Design and Construction of a Permeable Treatment Wall at the West Valley Demonstration Project
William T. Frederick, P.G., CPG
Supervisory Geologist -US Army Corps of Engineers -Buffalo
The West Valley Demonstration Project (WVDP) is as DOE site located about 30 miles south of Buffalo in the rural town of Ashford, NY. The Main Plant Process Building at the WVDP was used to reprocess irradiated nuclear fuel from 1966-1972. During routine groundwater sampling down gradient of the main plant, a Sr-90 plume was discovered migrating from the Plant to a distal surface-water discharge point near the project boundary. A pipe leaking supernatant from the plant was determined to be the source of the radionuclides. Several plume delineation efforts were conducted from 1990 to 2010, with a detailed delineation of the leading plume edge in 2008 & 2009.
An interim pump & treat measure was installed in 1995 and a pilot-scale permeable treatment wall (PTW) was installed in 1999 to test the preferential strontium sorption of a natural zeolite mineral called clinoptilolite.
The limited success of the pump & treat and pilot PTW led the way to additional zeolite testing and methods to install a full-size wall. The UB Environmental Engineering Department tested two zeolite types and determined that the Bear River clinoptilolite was the optimal media for strontium sorption and cation exchange. This decision paved the way for AMEC (Geomatrix) to performed hydrogeologic modeling and design a continuous wall along the leading edge of the plume. The presentation will cover the preliminary through final design and eventual construction of the wall using a 30-foot deep one-pass trencher. Performance monitoring has just begun and results are under evaluation.
Map of Romanello's South
This meeting is kindly sponsored by Ashtead Technologies