A nuclear reservation located in South Carolina, the Savannah River Site, has recently found a white, string-like growth that resembles a radioactive spiderweb growing on the racks of their spent fuel assemblies.
The spent fuel assemblies are cool when placed in the storage pools, not requiring water to cool down. But the water they are submerged in provides workers adequate protection from radiation. Where the thousands of radioactive spiderwebs come from is anyone's guess, living at a depth of 17 to 30 feet deep.
The Defense Facilities Safety Board feels they may be biological in nature, but has not come to any conclusions yet other than many sources consider it "creeping death" even though nobody knows much about them. The unknown material was found amidst thousands of empty fuel assemblies, submerged in deep storage pools. Located in the reservation's SRS's L Area Complex is the only fuel receipt and storage facility available for use.
It was reported in io9 that "the growth was reportedly found underwater on the submerged fuel assemblies themselves." It is speculated that the nuclear cobwebs may be an unknown species of extremophile - an organism said to live in physical or geochemical extreme conditions that are detrimental to most life on Earth.
One of the most extreme environments for the extremophile to thrive in is areas where there is high levels of radiation, the type of radiation that is detrimental to life, reports the Living Cosmos. Some of their environments are waste dumps and reactor water cores. The type of extremophile who chooses to live here is the Deinococcus radiodurans, and is considered to be a radiation-tolerant extremophile.
Fluorescently labeled Dictyostelium cells streaming together into a multicellular slug
A similar extremophilia life form was found at Chernobyl Nuclear Power Plant in Ukraine in 2007, according to Mysterious Universe. Robots had to gather samples as the area is still potentially dangerous, with some of the life forms growing within the destroyed reactor.
Researchers feel that the Savannah nuclear reservation may be growing a similar life form, with the radioactive spiderwebs immune to the otherwise deadly effects of exposure to radiation.
Living Cosmos says, "Incredibly, the molds were found to grow and absorb acetate faster in an environment when exposed to radiation 500 times higher than what are generally considered safe levels. Containing high levels of the pigment melanin, the molds were apparently capable of converting gamma radiation."
Robert T. Gonzales, writing for i09.com, similarly noted that, “Organisms with a natural resistance to radiation are said to be “radioresistant,” and certainly do exist; Deinococcus radiodurans, for example, is not only one of the most naturally radioresistant organisms on Earth, we’ve actually genetically engineered Deinococcus that can be used in the treatment of radioactive waste.” Radioactive spiderwebs...radioresistant organisms for waste control.