• 제목/요약/키워드: safety net

검색결과 1,566건 처리시간 0.026초

REVIEW AND FUTURE ISSUES ON SPENT NUCLEAR FUEL STORAGE

  • Saegusa, T.;Shirai, K.;Arai, T.;Tani, J.;Takeda, H.;Wataru, M.;Sasahara, A.;Winston, P.L.
    • Nuclear Engineering and Technology
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    • 제42권3호
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    • pp.237-248
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    • 2010
  • The safety of metal cask and concrete cask storage technology has been verified by CRIEPI through several research programs on demonstrative testing for the interim storage of spent fuel. The results have been reflected in the safety requirements for dry casks issued by NISA/METI (Nuclear and Industrial Safety Agency, Ministry of Economy, Trade and Industry) of the Japanese government. On top of that, spent fuel integrity has been studied by the Japan Nuclear Energy Safety Organization (JNES). This paper reviews these research programs. Future issues include the long-term integrity of cask components and high burn-up spent fuel.

원전 배관의 파손확률평가를 위한 P-PIE 프로그램의 개발 (Development of P-PIE Program for Evaluating Failure Probability of Pipes in Nuclear Power Plants)

  • 박재학;이재봉;최영환
    • 한국안전학회지
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    • 제25권6호
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    • pp.1-8
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    • 2010
  • P-PIE program is developed for evaluating failure probability of pipes in nuclear power plants based on the existing PRAISE program. In the program, crack growth due to fatigue loading and stress corrosion can be considered and the probability of fracture or leakage of pipes can be calculated. Crack growth simulation is performed based on stress intensity factor and a damage parameter and failure of a pipe is determined based on J integral or net section yielding. Using the developed program the failure probabilities of tubes in a domestic nuclear power is obtained and discussed.

CURRENT ISSUES ON PRA REGARDING SEISMIC AND TSUNAMI EVENTS AT MULTI UNITS AND SITES BASED ON LESSONS LEARNED FROM TOHOKU EARTHQUAKE/TSUNAMI

  • Ebisawa, Katsumi;Fujita, Masatoshi;Iwabuchi, Yoko;Sugino, Hideharu
    • Nuclear Engineering and Technology
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    • 제44권5호
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    • pp.437-452
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    • 2012
  • The Tohoku earthquake (Mw9.0) occurred on March 11, 2011 and caused a large tsunami. The Fukushima Dai-ichi NPP (F1-NPP) were overwhelmed by the tsunami and core damage occurred. This paper describes the overview of F1-NPP accident and the usability of tsunami PRA at Tohoku earthquake. The paper makes reference to the following current issues: influence on seismic hazard of gigantic aftershocks and triggered earthquakes, concepts for evaluating core damage frequency considering common cause failure with correlation coefficient against seismic event at multi units and sites, and concepts of "seismic-tsunami PSA" considering a combination of seismic motion and tsunami effects.

대체 보조전극을 이용한 접지저항 측정값 비교 (Comparison of Ground Resistance Measurement Value by the Substitute Auxiliary Electrode)

  • 이상익;유재근;전정채;전현재
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 춘계학술대회 논문집 전기설비전문위원
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    • pp.85-87
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    • 2007
  • This paper summarize about the auxiliary electrode measured a ground resistance The method to measure a ground resistance is the fall-of-potential method to using an auxiliary electrode. And an auxiliary electrode must be set up on the ground. Today it is so difficult to set up the auxiliary electrode on the ground because of many concrete building and many paved roads. So this paper is regarding of the ground resistance measurement by the substitute auxiliary electrode. It substituted a iron structure around the building, a wire net for auxiliary electrode. This information is confirmed by compared with the measurement value.

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Zigbee를 이용한 Wireless Home Safety Supervisor System 구현에 관한 연구 (The study on implementing Wireless Home Safety Supervisor System of using Zigbee)

  • 김국전;김영길
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2004년도 춘계종합학술대회
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    • pp.575-578
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    • 2004
  • 현재 및 미래에는 무선통신의 효용성이 증가되면서 다양한 분야에서 유선과 무선을 통합한 형태의 연결망이 구축되고 있으며, 이에 따라 저속, 저가, 저전력의 무선통신 분야의 필요성이 제기되고 있다. 본 논문에서는 저속, 저가, 저전력의 무선통신 분야인 Zigbee(IEEE 802.15.4)의 표준안과 이를 기반으로 한 Wireless Home Safety Supervisor System에 대해서 제안 고찰하였다.

