RE: Nuclear Planet in DISCOVER

["Nardi, A. Joseph" <nardiaj@WESTINGHOUSE.COM>]

I read the article and feel that there is a major problem with the concept.

The % U-235 would have to less than 0.71% to account for the U-235 burnup

over time.  At normal conditions it is not be possible for normal uranium to

achieve criticality without the presence of special moderators.  Also at

normal conditions it is not possible to have U-238 achieve a fast neutron

critical state.  But I am not sure if the conditions at the center of the

earth would be sufficient to achieve a "fast neutron criticality".  So it is

not clear to me that the theory proposed in the article has any possible

merit.  My impression on reading the article is that Mr. Herndon has only

looked at the issue from heat generation without answering the question of

whether nuclear criticality is possible.  I do know that the implosion

design of nuclear weapons achieve nuclear criticality by increasing the

density of the Plutonium.  So maybe the conditions at the center of the

earth might permit a nuclear criticality event that we do not encounter

under the normal conditions on the surface.



Does any nuclear criticality specialist out there know of data that would

answer the questions?

	What uranium density would have to be achieved to reach a fast

neutron critical state with 0.7% U-235 material?

	Is it possible to have U-238 reach a fast neutron critical state at

high densities?



And for the physicists among us:

	What would be the density of uranium under the pressure at the

center of the earth?



A. Joseph Nardi

Supervisory Engineer

Environment, Health and Safety

Westinghouse Electric Company

Phone: (412) 374-4652

Email: nardiaj@westinghouse.com







> ----------

> From: 	Susan L Gawarecki[SMTP:loc@icx.net]

> Reply To: 	Susan L Gawarecki

> Sent: 	Wednesday, July 17, 2002 6:17 PM

> To: 	RADSAFE

> Subject: 	Nuclear Planet in DISCOVER

> 

> What a teaser!  I'm gonna run right out and buy a copy!

> 

> --Susan Gawarecki

> 

> DISCOVER Vol. 23 No. 8 (August 2002) 

> Table of Contents 

> 

> Nuclear Planet - Is there a five-mile-wide ball of hellaciously hot

> uranium seething at the center of the Earth? 

> By Brad Lemley 

> 

> What is Earth? Poets say it's a celestial sapphire, a cerulean orb.

> Astronomers say it's a medium-size planet orbiting an average star. Some

> environmentalists say it's Mother. Biologists say it's life's only known

> home. But the most scientifically precise definition may prove to be the

> one that no one suspected.  Earth, says geophysicist J. Marvin Herndon,

> is a gigantic natural nuclear power plant. We live on its thick shield,

> while 4,000 miles below our feet a five-mile-wide ball of uranium burns,

> churns, and reacts, creating the planet's magnetic field as well as the

> heat that powers volcanoes and continental-plate movements. Herndon's

> theory boldly contradicts the view that has dominated geophysics since

> the 1940s: that Earth's inner core is a huge ball of partially

> crystallized iron and nickel, slowly cooling and growing as it

> surrenders heat into a fluid core. Radioactivity, in this model, is just

> a supplementary heat source, with widely dispersed isotopes decaying on

> their own, not concentrated. 

> 

> Full text of this article can be found in the current issue of Discover

> Magazine.

> 

> RELATED WEB SITES:

> 

> For more information about J. Marvin Herndon's theory, write to

> mherndon@san.rr.com. And to read about the natural fission reactions

> found in Africa, check out

> www.curtin.edu.au/curtin/centre/waisrc/OKLO/index.shtml. 

> --

> ************************************************************************

> You are currently subscribed to the Radsafe mailing list. To unsubscribe,

> send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

> radsafe" (no quote marks) in the body of the e-mail, with no subject line.

> You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/

> 

************************************************************************

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line.

You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/