• International Journal of Computer Science & Network Security
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• v.22 no.6
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• pp.109-114
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• 2022

The article is devoted to analyzing the police influence on road safety formation. The globalization processes confirm the study's relevance, provoking population mobility and the need to increase freight traffic. The study aims to identify the factors that affect road safety and the activities of the police and the EU transport safety units. An empirical analysis using factor analysis, correlation analysis, and general scientific methods of cognition were carried out to achieve the goal. The analysis results found that the number of police officers affects road safety, but not in all countries, which confirms the importance of other factors. Based on the analysis results of the scientific literature, the factors affecting transport safety are legislative regulation, the use of innovative technologies, transport infrastructure, geography, and psycho-physical and emotional drivers factors. It has been proved that the police authorities and units cannot fully ensure transport safety in the European Union because the safety is formed by a complex of actions by the state and road users.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.3879-3891
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• 2021

A heat pipe residual heat removal system is proposed to be incorporated into the reactor driven subcritical (RDS) facility, which has been proposed by MIT Nuclear Reactor Laboratory for testing and demonstrating the Fluoride-salt-cooled High-temperature Reactor (FHR). It aims to reduce the risk of the system operation after the shutdown of the facility. One of the main components of the system is an air-cooled heat pipe heat exchanger. The alkali-metal high-temperature heat pipe was designed to meet the operation temperature and residual heat removal requirement of the facility. The heat pipe model developed in the previous work was adopted to simulate the designed heat pipe and assess the heat transport capability. 3D numerical simulation of the subcritical facility active zone was performed by the commercial CFD software STAR CCM + to investigate the operation characteristics of this proposed system. The thermal resistance network of the heat pipe was built and incorporated into the CFD model. The nominal condition, partial loss of air flow accident and partial heat pipe failure accident were simulated and analyzed. The results show that the residual heat removal system can provide sufficient cooling of the subcritical facility with a remarkable safety margin. The heat pipe can work under the recommended operation temperature range and the heat flux is below all thermal limits. The facility peak temperature is also lower than the safety limits.

• Journal of the Korean Society of Safety
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• v.27 no.2
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• pp.127-133
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• 2012

This paper shows survey result on safety management status of laboratories in Korea. In Korea, many studies and reports on laboratory safety have been published since the ministry of education, science and technology (MEST) enforced the Act on Establishing a Safe Environment of Laboratories (Lab Safety Act) in 2006. The MEST has surveyed status of safety management in institutions subject to Lab Safety Act in 2008 and 2010. According to the survey result, safety management status of universities and colleges has been improved on several factors such as establishment of safety manual and implementation of safety inspection; while the number of safety managers of universities and colleges have increased. However, the difficulties in performing duties of safety managers has increased because the number of exclusive safety managers has decreased. This paper identifies the similarities and differences between Occupational Safety and Health Act and Lab Safety Act on assignment and duties of safety managers; therefore, this paper suggests a standard to determine the number of safety managers and decide whether or not their duties should be exclusive. Besides current standard that is based on the number of researchers, the number of individual laboratories should be considered. The new method would be helpful to determine the number of exclusive safety managers because the amount of safety managers' duties generally do not depend on only the number of people who may be exposed to any risk but also the number of facilities that may be cause of any accident.

• Nuclear Engineering and Technology
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• v.48 no.2
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• pp.419-433
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• 2016

One of the important severe accident management measures in the Light Water Reactors is water injection to the reactor core. The related phenomena are investigated by performing experiments and computer simulations. One of the most widely known is the QUENCH test-program. A number of analyses on QUENCH tests have also been performed by different computer codes for code validation and improvements. Unfortunately, any deterministic computer simulation is not free from the uncertainties. To receive the realistic calculation results, the best estimate computer codes should be used for the calculation with combination of uncertainty and sensitivity analysis of calculation results. In this article, the QUENCH-03 and QUENCH-06 experiments are modelled using ASTEC and RELAP/SCDAPSIM codes. For the uncertainty and sensitivity analysis, SUSA3.5 and SUNSET tools were used. The article demonstrates that applying the best estimate approach, it is possible to develop basic QUENCH input deck and to develop the two sets of input parameters, covering maximal and minimal ranges of uncertainties. These allow simulating different (but with the same nature) tests, receiving calculation results with the evaluated range of uncertainties.

• Journal of IKEEE
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• v.24 no.4
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• pp.1180-1183
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• 2020

Recently, the daily life safety detection functionalities such as fall accident detection and burn danger detection are widely disseminated along with the development of IoT and smart home. These safety detection functionalities are mostly performed by artificial intelligence. However, simple accuracy measurement of the safety detection in laboratory environment is often far from practical performance in daily life environment. To mitigate this problem, this paper introduces two techniques, i.e. living lab and confusion matrix. Living lab is more than simple simulation of daily life environment, and it enables users to directly participate technology development and product design. Various performance measures induced from confusion matrix significantly help to evaluate the performance of artificial intelligence system for proper application purposes.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1518-1527
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• 2023

A method was proposed for in-situ evaluating the thickness and resistivity of the oxide/hydroxide film formed on the surface of aluminum alloy exposed to sump water formed in the containment after a loss-of-coolant accident. The evaluation entailed fitting a model for the film impedance, which has film thickness and other variables describing the resistivity profile of the film along its thickness direction as fitting parameters, to the practically measured electrochemical impedance data. The obtained resistivity profiles implied that the films formed at pHs_25℃ 7, 8, 9, 10, and 11 all had a duplex structure; compared to the outer layer in contact with the solution, the inner layer of the film had a much higher resistivity and was inferred to be denser and provide most of the protectiveness of the film. Both the thickness and the total resistance of the film decreased with the increasing solution pH_25℃, suggesting that the films formed in more alkaline solutions had less protectiveness against corrosion, consistent with the increasing aluminum alloy corrosion rates previously identified.

