The impact of crystalline phase precipitation in glass during canister
cooling on chemical durability of the waste form limits waste loading in
glass, especially for vitrification of certain high-level waste (HLW)
streams rich in Na2O and Al2O3. This study
investigates compositional effects on nepheline precipitation in simulated
Hanford HLW glasses during canister centerline cooling (CCC) heat treatment.
It has been demonstrated that the nepheline primary phase field defined by
the Na2O-Al2O3-SiO2 ternary
system can be used as an indicator for screening HLW glass compositions that
are prone to nepheline formation. Based on the CCC results, the component
effects on increasing nepheline precipitation can be approximately ranked as
Al2O3 > Na2O > Li2O ≈
K2O ≈ Fe2O3 > CaO >
SiC2. The presence of nepheline in glass is usually
detrimental to chemical durability. Using x-ray diffraction data in
conjunction with a mass balance and a second-order mixture model for 7-day
product consistency test (PCT) normalized B release, the effect of glass
crystallization on glass durability can be predicted with an uncertainty
less than 50% if the residual glass composition is within the range of the
PCT model.
Acoustic telemetry is one of the primary technologies for studying the behavior and survival of fishes throughout the world. The size and performance of the transmitter are key limiting factors. The newly developed injectable transmitter is the first acoustic transmitter that can be implanted via injection instead of surgery. A two-part field study was conducted to evaluate the performance of the injectable transmitter and its effect on the survival of implanted fish. The injectable transmitter performed well and similarly to the proceeding generation of commercially-available JSATS transmitters tested concurrently. Snake River subyearling Chinook salmon smolts implanted with the injectable transmitter had a higher survival probability from release to each of eleven downstream detection arrays, because reach-specific survival estimates were significantly higher for the injectable group in three of the eleven reaches examined. Overall, the injectable group had a 0.263 (SE = 0.017) survival probability over the entire 500 km study area compared to 0.199 (0.012) for the surgically implanted group. The reduction in size and ability to implant the new transmitter via injection has reduced the tag or tagging effect bias associated with studying small fishes. The information gathered with this new technology is helping to evaluate the impacts of dams on fishes.
Acoustic telemetry is an important tool for studying the behavior of aquatic animals and assessing the environmental impact of structures such as hydropower facilities. However, the physical size, signal intensity, and service life of off-the-shelf transmitters are presently insufficient for monitoring certain species. In this study, we developed a small, long-life acoustic transmitter with an approximate length of 24.2 mm, diameter of 5.0 mm, and dry weight of 0.72 g. The transmitter generates a coded acoustic signal at 416.7 kHz with a selectable source level between 159 and 163 dB relative to 1 µPa at 1 m, allowing a theoretical detection range of up to 500 m. The expected operational lifetime is 1 yr at a pulse rate interval of 15 s. The new technology makes long-term acoustic telemetry studies of small fish possible, and is being deployed for a long-term tracking of juvenile sturgeon. C 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license
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