Saturday, 7 November 2015

The nuclear reactor two billion years old

They called him the 'atomic monster'. All over the world there has never been a power generator so big and so efficient: angled walls inclined, insulation for nuclear waste
and the best cooling system that engineering has never been able to develop. But it is two billion years old.
The nuclear reactor of the Republic of Gabon has a structure so well designed that it could work forever. Some say that it belonged to an ancient civilization super advanced, citing suggestive theory that sees human history as a succession of mass extinction and return of civilization. After the period of 'great destruction', many successive civilizations would try to take advantage of the remains of the 'monster', to return to the times of glory.
Over the years, the structure of the original reactor may have become too flaky and recycling system uranium may have stopped working. Eventually, over the millennia, the walls and the cooling channels, rusted, would eventually merge with the mountain that once had housed them. Billions of years later, the only remnant of that site can 'technology' was depleted uranium: the rest of the reactor was unrecognizable.
This fictitious scenario may not be very far from the real one, if we take into account that for the many scientists 'existence of' nuclear reactor in Gabon '- a giant uranium deposit discovered in Africa in the early 70s - is a phenomenon that would never have been able to occur naturally. With an approximate age of two billion years, in the Republic of Gabon, it was discovered when the crew of a French company became aware of the place that the uranium had already been extracted and used.
After analyzing samples of mine, technicians Nuclear Tricastin have realized that the mineral could not be used for industrial purposes. Suspecting a possible fraud by the company that exported, the leaders of the central Tricastin decided to investigate the reason why, compared to normal samples of uranium owned about 0.7 percent of the material used, the ones they had Oklo only 0.3 percent. Once confirmed that the material was what remained of an old nuclear reaction, researchers around the world have rushed to the site to study the phenomenon.
After extensive chemical and geological analysis, the scientific community comes to a surprising unanimous conclusion: the mine uranium in Gabon had been a reactor 35 thousand square kilometers, began operation 2 billion years ago and remained running for 500,000 years.
These enormous figures have led many specialists to work to find a plausible explanation. But even today the case of Gabon raises the same questions and uncomfortable than forty years ago. What or who had used nuclear power before any civilization set foot on Earth? As they managed to design a complex of reactors so large? How could they keep it running for so long?
The explanation unlikely:
In an attempt to explain the origin of the reactor, scientists have turned to an old theory of the Japanese chemical Kazuo Kuroda, who years earlier had been ridiculed after it disclosed.
Kuroda had argued that a nuclear reaction could take place without the intervention of man, if there were naturally a number of essential conditions: a uranium deposit of the right size, a mineral with a high proportion of fissile uranium, a element that it acted as the moderator, and the absence of dissolved particles, since hamper the reaction.
Although three of these conditions were highly unlikely, even more difficult to explain how a nuclear reaction was natural could have remained in balance without that the core of uranium disappeared or merged during an estimated period of 500,000 years. For this reason, scientists have added to the hypothesis of Kuroda a last factor: a random geological system that allowed for the entry of water in the tanks and the output of the steam reaction.
It is estimated that millions of years ago, the percentage of fissile uranium found in nature was much higher (about 3 percent of the ore), a key fact because the supposed reaction could take place. Based on this factor, the scientists proposed that every three hours uranium deposits could have triggered spontaneously when they were inundated by water filtered through the cracks, generating heat and cooling, when water, which functioned as a moderator, evaporated completely.
However, , according to the theory of Kuroda, the water had to have a good percentage of deuterium (heavy water), and had to be free of any particles that could prevent the neutrons to trigger the reaction. Could the filtered water from the rocks have characteristics so exceptional? Could exist in nature a liquid that even today requires a well developed production process?
Igegneria extreme:
After a series of geological analysis, the researchers found that the Oklo reactor still had one last surprise: the 'deposit' of waste were disposed in a manner such as to detect radioactivity still in the mine, even though they were a million years ago. In fact, it was estimated that the thermal impact of those reactors at Oklo did not exceed the range of 40 meters. Scientists recognize the impossibility of emulating a disposal system so efficient, and the reactor is still studied in order to design new technologies based on its structure.
In a nutshell, the giant reactor in Gabon was designed better than any other modern reactor.
Therefore, even if the theory of 'natural reactors' is now the most widespread in the academic, on the site of Oklo many questions they have yet to receive a reply. Because the uranium was found in deposits well defined and not scattered throughout the territory? A reaction can occur spontaneously and independently in twenty different places all over the field? Because this phenomenon happened exclusively in Africa and not in other parts of the world? Can the walls of a mine to form a random pattern that does not allow the radioactivity to escape? But above all, what exactly happened in Gabon two billion years ago?

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