The U.S. Department of Energy (DOE) Yucca Mountain Site Characterization Project Office (YMPO) assigned Science Applications International Corporation (SAIC), the Technical and Management Support Services (T&MSS) contractor to the YMPO, the task of conducting an Early Site Suitability Evaluation (ESSE) of the Yucca Mountain site as a potential site for a high-level radioactive waste repository.

In the course of producing electrical power in light water reactors (LWRs), the uranium<br/>fuel accumulates fission products until the fission process is no longer efficient for power<br/>production. At that point the fuel is removed from the reactor and stored in water basins<br/>to allow radioactivity to partially decay before further disposition. This fuel is referred<br/>to as &quot;spent fuel.&quot; Although spent fuel as it is discharged from a reactor is intensely<br/>radioactive, it has been stored safely in moderate quantities for decades.

In the course of producing electrical power in light water reactors (LWRs), the uranium<br/>fuel accumulates fission products until the fission process is no longer efficient for power<br/>production. At that point the fuel is removed from the reactor and stored in water basins<br/>to allow radioactivity to partially decay before further disposition. This fuel is referred<br/>to as &quot;spent fuel.&quot; Although spent fuel as it is discharged from a reactor is intensely<br/>radioactive, it has been stored safely in moderate quantities for decades.