原子炉プラント機器の高経年化と熱流動挙動に関する研究

概要

論文の詳細を見る
The number of aged nuclear power plants will increase in the future, because operation periods of the existing nuclear power plants are being extended from thirty years of initial supposition to sixty years at the longest. Therefore, it is important to establish the methodology to guarantee integrity of the aged nuclear power plants. Among the reported damages of nuclear power plant components due to the fatigue during long terms, many cases are considered to be related to their thermal-hydraulic behaviors during operation. Thus, quantitative understanding of thermal-hydraulic behaviors in the nuclear power plants is important to estimate many kinds of aging processes accurately. The research project, "study on relationship between nuclear power plant aging and its thermal-hydraulic behaviors", was conducted from 2001 to 2004 in order to clarify effects of thermal-hydraulic behaviors in the nuclear power plants on structural materials during aging processes. In this project, flow induced vibration of an array of circular cylinders was investigated experimentally and numerically. Rotating bending fatigue tests were also performed for the austenitic stainless steel SUS316L (JIS G4304) and Ni-Cr-Fe alloy NCF690 (JIS G4904, INCONEL alloy 690 equivalent material) in order to examine the fatigue strength in the ultra high cycle fatigue region, namely 10^7-10^9 cycles, and the notch effects. It was found that the reduced flow velocity at which the flow induced vibration of a single rod occurs in transverse direction decreases with the increase of the blockage ratio. When plural rods are inserted in the channel, the pitch has an effect on the behavior of the vibrating rods and its influence becomes remarkable as the blockage ratio decreases. As for fatigue test results in the ultra high cycle fatigue region, it turned out that the fatigue limit of SUS316L is 279 MPa and that of NCF690 ranges from 320 to 400 MPa.
2005-07-15

原子炉プラント機器の高経年化と熱流動挙動に関する研究

スポンサーリンク

概要

著者

関連論文

スポンサーリンク