In situ determination of rheological properties and void fraction: Hanford Waste Tank 241-SY-103

This report presents the results of the operation of the void fraction instrument (VFI) and ball rheometer in Hanford Tank 241-SY-103. The two instruments were deployed through risers 17C and 22A in July and August 1995 to gather data on the gas content and rheology of the waste. The results indicate that the nonconvective sludge layer contains up to 12% void and an apparent viscosity of 104 to 105 cP with a yield strength less than 210 Pa. The convective layer measured zero void and had no measurable yield strength. Its average viscosity was about 45 cP, and the density was less than 1.5 g/cc. The average void fraction was 0.047 {plus_minus} 0.015 at riser 17C and 0.091 {plus_minus} 0.015 at riser 22A. The stored gas volume based on these void fraction measurements is 213 {plus_minus} 42 M{sup 3} at 1 atmosphere.