Stress Evaluation Method of Baffle Former Bolt and its Maintenance Program

2016 ◽  
Author(s):  
Toru Matsubara ◽  
Yuichi Mogami
Keyword(s):  
Evaluation Method ◽  
Cold Work ◽  
Peak Stress ◽  
Time Dependent ◽  
Analysis Method ◽  
Irradiation Creep ◽  
Stress Evaluation ◽  
Maintenance Program ◽  
High Neutron ◽  
High Neutron Flux

Baffle Former Bolt (BFB) is a fastening part of Reactor Vessel Internals (RVI) of PWR. BFB is made of type 347 or 316CW (cold work) stainless steel and it is known to have the risk of cracking caused by Irradiation Assisted Stress Corrosion Cracking (IASCC) under high neutron flux and tensile stress. To evaluate the time to crack of BFB, BFB’s time-dependent stress change caused by irradiation creep (relaxation) and by the swelling deformation of a baffle structure should be obtained. The authors have developed the finite element (FE) analysis method to calculate time-dependent stress of BFB considering the irradiation effects. The method combines two kinds of models; “global model” to calculate the deformation of whole baffle structure and “local model” to calculate the peak stress at the stress concentrated area under the bolt head. Incorporating the above calculation method, a new BFB inspection and evaluation guideline has been established in Japan. The concept of the guideline is also outlined in the paper.

Damage Calculation for First Wall Submitted to High Neutron Flux in a Tokamak

2015 ◽  
Vol 1769 ◽  
Author(s):  
C.E. Velasquez ◽  
M. A. F. Veloso ◽  
A. L. Costa ◽  
C. Pereira
Keyword(s):  
Neutron Flux ◽  
Energy Deposition ◽  
Reaction Rates ◽  
Main Reaction ◽  
First Wall ◽  
Tokamak Reactor ◽  
Mcnp5 Code ◽  
Displacement Per Atom ◽  
High Neutron ◽  
High Neutron Flux

ABSTRACTThe displacement per atom (dpa) has been a specific issue to evaluate the damage in the first wall of the Tokamak. Two different first wall materials were evaluated. In this study, MCNP5 code was used to obtain the neutron flux, the energy deposition and the main reaction rates, on the inboard and outboard first wall. The damage calculations were performed by the SPECTER code using the neutronic parameters obtained by MCNP5. The Tokamak reactor modeled has similar dimensions to the ITER. Tungsten and beryllium alloys were simulated on the outboard first wall. The results indicate which material has a higher resistance to be damage and dpa values for the analyzed material.

Evaluation Method for Time-Dependent Corrosion Behavior of Carbon Steel Plate Using Atmospheric Corrosion Monitoring Sensor

2009 ◽  
Vol 417-418 ◽  
pp. 417-420 ◽  
Author(s):  
Shigenobu Kainuma ◽  
Kunihiro Sugitani ◽  
Yoshihiro Ito ◽  
In Tae Kim
Keyword(s):  
Carbon Steel ◽  
Corrosion Behavior ◽  
Atmospheric Corrosion ◽  
Evaluation Method ◽  
Steel Plates ◽  
Time Dependent ◽  
Corrosion Monitoring ◽  
Corrosion Sensor ◽  
Atmospheric Exposure ◽  
Corrosive Environments

The purpose of this research is to propose a method for evaluating the time-dependent corrosion behavior of carbon steel plates using an atmospheric corrosion monitor (ACM) corrosion sensor consisting of a Fe/Ag-galvanic couple. Atmospheric exposure tests were carried out on steel　plates for periods of 6, 12, and 24-months on the island of Okinawa in Japan. The Specimens were mounted on racks at angles of 0, 45 and 90 to the horizontal to obtain corrosion data in various corrosive environments. In addition, the environments of the skyward- and groundward-facing surfaces of the specimens were monitored using ACM sensors. The sensor outputs were recorded during the exposure tests.

scholarly journals Survey of Teacher’s Views on Teaching Evaluation Method: An Implication for Education

2017 ◽  
Vol 4 (2) ◽  
Author(s):  
Desalegn Alemu ◽  
M.V.R. Raju
Keyword(s):  
Professional Development ◽  
Performance Evaluation ◽  
Evaluation Method ◽  
Present Finding ◽  
Descriptive Analysis ◽  
Teaching Evaluation ◽  
Analysis Method ◽  
Evaluation Procedures ◽  
Performance Evaluation Method ◽  
Questionnaire Surveys

The purpose of the present study was to survey teachers views on the performance evaluation methods employed in the wolkite, Wachemo and Welaita sodo University. 280 randomly selected participants from the three universities were involved in the survey. Data gathered through questionnaire survey were analyzed using descriptive analysis method. The questionnaire surveys were used to examine the teachers views on the existing evaluation method. The present finding revealed that the performance evaluation method lacks objectivity, do not support teacher’s professional development and the evaluation procedures are in accordance with the purpose of evaluation. Based on the findings and discussions of study, conclusion and recommendations were forwarded.

scholarly journals Evaluation method of clean power grid development mode

2021 ◽  
Vol 236 ◽  
pp. 02002
Author(s):  
Bingqi Jiao ◽  
Zhicheng Xu ◽  
Kuan Zheng ◽  
Xiaoqing Yan ◽  
Junshu Feng
Keyword(s):  
Evaluation Method ◽  
Power Grid ◽  
Clean Energy ◽  
Power Grids ◽  
Analysis Method ◽  
Development Mode ◽  
Grid Construction ◽  
Development Evaluation ◽  
Relative Change

In response to the climate change, it has been becoming the consensus of most countries in the world to accelerate the development of a high proportion of clean energy. The power grid is the core to support the development of a high proportion of clean energy, and the key is to accelerate the construction of clean power grids. This paper focuses on the main characteristics of clean power grid construction, and proposes a set of clean power grid development evaluation indicators including 5 first-level indicators and 19 second-level indicators and an analysis method based on radar charts. Taking China Power Grid as an example, this paper analyzes in detail the characteristics of the medium and long-term development mode of clean power grids and the relative change trends of specific indicators, and discusses the key links and potential problems that need attention in the development of clean power grids.

scholarly journals Identification and decision making of social entrepreneurship opportunities based on family social capital and prior knowledge

2018 ◽  
Vol 57 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Feng Wang ◽  
Hongqu He
Keyword(s):  
Social Entrepreneurship ◽  
Evaluation System ◽  
Evaluation Method ◽  
Equilibrium Distribution ◽  
Analysis Method ◽  
Distribution Problem ◽  
Family Social Capital ◽  
Game Equilibrium ◽  
Decision Management ◽  
Improve Algorithm

To improve algorithm accuracy of social entrepreneurship decision evaluation, a kind of social entrepreneurship decision evaluation method based on strategy proof game equilibrium algorithm is proposed. Firstly, social entrepreneurship decision problem is analyzed, social entrepreneurship decision evaluation system is given, and normalization and factor analysis method are adopted to preprocess model indicator; then, aimed at social entrepreneurship decision equilibrium distribution problem, social entrepreneurship decision optimal distribution algorithm based on ideas from game theory is proposed, and respective characteristics of Nash equilibrium method and strategy proofriess method and its application in different aspects of social entrepreneurship decision management are analyzed, to maximize the benefits of each user in social entrepreneurship decision finally; finally, effectiveness of the algorithm is verified through empirical analysis.

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