Some comments on Herndon's nuclear georecator. Dedicated to Dr. Rudolf Weber who died too early by drowning in the Mediterranean Sea

Light was thrown on the nuclear aspects of Herndon's georeactor. His thesis is that a power producing droplet of liquid uranium, possessing a radius of about 5 km, operated during the last 4.5 billions of years in the center of the Earth and producing 3-6 TW of thermal power. It could be shown that indeed initial criticality was possible due to the high U-235/U-238 enrichment of approximately 30% at that time. Furthermore, the U-238/Pu-239/U-235 conversion cycle guarantees also a stabilized U-235/U-238 enrichment of about 10% during the whole history of Earth. For this, a constant critical neutron flux in the realm of 108 n/(cm2s) has to be present to convert U-238 via the Pu-239 route and its ed-decay into U-235 with a conversion ratio of exactly unity. Herndon's georeactor is compared with other exotic fission reactors in Nature, too, but the decisive answer whether such a georeactor really exists needs further - particularly chemical, thermodynamical and geological - research work. (orig.)