• Nuclear Engineering and Technology
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• v.55 no.7
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• pp.2604-2612
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• 2023

Spent nuclear fuel and long-lived radioactive waste must be carefully handled before disposing them off to a geological repository. After the pre-storage period in water pools, spent nuclear fuel is stored in casks, which are widely used for interim storage. Interim storage in casks is very important part in the whole cycle of nuclear energy generation. This paper presents the results of the numerical study that was performed to evaluate the thermal behavior of a metal-concrete CONSTOR RBMK-1500 cask loaded with spent nuclear fuel and placed in an open type interim storage facility which is under fire conditions (steady-state, fire, post-fire). The modelling was performed using the ANSYS Fluent code. Also, a local sensitivity analysis of thermal parameters on temperature variation was performed. The analysis demonstrated that the maximum increase in the fuel load temperatures is about 10 ℃ and 8 ℃ for 30 min 800 ℃ and 60 min 600 ℃ fires respectively. Therefore, during the fire and the post-fire periods, the fuel load temperatures did not exceed the 300 ℃ limiting temperature set for an RBMK SNF cladding for long-term storage. This ensures that fire accident does not cause overheating of fuel rods in a cask.

• Nuclear Engineering and Technology
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• v.12 no.2
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• pp.88-98
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• 1980

The process of solidification of a single-phase flowing hot fluid in a cylindrical tube has been investigated analytically and experimentally. A series of tests were performed, using paraffin -wax and Wood's metal as flowing hot fluids. These data verified the existing quasistatic numerical analysis model of freezing process developed at Brookhaven National Laboratory In addition, experimental results provided information regarding the effects of various parameters on the .process of transient flowing and freezing through a vertical channel. The experimental apparatus and techniques are described. Comparison of experimental data with predictions of mathematical models for transient molten fluid displacement are presented in graphical form. In addition, the mathematical model is applied to LMFBR post-accident conditions.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.268-271
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• 2008

If a reactor vessel is failed to retain a molten corium in a postulated severe accident, the molten corium is released outside the reactor vessel into a reactor cavity. The molten corium would attack the concrete wall and basemat of the reactor cavity, which may lead to inevitable concrete decompositions and possible radiological releases. In the OECD/MCCI project, a series of tests were performed to secure the data for cooling the molten corium spread out at the reactor cavity and for the long-term CCI (Core Concrete Interaction). Also, a MCCI (Molten Core Concrete Interaction) analysis code, CORQUENCH was upgraded at Argonne National Laboratory with embedding the new models developed for the tests. This paper deals with analyses of MCCI at plant scale under the conditions of top flooding using the upgraded CORQUENCH code. The modeling approach is briefly summarized first, followed by presentation of a validation calculation that illustrates the predicative capability of the modeling tool. With this background in place, the model is then used to carry out a parametric set of scoping calculations that define approximate coolability envelopes for the LCS (Limestone Common Sand) concrete that has been evaluated in the OECD/MCCI project.

• Nuclear Engineering and Technology
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• v.45 no.3
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• pp.295-310
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• 2013

Industry- or regulatory-sponsored research activities on the resolution of Generic Safety Issue (GSI)-191 were reviewed, especially on the chemical effects. Potential chemical effects on the head loss across the debris-loaded sump strainer under a post-accident condition were experimentally evidenced by small-scale bench tests, integrated chemical effects test (ICET), and vertical loop head loss tests. Three main chemical precipitates were identified by WCAP-16530-NP: calcium phosphate, aluminum oxyhydroxide, and sodium aluminum silicate. The former two precipitates were also identified as major chemical precipitates by the ICETs. The assumption that all released calcium would form precipitates is reasonable. CalSil insulation needs to be minimized especially in a plant using trisodium phosphate buffer. The assumption that all released aluminum would form precipitates appears highly conservative because ICETs and other studies suggest substantial solubility of aluminum at high temperature and inhibition of aluminum corrosion by silicate or phosphate. The industry-proposed chemical surrogates are quite effective in increasing the head loss across the debris-loaded bed and more effective than the prototypical aluminum hydroxide precipitates generated by in-situ aluminum corrosion. There appears to be some unresolved potential issues related to GSI-191 chemical effects as identified in NUREG/CR-6988. The United States Nuclear Regulatory Commission, however, concluded that the implications of these issues are either not generically significant or are appropriately addressed, although several issues associated with downstream in-vessel effects remain.