Anyone know what "Heavy Water" is?

[HEMI®Dart]

TTT

 

[nickleinonen]

Originally posted by Archive

Doc,

It wouldn't hurt you to drink it. But it would cost you to do so. Heavy water costs hundreds of dollars per gallon.

The Canadians use heavy water in their nuclear power reactors. It acts as both coolant and moderator(a moderator in a reactor is used to slow down the neutrons and make them available to split atoms, thereby allowing the reaction to continue). The fact that the hydrogen atoms in heavy water already have a neutron in the nucleus, they will not absorb a neutron. Normal or "light" water will, thereby absorbing some neutrons that would be available for fission. This property allows Canadian reactors to use natural, unenriched Uranium for fuel. American reactors use enriched Uranium fuel and normal water for both coolant and moderator.

Enrichment refers to the U235 isotope content. U235 makes up 0. 8% of natural Uranium and is fissile(splittable). This is the nuclear fuel reactors run on. American reactors need this isotope enriched to 3-4% before they can operate with light water acting as a moderator.

This enrichment process is very expensive. American power companies have chosen to use expensive fuel, and cheap coolant. The Canadians have chosen to use cheap fuel and expensive coolant. This is probably much more than any of you wanted to know, but here it is.

hmm, maybe that's why our power plants are not working well... maybe the reactors caught a ford bug... :-laf

 

[pdolan]

Sorry to wander a bit OT, but we use heavy water in Canada because of events in WWII. The entire world's supply of deuterium oxide was in Norway until just before the German's came in. It was smuggled out to the Curries in Paris, and then given to the English when France was being invaded. It was later sent to Canada for safekeeping (as was much of the Bank of England's gold reserves). I had been reading a book on the subject on one job last winter, then went on to another job where I would get some off time to finish the rather interesting tale. When I arrived on the site - Warield BC - my first question for the locals was what the heck the funny, tall, heavily built building with staggered floors just accross the road was intended for. The anser: "that's where the heavy water plant was put in during WWII" and that 's how the town got its name.



To this very day, AECL (atomic energy Canada Ltd) continues to use the same technology for reactors first pioneered during the formative years of nuclear science.

 

[SnoDawg]

I had some heavy water the other day... . problem was it was in my bladder after drinking a pitcher of beer Well it seemed pretty heavy at the time.

 

[Mike Ellis]

You can actually buy heavy water in the US via mail order from various chemical supply companies. A few years back I was doing some experiments that called for deuterium, and as I recall the price was something like $60 for a liter of regular water with a small % of heavy water. Not too bad.



At the time, there was a lot of interest in cold fusion so a lot of heavy water was flowing around the USA.



Cold fusion is dismissed as junk science today, but I wonder if people jumped the gun. Pons and Fleischmann were given a big pot of $$$$ by the Japanese and started a cold fusion research concern over there, supposedly they were planning a commercial reactor product (small scale). In the USA, scientists dismissed it pretty quickly because no hard evidence of actual fusion byproducts was detected - to many, this meant the entire phenomena was a fraud and not worth looking into.



And yet... some of the guys who ran the experiments experienced the fabled "anomalous energy production" in some of their cells. One professor I know built several cells and saw very high temps generated, but since his experiment did not detect fusion byproducts he lost interest.



So far not much has happened on the commercial fusion scene, we are still a long way from the "Back to the Future" style "Mr. Fusion" home reactor. But hope springs eternal Oo. Oo.

 

[moparguy]

OK Bill, I know you single guys up north need to do something with your time, but there's gotta be a better reason than boredom to bring this one TTT.



RJR

 

[Peter Campbell]

greek

Heavy water has a much better "moderator ratio" than light water. Way up there with graphite. Moderator ratio is the neuton scattering cross section divided by the neutron absorbing cross section quantity multiplied by average logarithmic energy decrement per collision. If that is all greek to you it is ok because you need a greek font to even write it! ( sigma sub A/ sigma sub S ) Xi

 

[HEMI®Dart]

Could Cold Fusion produce electricity like a Nuclear power plant?