A Criticality Analysis of the GBC-32 Dry Storage Cask with Hanbit Nuclear Power Plant Unit 3 Fuel Assemblies from the Viewpoint of Burnup Credit

AbstractNuclear criticality safety analyses (NCSAs) considering burnup credit were performed for the GBC-32 cask. The used nuclear fuel assemblies (UNFAs) discharged from Hanbit Nuclear Power Plant Unit 3 Cycle 6 were loaded into the cask. Their axial burnup distributions and average discharge burnups were evaluated using the DeCART and Multi-purpose Analyzer for Static and Transient Effects of Reactors (MASTER) codes, and NCSAs were performed using SCALE 6.1/STandardized Analysis of Reactivity for Burnup Credit using SCALE (STARBUCS) and Monte Carlo N-Particle transport code, version 6 (MCNP 6). The axial burnup distributions were determined for 20 UNFAs with various initial enrichments and burnups, which were applied to the criticality analysis for the cask system. The UNFAs for 20- and 30-year cooling times were assumed to be stored in the cask. The criticality analyses indicated that keff values for UNFAs with nonuniform axial burnup distributions were larger than those with a uniform distribution, that is, the end effects were positive but much smaller than those with the reference distribution. The axial burnup distributions for 20 UNFAs had shapes that were more symmetrical with a less steep gradient in the upper region than the reference ones of the United States Department of Energy. These differences in the axial burnup distributions resulted in a significant reduction in end effects compared with the reference

Development of the MICROMEGAS Detector for Measuring the Energy Spectrum of Alpha Particles by using a 241-Am Source

We have developed MICROMEGAS (MICRO MEsh GASeous) detectors for detecting {\alpha} particles emitted from an 241-Am standard source. The voltage applied to the ionization region of the detector is optimized for stable operation at room temperature and atmospheric pressure. The energy of {\alpha} particles from the 241-Am source can be varied by changing the flight path of the {\alpha} particle from the 241 Am source. The channel numbers of the experimentally-measured pulse peak positions for different energies of the {\alpha} particles are associated with the energies deposited by the alpha particles in the ionization region of the detector as calculated by using GEANT4 simulations; thus, the energy calibration of the MICROMEGAS detector for {\alpha} particles is done. For the energy calibration, the thickness of the ionization region is adjusted so that {\alpha} particles may completely stop in the ionization region and their kinetic energies are fully deposited in the region. The efficiency of our MICROMEGAS detector for {\alpha} particles under the present conditions is found to be ~ 97.3 %

GIST-AiTeR Speaker Diarization System for VoxCeleb Speaker Recognition Challenge (VoxSRC) 2023

This report describes the submission system by the GIST-AiTeR team for the VoxCeleb Speaker Recognition Challenge 2023 (VoxSRC-23) Track 4. Our submission system focuses on implementing diverse speaker diarization (SD) techniques, including ResNet293 and MFA-Conformer with different combinations of segment and hop length. Then, those models are combined into an ensemble model. The ResNet293 and MFA-Conformer models exhibited the diarization error rates (DERs) of 3.65% and 3.83% on VAL46, respectively. The submitted ensemble model provided a DER of 3.50% on VAL46, and consequently, it achieved a DER of 4.88% on the VoxSRC-23 test set.Comment: 2023 VoxSRC Track

Effects of 1-MCP on Quality and Storability of Cherry Tomato (Solanum lycopersicum L.)

Cherry tomato is a perishable fruit due to its high rate of ethylene production and respiration during ripening. 1-Methylcyclopropene (1-MCP) is known to control ripening and reduce decay of fruit by inhibiting ethylene action. In the present study, the influence of 1-MCP application on quality and storability of ‘Unicorn’ cherry tomato was observed. Fruit at pink and red maturity stages were put in the commercial plastic containers and sealed with 40 μm low density polyethylene (LDPE) film, treated with 1-MCP (0 µL L−1 (control), 0.035 µL L−1 and 0.1 µL L−1), and stored at 10 °C in 85 ± 5% relative humidity (RH). The results indicated that application of 1-MCP at 0.1 µL L−1 significantly affected firmness, cell wall thickness, water soluble pectin, weight loss, surface color, lycopene content and physiological parameters in both pink and red maturity stages compared to 0.035 µL L−1 and control. 1-MCP treatment at 0.1 µL L−1 kept the fruits firmer than 0.035 µL L−1 and the control throughout the storage period for both maturity stages. Cell wall degradation in the control treatment was higher compared to the 0.1 µL L−1 1-MCP treated fruits in both maturity stages throughout the storage period. Results of this study revealed the effectiveness of application of 0.1 µL L−1 1-MCP on quality and shelf life of cherry tomato

Torsional Vibration Transduction in a Solid Shaft by MPTs

In this study, we aim to investigate the feasibility to use MPTs (Magnetostrictive Patch Transducers) for torsional vibration measurement in solid ferromagnetic cylinders. MPTs consisting of thin magnetostrictive patches, permanent magnets and a solenoid coil have been widely used for elastic wave transduction in the ultrasound frequency range [1] but they have been seldom used for sonic-frequency range vibration measurement, in spite of their unique wireless transduction characteristics. While a MPT was used in Ref. [2] to perform torsional modal testing in a hollow cylinder or a pipe having relatively small torsional rigidity, no investigation has been reported yet on the use of MPTs in “solid” “ferromagnetic” shafts, common torsional power carrying elements in machines.While we will be mainly focused here on the torsional wave measurement in stationary shafts, the MPT-based torsional measurement can be also applied to rotating shafts. Because the torsional rigidities of solid shafts are much larger than those of hollow cylinders of the same radii, it is important to find optimal MPT configurations, such as the optimal number of rectangular patches to be installed around the surface of a solid shaft. Thereby, we performed numerical investigations and accordingly designed a series of experiments for torsional vibration testing in steel shafts. The actual modal testing experiments with the designed MPTs were found to predict the torsional Eigen-frequencies and Eigen-modes that agree well with the theoretical predictions. Also the relation between the measured vibration signals from MPTs and those from strain gages was checked experimentally and in fact, the experimental result favorably agreed with the theoretical prediction. Potential applications of the MPT-based torsional vibration measurement technique in rotating solid shafts for structural health monitoring are also briefly discussed