DNA evidence sentences nuclear waste to billion-year prison term

250 million-year-old DNA has been recovered intact from a nuclear waste disposal site in New Mexico and provides ample evidence that the waste will be imprisoned for life, but likely prison time will top a billion years.

Forensic teams of scientists working over a decade in laboratories at University of North Carolina, Los Alamos National Laboratory, New Mexico State University and West Chester University, carefully culled the evidence from original fluid inclusions in the massive salt rock that hosts America’s only operating deep underground nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico. The DNA and other biomolecules are remnants from ancient salt-loving bacteria that once lived in a drying-up ocean.

That biomolecules could survive a quarter of a billion years, by far the oldest intact biomolecules ever found, is evidence that this rock is the best choice to imprison any and all nuclear waste in a deep geologic repository, and will isolate the waste from the environment for over a billion years.

Unknown to most, the United States has a successful permanent deep geologic nuclear repository for nuclear waste, the WIPP. WIPP is presently licensed only for nuclear bomb waste (transuranic or TRU) but was designed to hold any and all nuclear waste. WIPP is located a half-mile below the Earth in the massive Permian age salts of the Salado Formation within the Delaware Basin that cuts across southeastern New Mexico into west Texas.

The Salado has geological, physical, chemical, redox, thermal, and creep-closure properties that make it possible for long-term disposal – long-term in this case being greater than 200 million years. These properties also are the same ones that allow biomolecules to survive so long.

At the time of this salt rock’s formation in the Permian, the North American plate was tilting eastward, and the sea in the Delaware Basin was periodically cut-off from the proto-Pacific. The sea would evaporate, the seawater reaching the solubility point for sodium chloride (NaCl), and salt would begin precipitating out. As the sea disappeared, the growing salt crystals would entrap small amounts of the residual seawater, including the halophylic bacteria that were the only things that could survive in its concentrated brine.

After a few million years of repeated re-flooding and evaporation, about 10,000 square miles of salt and sediment were precipitated, 2,000 feet of which are particularly pure and massive salt, massive meaning not interbedded with silts and sands like most other salt deposits. The repository is smack in the middle of this horizon.

Elsewhere in the world at this time, big things were afoot. An enormous extinction was wiping out most marine species. Conifers were coming to dominant plants on land. A new group of animals, called dinosaurs, were about to rise big time. Familiar friends like starfish and sea urchins were just arriving on the scene.  We see these from the hard parts left behind, but never from actual biomolecules.

http://www.forbes.com/sites/jamesconca/2014/01/01/dna-evidence-sentences-nuclear-waste-to-billion-year-prison-term/