PNNL

Abstract

In August 2007, Secretary of Energy Samuel W. Bodman approved the final seismic and ground motion criteria for the Waste Treatment and Immobilization Plant (WTP) at the Department of Energy’s (DOE) Hanford Site. Construction of the WTP began in 2002 based on seismic design criteria established in 1999 and a probabilistic seismic hazard analysis completed in 1996. The design criteria were re-evaluated in 2005 to address questions from the Defense Nuclear Facilities Safety Board (DNFSB), resulting in an increase by up to 40% in the seismic design basis. DOE announced in 2006 the suspension of construction on the pretreatment and high-level waste vitrification facilities within the WTP to validate the design with more stringent seismic criteria. In 2007, the U.S. Congress mandated that the Secretary of Energy certify the final seismic and ground motion criteria prior to expenditure of funds on construction of these two facilities. With the Secretary’s approval of the final seismic criteria this past summer, DOE authorized restart of construction of the pretreatment and high-level waste vitrification facilities.