Georeactor

The georeactor is a proposal by J. Marvin Herndon that a nuclear fission reactor may exist and operate at the Earth's core and serves as the energy source for the geomagnetic field. Herndon had earlier proposed the existence of fission reactors at the centers of large gaseous planets such as Jupiter.

A more accepted theory that explains how the magnetic field may be generated is the dynamo theory.

Natural nuclear reactors

In the 1970s, geochemists documented the existence of naturally-occurring slow fission reactors in uranium-bearing geologic formations at Oklo in Gabon, Africa. The Oklo natural nuclear fission reactors operated approximately 1.5 to 2.0 billion years ago, when the natural occurrence of the uranium-235 isotope (required for the fission chain-reaction) was much higher.

Planetary fission reactors

Large, gaseous planets, such as Jupiter, radiate more energy into space than they receive from the Sun. (In the case of Jupiter, the radiated energy is almost twice the received energy.) The source of this energy was originally attributed to gravitational contraction, since gravitational potential energy conversion into heat seemed to be the heat source of sufficient magnitude to account for the quantity of energy released. In 1992, J. Marvin Herndon postulated that the excess energy could be explained by the existence of a central nuclear reactor. High-density fissile elements (i.e. uranium) would be concentrated at the core and could undergo sustained nuclear fission chain reactions. Herndon demonstrated the feasibility of a planetocentric nuclear reactor using Fermi's nuclear reactor theory, calculations similar to those used in nuclear-reactor design.

The georeactor

Herndon subsequently realized that the calculations also permitted the existence of a similar reactor at the Earth's core. Herndon's calculations depend on certain unconventional assumptions regarding the composition of the core, in particular the oxidation state of uranium and the likelihood of its precipitating to the center. He justifies these assumptions by comparison with the composition of enstatite chondrite meteorites, which do have the necessary highly reduced oxidation states and are the only chondrite meteorites which have sufficient iron metal-alloy to match the composition of the Earth with its massive core.

Herndon argues that the georeactor is the energy source for the Earth's magnetic field, and that variations in the strength and direction of the field can be explained by natural variations in the operation of the georeactor.

Generalization to planetary magnetic fields

Currently active internally generated magnetic fields have been detected in six planets (Mercury, Earth, Jupiter, Saturn, Uranus, and Neptune) and in one satellite (Jupiter’s moon Ganymede). Magnetized surface areas of Mars and the Moon indicate the former existence of internally generated magnetic fields in those bodies.

tellar fission reactors

Another possible instance of central nuclear fission may occur in protostars. Ignition of fusion reactions in the cores of stars and protostars requires tremendous temperatures and pressures, which are difficult to attain. Herndon suggests that the fusion reactions may, in fact, be ignited by a central fission reactor in the same manner that a fusion bomb is triggered by a fission bomb.

Dynamo theory

In 2007, Herndon suggested a modification of dynamo theory, in which the electrically conducting operant fluid, and thus region of dynamo action, may be contained within the geocentric nuclear fission reactor, called the georeactor, in its fluid sub-shell, rather than the in Earth’s iron-alloy coreHerndon, J. M. (2007) Nuclear georeactor generation of Earth’s geomagnetic field. Curr. Sci. 93(11), 1485-1487] http://www.ias.ac.in/currsci/dec102007/1485.pdf] . Herndon has pointed out the following reasons why long-term stable convection would not be favorable within the Earth’s fluid core: Maintaining stable convection would require maintaining an adverse temperature gradient, which would require efficient removal of heat brought to the top of the core by convection , but the Earth’s core is insulated by a 2900 km thick blanket of silicate rock, the mantle, which has a much lower thermal conductivity, lower heat capacity, and higher viscosity than the core; all impediments to efficient removal of heat brought to the top of the core by convection. Herndon pointed out that these impediments would not be the case for convection within the georeactor sub-shell, which surrounds the actinide, heat producing sub-core, and which itself is surrounded by the inner core, acting as a heat sink, surrounded by another heat sink, the core, both of which are reasonably good conductors of heat. Moreover, radioactive decay of neutron-rich fission products in the georeactor sub-shell assures a continuous supply of charged particles for establishing a seed-field for dynamo initiation.

