<p>According to <a href="http://presolar.wustl.edu/laboratory_for_space_sciences/Publications_2004_files/Meshik-PRL-04.pdf">Record of Cycling Operation of the Natural Nuclear Reactor in the Oklo/Okelobondo Area in Gabon</a>, the Xe is trapped in crystalline cage-like structures formed of the aluminum phosphate that are similar to <a href="http://en.wikipedia.org/wiki/Zeolite">zeolites</a>.</p>

<p>The reference also explains that the aluminum phosphate structures grow quickly under hydrothermal conditions of 270-300 degrees C.</p>

CC BY-SA 3.0
2014-05-29T01:12:15.817Z
2014-05-29T01:12:15.817Z
DavePhD
<p>A number of popular writings on <a href="http://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor">the natural fission reactor at Oklo, Gabon</a> (e.g. <a href="http://gizmodo.com/there-s-a-naturally-occurring-nuclear-fission-reactor-i-1475445638">here</a>) state that some of the energetic byproducts (krypton and xenon, presumably <sup>85</sup>Kr and <sup>133</sup>Xe) of the reactor were "trapped" in aluminophosphate. </p>

<p>How, exactly, does "aluminophosphate" (I assume this is some sort of framework mineral?) trap gaseous elements? Is it related to the mechanism by which clathrates trap gases? </p>

CC BY-SA 3.0
2014-05-27T00:41:36.283Z
Huh, I never even knew there was a natural nuclear reactor. Thanks for asking this question, I wouldn't have found out otherwise!
hichris123
<geology><earth-history><mineralogy>
In what sense did the Oklo reactor "trap" its own nuclear waste?
senshin
# In what sense did the Oklo reactor "trap" its own nuclear waste?

(Asked by: username_0 on 2014-05-27)

A number of popular writings on [the natural fission reactor at Oklo, Gabon](http://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor) (e.g. [here](http://gizmodo.com/there-s-a-naturally-occurring-nuclear-fission-reactor-i-1475445638)) state that some of the energetic byproducts (krypton and xenon, presumably 85Kr and 133Xe) of the reactor were "trapped" in aluminophosphate.

How, exactly, does "aluminophosphate" (I assume this is some sort of framework mineral?) trap gaseous elements? Is it related to the mechanism by which clathrates trap gases?

**Tags:** geology, earth-history, mineralogy

> **Comments:**
> **username_1**: Huh, I never even knew there was a natural nuclear reactor. Thanks for asking this question, I wouldn't have found out otherwise!  

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## 1 answers

### Answer by username_2 on 2014-05-29. Score: 8 | Accepted answer

According to [Record of Cycling Operation of the Natural Nuclear Reactor in the Oklo/Okelobondo Area in Gabon](http://presolar.wustl.edu/laboratory_for_space_sciences/Publications_2004_files/Meshik-PRL-04.pdf), the Xe is trapped in crystalline cage-like structures formed of the aluminum phosphate that are similar to [zeolites](http://en.wikipedia.org/wiki/Zeolite).

The reference also explains that the aluminum phosphate structures grow quickly under hydrothermal conditions of 270-300 degrees C.


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