１．はじめに伊方１号機および２号機において、中央制御盤および主要制御盤等の総合デジタル式への更新工事（以下ＣＢＲ（Control Boards Replacement）工事という）を実施した。このような一括更新工事は世界で初めてのものであり、伊方発電所で初めてとなる１,２号機同時定検のもと、平成２１年８月に計画通りに完了した。（図－１）２．工事目的　伊方１号機は昭和５２年９月、伊方２号機は昭和５７年３月から、それぞれ運転を開始して以来、アナログ式の中央制御盤で運転し、これまで装置を部分的に取り替えて機......

Stress corrosion cracking (SCC) behavior of low-carbon stainless steel welds in high temperature water has been discussed with special attention on relation to the characteristics of microstructure. To investigate the effect of .-ferrite on SCC behavior, simulated heat-affected zone (partially melted zone) microstructure, where .-ferrite islands were widely distributed on grain boundary, was made by induction heating up to just below melting point. From the results of constant strain SCC test in high ...
英字タイトル:
Effect of .-ferrite on stress corrosion cracking behavior of low-carbon stainless steel weld in high temperature water

Abstract: Crevice corrosion was occurred at the adsorption tower with silver impregnated carbon of Advanced Liquid Processing System (ALPS). The influence of silver impregnated activated carbon on crevice corrosion of 316L stainless steel was investigated by corrosion test and electrochemical measurement. Crevice corrosion was observed on the specimen tested with the activated carbon. On the other hand, no corrosion was observed on that without the activated carbon in both pH7.4 and pH12 solution (art...
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Influence of activated carbon on crevice corrosion in adsorption tower of Advanced Liquid Processing System (ALPS)

SCC behavior near the fusion line of 316L SS welds in high SCC behavior near the fusion line of 316L SS welds in high temperature water has been investigated with special attention on relation to the characteristics of microstructure. Island-type S-ferrite has been distributed on grain boundary, namely along the potential crack path, in partially melted zone of 316L SS weld samples. Most of crack tips have been located on d-ferrite in partially melted zone of both weld samples. Cr2O3 which makes low oxida...
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SCC Retardation Mechanism near Fusion Boundary in 316L SS Welds from Microstructure Point of View

Oxidation behavior and cracking susceptibility of the Ni-Cr alloys (Ni-14Cr, Ni-22Cr and Ni-30Cr) under extremely-low oxygen partial pressure have been investigated by experiments used as plate specimen and Reverse U-Bend (RUB) specimen for 750 hours at 400 °C in two kinds of gas system (inert gas and dry steam) under various oxygen potential (Ni stable, Ni/NiO equilibrium and NiO stable).The Ni-Cr alloys cracked along grain boundary both in inert gas system (with trace O2, without H2O ) and in hydrogenat...
英字タイトル:
Oxidation behavior under stress of Ni-Cr alloys in gas phase under extremely-low oxygen potential

Wet polish with fine emery paper is most commonly used for final finish of SCC specimens and corrosion coupons. Although cold w ork introduced by the fine emery finish is slight, a series of experiments have demonstrated that the very slight cold work can ffect oxidation behaviors and apparent SCC susceptibility of Ni base alloys in hydrogenated steam. Oxidation tests and reverse type SCC experiments have been done in hydrogenated steam at 400C for Ni-Cr binary alloys with various Cr content from 14% t o 3...
英字タイトル:
Effect of slight cold work introduced with fine emery finish on oxidation and cracking behaviours of Ni base alloys in hydrogenated steam

In order to proceed the decommissioning of the FuNushima Daiichi Nuclear Power Plant safely, it is important to maintain integrity of cooling system for fuel debris and spent fuels. Most part of the piping systems are made of carbon steel. This study has been done to understand rate-determining processes of carbon steel corrosion under current and future FuNushima Daiichi NPP conditions as functions of flow conditions and dissolved oxygen level by using electrochemical tests with rotating cylindrical ...
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Corrosion behavior of carbon steels under flow and its rate-determining processes 渡邉 豊 YutaNa WATANABE Member

（株）JERAは燃料の上流調達から発電、電力・ガスの販売に至る一連のバリューチェーンを確立し事業開発、燃料調達電力販売、発電所運営にそれぞれ責任をもつ事業開発本部、最適化本部、 O&M･エンジニアリング本部の３本部制を敷きグローバルに役割を果たす企業を目指している。第一編では、取り組み概要を紹介したが、ここではその取り組みの実例について紹介することとする。...

Ferromagnetic materials have the interaction between mechanical and magnetic fields which is called the magnetomechanical coupling. Typical examples of such couplings are the magnetostriction and dependen ce of the stress strain relation on the magnetic field. The magnetoacoustic effect focused in this paper is also one of the magnetomechanical couplings. It has been shown that from the effect there exists the correlation of the plastic strain and the ultrasonic velocity change due to the magnetization. Th...
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Non-Destructive Evaluation of Plastic Deformation of Steelusing Magnetoelastic Coupling Effect

Corrosion rate of carbon steel SS400 was investigated in test solution (NaClaq, Cl-:200ppm) with a rotating cylinder electrode system. Polarization resistance measurement was used to determine variation of corrosion rate with time and specimens surface were observed after the measurements. Under aerated condition (dissolved oxygen: 7.3ppm), the corrosion rate increased with increasing rotating speed in low rotation speed ranges , but the corrosion rate decreased in high rotating speed ranges. The reas...
英字タイトル:
Evaluation of corrosion of cooling system piping of Fukushima Daiichi NPP