Page 4 - SRNS_Today_July_2019
P. 4

4   |   SRNS TODAY   |   JULY 2019

         Recycled iron

         used to neutralize

         solvents in P Area

        SRNS is using 760 tons of recycled iron filings from engines to treat
        contaminated groundwater in a section of the aquifer beneath P Area.
        From 1954 to 1984, the site’s P Reactor supported the nation’s
        nuclear deterrent during the Cold War, producing tritium and plutonium.
        Solvents used at P Reactor and other waste units across SRS seeped
        into the subsurface over time creating the need for innovative remedial
        technologies to clean-up the groundwater at these locations.
        In this remedial technology, the filings are mixed with a food-grade,                                 A worker
        starch-like material and injected into 22 wells, each 12 feet apart. A                                prepares
        high-pressure injection process creates fractures in the subsurface                                   injection
        rock, creating space for the mixture to fill. Upon completion, a four-                                equipment to
        inch thick, water-permeable wall consisting of iron filings will extend                               be used in the
        down 135 feet below the earth’s surface.                                                              groundwater
        The 264 foot-long, 23,000 square-foot metal wall will allow                                           process near
        groundwater to flow through and destroy the solvents in the process.                                  the former P
                                                                                                              Reactor, seen in
        “The contaminated water cascades down through the filings,                                            the background.
        significantly increasing the amount of contact with the iron.
        The interaction with the iron breaks down the structure of the
        contaminants, becoming harmless,” said Philip Prater, Senior Physical
        Scientist, U.S. Department of Energy-Savannah River. “And this
        system is designed to work for decades with little maintenance, as it
        has in other parts of the country.”
        According to Prater, the remedial technology SRS is deploying at
        P Area is cutting-edge in that it is trench-less, and unlike permeable
        reactive barriers of the past, it can be installed at greater depths.
        This technology also allows for precision placement, enabling SRS to
        intercept the contaminated groundwater plume in a narrow zone as it
        travels along an old, subsurface stream bed channel.
        “This is the first time we have experimented with this approach (at
        SRS) using a subsurface wall to capture and neutralize solvents.
        We are confident that our goals will be fully achieved related to this
        remarkably cost-effective project at the Savannah River Site’s P Area,”
        said Mark Amidon, a scientist at Savannah River National Laboratory.
        “This highly efficient environmental cleanup technology is another
        asset within the arsenal of environmental restoration tools assembled
        for use across SRS,” said Seth Miller, the SRNS Project Manager for
        this cleanup campaign.
   1   2   3   4   5   6   7   8   9