Criticism

Herndon's concepts are not accepted by the scientific community. However, Rob de Meijer and associates at the Nuclear Physics Institute in Groningen, the Netherlands, have proposed an experiment to measure the antineutrino flux from the Earth's core which they believe will validate Herndon's hypothesis. At present they are seeking funding for the project, which involves development of an underground laboratory in Curaçao.Fact|date=June 2008

The following is taken from a San Francisco Chronicle article by Keay Davidson describing that test [ [http://sfgate.com/cgi-bin/article.cgi?file=/c/a/2004/11/29/MNGPIA17BL45.DTL Scientific maverick's theory on Earth's core up for a test] Keay Davidson, San Francisco Chronicle, November 29, 2004] :

:One of Herndon's leading critics is planetary scientist David Stevenson of the California Institute of Technology. He says in an e-mail: "Herndon is a solid and knowledgeable person when it comes to (nuclear) reactors. But the amount of attention this (georeactor) idea has received is out of proportion with its plausibility. ... It's not complete nonsense, but it's highly unlikely. There are many instances in science where this happens. This one has merely received more attention than most.

:"The idea is based on two very dubious propositions: (a) That uranium (or any heavy element) would naturally go to the center of the Earth. This is almost certainly untrue. It is a misunderstanding of chemistry and statistical physics at a very fundamental level. (b) That there is something about Earth's heat flow or helium that is so wildly discordant with our usual ideas that it requires an outrageous hypothesis to explain it. This is incorrect."

Planetary fusion reactions

In seemingly unrelated work, Steven E. Jones of Brigham Young University (BYU) has speculated on the existence of natural "fusion" reactions at planetary cores, continuing work initiated by Dr. Paul Palmer (also of BYU) in 1986. Their initial work was also focused on explaining the excess heat given off by Jupiter and then extended to include possible application to Earth. The term "geo-fusion" is used to describe their theory. Geo-fusion is a form of cold fusion, although not the type of room-temperature fusion described by Stanley Pons and Martin Fleischmann. Jones was working on muon-catalyzed fusion and was intending to publish his results simultaneously with Pons and Fleischmann, at the nearby University of Utah, when they "scooped" him with their public announcement). Jones hypothesizes that geo-fusion is driven by the high pressures present at planetary cores. Jones has suggested that measurements of the levels of tritium released by volcanic processes may provide a possible confirmation of the theory.Fact|date=June 2008

The georeactor in popular fiction

Herndon speculated as to the effects of a possible shutdown of the theoretical fission process in the Earth's core, which was subsequently, without attribution, paralleled in the pulp science fiction book and film from 2003, The Core.

The alternative core of earth

Beginning in 1979, Herndon published a series of papers revealing a fundamentally different view of Earth’s interior, including the inner core being nickel silicide, CaS and MgS at the core mantle boundary, the lower mantle consisting of essentially FeO-free MgSiO₃, and the boundary between the upper and lower mantle being a compositional boundary with the matter below that boundary, the endo-Earth, being like an enstatite chondrite. [Herndon, J. M., The chemical composition of the interior shells of the Earth. Proc. R. Soc. Lond, 1980, A372, 149-154.] [Herndon, J. M., Scientific basis of knowledge on Earth's composition. Curr.Sci., 2005, 88(7), 1034-1037.] [Herndon, J. M., The nickel silicide inner core of the Earth. Proc. R. Soc. Lond, 1979, A368, 495-500.] [Herndon, J. M., Composition of the deep interior of the earth: divergent geophysical development with fundamentally different geophysical implications. Phys. Earth Plan. Inter, 1998, 105, 1-4.]

References

* "Nuclear Fission Reactors as Energy Sources for the Giant Outer Planets", "Naturwissenschaften" 79:7-14, 1992
* J.M. Herndon, "Feasibility of a Nuclear Fission Reactor at the Center of the Earth as the Energy Source for the Geomagnetic Field", "Journal of Geomagnetism and Geoelectricity" 45: 3423-437, 1993
* "Current Biography" 64: 45-49, November, 2003
* "Discover Magazine", pp 37-42, August, 2002
* "Nuclear Georeactor Origin of Oceanic Basalt 3he/4he, Evidence, and Implications", "Proceedings of the National Academy of Science 100" pp. 3047-3050, 18 march 2003
* [http://sfgate.com/cgi-bin/article.cgi?file=/c/a/2004/11/29/MNGPIA17BL45.DTL Davidson, Keay (Nov. 29, 2004). "Scientific maverick's theory on Earth's core up for a test" "San Francisco Chronicle" ]
* Jones, S.E. and J. Ellsworth (2003) "Geo-fusion and Cold Nucleosynthesis" "Tenth International Conference on Cold Fusion".
* Peat, David E. Cold Fusion: The Making of a Scientific Controversy. Chicago: Contemporary Books, Inc., 1989. ISBN 0-8092-4243-5.

External links

* [http://nuclearplanet.com Nuclear Planet.com] J. Marvin Herndon's Website
* [http://arxiv.org/abs/0707.2850 Nuclear Georeactor Generation of Earth’s Geomagnetic Field] latest paper