• Title/Summary/Keyword: Nuclear power plant concrete

Search Result 188, Processing Time 0.033 seconds

Performance Evaluation of Welding Method for Modular of High-Strength Reinforcing Bars to the Nuclear Power Plant Structures (원전구조물 고강도철근 모듈화를 위한 용접방법 성능평가)

  • Lim, Sang-Joon;Lee, Han-Woo;Kim, Hyeong-Seob;Bang, Chang-Joon
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2013.05a
    • /
    • pp.278-280
    • /
    • 2013
  • To minimize construction quantity of nuclear facility, it is required to reduce reinforcing bar amount and solve reinforcing bar concentration and for this, it is necessary to develop application design technology and modular of high strength reinforcing bar. Hence, KHNP reduces excessive reinforcing bar amount which can cause possibility of poor construction of concrete through design standard development and modular of nuclear facility structure using high strength reinforcing bar to raise economics and has its purpose to maintain high-level safety and durability as they are.

  • PDF

Seismic performance evaluation of reactor containment building considering effects of concrete material models and prestressing forces

  • Bidhek Thusa;Duy-Duan Nguyen;Md Samdani Azad;Tae-Hyung Lee
    • Nuclear Engineering and Technology
    • /
    • v.55 no.5
    • /
    • pp.1567-1576
    • /
    • 2023
  • The reactor containment building (RCB) in nuclear power plants (NPPs) plays an important role in protecting the reactor systems from external loads as well as preventing radioactive leaking. As we witnessed the nuclear disaster at Fukushima Daiichi (Japan) in 2011, the earthquake is one of the major threats to NPPs. The purpose of this study is to evaluate effects of concrete material models and presstressing forces on the seismic performance evaluation of RCB in NPPs. A typical RCB designed in Korea is employed for a case study. Detailed three-dimensional nonlinear finite element models of RCB are developed in ANSYS. A series of pushover analyses are then performed to obtain the pushover curves of RCB. Different capacity curves are compared to recognize the influence of different material models on the nonlinear behavior of RCB. Additionally, the effects of prestressing forces on the seismic performances of the structure are also investigated. Moreover, a set of damage states corresponding to damage evolutions of the structures is proposed in this study.

Durability Properties of High Volume Blast Furnace Slag Concrete for Application in Nuclear Power Plants (고로슬래그 다량치환 콘크리트의 원전 콘크리트 적용을 위한 내구성능 평가)

  • Seo, Eun-A;Lee, Jang-Hwa;Lee, Ho-Jea;Kim, Do-Gyeum
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.5 no.1
    • /
    • pp.45-52
    • /
    • 2017
  • This study evaluated the durability of nuclear power plant concrete. The main parameters were the water-to-binder ratio and admixture type. The results revealed that high-volume ground granulated blast-furnace slag(GGBS) concrete had lower initial strength, while the strength reached higher after 28 days. On the other hand, the initial strength of fly ash blended concrete was high, but the long-term strength of the robbery was low. The measured durability of GGBS blended concrete was found to be better than that of the existing concrete mix for use in the construction of nuclear power plants. Especially, the GGBS blended concrete was more durable than the fly ash blended concrete in terms of chloride attack, carbonation resistivity and freezing-thawing durability in low compressive strength. The effects of concrete compressive strength according to gamma rays were minor.

Development of Aging Management System for the Concrete Structure (원전 콘크리트 구조물의 열화관리시스템 개발)

  • 조명석;방기성;송영철
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1996.10a
    • /
    • pp.546-550
    • /
    • 1996
  • The personal-computer software program named SAMS(Structural Aging Management System) was developed for the concrete structure of NPP(Nuclear Power Plant). SAMS is constituted of three part, detabase system containing various inspection data, operation program for standard input/output of the inspection data, and application program for efficient operation of database system. Using the SAMS, the field engineers can easily acquire the information about the various inspection data, repair and accidental histories of NPP structures. SAMS will contribute to the effcient maintenance of NPP structures.

