Then outlying buildings would be demolished and the main reactor building demolished and sealed off. Most of the work on outlying buildings is complete, said Bechtel and DOE officials. The remaining hurdle is N Basin - which is two connecting indoor pools that once held spent nuclear fuel until it was transferred elsewhere. The N Basin holds about 1 million gallons of water that is about 24 feet deep. Much of its bottom consists of deep cubicles, giving its floor a waffled appearance.
Radioactive sediment ranging from a thin layer to a few feet deep covers the bottom.
Other radioactive debris and equipment, plus small broken-off bits of spent fuel, are scattered in the basin. In August, tests showed the basin's walls and floor were more contaminated than expected, said Heather Trumble, DOE project manager for the work. A second hurdle is shipping the basin water to Hanford's effluent treatment plant for purification, said Paul Pak, DOE senior project manager for the 100N Area. Waste Management of Hanford operates that plant, which serves several projects. While Bechtel believes it can guarantee a steady flow of tanker trucks from N Basin to the treatment plant, it still has to work out scheduling and prioritizing with Waste Management, said Pak and Tom Logan, Bechtel project manager for the 100N Area.