Showing papers in "Journal of Nuclear Science and Technology in 2021"
TL;DR: Silicone rubber (SiR) is an important electrical insulating material for safety-related cables in nuclear power plants as mentioned in this paper, and it must withstand the irradiation of gamma rays and the expo...
Abstract: Silicone rubber (SiR) is an important electrical insulating material for safety-related cables in nuclear power plants. This means that SiR must withstand the irradiation of gamma rays and the expo...
24 citations
TL;DR: In this article, a deuteron nuclear data library is proposed to contribute to the design study of fast fast neutron sources using deuterons accelerators for various applications, such as nuclear power and nuclear power.
Abstract: Intensive fast neutron sources using deuteron accelerators have been proposed for various applications. To contribute to the design study of such neutron sources, a deuteron nuclear data library fo...
17 citations
TL;DR: Following the NPP accident, several hundred tons of heat-generating corium and fuel debris have been cooled permanently by millions of m3 of flowing water as mentioned in this paper, and knowledge on the interaction with water is cruc...
Abstract: Following the NPP accident, several hundred tons of heat-generating corium and fuel debris have been cooled permanently by millions of m3 of flowing. Knowledge on the interaction with water is cruc...
16 citations
14 citations
TL;DR: In this paper, the independent and cumulative fission product yields and their covariance matrices were evaluated for thermal and fast-neutron induced fission and spontaneous fission.
Abstract: The independent and cumulative fission product yields (FPYs) and their covariance matrices were newly evaluated for thermal- and fast-neutron induced fission and spontaneous fission. We principally...
12 citations
TL;DR: In this article, the production and dispersion of contaminated aerosols during the laser cutting of corium can potentially provide useful insights into the dispersion during the evacuation of damag...
Abstract: The production and dispersion of contaminated aerosols during the laser cutting of corium can potentially provide useful insights into the dispersion of contamination during the evacuation of damag...
10 citations
TL;DR: In this paper, the impact of disposal of mixed oxide (MOX) fuel from light water reactors (LWRs) has been considered from the viewpoint of the thermal properties and the number of the vitrified waste for various...
Abstract: The impact of disposal of mixed oxide (MOX) fuel from light water reactors (LWRs) has been considered from the viewpoint of the thermal properties and the number of the vitrified waste for various ...
9 citations
TL;DR: In this article, the multi-group cross-section generation capability for neutrons is implemented in the FRENDY nuclear data processing code and ACE-formatted files are used as the source of nuclear data instead of end-to-end data.
Abstract: The multi-group cross-section generation capability for neutrons is implemented in the FRENDY nuclear data processing code. ACE-formatted files are used as the source of nuclear data instead of END...
9 citations
TL;DR: In this article, the authors predict 3D magnetohydrodynamic (MHD) pressure losses associated with liquid metal flows in complex geometry ducts is required to design breeding blankets for fusion reactors.
Abstract: Predicting 3D magnetohydrodynamic (MHD) pressure losses associated with liquid metal flows in complex geometry ducts is required to design breeding blankets for fusion reactors. Of such components,...
9 citations
TL;DR: In 2019, TEPCO and TOSHIBA designed a robot that can handle the debris, performed a trial investigation of primary containment vessel (PCV) of the Fukushima Dai-Ichi (1F) Unit 2 and publis...
Abstract: In February 2019, TEPCO and TOSHIBA designed a robot that can handle the debris, performed a trial investigation of primary containment vessel (PCV) of the Fukushima Dai-Ichi (1F) Unit 2 and publis...
9 citations
TL;DR: In this article, a novel amine functionalized magnetic large-pore SBA-15 obtained via in situ approach and the post-grafting method was employed as a new adsorbent for removal of uranium from aqueous solutions.
Abstract: A novel amine-functionalized magnetic large-pore SBA-15 obtained via in situ approach and the post-grafting method was employed as a new adsorbent for removal of uranium from aqueous solutions. Res...
TL;DR: A deep transfer learning method based on fully categorized alignment subdomain adaptation (FCA-SAN) that reaches the highest fault diagnosis accuracy in different transfer tasks, which demonstrates the potential application value in rotating machinery of NPPs.