  • PDF

Ubiquitous Radioactivity Care System (유비쿼터스 방사성 CARE 시스템에 관한 보고서)

  • Jung, Chang-Duk;Park, Chan-Hyuk;Hwang, Sun-Il
    • 한국IT서비스학회:학술대회논문집
    • /
    • 2009.05a
    • /
    • pp.409-414
    • /
    • 2009
  • I have not seen each of the existing technology, RFID/USN technology combined with the wireless communication channel for the state of nuclear safety in real-time remote monitoring and operation system technology CARE existing radioactive accident information collected by the nuclear power and nuclear power status, 10-20 second intervals to monitor the safety network (SIDS), and nuclear power plants located on the site within 40 ㎞ radius around the 13~15 of the wind speed from the automatic weather network weather information such as rainfall and temperature every 10 minutes to collect as automatic weather network (REMDAS), Evaluation of atmospheric radiation and radiation of the bomb radiation impact assessment system to calculate the goodness (FADAS) and thicken the radiation-related information consists of real-time web technology to collect, the last robot on behalf of the human will to manage the nuclear power plant accident of the technology to prevent the concrete from the following narrative about to have.

  • PDF

A study on the Reliability Analysis of Nuclear Steel Containment Structures Subject to Internal Pressure (내압을 받는 원전 강재격납건물의 신뢰성 해석)

  • 오병환;최성철
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1999.04a
    • /
    • pp.229-232
    • /
    • 1999
  • Nuclear power plant structures may be exposed to aggressive environmental effects that may cause their damage mechanisms are reasonably well understood and quantitative evaluation of their effects on time-dependent structural behavior is possible in some instances, such evaluations are generally very difficult and remain novel. The assessment of existing steel containment in nuclear power plants for continued service must provide quantitative evidence that they are able to withstand future extreme loads during a service period with an acceptable level of reliability. Rational methodologies to perform the reliability assessment can be developed from mechanistic models of structural deterioration, using time-dependent structural reliability analysis to take loading and strength uncertainties into account. The final goal of this study is to develop the analysis method for the analysis for the reliability of containment structures. The cause and mechanism of corrosion is first clarified and the reliability assessment method has been established. By introducing the equivalent normal distribution, the procedure of reliability analysis which can determine the failure probabilities has been established.

  • PDF

Study of concrete de-bonding assessment technique for containment liner plates in nuclear power plants using ultrasonic guided wave approach

  • Lee, Yonghee;Yun, Hyunmin;Cho, Younho
    • Nuclear Engineering and Technology
    • /
    • v.54 no.4
    • /
    • pp.1221-1229
    • /
    • 2022
  • In this work, the guided wave de-bonding area-detecting technique was studied for application to containment liner plates in nuclear power plant areas. To apply this technique, an appropriate Lamb wave mode, symmetric and longitudinal dominance, was verified by the frequency shifting technique. The S0 2.7 MHz mm Lamb wave mode was chosen to realize quantitative experimental results and their visualization. Results of the bulk wave, longitudinal wave mode, and comparison experiments indicate that the wave mode was able to distinguish between the de-bonded and bonded areas. Similar to the bulk wave cases, the bonded region could be distinguished from the de-bonded region using the Lamb wave approach. The Lamb wave technique results showed significant correlation to the de-bonding area. As the de-bonding area increased, the Lamb wave energy attenuation effect decreased, which was a prominent factor in the realization of quantitative tomographic visualization. The feasibility of tomographic visualization was studied via the application of Lamb waves. The reconstruction algorithm for the probabilistic inspection of damage (RAPID) technique was applied to the containment liner plate to verify and visualize the de-bonding condition. The results obtained using the tomography image indicated that the Lamb wave-based RAPID algorithm was capable of delineating debonding areas.