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DYNAMIC CHARACTERISTICS OF A PARTIALLY FLUIDFILLED CYLINDRICAL SHELL

  • Jhung, Myung-Jo;Yu, Seon-Oh;Lim, Yeong-Taek
    • Nuclear Engineering and Technology
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    • 제43권2호
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    • pp.167-174
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    • 2011
  • A pressurizer in a small integral type pressurized water reactor is located inside the upper region of the reactor vessel, and uses a space between the upper head of the reactor vessel and the upper region of the upper guide structure which is partially filled with fluid depending on the operating power. This new design requires a comprehensive investigation of vibration characteristics. This study investigates the modal characteristics of a pressurizer which uses a simplified cylindrical shell model, focusing on how having fluid in the shell affects vibration and response characteristics. In addition, an analysis of sloshing is performed and the response characteristics are addressed.

TECHNICAL EVALUATION OF THE CONTINUED OPERATION OF NPP

  • Kim, Tae-Ryong;Jin, Tae-Eun
    • Nuclear Engineering and Technology
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    • 제40권4호
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    • pp.277-284
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    • 2008
  • Recently, the long-term operation of a nuclear power plant beyond its licensed term has become a worldwide trend as long as the safety of the plant is maintained in the extended period. Kori Unit 1, the oldest PWR in Korea, is the foremost example of this type of long-term operation in Korea. Comprehensive technical evaluation of the long-term operation of this plant was completed to confirm the overall safety of the plant. The technical evaluation included a review of PSR results, an assessment on aging management programs and time limited aging analyses, and a statement of radiological impact on the environment. Based on all of the results of the technical evaluation activities, Kori Unit 1 was approved to operate for an additional 10 years beyond its original design life of 30 years.

A DEVELOPMENT FRAMEWORK FOR SOFTWARE SECURITY IN NUCLEAR SAFETY SYSTEMS: INTEGRATING SECURE DEVELOPMENT AND SYSTEM SECURITY ACTIVITIES

  • Park, Jaekwan;Suh, Yongsuk
    • Nuclear Engineering and Technology
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    • 제46권1호
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    • pp.47-54
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    • 2014
  • The protection of nuclear safety software is essential in that a failure can result in significant economic loss and physical damage to the public. However, software security has often been ignored in nuclear safety software development. To enforce security considerations, nuclear regulator commission recently issued and revised the security regulations for nuclear computer-based systems. It is a great challenge for nuclear developers to comply with the security requirements. However, there is still no clear software development process regarding security activities. This paper proposes an integrated development process suitable for the secure development requirements and system security requirements described by various regulatory bodies. It provides a three-stage framework with eight security activities as the software development process. Detailed descriptions are useful for software developers and licensees to understand the regulatory requirements and to establish a detailed activity plan for software design and engineering.

Fluid effect on the modal characteristics of a square tank

  • Jhung, Myung Jo;Kang, Sung-Sik
    • Nuclear Engineering and Technology
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    • 제51권4호
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    • pp.1117-1131
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    • 2019
  • Tanks are used extensively in many engineering areas for spent fuel pool structures at nuclear power plants or for water storage tanks in bulk carriers. To ensure the structural integrity of such tanks when under dynamic loads, modal characteristics such as natural frequencies, participation factors and mode shapes should be known. Investigated in this study are the modal characteristics of a square tank by the finite element method. This approach can be used with subsequent dynamic analyses such as a response spectrum analysis or a harmonic analysis. Finite element models are prepared to determine the natural frequencies and mode shapes, which are easy to find the modal characteristics of a fluid-filled square tank. The effects of the fluid contained in the tank and the boundary conditions at top and bottom ends on the modal characteristics are assessed by several finite element analyses.

Two-fluid equations for two-phase flows in moving systems

  • Kim, Byoung Jae;Kim, Myung Ho;Lee, Seung Wook;Kim, Kyung Doo
    • Nuclear Engineering and Technology
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    • 제51권6호
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    • pp.1504-1513
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    • 2019
  • Recently, ocean nuclear reactors have received attention due to enhanced safety features. The movable and transportable characteristics distinguish ocean nuclear reactors from land-based nuclear reactors. Therefore, for safety/design analysis of the ocean reactor, the thermos-hydraulics must be investigated in the moving system. However, there are no studies reporting the general two-fluid equations that can be used for multi-dimensional simulations of two-phase flows in moving systems. This study is to systematically formulate the multi-dimensional two-fluid equations in the non-inertial frame of reference. To demonstrate the applicability of the formulated equations, we perform a total of six different simulations in 2D tanks with translational and/or rotational motions.