sodium wiring - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 09, 2019, 03:19:04 pm
content: Slashdot just posted an interesting story.https://hardware.slashdot.org/story/19/06/08/1827250/the-lost-history-of-sodium-wiring

author: MadTux
author_rank: Frequent Contributor
timestamp: June 09, 2019, 03:53:05 pm
content: Isolated wire by itself probably works fine, the problem is how to wire stuff to exposed sodium wire?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 09, 2019, 03:55:34 pm
content: I'm guessing a kerosene-filled junction box that contains a sodium to something contact in it.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 09, 2019, 04:02:48 pm
content: Hmm, now I wonder what kind of metallurgy you can do with sodium. Alkaline-earth metals are probably all that would help to harden it, at some cost to resistivity. Other alkaline metals certainly won't help (NaK is a liquid at RT!). Transition metals tend to be indifferent (e.g., steel), and regular metals tend to form intermetallics or compounds.Thing is without strength, how can you make a connection to the stuff? You'd practically have to... melt it into a cup that it effectively solders itself into, and which is strong enough to make a bolted connection (say, some harder aluminum, if metallurgically compatible).In any case, cool to think about, even if it's never going to work out.Tim

author: shteii01
author_rank: Frequent Contributor
timestamp: June 09, 2019, 05:04:19 pm
content: There was talk of something similar in April series by Mackey Chandler. Basically spacers were doing very limited mining (not asteroid belt, not advanced enough yet). They were getting very small amount of copper, but they were getting a lot of something, maybe Calcium. So some started floating idea, since they are in space, no oxidation, most wiring will be rigid (Moon tunnels, air evacuated, only living spaces are aired), that materials other than copper can be used for wiring.April seriesAlso. One of the main characters has a connection to Australia.Australian politics also shows up in the later books.

author: duak
author_rank: Super Contributor
timestamp: June 09, 2019, 05:46:47 pm
content: We do have lithium batteries in general circulation. I understand it's the electrolyte that's the problem rather than the lithium per se.Utilities were already using hydrogen cooled generators. I'l bet there are more accidents due to steam leaks than from hydrogen leaks. (Oh, the humanity!)The Fermi breeder reactor near Detroit used a sodium coolant. I suppose that when it was conceived in the can-do 50's, any hazards from the sodium were considered secondary to the hazards from the radioactives - sort of like a last cigarette before the execution. Besides, nothing credibly bad will happen, right?A goofy sunday morning idea: if a flexible polymer tube were filled with sodium or sodium alloy it could make a formable structural element. Run a current thru it or a segment of it to make if flexible, form it, then let it cool and solidify. The idea of a one-off lightweight malleable structure appeals to me. When I'm repairing something, say a flat panel display where I have to unfold boards yet keep them connected and still allow 3-D access, something that can be bent to fit is good. Think of a Dr. Suess structure where the support is in just the right place.

author: Brutte
author_rank: Frequent Contributor
timestamp: June 09, 2019, 06:49:35 pm
content: I thought about it some time ago as the mass specific resistance of sodium is 63% of the aluminium.It seems strange there are no sodium-based composite overhead power lines..

author: apis
author_rank: Super Contributor
timestamp: June 09, 2019, 08:28:15 pm
content: Low tensile strength so you would have to reinforce it with e.g. steel. The article did say the reason it went away was that it wasn't cost effective compared to aluminium.

author: David Hess
author_rank: Super Contributor
timestamp: June 10, 2019, 02:34:25 am
content: Quote from: duak on June 09, 2019, 05:46:47 pmLiquid metal cooled reactors have advantages like greater power density, greater efficiency, and perhaps not as obvious, better safety compared to water cooled reactors because of the low vapor pressure of the coolant. Sodium fires are not fun but neither are steam explosions. This was suppose to be one of the big advantages of liquid salt reactors; they operate at atmospheric pressure.Fermi used sodium for a different reason. It was a fast fission reactor making it suitable as a breeder reactor so required a coolant which is not a neutron moderator.Sodium and mercury form an amalgam but it is awfully crumbly and reacts slowly in air anyway.Using sodium wire for power distribution makes sense for the reasons given in the article but it was only marginally better at best compared to aluminum. The low temperature physics people use some pretty weird things for wire sometimes.Quote from: apis on June 09, 2019, 08:28:15 pmI assume they did but aluminum for power distribution is reinforced with steel also.