Liquids Can't Melt Down - General

November 2024

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Comments migrated from WordPress:

William Jacob Zitterich <willyz96@msn.com> on 2017-12-18 10:18:18 wrote:

Long time lurker here. I have two concerns. The first is that the high-density uranium might try to settle out either in the reactor or elsewhere in the supply chain forming a prompt criticality. I know that a Japanese radiation worker working with dissolved uranium accidentally poured it into a jug that was shaped wrong and later died of the 600 rem acute dose he took. Meltdowns are chronic environmental hazards but can be worked with. A prompt criticality will kill you before you know something is wrong. The other issue I have is the risk of thermal dissociation of your water during an overheat scenario. dissociation will make corrosive oxygen damaging the reactor/causing holes and explosive hydrogen to blow up the reactor and throw intensely radioactive steam into the air.

William Jacob Zitterich <willyz96@msn.com> on 2017-12-18 10:19:31 wrote:

I should be clear that the reason for this criticism is that molten salt is less susceptible to those particular problems.

Alistair Young <athanasius.skytower@arkane-systems.net> on 2017-12-19 00:38:10 wrote:

Thanks for your comments!

On the former, in the reactor at least, I had preventing that in mind as a convenient side-effect of the gas cooling; the turbulent flow induced by the helium being blown through - apart from improving thermal transfer - helping to keep the fuel agitated to prevent density-related hot spots or prompt criticalities from forming.

On the latter, on reflection, I’m inclined to agree with you. Fortunately, it shouldn’t be too much trouble to adapt this to be a molten-salt LCGCR assuming the fuel regenerator can be made to function with a carrier-salt solvent and at temperatures sufficient to keep the salt molten.

Eric Manwill <ericmanwill@gmail.com> on 2017-12-25 17:06:05 wrote:

Chem. engineering alumnus speaking here: gases make a very poor heat carrier compared to liquids, especially given the quantity of thermal energy you want to move out of the reactor core to drive your generators. You’ve already got a liquid loop in your design; I’d recommend that you slap a heat exchanger on there to move your thermal energy to your generator’s working fluid loop (and sparing you the worry about radioactive contamination outside the fuel system).
Also, one of the main reasons molten salts are considered as a thermal transfer medium in reactor designs is that they can take the high core temperatures as liquids without needing the kinds of pressures that are needed to keep water from (rather enthusiastically) flashing to steam in the last place you want it to.

November 2024

JAPH

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November 2024 ▶ JAPH

avatar The Author

And now the post is updated. Thanks.