• Title/Summary/Keyword: Nuclear power program

Search Result 508, Processing Time 0.028 seconds

Development of CANDU Reactor Aging Monitor (CANDU형 원전 경년열화 감시시스템(Aging Monitor) 개발)

  • Kim, Hong Key;Choi, Young Hwan;Ko, Han Ok
    • Transactions of the Korean Society of Pressure Vessels and Piping
    • /
    • v.5 no.2
    • /
    • pp.13-19
    • /
    • 2009
  • As the operating time in nuclear power plants (NPPs) increases, the integrity of nuclear components may be continually degraded due to aging effects of systems, structures and components. Recently, a number of NPPs are being operated beyond their design life to produce more electricity without shutting down. The critical issue in extending a lifetime is to maintain the level of safety during the extended operation period while satisfying the international regulatory standards. Therefore, it is beneficial to build a monitoring system to measure an aging status. In this paper, the Aging Monitor (AM) based on lots of aging database obtained from the operating plants and research results on the aging effects was developed to monitor, manage and evaluate the aging phenomena systematically and effectively in NPPs. The AM for the CANDU is divided into 6 modules: (1) Aging Alarm/Coloring Monitor, (2) Aging Database, (3) Aging Document, (4) Real-time Integrity Monitor, (5) Surveillance and Inspection Management System, and (6) Continued Operation and Periodic Safety Review (PSR) Safety Evaluation. The proposed system is expected to provide the integrity assessment for the major mechanical components of an NPP under concurrent working environments.

  • PDF

THERMAL-HYDRAULIC TESTS AND ANALYSES FOR THE APR1400'S DEVELOPMENT AND LICENSING

  • Song, Chul-Hwa;Baek, Won-Pil;Park, Jong-Kyun
    • Nuclear Engineering and Technology
    • /
    • v.39 no.4
    • /
    • pp.299-312
    • /
    • 2007
  • The program on thermal-hydraulic evaluation by testing and analysis (THETA) for the development and licensing of the new design features in the APR1400 (Advanced Power Reactor-1400) is briefly introduced with a presentation on the research motivation and typical results of the separate effect tests and analyses of the major design features. The first part deals with multi-dimensional phenomena related to the safety analysis of the APR1400. One research area is related to the multidimensional behavior of the safety injection (SI) water in a reactor pressure vessel downcomer that uses a direct vessel injection type of SI system. The other area is associated with the condensation of steam jets and the resultant thermal mixing in a water pool; these phenomena are relevant to the depressurization of a reactor coolant system (RCS). The second part describes our efforts to develop new components for safety enhancements, such as a fluidic device as a passive SI flow controller and a sparger to depressurize the RCS. This work contributes to an understanding of the new thermal-hydraulic phenomena that are relevant to advanced reactor system designs; it also improves the prediction capabilities of analysis tools for multi-dimensional flow behavior, especially in complicated geometries.

Soil Radioactivity in Urban Parks of Incheon (인천지역 근린공원의 토양 방사능 농도)

  • Jun-Su, Jang;Sang-Bok, Lee;Ga-Eun, Baek;Hee-Cheol, Shin;Gyeong-Jae, Lee;Do-Hwa, Lee;Sungchul, Kim
    • Journal of radiological science and technology
    • /
    • v.46 no.1
    • /
    • pp.37-42
    • /
    • 2023
  • Most of research on environmental radioactivity is conducted in areas near nuclear power plants, so basic data about the distribution of environmental radioactivity in soil in other areas are insufficient. Therefore, in this study, divide into four categories by the land development characteristics of Incheon and the purpose of development, and confirm the stability of the Incheon through soil sample collection and gamma-ray analysis based on 40K, 137Cs and 226Ra (214Pb, 214Bi). The spectrum obtained by measuring for 80,000 seconds by using the HPGe detector was analyzed by Genie 2000 program. Soil radioactivity concentrations in urban parks of Incheon area are generally within a safe range compared to the results of the Nuclear safety and security commission. However, as 137Cs was detected in one park, which will require continuous monitoring.

Simulations for the cesium dynamics of the RF-driven prototype ion source for CRAFT N-NBI

  • Yalong Yang;Yong Wu;Lizhen Liang;Jianglong Wei;Rui Zhang;Yahong Xie;Wei Liu;Chundong Hu
    • Nuclear Engineering and Technology
    • /
    • v.56 no.4
    • /
    • pp.1145-1152
    • /
    • 2024
  • To realize an initial objective of the negative ion-based neutral beam injection (N-NBI) at the Comprehensive Research Facility for Fusion Technology (CRAFT) test facility, which targets an H0 beam power of 2 MW at an energy of 200-400 keV and a pulse duration of 100 s, it is crucial to study the cesium dynamics of the negative ion source. Here a numerical simulation program CSFC3D is developed and applied to simulate the distribution and time dynamics of cesium during short pulses. The calculations show that most of the cesium on the plasma grid (PG) area originates from the release of cesium that is accumulated within the ion source in the plasma phase. Increasing the wall temperature reduces the loss of cesium on the wall of the ion source. Furthermore, the thickness of the cesium monolayer is directly influenced by the PG temperature. Both simulated and experimental results demonstrate that maintaining the PG temperature between 180 ℃ and 200 ℃ is essential for enhancing the performance of the ion source and optimizing the cesium behavior.

