• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.10
• /
• pp.991-1004
• /
• 2009

Operating experience of the various components in the nuclear power plants has shown that a variety of degradation mechanisms can occur during operation. Therefore, the accurate lifetime evaluation and systematic management are very important for the safe as well as the economical operation of the nuclear power plants. In this paper, the characteristics of a total of 17 degradation mechanisms were reviewed and the plausible degradation mechanisms such as stress corrosion cracking, fatigue, irradiation embrittlement, and so on, were identified. Also, the lifetime evaluation technologies which have been developed for the application to the domestic nuclear power plants are described. In addition, a total of 48 aging management programs which have been established for the safe operation of the various components are explained.

• Journal of the Ergonomics Society of Korea
• /
• v.25 no.4
• /
• pp.1-7
• /
• 2006

The purpose of this study is to develop an efficient algorithm for the management of the shift schedule in nuclear power plants in consideration with the ergonomic criteria and the regulatory codes. The ergonomic criteria considered are the work hours, overtime-work frequency and working time, start and finishing time of works, allocation of rest times and duty-offs, rotating of shifts, etc. to comply with the regulations such as the Labor Standard Act, the ILO Convention No. 171, 178, "the detailed content of a periodic safety review," enforcement regulations 19-2 of the Atomic Energy Act. The developed algorithm for the shift schedule program adopts a heuristic method to minimize the difference the workload for shift workers in nuclear power plants.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2003.11a
• /
• pp.305-309
• /
• 2003

In recent large power plants, the excitation system has the static type, which is characterized by the fast response to increase the transient stability. The high capacity excitation systems developed in KEPRI is either a hot back-up, hybrid hot back-up (analog + digital) or triple modular redundant digital type, both well proven by actual tests and applied in commercial operation. The large excitation systems have been developed taking into consideration the parameters of large scale power plants, resulting in high costs and subsequently are supplied at higher prices. When used at small sized power plants, the cost impact is relatively high. As a countermeasure to such a situation, KEPRI has recently developed a reliable, miniature digital excitation system, which is one-board type, convenient and adequate for low-price, small-sized (0.5MW∼200MW) power plants.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.3464-3466
• /
• 2007

Power uprate is the process of increasing the maximum power level at which a commercial nuclear power plant may operate. Power uprate applications(113 units) for NPPs(Nuclear Power Plants) were recently approved in the United States. Utilities have been using power uprates since the 1970s as a way of increasing the power output of their nuclear plants. To increase the power output of a reactor, typically more highly enriched uranium fuel and/or more fresh fuel is used. This enables the reactor to produce more thermal energy and therefore more steam, driving a turbine generator to produce electricity. In this paper, the propriety of power uprate is explained through the review on the power uprate method and the changes of the physical parameters due to power uprate. The analysis results showed that the CDF(Core Damage Frequency) and LERF(Large Early Release Frequency) are affected in the current probabilistic safety assessment (PSA) model.

• Fire Science and Engineering
• /
• v.30 no.3
• /
• pp.62-66
• /
• 2016

There have been happening small and big fires due to the various causes in the thermal power plants which are the high risk buildings with the high possibility of big sizes of accidents, so the people in the power plants distribute the workers "the site action manuals in thermal power plants" and try to minimize the rate of disasters like fires through the regular education and training. However, in the Five Thermal Power Plants in Korea, there are no the standard of "the site action manuals" and Furthermore, the present educational manuals are mostly the hard copies with poor readability. So the standardization of the manuals are definitely needed. Therefore, in this research, we proceed the standardization of the manuals for the five areas of the site action manual s in the thermal power plants which are oil fires, electric fires, building fires, facility fires and gas leaking reaction SOP to improve the reaction power on the disasters in the power plants which are the national significant infrastructures, thus by using the manual, we propose the safety education contents for the thermal power plants based on the visualization technology using story-viewing method to complement the hard copy type disaster manuals.

