out of their latices.
- adrianN 3y ago
  Hm, the fusion plasma would rapidly cool and stop fusing as soon as containment fails. I don't see how a few grams of very hot gas can do more that a little scratch to a reactor wall that is designed to be bombarded by radiation and carry off megawatts of power to a steam turbine.
  - ben_w 3y ago
    I suspect there are multiple PhDs each focussed entirely on one aspect of the problem of damage from the fusion plasma. The example I gave, of atoms being knocked from their lattices? I only know about that because of meeting someone in an infamous Cambridge geek pub who was working on it.
  - howenterprisey 3y ago
    It's not just gas, it's VERY angry gas. One part of it is that the plasma sometimes carries a massive current - like, megaamps - that gets dumped into the wall when the plasma contacts it, melting it. This scenario isn't theoretical - it's a big concern when designing and operating tokamaks. The speed of the particles themselves is also relevant. They're moving rather fast, so they impart a lot of energy when they hit the wall. It doesn't take very many to melt the wall, actually. If some part of the wall sticks out a bit, particles on what are called "banana orbits" will often melt that part off, which isn't good if it's an important part of the wall (e.g. it had been protecting some sensors).

3 ms·

How much damage can a few grams of gas do to a massive reactor vessel?

by adrianN 3y ago

How much damage can a few grams of gas do to a massive reactor vessel?

ben_w 3y ago
Gas? Not much. 14 grams of D-D fusion byproduct plasma? This much damage: https://www.youtube.com/shorts/wqKn_3iJOP4 https://www.youtube.com/shorts/wqKn_3iJOP4 (I chose 14 grams to make it the same). While it's ridiculously difficult for fusion to go off like that, even spreading that same energy over 2.488 hours (for a nice 1 GW-thermal reactor) leaves you with the problem that it is in the form of high energy radiation that's more than strong enough to knock atoms out of their latices.
- adrianN 3y ago
  Hm, the fusion plasma would rapidly cool and stop fusing as soon as containment fails. I don't see how a few grams of very hot gas can do more that a little scratch to a reactor wall that is designed to be bombarded by radiation and carry off megawatts of power to a steam turbine.
  - ben_w 3y ago
    I suspect there are multiple PhDs each focussed entirely on one aspect of the problem of damage from the fusion plasma. The example I gave, of atoms being knocked from their lattices? I only know about that because of meeting someone in an infamous Cambridge geek pub who was working on it.
  - howenterprisey 3y ago
    It's not just gas, it's VERY angry gas. One part of it is that the plasma sometimes carries a massive current - like, megaamps - that gets dumped into the wall when the plasma contacts it, melting it. This scenario isn't theoretical - it's a big concern when designing and operating tokamaks. The speed of the particles themselves is also relevant. They're moving rather fast, so they impart a lot of energy when they hit the wall. It doesn't take very many to melt the wall, actually. If some part of the wall sticks out a bit, particles on what are called "banana orbits" will often melt that part off, which isn't good if it's an important part of the wall (e.g. it had been protecting some sensors).