Talk:Gas centrifuge

Just a note to people who maintain these pages.. CNN was recently referencing the P1 and P2 centrifuges, and searching for "P1 Centrifuge" or "P2 Centrifuge" does not lead you here, which is the only place I found any information on what it was they were talking about.

Thanks for the input. I've created "redirect" pages from those names to here, to help future readers find this article. Cheers, -Will Beback 21:49, 25 April 2006 (UTC)

Top vs. Bottom, wall vs. center

The picture and text do not make any sense. The NRC URL says that heavier (that would be U-238, depleted) uranium is drawn to the wall of the centrifuge, and lighter stuff is in the middle. The picture, on the other hand, indicates that heavier uranium is drawn to the bottom of the centrifuge, and lighter is drawn to the top (as does the text, which states that gravity achieves the separation.) I think NRC URL text is correct, and think that the picture should be corrected.

in any event, the text at the bottom of the article says that heavier uranium is drawn from the top of the centrifuge, which is definitely wrong, and that lighter uranium is drawn from the bottom of the centrifuge, which also must be incorrect. I've been wondering how this process works as Iran today stated it had put 1000 new centrifuges to work. SystemBuilder (talk) 19:26, 11 April 2008 (UTC)

I believe there is a thermal convection current (that is not mentioned) that causes the flow of the gas as shown in the picture. I am not having the reference with me right now, but this causes the heavier particle to follow the designated path as seen in the picture. The thermal gradient is perpendicular to the direction of the centrifugal force and drawing off the heavier and ligher fractions from the bottom and top is so simpler!Ck.mitra (talk) 07:06, 23 September 2008 (UTC)

Completely agree. This picture may illustrate how a Zippe centrifuge works, but the article does not describe this type of centrifuge. So change the article (I would love to know how convection changed the way it works, but haven't found any good descriptions), or change the diagram to match the article (here's a good one http://www.euronuclear.org/info/encyclopedia/images/gascentrifuge.jpg ). — Preceding unsigned comment added by 220.233.65.12 (talk) 08:46, 23 October 2011 (UTC)

IMHO the picture is definitely wrong. The centrifuge rotates because gravity is not strong enough to separate the two gasses. It has to generate a G-force that is much more then natural gravity and it is directed towards the walls. As far as I know it rotates at about 60,000rpm and the heavier gas must accumulate near the walls. If there was a flow like in the picture it would again mix the two. I give 99% that this picture is complete nonsense! I would even bet they are heavily cooled to reduce the mixing effect of Brownian motion. --188.105.239.42 (talk) 17:12, 26 February 2012 (UTC)Robert

Without the convection, the heavy gas will accumulate towards the wall and the ligher gas near the centre. Now consider convection current: as long as the flow is streamline, the heavier gas will come down and stay there, and it will not get mixed as you say. The effect of gravitation is negligible and the convection currents are needed to sweep the thin layer of heavy molecules to the bottom. Consider a test tube containing sugar (heavy molecule) and salt (light molecule) in solution (forget centrifugation and gravity for this example). The solution will be uniformly mixed. Now increase the temp of the bottom part by 50 degree compared to the top. We get a convection current. Heavy molecules will travel only little bit but light molecules will travel further. We shall end up with a solution that has more sugar and less salt at the bottom. I hope it is clear now. Now you can combine both these effects (convection and centrifugation). chami 17:48, 3 May 2012 (UTC) — Preceding unsigned comment added by Ck.mitra (talk • contribs)

Hyper?

In the first sentence, does "hyper-" in "hyper-centrifuge" actually have any meaning? Kaleja 21:10, 13 October 2006 (UTC)

I can't find anything on the Internet that tells me what that is. --Gbleem 14:06, 4 April 2007 (UTC)

Pakistan and Irak centrifuges

There is some interesting information on centrifuge types in an 15 years old Atomic Scientist article: [1] The article mentions:

• Ultra-Centrifuge Nederland (UCN),
  • CNOR machines, 2 separative work units
  • SNOR, 5 separative work units
• Urenco consortium
  • G-1 centrifuge, between 2 and 3 separative work units per year
  • G-2, 5 to 6 separative work units

It is believed that most of Pakistan's centrifuges are based on the G-2 design. -- Petri Krohn 11:05, 7 December 2006 (UTC)

There is no history of this technology. pleas add

Advantage of the centrifuge over the gaseous diffusion process

The significant advantage of the gas centrifuge is that it relies on multiple centrifugal runs using cascades of centrifuges. This process yields higher concentrations of the uranium-235 isotopes with significantly less energy usage compared to the previous gaseous diffusion process.

This first statement is incorrect. Both of these processes rely on a cascade to yield higher concentrations of U235. The advantage of centrifuge is that the cost per SWU of the centrifuge in terms of electric power consumption is about 25 times less than the diffusion process. —Preceding unsigned comment added by 160.84.254.241 (talk) 18:53, 18 June 2010 (UTC)

Wrong Picture...

In the picture shown for a bank of gas centrifuges, the legend says that each centrifuge is 40 ft tall. This number is probably wrong and a more accurate value should be closer to 4 ft or about 1 meter.

I could not find any reference object in the picture to compare the length but the window (with drapes) is clearly seen and is very unlikely to be above 40 ft on the wall. There are few references in the picture with which the scale can be inferred.

A 40 ft tall centrifuge will have tons of engineering problems. Let us not bother about the details but unless a proper source is there for the length of the centrifuge, we should delete it. It might have been just a typo. chami 08:27, 24 July 2011 (UTC) — Preceding unsigned comment added by Ck.mitra (talk • contribs)

No, the American centrifuges shown there are really ~40 ft tall. They are truly huge: [2] [3]. Not a typo... Google "American centrifuge Piketon" for more info. It's a design that the US explored in some detail in the 1980s for pilot plants. I don't know the details, only that it is much taller than the sorts of centrifuges which URENCO, Pakistan, etc., use. --Mr.98 (talk) 20:15, 25 December 2011 (UTC)

The critical factor is the aspect ratio (length by diameter) but if you increase the length you need to maintain a constant thermal gradient which is the real problem. If the length is 40 ft the diameter may be only a couple of inches. There is no reference and I still doubt it.

In the DoE picture caption, they do not mention the thermal gradient which is a key feature. Certain information can be discovered only by reading journal papers/ technical reports. chami 18:07, 3 May 2012 (UTC)