Monday, May 21, 2018

Nuclear Power part 2: Waste

                                                                                                written 16 March, 2018
                                                                                                published 24Mar18

            This second article on the unsuitability of nuclear power discusses radioactive waste.  Waste disposal assumes there is a place 'away', where unwanted things can be discarded.  This is a dualistic assumption.  Holism recognizes that everything is connected: there is no 'away'.  In nature, everything is recycled, but humans have yet to learn this.  Since 1945, more than 80K chemicals have been created and dispersed into our air, water, and soil, 90% of them untested for biological toxicity.  Bacteria and fungus can break these chemicals into component parts, rendering them non-toxic and available for reintroduction into living systems. 
            However, radioactive waste is toxic by processes of nuclear physics (not chemistry), and only becomes safe over long periods of time.  The life span of radioactive isotopes is measured by the time needed for 50% decay, a half-life, which can be tens of thousands of years.
            The Nuclear Regulatory Commission (NRC) legislates that nuclear waste be categorized and treated based on level of radioactivity.  Very Low Level Waste, twice as radioactive as natural granite, will decay to natural levels within 30 years.  This material is disposed of in monitored landfills.  Low Level Waste, about 20 times more radioactive than granite, contains isotopes with long half-lives.  In the US, this material must be buried in one of four NRC regulated sites.
            Intermediate Level Waste, generated from reprocessing spent fuel rods, is 100K to 100M times more radioactive than granite and can take more than 100 thousand years to return to natural levels.  High Level Waste, spent fuel rods, is a billion times more radioactive than granite (an exposure of less than 20 seconds is lethal), and remains radioactive for millions of years.  The 99 reactors currently operating in the US, have already produced 80,000 tons of High Level Waste.  This will double by the time the reactors are decommissioned.  These rods are stored in cooling pools, or dry cask storage, within the reactor facilities, but space is limited. 
            The only safe disposal of Intermediate and High Level waste requires geologic and social stability for hundreds of thousands of years.  Globally, there are six research facilities studying the problem but, after 60 years of commercial nuclear power, there are no repositories that accept this type of radioactive waste.  Geologic sites might exist with this kind of longevity, but human structures, social and physical, are relatively short lived.  The Pandyan Empire in southern India, lasted 2000 years, and the oldest culture, the Australian Aborigines, dates only 50,000 years.  Warning signs about enduring danger are problematic, since language originated about 10,000 years ago.
            Yucca Mountain, designated as the High Level depository in the US, was shut down in 2011, after decades of construction and billions in cost, because of unexpected ground water intrusion and political resistance from the State of Nevada.  In any event, it is too small to store the waste now in storage, let alone future production, and would require air conditioning for a century.  There are no plans for alternative sites, although the Trump administration wants to reopen Yucca for consideration.
            "Spent fuel rods" contain 90% of the original enriched uranium and fissionable plutonium is produced within the rods, as a result of nuclear reactions.  Advocates of nuclear technology and weapons, see this as a potential resource, and want consideration for future access.  High Level waste must not be allowed to migrate into the environment for health reasons, and national security demands that this material be kept out of the hands of terrorists.  Constructing geologic depositories with possible future access complicates an already difficult design problem.            
            A nuclear power plant boils water for less than half a century, and leaves a legacy lethal to life for a million years, with the added risk of it falling into the hands of terrorists to produce weapons of mass destruction.  Such short-sighted thinking is typical of the dualistic mindset, which seems comfortable sacrificing future generations for the immediate gain of a few.  We must be better than that.