4 ms·

> There are good answers to that in the U.S. and Russian experience. What are your personal favorites of what those good answers are? One write up I found [1]

> There are good answers to that in the U.S. and Russian experience. What are your personal favorites of what those good answers are? One write up I found [1] doesn't go into much engineering details, and I find similar high-level descriptions elsewhere. This reminds me of a documentary I once saw about what seemed to me a completely balls-to-the-wall experimental lab (the best kind) studying the earth's magnetic field by rotating a 12+ ton ball of molten sodium. The way they solved the fire question was by suspending dewars of liquid nitrogen above the ball of death metal. The only way I could think of to improve upon that is a passive trigger design, wrapping the ball with walls of dewars with spring-loaded lids that open up when pressure drops below the level that the liquid nitrogen is normally contained at. If one is breached, they all breach at the same time enveloping the entire sodium footprint. [1] http://nucleargreen.blogspot.com/2010/01/fire-in-sodium-cooled-reactors-sandia.html http://nucleargreen.blogspot.com/2010/01/fire-in-sodium-cool...

PaulHoule 5y ago
Sodium fires are often flashy but not that bad. They look scary because they form hot aerosol particles that radiate a lot of light and heat. It's nothing like a hydrogen fire you might walk into before you see or feel anything. Sometimes you spill a few liters of sodium and it goes poof and makes some caustic aerosol you have to clean up. If the heat exchanger with a carbon dioxide secondary pops it forms a crust that will probably keep the carbon dioxide inside. Even if a water tertiary heat exchanger develops a pinhole leak the reaction happens on a 2-d surface and develops more slowly than you might think it would. https://www.fireengineering.com/leadership/dry-extinguishing-agents-protect-key-areas-in-nuclear-power-plants/ https://www.fireengineering.com/leadership/dry-extinguishing... https://www.osti.gov/etdeweb/servlets/purl/21330020 https://www.osti.gov/etdeweb/servlets/purl/21330020 https://www.osti.gov/biblio/6669413-xoXD4J/ https://www.osti.gov/biblio/6669413-xoXD4J/ Russians documented hundreds of fires at a reactor in the 1970s most of which were little poofs, they kept calm and carried on because the prize is clean energy to power civilization for 1000s of years.

PaulHoule 5y ago

Sodium fires are often flashy but not that bad. They look scary because they form hot aerosol particles that radiate a lot of light and heat. It's nothing like a hydrogen fire you might walk into before you see or feel anything. Sometimes you spill a few liters of sodium and it goes poof and makes some caustic aerosol you have to clean up. If the heat exchanger with a carbon dioxide secondary pops it forms a crust that will probably keep the carbon dioxide inside. Even if a water tertiary heat exchanger develops a pinhole leak the reaction happens on a 2-d surface and develops more slowly than you might think it would. https://www.fireengineering.com/leadership/dry-extinguishing-agents-protect-key-areas-in-nuclear-power-plants/ https://www.fireengineering.com/leadership/dry-extinguishing... https://www.osti.gov/etdeweb/servlets/purl/21330020 https://www.osti.gov/etdeweb/servlets/purl/21330020 https://www.osti.gov/biblio/6669413-xoXD4J/ https://www.osti.gov/biblio/6669413-xoXD4J/ Russians documented hundreds of fires at a reactor in the 1970s most of which were little poofs, they kept calm and carried on because the prize is clean energy to power civilization for 1000s of years.