• Nuclear Engineering and Technology
• /
• v.56 no.2
• /
• pp.389-401
• /
• 2024

In recent decades, numerous instances of blockages have been reported in coastal nuclear power plants globally, leading to serious safety accidents such as power reduction, manual or automatic power loss, or shutdown of nuclear power units. Loss or shortage of cooling water may compromise the reliability of the cooling water system, thus threatening the operational safety of power plants and resulting in revenue reduction. This study provides a comprehensive review of the current state of cooling water system safety in coastal nuclear power plants worldwide and the common challenges they face, as well as the relevant research on cooling water system safety issues. The research overview and progress in investigation methods, outbreak mechanisms, prevention and control measures, and practical cases of blockages were summarized. Despite existing research, there are still many shortcomings regarding the pertinence, comprehensiveness and prospects of related research, and many problems urgently need to be solved. The most fundamental concern involves understanding the list of potential risks of blockages and their spatially distributed effects in surrounding waters. Furthermore, knowledge of the biological cycles and ecological habits of key organisms is essential for implementing risk prevention and control and for building a scientific and effective monitoring system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.5
• /
• pp.97-107
• /
• 2001

Many power plants in the thermal and hydraulic utilities, the pulp and the paper industry are faced with high maintenance and down time due to the aged excitation system. For the life extension of the aged power plants, the static excitation system of triple module redundancy type had been developed by KEPRI(Korea Electric Power Research Institute). This paper will discuss the design conception and the application results of system which includes the power control devices(thyristors, GTO), power potential transformer(excitation transformer) and triple module redundancy controller(voltage regulator).

• Journal of Electrical Engineering and Technology
• /
• v.13 no.6
• /
• pp.2561-2567
• /
• 2018

The extension of DC battery backup time in the DC power supply system of nuclear power plants (NPPs) remains a challenge. The lead-acid battery is the most popular at present. And it is generally the most popular energy storage device. However, extension of backup time requires too much space. The lithium-ion battery has high energy density and advanced gravimetric and volumetric properties. The aim of this paper is development of the sizing formula of stationary lithium-ion batteries. The ongoing research activities and related industrial standards for stationary lithium-ion batteries are reviewed. Then, the lithium-ion battery sizing calculation formular is proposed for the establishment of industrial design standard which is essential for the design of stationary batteries of nuclear power plants. An example of calculating the lithium-ion battery capacity for a medium voltage UPS is presented.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.10 no.1
• /
• pp.31-36
• /
• 2014

For decreasing an unexpected shutdown of Nuclear Power Plants, Korea Hydro & Nuclear Power co.(KHNP) has developed Single Point Vulnerability(SPV) of NPPs since 2008. SPV is the equipment that cause reactor shutdown & turbine trip or more than 50% power rundown due to its malfunction. New type Nuclear Power Plants need to develop the SPV list, so performed the SPV selection for about 1 year. To develop this, Failure Mode Effect Analysis(FMEA) methods are used. As results of FMEA analysis, about 700 equipment are selected as SPV. Thereafter those are going to be applied to new type Nuclear Power Plants to enhance equipment reliability.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.61 no.4
• /
• pp.509-512
• /
• 2012

For decreasing an unexpected shutdown of Nuclear Power Plants, Korea Hydro & Nuclear Power co.(KHNP) has developed Single Point Vulnerability(SPV) of NPPs since 2008. SPV is the equipment that cause reactor shutdown & turbine trip or more than 50% power rundown due to its malfunction. Newly built Nuclear Power Plants need to develop the SPV list, so performed the job which analyse equipment failure effect for SPV selection for 1 year. To develop this, Failure Mode Effect Analysis(FMEA) and Fault Tree Analysis(FTA) methods are used. As results of this analysis, about 900 equipment are selected as SPV. Thereafter those are going to be applied to Nuclear Power Plants to enhance equipment reliability.