The University of Tennessee and Battelle will operate the Oak Ridge National Laboratory in Tennessee for five more years, Energy Secretary Spencer Abraham announced Monday.

Battelle also operates Pacific Northwest National Laboratory in Richland for the Department of Energy.

The estimated value of the contract extension, which begins April 1, is $4.8 billion.

"Continuing this contract is very important to the future of DOE's science programs in Oak Ridge, particularly as we near the completion of the Spallation Neutron Source and other important research facilities," Abraham said. The Spallation Neutron Source is a linear accelerator being developed for research.

DOE's national laboratory in Tennessee employs 4,500 people and does DOE research in basic energy sciences, material and neutron science, biological and environmental research, fusion energy science, advanced scientific computation, nuclear physics, energy efficiency, renewable energy and national security.

Battelle also is involved in the management and operations of the Brookhaven National Laboratory in New York, the National Renewable Energy Laboratory in Colorado and the Idaho National Laboratory.