Comments on: It'll be heavy water next

by: Jonadab

Thu, 25 Dec 2008 13:48:15 +0000

At least NaK isn't shock-sensitive, nor environmentally dangerous, nor particularly toxic to biological systems, nor is it particularly likely to react with the metal tubing. All in all the thing's actually fairly safe.

But yeah, you probably don't want to crack it open and pour the contents into the kitchen sink.

by: tobyc

Tue, 16 Dec 2008 08:56:56 +0000

I don't think the use of NaK in reactors is all to do with its nuclear properties: as I recall from my Mech Eng days, it's something to do with the Prandtl Number of the substance - a dimensionless number which incorporates density, specific heat capacity, viscosity and thermal conductivity. The lower the number, I think, the better suited the fluid is to a slow-moving (ie predominantly conductive) coolant circuit - and liquid metals have much lower Prandtl numbers than water. It's too late at night for me to do any calculations, but... Oh! Or is it the Nusselt number?

by: SparkyTWD

Wed, 10 Dec 2008 04:03:10 +0000

In the early days of the US Naval nuclear reactor program, one of the first engineering problems they needed to solve was coolant choice. A reactor with a water coolant loop was installed in the first nuclear submarine "Nautilus", and one with a NaK coolant loop was installed in the second "Seawolf". I can't find the exact quote, but the director of the project Hyman Rickover, said something along the lines of "If the ocean was made of sodium and potassium, some idiot would want to put a water cooled reactor on a submarine"

by: Alex Whiteside

Mon, 08 Dec 2008 20:17:45 +0000

DBT: sodium and potassium ions are important in various biochemical processes (an Na/K pump of a wholly different kind is important in almost all cells IIRC). However the cooler works with sodium and potassium metal. The metal atoms have a electron just lightly wafting around at their extremities, and will merrily give that up to pretty much absolutely anything to form the +1 ion. So they're good reducing agents, and correspondingly, they oxidise very easily.

by: DBT

Mon, 08 Dec 2008 20:03:43 +0000

Chemistry is not my strong point, but aren't Sodum and Potassium key ingredients for action potential in neuronal activity?

Why don't people explode when they think too much?

... or is that the secret of the "Chewbacca Defense"?

by: FuzzyPlushroom

Mon, 08 Dec 2008 05:30:40 +0000

If it were a fair bit cheaper, I'd totally use it. Just let someone try to screw with my computer!

by: Alex Whiteside

Sun, 07 Dec 2008 23:35:51 +0000

I'd say a computer that refuses to die gracefully in an axe fight is a selling point to much of the cooler's target audience.

by: Ziggyinc

Sun, 07 Dec 2008 21:45:32 +0000

Oh, we have got to send one of these to Dan, cause I want to see him break one open to verify, that yes there is indeed a corrosive, flammable fluid inside.

by: Stuart

Sun, 07 Dec 2008 21:44:35 +0000

They're just preparing for the day that CPU dies are made from uranium.

by: Shadowdancer

Sun, 07 Dec 2008 21:44:07 +0000

Yeah, ClF_3 is fun. Did you read the safety sheet? It's absolutely hilarious to handle, as would be expected for a substance that was intended to burn down concrete bunkers.

The electromagnetic pump has something going for it, since I suppose it potentially lasts pretty long, but then you'll need a fan as well. So in the end it's a pretty useless thing, at least until CPUs get well into the petahertz range.