• Journal of Science Education
• /
• v.37 no.2
• /
• pp.294-309
• /
• 2013

This study addressed the awareness of social issues related to science of future elementary school teachers. Fukushima Nuclear Power Plant Accident was used by concrete issue connected with SSI for this study. Twelve second-year students attending a university of education participated in the study, who were taking a class of science teacher preparation at that time that consists of the content of the elementary science education courses. The study revealed that all the pre-service elementary teachers recognized Fukushima Nuclear Power Plant Accident and received such information through various medias. In particular, they were receiving more information about the Nuclear Power Plant Accident through the internet than any other media by using the internet a lot, and also gained additional information through the internet. However, despite the fact that they recognized Nuclear Power Plant Accident, they neither had much information about it nor had been interested in SSI such as the Nuclear Power Plant Accident. Moreover, they had been basically uneducated about SSI. Despite of having no interest in SSI such as Nuclear Power Plant Accident, the study revealed that the pre-service elementary teachers recognized that scientific problems such as Nuclear Power Plant Accident may affect a society closely. In addition, they together sympathized with the point that SSI education should be applied on the current education courses by identifying the problem in application. As the study revealed above, the application of SSI education to the formal education courses as well as more lively research on that subject is very important and urgent for boosting interest in science subjects and enlightening the nature of science that is one of the objectives of science education.

• Journal of Radiation Protection and Research
• /
• v.49 no.2
• /
• pp.65-67
• /
• 2024

This review is based on articles published in Japanese Journal of Health Physics on "Radiation-exposed medical care and waste" related to Tokyo Electric Power Company Incorporated (TEPCO)'s Fukushima Daiichi Nuclear Power Station accident. Here, we have considered three original articles; one technical data, one special article, one 50^th anniversary article, one preface, three topics, and two cases of From Japan to the World (J to W). These articles have reported the system and standards that were established after the accident. Moreover, they have summarized rare experiences such as the fumbling response at the time and the evaluation of samples in that disaster. These articles constitute valuable records of the situation.

• Journal of Radiation Industry
• /
• v.17 no.3
• /
• pp.283-292
• /
• 2023

Spent nuclear fuel corresponds to high-level radioactive waste that has high decay heat and radioactivity. Accordingly, Spent nuclear fuel withdrawn from the reactor core is primarily stored and managed in a spent nuclear fuel pool in the nuclear power plant to reduce decay heat and radioactivity. In Korea, most nuclear power plant store all spent nuclear fuel in a spent nuclear fuel pool. For wet storage, there are no defense in depth different with reactor core. The study related to spent nuclear fuel pool accident should be carried out to ensure safety. Therefore, it is necessary to analyze previous study cases related to safety of spent nuclear fuel pool and accident cases to build foundational knowledge. The Objective of this study is to analyze study cases of safety assessment and cases for spent nuclear fuel pool accident. For analyzing study cases of safety assessment, possible phenomena when spent nuclear fuel pool accident occurring identified, Subsequently, study cases for safety assessment about each phenomena were investigated, and materials & methods and results for each study are analyzed. For analyzing cases for spent nuclear fuel pool accident, we analyzed accident cases caused by loss of cooling and loss of coolant in spent nuclear fuel pool. Subsequently, causes and change of water level and temperature by each accident case are analyzed. As a result of the analysis on study cases of spent nuclear fuel pool accident, the results of the study conducted by each research institute were vary depending on the computer code, materials & methods of experiment and major assumptions used in the study. As a result of analyzing cases for spent nuclear fuel pool accident, it was found that accident cases for loss of cooling is more than cases for loss of coolant accident. Even though the types of accident in spent nuclear fuel pool were similar, the specific causes were different by each accident case. All the accident cases analyzed did not lead to severe accidents, such as nuclear fuel being exposed to the air. The result of this study will be used as fundamental data for study on spent nuclear fuel pool accident that will be conducted in the future.

• Journal of the Ergonomics Society of Korea
• /
• v.20 no.2
• /
• pp.1-28
• /
• 2001

This paper deals with the selection of the important Influencing Factors (IFs) under accident management situations in nuclear power plants for use in the assessment of human errors. In order to achieve this goal, we collected two types of IF taxonomies, one is the full set IF list mainly developed for human error analysis. and the other is the IFs for human reliability analysis (HRA) in probabilistic safety assessment (PSA). Five sets of IF taxonomy among the full set IF list and ten sets of IF taxonomy among HRA methodologies were collected in the study. From the review and analysis of BRA IFs, we could obtain some insights for the selection of HRA IFs. By considering the situational characteristics of the accident management domain, candidate IFs are chosen. Finally, those IFs are structured hierarchically to be appropriate for the use in the assessment of human error under accident management situation. Three nuclear accidents such as TMI. Chernobyl and JCO were analysed to validate the proposed taxonomy.

• Nuclear Engineering and Technology
• /
• v.53 no.9
• /
• pp.2859-2865
• /
• 2021

One of the important issues raised from the Fukushima-Daiichi accident is the safety of multi-unit sites when simultaneous accidents occur at the site and recently a multi-unit PSA methodology is being developed worldwide. Since all operation modes of the plant should be considered in the multi-unit PSA, the accident analysis needs to be performed for shutdown operation modes, too. In this study, a station blackout during the mid-loop operation is selected as a reference scenario. The overall accident progression for the mid-loop operation is slower than that for the full-power operation because the residual heat per mass of coolant is about 6 times lower than that in the mid-loop scenario. Though the fractions of Cs released from the core to the RCS in both operation modes are almost the same, the amount of Cs delivered to the containment atmosphere is quite different due to the chemisorption in the RCS. While 45.5% of the initial inventory is chemisorbed on the RCS surfaces during the full-power operation, only 2.2% during the mid-loop operation. The containment remains intact during the mid-loop operation, though 83.9% of Cs is delivered to the containment.