An Evaluation of Transfer of Training Effects on Nuclear Power Plant MCR Operators

  • Kim, Jung Ho;Byun, Seong Nam
    • Journal of the Ergonomics Society of Korea
    • /
    • v.32 no.1
    • /
    • pp.77-85
    • /
    • 2013
  • Objective: The aim of this study sets factors from previous research known to impact transfer effects as the independent variables, and examines their relationship with the dependent variables, near transfer effects and far transfer effects. Background: Transfer of Training refers to the application of what learners acquire knowledge and skills in training programs to their job. The ultimate goal of training is to apply what employees learn in training sessions to their workplace. In this sense, transfer of training has been a vital concern for training effectiveness. For training to be effective, trainees(learners) should be able to use what they learn in training program back on the job. Method: For this research purpose, this study conducted a survey on 170 nuclear operators in nuclear education and training center. Of these, survey result from the 167 recruits were sampled. Theoretical model of this study is based on Holton & Baldwin's(2003) distance model of transfer effects. This study sets transfer effects(near transfer, far transfer) as the main dependent variables. Meanwhile, the independent variables are trainee characteristics, training characteristics, organizational transfer climate. Each independent variable has subordinate variables. Subordinate variables of trainee characteristics are self-efficacy, motivation to learn, motivation to transfer and ability to transfer. Subordinate variables of training characteristics are training contents, ability of trainers, training design, training climate. The last Subordinate variables of organizational transfer climate are support of supervisors, support of peer, support of organization. Conclusion: As a analysis result, trainee characteristics appeared to be in effect only significant influence near far transfer of training, the effect of the far transfer of training, there is no significant. In addition, the training characteristics appeared to be having a significant influence on near and far transfer effects. Organizational transfer climate appeared to be having a significant influence on near and far transfer effects. Finally, near transfer effect appeared to be having a significant influence on far transfer effects. Application: Results of this analysis in the study to training organization and training characteristics of the transition environment effects on nuclear power institutions and operators training organization having a significant impact that says. The transfer of knowledge and technology, as well as that can be applied to a new situation in terms of education and training are important characteristics.

Radiological Impact on Decommissioning Workers of Operating Multi-unit NPP (다수호기 원전 운영에 따른 원전 해체 작업자에 대한 방사선학적 영향)

  • Lee, Eun-hee;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.17 no.1
    • /
    • pp.107-120
    • /
    • 2019
  • The decommissioning of one nuclear power plant in a multi-unit nuclear power plant (multi-unit NPP) site may pose radiation exposure risk to decommissioning workers. Thus, it is essentially required to evaluate the exposure dose of decommissioning workers of operating multi-unit NPPs nearby. The ENDOS program is a dose evaluation code developed by the Korea Atomic Energy Research Institute (KAERI). As two sub-programs of ENDOS, ENDOS-ATM to anticipate atmospheric transport and ENDOS-G to calculate exposure dose by gaseous radioactive effluents are used in this study. As a result, the annual maximum individual dose for decommissioning workers is estimated to be $2.31{\times}10^{-3}mSv{\cdot}y^{-1}$, which is insignificant compared with the effective dose limit of $1mSv{\cdot}y^{-1}$ for the public. Although it is revealed that the exposure dose of operating multi-unit NPPs does not result in a significant impact on decommissioning workers, closer examination of the effect of additional exposure due to actual demolition work is required. The calculation method of this study is expected to be utilized in the future for planned decommissioning projects in Korea. Because domestic NPPs are located in multi-unit sites, similar situations may occur.

OVERVIEW OF FUSION BLANKET R&D IN THE US OVER THE LAST DECADE

  • ABDOU M. A.;MORLEY N. B.;YING A. Y.;SMOLENTSEV S.;CALDERONI P.
    • Nuclear Engineering and Technology
    • /
    • v.37 no.5
    • /
    • pp.401-422
    • /
    • 2005
  • We review here research and development progress achieved in US Plasma Chamber technology roughly over the last decade. In particular, we focus on two major programs carried out in the US: the APEX project (1998-2003) and the US ITER TBM activities (2003-present). The APEX project grew out of the US fusion program emphasis in the late 1990s on more fundamental science and innovation. APEX was commissioned to investigate novel technology concepts for achieving high power density and high temperature reactor coolants. In particular, the idea of liquid walls and the related research is described here, with some detailed examples of liquid metal and molten salt magnetohydrodynamic and free surface effects on flow control and heat transfer. The ongoing US ITER Test Blanket Module (TBM) program is also described, where the current first wall/blanket concepts being considered are the dual coolant lead lithium concept and the solid breeder helium cooled concepts, both using ferritic steel structures. The research described for these concepts includes both thermofluid MHD issues for the liquid metal coolant in the DCLL, and thermomechanical issues for ceramic breeder packed pebble beds in the solid breeder concept. Finally, future directions for ongoing research in these areas are described.

