TLG Services, a subsidiary of Entergy, has been awarded a multi-million dollar contract from GPU Service for the removal of the containment vessel concrete from the Saxton Nuclear Experimental Corporation (SNEC) facility. The project is scheduled to be completed in six months.
The SNEC facility, located in Pennsylvania, was removed from service in 1972. For the last several years GPU has been actively decommissioning the site. The majority of the mechanical equipment has been removed, including the reactor vessel, steam generator and various support buildings.
About half of the containment vessel is underground and there is a relatively high water table. Various physical modifications and engineering controls need to be established to reduce and resist the buckling and flotation loads on the containment vessel during concrete removal. TLG will use multiple and redundant methods to prevent flotation and buckling of the vessel due to hydraulic and structural loads. This includes establishing a ring of rock anchors to anchor the vessel to bedrock, installing an overburden dewatering system and bedrock dewatering system, and bracing the vessel shell to prevent buckling.
