Preliminary engineering evaluation of heat and digest treatment for in-tank removal of radionuclides from complexed waste

摘要

This report uses laboratory data from low temperature-ambient pressure digestion of actual complexed supernatant to evaluate digestion as a pretreatment method for waste in double-shell tanks 241-AN-102, 241-AN-107 and 241-AY-101. Digestion time requirements were developed at 100 degrees celsius to remove organic and meet NRC Class C criterion for TRU elements and NRC Class B criterion for 90Sr. The incidental waste ruling will establish the need for removal of 90Sr. Digestion pretreatment precipitates non radioactive metal ions and produces additional high-level waste solids and canisters of high level glass. This report estimates the amount of additional high-level waste produced and preliminary capital and operating costs for in-tank digestion of waste. An overview of alternative in-tank treatment methods is included.