HANFORD'S SY-101 WASTE TRANSFER

The surface level in the 241-SY-101 (SY-101) waste storage tank at the U.S. Department of Energy Hanford Site has risen in recent years without waste addition. This resulted in the declaration of an unreviewed safety question and prompted actions to remediate the surface level rise which was caused by the formation of a thick floating crust which was trapping flammable gasses. The technique chosen to accomplish this was to dilute and transfer waste from SY-101 to an adjacent tank, 241-SY-102 (SY-102) and dilution of the remaining waste in the tank. The schedule to perform this transfer was very aggressive because the waste surface level was approaching the point where the tank becomes a single-walled rather than double-walled vessel. This is both an environmental concern and a safety concern.