Uniqueness of Herndon’s Georeactor: Energy Source and Production Mechanism for Earth’s Magnetic Field by

Herndon‟s georeactor at the center of Earth is immune to meltdown, which is not the case for recently published copy-cat georeactors, which would necessarily be subject to “hot” nuclear fuel, prevailing high-temperature environments, and high confining pressures. Herndon‟s georeactor uniquely is expected to be self-regulating through establishing a balance between heat-production and actinide settling-out. The seventy year old idea of convection in the Earth‟s fluid core is refuted because thermal expansion cannot overcome the 23% higher density at the core‟s bottom than at its top. The dimensionless Rayleigh Number is an inappropriate indicator of convection in the Earth‟s core and mantle as a consequence of the assumptions under which it was derived. Implications bearing on the origin of the geomagnetic field, the physical impossibility of mantle convection, and the concomitant refutation of plate tectonics theory are briefly described. In 1993 and 1994, Herndon [1, 2] published the concept and applied Fermi‟s nuclear reactor theory [3] to demonstrate the feasibility of a naturally occurring nuclear fission at the center of the Earth, now called the georeactor, as the energy source for the geomagnetic field. In 1996, Herndon [4] disclosed the sub-structure of the inner core, describing the two-component structure of the georeactor as consisting of an actinide sub-core, surrounded by a sub-shell composed of the products of nuclear fission and radioactive decay, all surrounded by the inner core. He also noted the possibility that the sub-shell might be a liquid or slurry. In 2001, Hollenbach and Herndon [5] published the first georeactor numerical simulation conducted using Oak Ridge National Laboratory‟s SCALE software, which has been validated with nuclear reactor operating data combined with analyses of spent fuel rods [6]. The numerical 2 simulations showed that georeactor-produced 3 He and 4 He would have the same range of compositions as helium measured in oceanic basalts [7]. Subsequently, Herndon [8] published more precise numerical simulation data, examples of which are shown in Figure 1 from [9]. The marked, progressive increase in 3 He/ 4 He ratios over time occurs as a consequence of diminished 4 He production from radioactive decay as uranium is consumed. Herndon suggested that the high 3 He/ 4 He ratios observed in Hawaiian and Icelandic lavas [10] portend the demise of the georeactor, although the time scale is uncertain [11]. Figure 1. Georeactor numerical simulation 3 He/ 4 He ratios, relative to those in air, over the age of the Earth, calculated at power levels of 3 and 5 terawatts (TW). Arrow indicates present age of Earth. Range of measured oceanic basalt helium ratios at 95% confidence intervals are shown for two major oceanic provinces. Note that helium ratios as high as 37 relative to air are observed in some samples of Icelandic and Hawaiian lavas. As individuals started to appreciate the importance of the georeactor concept, “copy-cat” georeactors began to be published in the scientific literature. These all possess the common feature of supposedly occurring at places other than at the center of the Earth, specifically, at the core-mantle boundary [12] and at the surface of the inner core [13, 14]. All copy-cat georeactors are absent one consideration, which is their common Achilles heel – the potential for meltdown. Figure 2 shows the 235 U/ 238 U ratio of Herndon‟s georeactor over the age of Earth from numerical simulation calculations [8]. For reference, the 235 U/ 238 U ratio is also shown for (i) the Oklo 3 natural nuclear reactor in the Republic of Gabon at time of its operation, (ii) the Chernobyl nuclear reactor which suffered meltdown and (iii) natural uranium at present time. Note the high georeactor 235 U/ 238 U ratios, especially during the first 1.5 billion years of Earth‟s existence. Even at present, that ratio is still “hot” from a nuclear fission standpoint as compared, for example, to Chernobyl fuel. Such high 235 U/ 238 U ratios strongly enhance copy-cat georeactor meltdown, which would lead to the dense uranium progressing downward to Earth‟s center, if not being diluted by the molten underlying matter until criticality ceases. Figure 2. Georeactor 235 U/ 238 U ratios over the age of the Earth. Reference points are shown for the Oklo natural reactor, Chernobyl reactor, and natural uranium at present. Copy-cat georeactor meltdown to the location of Herndon‟s georeactor appears inevitable as no nuclear fission control mechanism for these hypothetical reactors is known. Unlike, for example, the Earth-surface natural reactor at Oklo which did not experience meltdown as it began to function with a significantly lower 235 U/ 238 U ratio in a low-temperature environment and functioned primarily as a thermal neutron reactor, moderated by and pulse-controlled by easily volatilized groundwater [15].