In February 2005, the American Council of Engineering Companies of Pennsylvania held its annual awards ceremony at the Hershey Convention Center. GTS Technologies received the Diamond Honor Award in the Environmental category for its work in the decommissioning of the Saxton Nuclear Experimental Facility.

Following is a description of the project:

GTS played a critical role on a project team that recently decommissioned (disassembled and removed) the Saxton Nuclear Experimental Facility in Bedford County, PA.   The Saxton facility, designed by Westinghouse and now owned by First Energy, was primarily used as a research and training reactor for the 10 years it was in operation from 1962 to 1972, providing valuable information on operations and training for future nuclear power plants and the domestic nuclear energy industry.

In 1972, the facility was shut down, and its nuclear fuel was shipped off the site for disposal. At that time, a four-phase decommissioning project began.

In the final phase, GTS worked as a subcontractor to TLG Services, Inc., the prime contractor, to provide engineering and design services during the removal of 2,600 tons of interior concrete from the cylindrical nuclear containment vessel.

Dismantling of the dome-shaped CV began in 2001. Due to high groundwater, removal of the CV’s concrete interior threatened overall stability of the CV and groundwater contamination.

Safety requirements mandated a redundant dewatering and stabilization system. GTS offered a multi-staged solution. First, approximately 700 linear feet of interceptor trench was installed around the site at the soil bedrock interface, up to 11 feet deep, to divert clean groundwater from within the soil matrix. Next, approximately 300 linear feet of sheet piling was driven through the soil into the bedrock around the CV to intercept and divert groundwater that bypassed the interceptor trench. Approximately 130 holes up to 100 feet deep were drilled near the sheet piles to install a grout curtain to minimize the migration of groundwater through the bedrock to the CV. Finally, an active three-part pumping system composed of 14 wells was installed to move water away from the CV. The wells were located within the immediate vicinity of the CV annulus and both within and outside the sheet piling. All pumps operated 24- hours a day. They were routed through an integrated control panel that monitored groundwater levels and pump performance and connected to an emergency diesel generator system.

To stabilize the CV, GTS braced the vessel using 40 specially designed anchor bolt tie-downs grouted into the bedrock within 36 inches of the CV. These were welded to the CV with a fabricated bracket system attached to dual Ibeam stiffener rings. Bolt installation had to be exact and within very strict tolerances to ensure the vessel’s overall stability.

Although it was designed to be in place for less than one year, the system remained in place for three years. Once the interior concrete was removed, SNEC began radiological clearance of the CV and ultimately removed the above-ground portion. The below-ground portion of the CV was backfilled and capped in March 2004.