Estimation of Tritium Concentration in the Environment based upon Global Tritium Cycling Model (글로벌 삼중수소 순환 모델을 이용한 삼중수소 환경 방사능 추정)

  • Choi, Heui-Joo;Lee, Han-Soo;Kang, Hee-Suk;Lee, Chang-Woo
    • Journal of Radiation Protection and Research
    • /
    • v.28 no.1
    • /
    • pp.1-8
    • /
    • 2003
  • The periodic safety review of operational nuclear power plants requires that the plants should keep a well organized environmental monitoring program. The past records of environment monitoring data were analyzed. and the tritium concentrations of the samples in the surface and ground water around Kori site were measured. It was shown that the tritium concentrations around the Kori site were slightly higher than that of natural background. The change of background tritium concentration was estimated through a numerical modeling. Two different versions of 7 compartments model - the world and the northern hemisphere - defined in NCRP-62 were modeled for the global tritium cycling. The numerical solution of the model was obtained using a computer program, AMBER. The four cases of tritium source-terms into the atmosphere were considered. The results showed that the tritium concentration in the surface soil water was higher than that in sea water or surface stream water. Also, it was shown that the tritium produced by the interaction between cosmic rays and the gases were the major source of tritium, and the tritium produced by nuclear weapon test decreased considerably.

Effect of 1 Year E-mail Nutrition Education after Face-to-Face Encounter at Worksite: Changes in Cardiovascular Risk Factors (면대면 영양교육 후 1년간의 E-mail 영양교육이 직장인 남성의 심혈관 질환 위험인자 감소에 미치는 효과)

  • Oh, Hye-Sun;Jang, Mi;Hwang, Myung-Ok;Cho, Sang-Woon;Paek, Yun-Mi;Choi, Tae-In;Park, Yoo-Kyoung
    • Journal of Nutrition and Health
    • /
    • v.42 no.6
    • /
    • pp.559-566
    • /
    • 2009
  • Effective nutrition educations for prevention of chronic diseases for the general population are of great importance these days. The purpose of this study was to evaluate the feasibility of nutrition education for cardiovascular risk factor reduction by e-mail education in male workers. The participants were divided into three groups by age; 28-39 age group, 40-49 age group, and 50-59 age group who got regular checkups for anthropometry and biochemistry. The 1 year program consisted of 15 topics containing information about metabolic syndrome (MS) and healthy eating behavior (intake of salt, fat and alcohol). Seven hundred thirty nine participants volunteered for the study [28-39 age group, n = 240; body mass index (BMI) = 24.9 $\pm$ 2.7 kg/m$^2$: 40' group, n = 276; BMI = 24.8 $\pm$ 2.6 kg/m$^2$: 50' group, n = 223; BMI = 24.9 $\pm$ 2.7 kg/m$^2$]. Percentage body fat (p < 0.05) and percentage of abdominal fat (p < 0.05), total cholesterol (p < 0.05), systolic blood pressure (p < 0.05), and diastolic blood pressure (p < 0.05) were significantly decreased in all participants after the 1 year program. The total number of participants who had MS was decreased from 216 to 199 and especially the incidence of MS was decreased 27% in the group of subjects who were under the age 39. The e-mail worksite nutrition education program shows a substantial contribution to the development of effective CVD and chronic disease control and lifestyle nutrition educations that are applicable to and attractive for the large population at risk.

In-Cabinet Response Spectrum Generation Using Frequency Domain Analysis Method (진동수영역해석법을 이용한 캐비닛내부응답스펙트럼 생성 기법)

  • Cho, Sung Gook;So, Gihwan
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.24 no.2
    • /
    • pp.103-110
    • /
    • 2020
  • Seismic qualification of instruments and devices mounted on electrical cabinets in a nuclear power plant is performed in this study by means of the in-cabinet response spectrum (ICRS). A simple method and two rigorous methods are proposed in the EPRI NP-7146-SL guidelines for generating the ICRS. The simple method of EPRI can give unrealistic spectra that are excessively conservative in many cases. In the past, the time domain analysis (TDA) methods have been mostly used to analyze a structure. However, the TDA requires the generation of an artificial earthquake input motion compatible to the target response spectrum. The process of generating an artificial earthquake may involve a great deal of uncertainty. In addition, many time history analyses should be performed to increase the accuracy of the results. This study developed a numerical analysis program for generating the ICRS by frequency domain analysis (FDA) method. The developed program was validated by the numerical study. The ICRS calculated by FDA thoroughly matched with those obtained from TDA. This study then confirms that the method it proposes can simply and efficiently generate the ICRS compared to the time domain method.