• Journal of Power System Engineering
• /
• v.22 no.6
• /
• pp.5-10
• /
• 2018

Nuclear energy issues such as safety and social acceptance can not only influence the production costs of generating nuclear power, but also the external costs that are not reflected in market prices. Consequently, the social issues affiliated with nuclear power, beyond a severe accident, require some form of financial expense. The external social issues considered here are accident risk and realization, regulatory costs, and nuclear energy policy costs. Through several calculations and analyses of these external costs for nuclear power generation, it is concluded that these costs range from 7 to 27 \/kWh. Considering external costs are required for making energy plans, it could have an influence on generation costs.

• Nuclear Engineering and Technology
• /
• v.45 no.5
• /
• pp.597-604
• /
• 2013

Containment Filtered Vent Systems (CFVSs) have been mainly equipped in nuclear power plants in Europe and Canada for the controlled depressurization of the containment atmosphere under severe accident conditions. This is to keep the containment integrity against overpressure during the course of a severe accident, in which the radioactive gas-steam mixture from the containment is discharged into a system designed to remove the radionuclides. In Korea, a CFVS was first introduced in the Wolsong unit-1 nuclear power plant as a mitigation measure to deal with the threat of over pressurization, following post-Fukushima action items. In this paper, the overall features of a CFVS installation such as risk assessments, an evaluation of the performance requirements, and a determination of the optimal operating strategies are analyzed for the Wolsong unit 1 nuclear power plant using a severe accident analysis computer code, ISAAC.

• STI Policy Review
• /
• v.4 no.1
• /
• pp.135-161
• /
• 2013

This paper examines Japan's Science and Technology (S&T) Basic Plans in accordance with its S&T Basic Law. The Basic Plans promote two major innovation (Green Innovation and Life Innovation) towards the creation of new markets and jobs, specifically under the Fourth S&T Basic Plan enacted on August 2011. Successful smart community demonstration projects at four urban localities were launched under plans to promote Green Innovation research and development of renewable energy technologies. However, the expectation that renewable energy such as solar or wind power can replace nuclear power is not backed by sufficient evidence. Furthermore, the electricity produced by these sources is expensive and unstable owing to its reliance on weather conditions. The Fukushima nuclear power plant accident on March 2011 has also seriously affected Japan's future energy plans. According to a government estimate, electricity charges would double if nuclear power generation were abandoned, imposing a heavy burden on the Japanese economy. Japan is in need of energy policies designed on the basis of more far-sighted initiatives.

• Journal of the Korean Society of Safety
• /
• v.35 no.4
• /
• pp.84-91
• /
• 2020

The Korean nuclear industry developed the SPACE (Safety and Performance Analysis Code for nuclear power plants) code and this code adpots two-phase flows, two-fluid, three-field models which are comprised of gas, continuous liquid and droplet fields and has a capability to simulate three-dimensional model. According to the revised law by the Nuclear Safety and Security Commission (NSSC) in Korea, the multiple failure accidents that must be considered for accident management plan of nuclear power plant was determined based on the lessons learned from the Fukushima accident. Generally, to improve the reliability of the calculation results of a safety analysis code, verification work for separate and integral effect experiments is required. In this reason, the goal of this work is to verify calculation capability of SPACE code for multiple failure accident. For this purpose, it was selected the experiment which was conducted to simulate a Multiple Steam Generator Tube Rupture(MSGTR) accident with Passive Auxiliary Feedwater System(PAFS) operation by Korea Atomic Energy Research Institute (KAERI) and focused that the comparison between the experiment results and code calculation results to verify the performance of the SPACE code. The MSGR accident has a unique feature of the penetration of the barrier between the Reactor Coolant System (RCS) and the secondary system resulting from multiple failure of steam generator U-tubes. The PAFS is one of the advanced safety features with passive cooling system to replace a conventional active auxiliary feedwater system. This system is passively capable of condensing steam generated in steam generator and feeding the condensed water to the steam generator by gravity. As the results of overall system transient response using SPACE code showed similar trends with the experimental results such as the system pressure, mass flow rate, and collapsed water level in component. In conclusion, it could be concluded that the SPACE code has sufficient capability to simulate a MSGTR accident.

• Nuclear Engineering and Technology
• /
• v.53 no.12
• /
• pp.3990-4002
• /
• 2021

CSPACE (Core meltdown, Safety and Performance Analysis CodE for nuclear power plants) for a simulation of severe accident progression in a Pressurized Water Reactor (PWR) is developed by coupling of verified system thermal hydraulic code of SPACE (Safety and Performance Analysis CodE for nuclear power plants) and core damage progression code of COMPASS (Core Meltdown Progression Accident Simulation Software). SPACE is responsible for the description of fluid state in nuclear system nodes, while COMPASS is responsible for the prediction of thermal and mechanical responses of core fuels and reactor vessel heat structures. New heat transfer models to each phase of the fluid, flow blockage, corium behavior in the lower head are added to COMPASS. Then, an interface module for the data transfer between two codes was developed to enable coupling. An implicit coupling scheme of wall heat transfer was applied to prevent fluid temperature oscillation. To validate the performance of newly developed code CSPACE, we analyzed typical severe accident scenarios for OPR1000 (Optimized Power Reactor 1000), which were initiated from large break loss of coolant accident, small break loss of coolant accident, and station black out accident. The results including thermal hydraulic behavior of RCS, core damage progression, hydrogen generation, corium behavior in the lower head, reactor vessel failure were reasonable and consistent. We demonstrate that CSPACE provides a good platform for the prediction of severe accident progression by detailed review of analysis results and a qualitative comparison with the results of previous MELCOR analysis.