IDENTIFICATION AND ASSESSMENT OF AGING-RELATED DEGRADATION OCCURRENCES IN NUCLEAR POWER PLANTS

  • Choi, In-Kil;Choun, Young-Sun;Kim, Min-Kyu;Nie, Jinsuo;Braverman, Joseph I.;Hofmayer, Charles H.
    • Nuclear Engineering and Technology
    • /
    • v.44 no.3
    • /
    • pp.297-310
    • /
    • 2012
  • Aging-related degradation of nuclear power plant components is an important aspect to consider in securing the long term safety of the plant, especially the seismic safety, since the degradation of the components affects not only their seismic capacity but their response. This can cause a change in the seismic margin of a component and the overall seismic safety of a system. To better understand the status and characteristics of degradation of components in Nuclear Power Plants (NPPs), the degradation occurrences of components in the U.S. NPPs were identified by reviewing recent publicly available information sources and the characteristics of these occurrences were evaluated and compared to observations from the past. Ten categories of components that are of high risk significance in Korean NPPs were identified, comprising anchorage, concrete, containment, exchanger, filter, piping systems, reactor pressure vessels, structural steel, tanks, and vessels. Software tools were developed to expedite the review process. Results from this review effort were compared to previous data in the literature to characterize the overall degradation trends.

Structural safety reliability of concrete buildings of HTR-PM in accidental double-ended break of hot gas ducts

  • Guo, Quanquan;Wang, Shaoxu;Chen, Shenggang;Sun, Yunlong
    • Nuclear Engineering and Technology
    • /
    • v.52 no.5
    • /
    • pp.1051-1065
    • /
    • 2020
  • Safety analysis of nuclear power plant (NPP) especially in accident conditions is a basic and necessary issue for applications and commercialization of reactors. Many previous researches and development works have been conducted. However, most achievements focused on the safety reliability of primary pressure system vessels. Few literatures studied the structural safety of huge concrete structures surrounding primary pressure system, especially for the fourth generation NPP which allows existing of through cracks. In this paper, structural safety reliability of concrete structures of HTR-PM in accidental double-ended break of hot gas ducts was studied by Exceedance Probability Method. It was calculated by Monte Carlo approaches applying numerical simulations by Abaqus. Damage parameters were proposed and used to define the property of concrete, which can perfectly describe the crack state of concrete structures. Calculation results indicated that functional failure determined by deterministic safety analysis was decided by the crack resistance capability of containment buildings, whereas the bearing capacity of concrete structures possess a high safety margin. The failure probability of concrete structures during an accident of double-ended break of hot gas ducts will be 31.18%. Adding the consideration the contingency occurrence probability of the accident, probability of functional failure is sufficiently low.

Numerical simulation of reinforced concrete nuclear containment under extreme loads

  • Tamayo, Jorge Luis Palomino;Awruch, Armando Miguel
    • Structural Engineering and Mechanics
    • /
    • v.58 no.5
    • /
    • pp.799-823
    • /
    • 2016
  • A finite element model for the non-linear dynamic analysis of a reinforced concrete (RC) containment shell of a nuclear power plant subjected to extreme loads such as impact and earthquake is presented in this work. The impact is modeled by using an uncoupled approach in which a load function is applied at the impact zone. The earthquake load is modeled by prescribing ground accelerations at the base of the structure. The nuclear containment is discretized spatially by using 20-node brick finite elements. The concrete in compression is modeled by using a modified $Dr{\ddot{u}}cker$-Prager elasto-plastic constitutive law where strain rate effects are considered. Cracking of concrete is modeled by using a smeared cracking approach where the tension-stiffening effect is included via a strain-softening rule. A model based on fracture mechanics, using the concept of constant fracture energy release, is used to relate the strain softening effect to the element size in order to guaranty mesh independency in the numerical prediction. The reinforcing bars are represented by incorporated membrane elements with a von Mises elasto-plastic law. Two benchmarks are used to verify the numerical implementation of the present model. Results are presented graphically in terms of displacement histories and cracking patterns. Finally, the influence of the shear transfer model used for cracked concrete as well as the effect due to a base slab incorporation in the numerical modeling are analyzed.