Material Balance Assessment for Double-Shell Tank Waste Pipeline Transfer

Abstract

SummaryPacific Northwest National Laboratory researchers developed a material balance assessment methodology based on conservation of mass to detect possible waste leaking and mis-routings during the pipeline transfer of double-shell tank waste with variable waste properties and tank conditions at Hanford. It is intended to be a backup method to pit leak detectors.The main factors causing variable waste properties and tank conditions are waste density changes caused by chemical reactions and gas generation/retention/release, the existence of a crust layer, and waste surface disturbance due to mixer pump operation during the waste transfer. If waste properties and tank conditions were constant, this mass-based material balance methodology could be simplified to a volume-based material balance.The material balance assessment methodology was applied to three waste transfers: AN-105 first transfer of 911,400 gallons of in-line diluted supernatant liquid; AN-105 second transfer with 673,000 gallons of liquid waste; and AZ-102 slurry transfer of 150,000 gallons. Three instrumentation setups were considered: (A) feed and receiver tank levels and diluent flow meter; (B) flow meter at the beginning of the transfer pipeline and receiver tank level; and (C) diluent, feed, and receiver tank levels.