Abstract: ABSTRACT Bearings are widely applied in rotating machinery of nuclear power plants (NPPs). Data-driven fault diagnosis technology is critical to ensuring the reliable operation of rotating machinery. Aiming at the problem of poor model generalization ability caused by discrepant data distribution of monitoring signals under various working conditions, a deep transfer learning method based on fully categorized alignment subdomain adaptation (FCA-SAN) is proposed in this paper. Firstly, the bearing vibration signals of the source and target operating conditions are preprocessed and converted into time-frequency domain images suitable for model input. Subsequently, a pre-trained deep convolutional neural network (DCNN) model is adopted as the feature extractor, which is combined with FCA-SAN to extract transferable features across different working conditions. The subdomain adaptation method reduces the data distribution discrepancy more fine-grained by aligning the feature distribution of different working conditions, thereby effectively improving the model generalization ability. Finally, the experimental results show that, compared with the traditional method, the proposed subdomain adaptation method reaches the highest fault diagnosis accuracy in different transfer tasks, which demonstrates the potential application value in rotating machinery of NPPs.
TL;DR: In this article, a β counting-based analysis of the Strontium-90 fission product is presented. But, the analysis is limited to a single fission unit.
Abstract: Strontium-90 is one of the most important fission products due to the potential health risks of its uptake and retention in the human body. Conventional analysis techniques involve β counting, whic...
TL;DR: In this paper, the authors developed a LOcal-scale high-resolution atmospheric DIspersion model using Large-Eddy Simulation (LOHDIM-LES) for the safety assessment of nuclear facilities and emergency responses to accident.
Abstract: We developed a LOcal-scale High-resolution atmospheric DIspersion Model using Large-Eddy Simulation (LOHDIM-LES) for the safety assessment of nuclear facilities and emergency responses to accidenta...
TL;DR: In this paper, a new measurement system was developed for continuous measurement of radon-in-soil concentration in-situ, and field measurement of vertical profile with 7 radon probes at different depths was performed.
Abstract: ABSTRACT Radon in soil is a valuable radioactive tracer in earth science, especially for earthquake and volcanic precursors. For the purpose of continuous measurement of radon-in-soil concentration in-situ, a new-designed measurement system was developed. Calibration and experiments for humidity response correction were carried out in details, and field measurement of vertical profile with 7 radon probes at different depths was performed. Calibration results show that the sensitivity of the radon probes is 16.1 ± 1.0 cph (kBq m−3)−1, and the lower level detection limit is 231 ± 15 Bq m−3 for 1-hour measurement cycle under the absolute humidity of 32.8 g m−3. Field measurement results show that radon concentrations at different depths change with time and increase with depth in the soil. The vertical profile presents a negative exponential distribution with different diffusion length in sunny days, while rainfall can disturb the vertical distribution and lead to increase of radon concentration in the near ground surface. Radon concentration in underground deeper than 80 cm appears quite stable and hardly affected by rainfall in our observation.
TL;DR: In this paper, energy-dependent calculations of independent and cumulative fission product yields for the first chance fission region were performed for three types of fission products: 235U, 238U, and 239Pu.
Abstract: We perform energy-dependent calculations of independent and cumulative fission product yields for 235U, 238U, and 239Pu in the first chance fission region. Starting with the primary fission frag...
TL;DR: To investigate the leaching behavior of radioactive nuclides in leaching samples comparable to core debris (partially molten ZrO2/UO2 between fuel rods) in the Fukushima Daiichi Nuclear Power Stati...
Abstract: To investigate the leaching behavior of radioactive nuclides in leaching samples comparable to core debris (partially molten ZrO2/UO2 between fuel rods) in the Fukushima Daiichi Nuclear Power Stati...
TL;DR: In this article, Monte Carlo, Latin hypercube, grid-point, and quasi-Monte Carlo sampling methods were applied to the dynamic probabilistic risk assessment (PRA) of a station blackout sequence in a boiling water reactor and compared each method.
Abstract: ABSTRACT Dynamic probabilistic risk assessment (PRA), which handles epistemic and aleatory uncertainties by coupling the thermal-hydraulics simulation and probabilistic sampling, enables a more realistic and detailed analysis than conventional PRA. However, enormous calculation costs are incurred by these improvements. One solution is to select an appropriate sampling method. In this paper, we applied the Monte Carlo, Latin hypercube, grid-point, and quasi-Monte Carlo sampling methods to the dynamic PRA of a station blackout sequence in a boiling water reactor and compared each method. The result indicated that quasi-Monte Carlo sampling method handles the uncertainties most effectively in the assumed scenario.
