Re: Are there any more "OKLO's?

[Chris Alston <alstonc@odrge.odr.georgetown.edu>]

It's my recollection that the article, which was indeed in Sci Am (Cowan,
GA. 1976. A Natural Fission Reactor. Vol 235. 36-47), estimated that there
could have been as many as 100 natural reactors.  But I've never heard of
the finding of physical evidence for others. The fourth edition of
Environmental Radioactivity (Eisenbud/Gesell, 1997) cites, in addition to
the article, a piece by the IAEA (1975): The OKLO Phenomenon. Report
STI/PUB/405. Intl. Atomic Energy Agency, Vienna and UNIPUB, Lanham, Maryland.

chris alston

At 06:47  11/25/97 -0600, you wrote:
>Some 25 years ago reports were published on a "natural reactor" which
>fissioned high content uranium ore some 2 billion years ago in Gabon,
>Africa.  The geologic sleuthing was a fascinating story and showed that the
>plutonium (and its decay products), which was naturally produced over
>several centuries of spontaneous fissioning of U-235, did not migrate far
>from the original ore seam.  The U-235 concentration back then was about
>3-4%, not the 0.7 % U-235 of today's ore, and thus needed just some neutron
>moderation from water to spontaneously fission.  I think it was all
>summarized in a Scientific American article in about 1979.
>
>My question is whether any of you  knows of other locations on earth
>besides OKLO where this "natrual reaction" took place.  What are the odds
>that only one uranium ore body on our planet underwent this action?   With
>all the debate about high and low level radioactive waste disposal, and the
>accompanying long term scenarios about  real and imagined consequences,
>OKLO provides a valuable and interesting case study and object lesson.  But
>are there any other lessons like it out there?  I'd appreciate your help on
>this.
>
>Marvin Goldman
>mgoldman@ucdavis.edu
>
>
>