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Portions of this AbstractThis 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 f 0.015 at riser 17C and 0.091 f 0.015 at riser 22A. The stored gas volume based on these void fraction measurements is 2 13 f 42 m3 at 1 atmosphere.... lll SummaryHanford waste Tank 241-SY-103 is filled to about two-thirds capacity, and the current waste level is about 6.9 m. The waste consists of a relatively thin, incomplete crust layer floating on a convective layer about 3.6 m thick with a 3.3-m nonconvective sludge layer on the bottom. This tank has experienced gas release events (GREs) at irregular intervals of roughly three months since its last fill in 1988. Though these events are much smaller than those of its neighbor, Tank 241-SY-101, there is a need to obtain measurements of the void fraction profile and waste rheology in order to estimate the stored gas volume and the amount that could potentially be released.The ball rheometer was deployed July 14 and August 8, 1995, and the void fraction instrument (VFI) on July 19 and August 18, 1995, to supply this information. Each instrument was deployed in risers 17C and 22A, which are located in the southeast and northwest quadrants at 8.5 m and 6.1 m from tank center, respectively. Because riser 17C is not vertical, the ball rheometer cable rubbed on the riser lip, requiring a load cell of relatively low resolution.The rheological properties of the convective layer were uniform and characterized by a low viscosity (about 45 cP), no yield strength (e 2 Pa), zero void fraction, and a density of about 1 . 5 gkc. The nonconvective sludge layer had a yield strength of less then 2 1 0 Pa and an apparent viscosity of 104 to 105 cP. The rheology of the sludge varied widely with depth and was very sensitive to shear history, more so in riser 22A than 17C. The ball rheometer was not able to penetrate a heavier heel layer, about 120 cm thick, on the tank bottom.The data also revealed much different void fractions in the nonconvective layers in each riser. The local void ranged up to 12.5% in the lower portion of the sludge layer. The average void fraction at 17C was 0.047 k 0.015; it was 0.091 4 0.015 at riser 22A. This difference may be attributed to differences in GRE history at the two locations. The waste in the vicinity of 17C may have participated in more of the recent rollover events, while the waste around riser 22A may have remained relatively undisturbed. Assuming approximately equal portions of the tank a...

The continuing need for in-situ measurements of physical properties of wastes contained within many high level radioactive waste tanks within the Hanford Site has initiated experimental and theoretical investigations of candidate measurement methods. This paper describes experiments performed with acoustic waveguide sensors. This technology has potential application at the Hanford Site for in-situ measurements of density, viscosity, and temperature of liquid wastes. Waveguides of both circular and rectangular geometry were used in these studies for determination of the densities and viscosities of various fluids. The flight time of a torsional pulse through the sensing region of the waveguide forms the measured quantity. The flight time depends on the velocity of the wave through the sensing region of the waveguide, and this velocity in turn depends upon the properties of the fluid in contact with the waveguide. We performed experiments with 15 different fluids, most of which were single-phase Newtonian fluids. However, three of the fluids were particle-liquid mixtures, and one of these Newtonian in behavior. Most of the wastes held in Hanford tanks contain high solids content. The results of our experiments showed that acoustic waveguides were well suited for measurements in most Newtonian fluids, in agreement with earlier research presented in the literature. However, results for two-phase Newtonian fluids containing particles indicate that, in our case, the waveguides responded primarily to the background fluid rather than the mixture. Very poor results were obtained with the non-Newtonian fluid. In addition, there was a class of fluids, which serve the community as viscosity standards, for which viscosities determined with torsional waveguides were in disagreement with viscosities obtained with standard viscometers.

SummaryFour double-contained receiver tanks (DCRTs) at Hanford will be used to store salt-well pumped liquids from tanks on the Flammable Gas Watch List. This document was created to serve as a technical basis or reference document for flammable gas issues in DCRTs. The document identifies, describes, evaluates, and attempts to quantify potential gas carryover and release mechanisms. It estimates several key parameters needed for these calculations, such as initial aqueous concentrations and ventilation rate, and evaluates the uncertainty in those estimates. It justifies the use of the Schumpe model for estimating vapor-liquid equilibrium constants. It identifies several potential waste compatibility issues (such as mixing and pH or temperature changes) that could lead to gas release and provides a basis for calculating their effects. It evaluates the potential for gas retention in precipitated solids within a DCRT and whether retention could lead to a buoyant displacement instability (rollover) event. It discusses rates of radiolytic, thermal, and corrosive hydrogen generation within the DCRT. It also describes in detail the accepted method of calculating the lower flammability limit (LFL) for mixtures of flammable gases.The report incorporates these analyses into two models for calculating headspace flammability, one based on instantaneous equilibrium between dissolved gases and the headspace and one incorporating limited release rates based on mass-transfer considerations. Finally, it demonstrates the use of both models to estimate headspace flammable gas concentrations and minimum ventilation rates required to maintain concentrations below 25% of the LFL. The report describes the methodology, the results at the only known (but probably highly underestimated) ventilation rate of 3 cfh, and the parametric sensitivity of the results.However, no actual predictions of DCRT headspace flammability are implied. This document is intended to provide background information for future DCRT modeling and recommendations for improving the technical basis of modeling. Although modeling results are presented here, the waste properties and potential pumping scenarios are so variable as to require case-by-case modeling for a safety basis. This document, therefore, does not and cannot provide a safety basis but rather guidance (based on current knowledge) as to conditions that a safety basis should meet.We have identified no major flaws in the approach previously published in a calc-note by Hedengren et aL (1997). Although we developed a somewhat different mathematical model for predicting flammable gas concentrations within the DCRT, we found little difference between our predictions and those from Hedengren et aL when the same initial dissolved gas concentrations were assumed. We also found that for most purposes the assumption of equilibrium does not produce large overestimates of DCRT headspace flammability until ventilation rates are much higher than the 3 cfh assumed in the other analyses. The analyses in this document in...