TL;DR: In this article, the completeness of nuclear decommissioning is investigated and an important step in safely utilizing nuclear power is discussed. But, the decommission of nuclear power plants is a complex process.
Abstract: Determining the completeness of nuclear reactor decommissioning is an important step in safely utilizing nuclear power. For example, 137Cs from the Fukushima Daiichi Nuclear Power Station (FDNPS) a...
TL;DR: In this article, the vapor formation within the reactor pressure vessel (RPV) was regarded as heat removal from core materials to the coolant, while the hydrogen generation within the RPV was regarded to re...
Abstract: The vapor formation within the reactor pressure vessel (RPV) is regarded to represent heat removal from core materials to the coolant, while the hydrogen generation within the RPV is regarded to re...
TL;DR: In this article, the authors developed a desor... to remediate the contaminated soil, which was developed as a result of the Fukushima nuclear power plant accident in March 2011, massive amounts of soil were contaminated with radioactive Cs.
Abstract: As a result of the Fukushima nuclear power plant accident in March 2011, massive amounts of soil were contaminated with radioactive Cs. To remediate the contaminated soil, we are developing a desor...
TL;DR: The dynamics of radionuclides in terrestrial environments is a crucial consideration for environmental remediation and radiation protection after a severe nuclear disaster as mentioned in this paper, although the dynamics of Radionuclidea are not well understood.
Abstract: The dynamics of radionuclides in terrestrial environments is a crucial consideration for environmental remediation and radiation protection after a severe nuclear disaster. Although the dynamics of...
TL;DR: In this study, a Bayesian network (BN) is used as a guide for human reliability analysis for severe accidents in nuclear power plants.
Abstract: Human reliability analysis (HRA) for severe accidents is an important component of a Level 2 probabilistic risk assessment (PRA) for nuclear power plants. In this study, a Bayesian network (BN) is ...
TL;DR: In this article, an efficient reduced order model for time-dependent diffusion calculations using the proper orthogonal decomposition (POD) is proposed, employing the singular value decomposition and LoSVD.
Abstract: An efficient reduced order model (ROM) for time-dependent diffusion calculations using the proper orthogonal decomposition (POD) is proposed. Employing the singular value decomposition (SVD) and lo...
TL;DR: In this article, it is shown how the two types of uranyl peroxides, studtite and metastudtite, are formed on nuclear fuel in water through the reaction with H2O2 produced by the radiolysis of water.
Abstract: Studtite and metastudtite are uranyl peroxides formed on nuclear fuel in water through the reaction with H2O2 produced by the radiolysis of water. However, it is unclear how the two types of uranyl...
TL;DR: The accident at the Fukushima Daiichi Nuclear Power Plant in 2011 released many radioactive elements into the environment, contaminating a large amount of soil as mentioned in this paper, and currently, 14 million m3 of contamin...
Abstract: The accident at the Fukushima Daiichi Nuclear Power Plant in 2011 released many radioactive elements into the environment, contaminating a large amount of soil. Currently, 14 million m3 of contamin...
TL;DR: The neutron capture cross section of 243Am was measured by the time-of-flight method with a pulsed neutron beam from a spallation neutron source of the Japan Proton Accelerator Research Complex as mentioned in this paper.
Abstract: The neutron capture cross section of 243Am was measured by the time-of-flight method with a pulsed neutron beam from a spallation neutron source of the Japan Proton Accelerator Research Complex. An...
TL;DR: A Bayesian-estimation-based seismic fragility assessment method that can significantly reduce the computational burden was presented and the results revealed that the fragility curves determined with 12 repetitions of the simulations were comparable to those using a detailed method developed by the Atomic Energy Society of Japan with 500 repeated simulations.
Abstract: This paper presents a Bayesian-estimation-based seismic fragility assessment method that can significantly reduce the computational burden. The likelihood function and prior distribution used in th...
TL;DR: In this article, the properties of a compact fiber-optic laser-induced breakdown spectroscopy (LIBS) system with a monolithic Nd:YAG/Cr: YAG composite ceramics were investigated.
Abstract: Radiation dose rate effects on the properties of a compact fiber-optic laser-induced breakdown spectroscopy (LIBS) system with a monolithic Nd:YAG/Cr:YAG composite ceramics were investigated for re...