Assessment of Physical Properties of Transuranic Waste in Hanford Single-Shell Tanks

Abstract

range from 70 to 85 wt%; the reported water content is somewhat higher in Tank T-111 (85 to 90 wt%) and lower in a few samples from T-201 (~65 wt%). Most of the data for bulk solids samples, a matrix of waste solids and interstitial liquid, show bulk densities of 1.15 to 1.30 g/mL, and the density generally increases with decreasing water content. The shear strength estimates obtained from the extrusion methods were compared with the water content and bulk density of waste samples from the same core segments. The shear strength and, to a lesser extent, the density show some tendency to decrease with increasing water, but significant scatter exists in the data. The physical properties of in situ and diluted SST TRU waste described in this report and summarized in the discussion above are tabulated in Table ES.1. In many cases, the expected range of properties is estimated from limited data. However, in those instances where data are available for many tanks and multiple locations within tanks, the data do not indicate major differences among individual tanks. Therefore, it appears reasonable to treat individual tank results as typical of Hanford SST TRU waste. Table S.1. Expected Range of Physical Properties of In Situ and Diluted SST TRU Waste Property Expected Range Comments Shear strength 200 to 2,000 Pa (majority of waste) 0 to 4,000 Pa (range, including liquid) Estimated from data obtained from core extrusions (Sections 3.1 and 3.2) and reported shear vane measurements (Section 4.1). Viscosity 2 to 25 cP at 10 s-1 2 to 15 cP at 100 s-1 Results for 1:1 dilution with water; higher viscosities expected for waste diluted less and at lower strain rates. Waste exhibited pseudoplastic rheology. Section 4.1. Waste settling ~0 vol% free liquid (1 G) 2 to 40 vol% free liquid (>1000 G, 1 hr) Undiluted waste, >200 Pa shear strength. Weaker waste (liquid in the extreme) is expected to produce more free liquid on settling. Section 4.2. Waste settling 5 to 25 vol% free liquid (1 G, ~2 days) 40 to 60 vol% free liquid (>1000 G, 1 hr) 1:1 diluted waste, >200 Pa shear strength prior to dilution. See comment above. Section 4.2. Waste settling 40 to 65 vol% free liquid (1 G, ~2 days) 70 to 85 vol% free liquid (>1000 G, 1 hr) 3:1 diluted waste, >200 Pa shear strength prior to dilution. See comment above. Section 4.2. Particle size, mean 7 to 70 µm (volume density) < 2 µm (number density) Section 4.3. Water content 70 to 85 wt% (majority of waste) 65 to 90 wt% (range) Section 5.1. Liquid Density ~1.05 g/mL Section 5.2 Bulk Density 1.15 to 1.3 g/mL (majority of waste) 1.1 to 1.4 g/mL (range) Section 5.2 vii

An Approach to Understanding Cohesive Slurry Settling, Mobilization, and Hydrogen Gas Retention in Pulsed Jet Mixed Vessels

“…Results with this methodology (termed "extrusion length") were generally within a factor of two or better of the ball rheometer measurements (typically accepted as being more representative of in situ waste conditions than laboratory measurements; for select saltcake DSTs. It was concluded that, in the absence of definitive in situ measurements, or in support of them, this extrusion length methodology is expected to produce representative results for the material's shear strength (Rassat et al 2003a). A relatively favorable comparison of shear vane and extrusion length results can also be made for AY-102 sediment (see data in , and the similarity of extrusion length and shear vane results in sludge is reported in Appendix F of Hu (2007). 3.8 Based on this extrusion length methodology, horizontal core extrusion videos from AZ-101 were investigated.…”

“…developed the methodology to determine waste-extrusion behavior whereby the shear strength of a waste sediment is determined based on visually comparing the behavior of horizontal waste-core extrusion for simulants with known shear strength to that of Hanford Waste. An "extrusion length" methodology based on the simulant extrusion data of for estimating the yield stress in shear of Hanford Waste was developed in Rassat et al (2003a). This methodology relies on measuring the initial extrusion length of the waste core at plastic failure.…”

“…Cumulative shear-strength distributions for shear-vane and waste-extrusion data are provided in , Rassat et al 2003a) and the waste-extrusion results are from individual core segment extrusions (extrusions are typically performed days to months after sampling). (a) Relative to the rest of the Hanford waste tanks, the shear strength of AY-102 sediment samples has been extensively evaluated (see Section 3.2.2).…”

“…As described in Section 2.2.1, the extrusion length methodology is an extension of the visual comparison of horizontal core extrusion methodology of for estimating the shear strength of Hanford Waste developed in Rassat et al (2003a). In summary, Gauglitz and Aikin horizontally extruded bentonite/water and kaolin/Ludox/water simulants of known shear strength and reported the length at which the extrusion exhibited "failure."…”

“…Insight into the applicability of Y~0.061 for cessation of downward motion for a sludge weight or densitometer may be gained by examining the ball rheometer results as compared to shear strength estimates from the extrusion length methodology (Rassat et al 2003a). The extrusion length methodology uses waste simulant data to correlate the horizontal extrusion length of waste core samples to a shear strength.…”