August 1, 2006
Conference Paper

Axial Dispersion during Hanford Saltcake Washing

Abstract

Clean up of Hanford salt cake wastes begins with dissolution retrieval of the sodium rich salts that make up the dominant majority of mass in the tanks. Water moving through the porous salt cake dissolves the soluble components and also displaces the soluble radionuclides (e.g. 137Cs and 99TcO4- ). The separation that occurs from this displacement, known as Selective dissolution, is an important component in Hanford’s pretreatment of low activity wastes for subsequent Supplemental treatment. This paper describes lab scale testing conducted to evaluate Selective dissolution of cesium from non-radioactive Hanford tank 241-S-112 salt cake simulant containing the primary chemicals found the the actual tank. An modified axial dispersion model with increasing axial dispersion was developed to predict cesium removal. The model recognizes that water dissolves the salt cake during washing, which causes an increase in the axial dispersion during the wash. This model was subsequently compared with on-line cesium measurements from the retrieval of tank 241-S-112. The model had remarkably good agreement with both the lab scale and full scale data.

Revised: April 20, 2011 | Published: August 1, 2006

Citation

Josephson G.B., J.G. Geeting, D.L. Lessor, and W.B. Barton. 2006. Axial Dispersion during Hanford Saltcake Washing. In 14th Symposium on Separation Science and Technology for Energy Applications held in Gatlinburg TN Oct.23-27, 2005. Published in Separation Science and Technology, 41, 2267-2282. Philadelphia, Pennsylvania:Taylor & Francis Inc. PNNL-SA-47198. doi:10.1080/01496390600745586