3 ms·

Isn't corrosion from molten hot salt still an unresolved issue? Or at least a potential problem as big as loss of coolant in PWRs?

Kalium 4y ago
Same here, as far as I'm aware Thorium salt reactors are still solidly in the experimental stages. Demanding a switch to something that isn't ready yet strikes me as making perfection the enemy of better.
pfdietz 4y ago
There are lots of unresolved issues for MSRs. https://gain.inl.gov/SiteAssets/MoltenSaltReactor/Module2-OverviewofMSRTechnologyandConceptsML17331B114.pdf https://gain.inl.gov/SiteAssets/MoltenSaltReactor/Module2-Ov...
abracadaniel 4y ago
Unfortunately true. The molten salt solar concentrators couldn’t make it economical with a free source of heat. Replacing the heat source with a fission reaction only adds complexity to a system that’s already too difficult to maintain.
AtlasBarfed 4y ago
I'm definitely not saying LFTR has the materials solved. But liquid fuel leaks lead to immediate loss of neutron economy and the reaction stops. Solid fuel rods are always at risk of meltdown because once the solid fuel starts chain reacting out of control, you can't separate the fuel apart and stop the chain reaction. You're basically praying the moderators will slow it down. I believe pebble bed relies on small chunks of solid uranium, and if there is a meltdown risk, you separate the pebbles apart and like LFTR liquid safety pools and plugs, that kills the neutron economy and reactions stop. If the MSR vessel leaked from corrosion, it would likely fall into the safety pool and simply lose criticality. Anyway, I'm not advocating for LFTR to the exclusion of all other things. Just that solid fuel issues: lots of waste, meltdown danger, are just not palatable when there are designs and approaches that eliminate them. I don't care if it's "the only way that currently works", that is the "old guard" of nuclear protecting their current economic interests, not producing a nuclear design that is ACTUALLY next generation that will have relevance in a power generation ecosystem that will be dominated by solar, wind, and storage. Nuclear is already not price competitive. New nuclear projects will come online in 5-10 years in best case, and that's 5-10 years of wind/solar hitting economies of scale and research improvement (which are improving at 5-20% geometric improvements year on year), and battery storage is seeing high density LFP and sodium ion designs come into production. I simply view this approval as a rehash of old crappy design from the entrenched nuclear economic interests. Even with this rehash, it won't be remotely price competitive. Here's the thing with scalability and waste: If you scale it down, it's in a LOT more places, and then if you hae substantial waste generation, that is a LOT LOT LOT more transport issues and concerns with dirty bomb nuclear, crashes, accidents in transport. So that's why near-100% fuel use of LFTR is so important with scalability. Nuclear dismisses the NIMBYism, but the concerns over waste transport are real.

Kalium 4y ago

Same here, as far as I'm aware Thorium salt reactors are still solidly in the experimental stages. Demanding a switch to something that isn't ready yet strikes me as making perfection the enemy of better.

pfdietz 4y ago

There are lots of unresolved issues for MSRs. https://gain.inl.gov/SiteAssets/MoltenSaltReactor/Module2-OverviewofMSRTechnologyandConceptsML17331B114.pdf https://gain.inl.gov/SiteAssets/MoltenSaltReactor/Module2-Ov...

abracadaniel 4y ago

Unfortunately true. The molten salt solar concentrators couldn’t make it economical with a free source of heat. Replacing the heat source with a fission reaction only adds complexity to a system that’s already too difficult to maintain.

AtlasBarfed 4y ago

I'm definitely not saying LFTR has the materials solved. But liquid fuel leaks lead to immediate loss of neutron economy and the reaction stops. Solid fuel rods are always at risk of meltdown because once the solid fuel starts chain reacting out of control, you can't separate the fuel apart and stop the chain reaction. You're basically praying the moderators will slow it down. I believe pebble bed relies on small chunks of solid uranium, and if there is a meltdown risk, you separate the pebbles apart and like LFTR liquid safety pools and plugs, that kills the neutron economy and reactions stop. If the MSR vessel leaked from corrosion, it would likely fall into the safety pool and simply lose criticality. Anyway, I'm not advocating for LFTR to the exclusion of all other things. Just that solid fuel issues: lots of waste, meltdown danger, are just not palatable when there are designs and approaches that eliminate them. I don't care if it's "the only way that currently works", that is the "old guard" of nuclear protecting their current economic interests, not producing a nuclear design that is ACTUALLY next generation that will have relevance in a power generation ecosystem that will be dominated by solar, wind, and storage. Nuclear is already not price competitive. New nuclear projects will come online in 5-10 years in best case, and that's 5-10 years of wind/solar hitting economies of scale and research improvement (which are improving at 5-20% geometric improvements year on year), and battery storage is seeing high density LFP and sodium ion designs come into production. I simply view this approval as a rehash of old crappy design from the entrenched nuclear economic interests. Even with this rehash, it won't be remotely price competitive. Here's the thing with scalability and waste: If you scale it down, it's in a LOT more places, and then if you hae substantial waste generation, that is a LOT LOT LOT more transport issues and concerns with dirty bomb nuclear, crashes, accidents in transport. So that's why near-100% fuel use of LFTR is so important with scalability. Nuclear dismisses the NIMBYism, but the concerns over waste transport are real.