Slab Tank Research Articles

A snail's pace: A preliminary analysis of the effects of stress and genetics on movement of Haliotis

Aquaculture producers' desire animals that are better able to tolerate and survive stress, but selecting animals with these traits is hampered by a lack of reliable stress indicators in aquatic organisms. Here we undertake a preliminary study to explore behavioural response, in terms of distance travelled, under differing stress histories, in greenlip abalone Haliotis laevigata. Movement trials were performed on labelled abalone of known pedigree relationships by measuring distance and direction travelled in a grid marked slab tank with unidirectional current. Animal and sire models were fitted to the data using a Markov chain Monte Carlo multi trait generalised linear mixed effect model. Distance travelled with respect to water flow was found to be influenced by stress inflicted by sampling tentacles either immediately prior to the movement trial, or inflicted >24hours prior to the trial (P<0.05), while distance travelled from the starting grid (not direction) was significantly affected by stress inflicted >24hours prior to the movement trials (P<0.05), which may be indicative of a delayed or accumulated stress response. There was no evidence that abalone size (length or weight), or the accumulated effects of handling, influenced the distance travelled or direction. The narrow sense heritability of distance and direction travelled was low (0.05 and 0.07 respectively), but significantly greater than zero (95% Bayesian confidence intervals of 0.02–0.16 and 0.03–0.18 respectively), while that of weight and length were moderate to high (>0.4). Parental origin affected distance travelled, such that progeny with parents whose ancestors were selected for faster growth rate for 3 generations, moved longer distances. This difference between animals with different parental origins was exacerbated by stress. The results suggest that behaviour could be a good indicator of some forms of stress.

Kinetic Parameter βeff/ℓ Measurement on Low Enriched Uranyl Nitrate Solution with Single Unit Cores (600𝛗;, 280T, 800𝛗;)of STACY

The kinetic parameter βeff/ℓ of low enriched (10% EU) uranyl nitrate solution was measured by the pulsed neutron source (PNS) method in STACY This measurement was repeated systematically over several uranium concentrations from about 195 gU/l to about 430 gU/l. Used core tanks were two cylindrical tanks whose diameters are 600 mm and 800 mm and one slab tank which has 280 mm thickness and 700 mm width. In this report, experimental data such as solution conditions, critical solution level for each solution condition, subcritical solution levels where measurements were conducted, measured decay time constants of prompt neutron and extrapolated βeff/ℓ values are described as well as basic principle of the PNS method. The kinetic parameter βeff/ℓ values were evaluated also by computation with the diffusion code CITATION in SRAC and the nuclear data library JENDL 3.2. Strong linear correlation has been found between kinetic parameter βeff/ℓ and uranium concentration regardless of differences of reflecting conditions or core tank conditions. Experimentally or computationally evaluated βeff/ℓ value is about 90 s-1 at 195 gU/l and about 170 s-1 at 430 gU/l and both experimental and computational values show good agreement within an error of 3% which is comparable to about 2% uncertainty of measurement.

Benchmark Evaluation on Single Core System Composed of 10% Enriched Uranyl Nitrate Solution at STACY

Critical experiments on 10% enriched uranyl nitrate solution have been conducted for obtaining benchmark data using a Static Experiment Critical Facility, STACY, in the Nuclear Fuel Cycle Safety Engineering Research Facility, NUCEF. Two cylindrical and one slab tank were used to construct a single core system. Critical solution levels were measured for three core tanks with changing the uranium concentration of uranyl nitrate solution. Fundamental data were obtained for unreflected or water reflected cores. The sensitivities of the fuel composition and tank geometry on the criticality were calculated, and total uncertainty of the experiments are evaluated less than 0.15% Δ k. Calculations of the neutron multiplication factor keff for the critical conditions were performed using a continuous-energy Monte Carlo code MCNP-4B employing JENDL-3.2. This paper presents the core configurations of STACY, their experimental uncertainties and calculation results with above calculation system.

Kinetic Parameter .BETA.eff/l Measurement on Low Enriched Uranyl Nitrate Solution with Single Unit Cores (600.PHI., 280T, 800.PHI.) of STACY.

The kinetic parameter βeff/ℓ of low enriched (10% EU) uranyl nitrate solution was measured by the pulsed neutron source (PNS) method in STACY This measurement was repeated systematically over several uranium concentrations from about 195 gU/l to about 430 gU/l. Used core tanks were two cylindrical tanks whose diameters are 600 mm and 800 mm and one slab tank which has 280 mm thickness and 700 mm width. In this report, experimental data such as solution conditions, critical solution level for each solution condition, subcritical solution levels where measurements were conducted, measured decay time constants of prompt neutron and extrapolated βeff/ℓ values are described as well as basic principle of the PNS method. The kinetic parameter βeff/ℓ values were evaluated also by computation with the diffusion code CITATION in SRAC and the nuclear data library JENDL 3.2. Strong linear correlation has been found between kinetic parameter βeff/ℓ and uranium concentration regardless of differences of reflecting conditions or core tank conditions. Experimentally or computationally evaluated βeff/ℓ value is about 90 s-1 at 195 gU/l and about 170 s-1 at 430 gU/l and both experimental and computational values show good agreement within an error of 3% which is comparable to about 2% uncertainty of measurement.

Criticality Data and Validation Studies of Plutonium-Uranium Nitrate Solutions in Cylindrical and Slab Geometry

A series of critical experiments was performed with mixed plutonium-uranium nitrate solutions in two cylinders and in a variable thickness slab tank. The solution concentrations ranged from 12 to 1...

252Cf-Source-Driven Neutron Noise Measurements of Subcriticality for an Annular Tank Containing Aqueous Pu-U Nitrate

In order to study nuclear criticality safety related to the development of fast breeder technology, /sup 252/Cf-source-driven neutron noise analysis measurements were performed with a Pu-U nitrate solution in a slab tank of various heights and thickness varying 11.43 cm to 19.05 cm. The results and conclusions of these experiments are (1) a capability to measure the subcriticality of a multiplying system of slab geometry to a k/sub eff/ as low as 0.7 was demonstrated, (2) calculated neutron multiplication factors agreed with those from the experiments within approx.0.02, and (3) the applicability of the method for plutonium solution systems was demonstrated. This paper describes measurements in which the height of the slab was varied for a fixed thickness and the thickness varied for a fixed height, which are the first applications of this measurement method to slab geometry.

Mixing and solid suspension by up‐down agitators in a slab tank

Seven different up-down agitators were studied for their ability to produce mixing and solid suspension in a slab tank. Mixing times were measured as the time needed to disperse injected dye. The solid suspension studies determined the minimum stroke frequency of the agitators needed for complete off-bottom suspension. The effects of stroke frequency, n; amplitude, a; blade width, w; blade clearance, c; and liquid depth, h, and weight percent solids, X, were studied. The most effective geometry, in terms of mixing, solid suspension and design simplicity, was a single flat blade with minimum off-bottom clearance and a blade width/tank thickness ratio, w/T, of 0.74 at the maximum stroke amplitude studied. 15 refs., 7 figs.