As for BWR, Core components made of austenitic stainless steels where IASCC is assumed are Top Guide, Core Shroud and Core Plate. Since Top Guide has been exposed to high flux of neutron irradiation during plant operation, the evaluation method should be established using reasonable and proper evaluation conditions. Based on this background, study on evaluation method for Top Guide was performed in this research as described below. ...
英字タイトル:
Optimizing evaluation method of irradiation-assisted stress corrosion cracking in Top Guide of BWR

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......

Rapid growth in renewable energy (RE) is essential for achieving carbon neutrality. However, the resilience of bulk power system is decreased due to the installation of large amount of RE, and there is a possibility that the transmission accident causes disasters such as a large-scale blackout. As a result, the amount of RE is limited in order not to cause such disasters. In such a situation, nuclear power plants will be useful items to reinforce the resilience of bulk power system. In this research, we eva...
英字タイトル:
Study of utilization of nuclear power plants for increasement of renewable energy installation

Muography is an imaging technique using cosmic-ray muons. The principle of this technique is similar to that of X-ray radiography. However, the muography can be applied to much larger object, since the muon has high penetrating power. We have developed a portable prototype muography detector for investigation of infrastructure degradation. Through some feasibility measurements, it was found that long measurement time is required to investigate degradation. To shorten the measurement time, we have designed a...
英字タイトル:
Development of Muography Detector to Investigate Degradation for Infrastructure Buildings

In the process of achieving cold shutdown following the shutdown of Hamaoka Nuclear Power Station Unit 5 on May 14, 2011, the readings of conductivity meters monitoring the purity of the water in the main condensers began to rise, and the conductivity of the water in the reactor also began to rise. After cold shutdown, investigation identified that a high volume of sea water had flowed into the reactor facility due to damage to the main condenser tubes. Evaluations focusing on corrosion of materials have b...
英字タイトル:
Effect of sea water intrusion from main condenser, damaged by breakon reactor core internals, Hamaoka Unit 5