Later, other natural nuclear fission reactors were discovered in the region.

In 1972, remains of a natural nuclear fission reactor were found at the Oklo deposits.

There is also evidence that the Oklo natural nuclear fission reactor produced significant amounts of technetium-99, which has since decayed into ruthenium-99.

A natural nuclear fission reactor can occur under certain circumstances that mimic the conditions in a constructed reactor.

Einsteinium and fermium did occur naturally in the natural nuclear fission reactor at Oklo, but no longer do so.

A natural nuclear fission reactor is a uranium deposit where self-sustaining nuclear chain reactions have occurred.

In two regions of Oklo, Gabon, Africa, natural nuclear fission reactors were active over 1.5 billion years ago.

The ability of natural geologic barriers to isolate radioactive waste is demonstrated by the natural nuclear fission reactors at Oklo, Africa.

Moreover, even more stringent constraints, placed by study of certain isotopic abundances in the Oklo natural nuclear fission reactor, seem to indicate no variation is present.

The first experimental tests of this question examined the spectral lines of distant astronomical objects, and the products of radioactive decay in the Oklo natural nuclear fission reactor.

In rare occasions, earlier in geologic history when U-235 was more abundant, uranium ore was found to have naturally engaged in fission, forming natural nuclear fission reactors.

Brooks also discusses the Oklo natural nuclear fission reactor, in which the natural conditions in caves in Gabon 2 billion years ago caused the uranium there to react.

About 1.5 billion years ago in a uranium ore body in Africa, a natural nuclear fission reactor operated for a few hundred thousand years and produced approximately 5 tonnes of fission products.

Small traces of plutonium-239, a few parts per trillion, and its decay products are naturally found in some concentrated ores of uranium, such as the natural nuclear fission reactor in Oklo, Gabon.

A.I. Shlyakhter is a Russian physicist who noted that the existence of the natural nuclear fission reactor at Oklo in Gabon gave evidence that the physical fine-structure constant α has changed less than 10 per year over the last two billion years.

The present best limits on the variation of the fundamental constants have mainly been set by studying the naturally occurring Oklo natural nuclear fission reactor, where nuclear reactions similar to ones we observe today have been shown to have occurred underground approximately two billion years ago.

Also on Earth, natural transmutations from the different mechanism of natural nuclear reactions occur, due to cosmic ray bombardment of elements (for example, to form carbon-14), and also occasionally from natural neutron bombardment (for example, see natural nuclear fission reactor).

There is strong geochemical evidence that the Oklo uranium deposit behaved as a natural nuclear fission reactor in Precambrian times: some of the mined uranium was found to have a lower concentration of uranium-235 than expected, as if it had already been in a reactor.

In 1972 French physicist Francis Perrin discovered fifteen ancient and no longer active natural nuclear fission reactors in three separate ore deposits at the Oklo mine in Gabon, West Africa, collectively known as the Oklo Fossil Reactors.

There is an "international consensus on the advisability of storing nuclear waste in deep geological repositories", with the lack of movement of nuclear waste in the 2 billion year old natural nuclear fission reactors in Oklo, Gabon being cited as "a source of essential information today."

It is interesting to note that in Africa at Oklo where the natural nuclear fission reactor operated millions of years ago the isotopic mixture of neodymium is not the same as 'normal' neodymium, it has an isotope pattern very similar to the neodymium formed by fission.