検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年

耐放射線モータ駆動装置の高線量率ガンマ線照射下での連続動作試験

Continuous running test of radiation resistance motor driving equipment under high gamma ray irradiation

小原 建治郎; 角舘 聡; 八木 敏明; 森下 憲雄; 柴沼 清

Obara, Kenjiro; Kakudate, Satoshi; Yagi, Toshiaki; Morishita, Norio; Shibanuma, Kiyoshi

国際熱核融合実験炉(ITER)の真空容器内に取り付けられるブランケットやダイバータの保守・交換作業には専用のITER保守装置が使用される。作業時の真空容器内は高線量率のガンマ線雰囲気となるため、ITER保守装置には長期間(1年程度)の使用が可能な耐放射線性が求められる。耐放射線モータ駆動装置は、ITER保守装置の耐放射線駆動源の開発を目的としたもので、耐放射線レベルの異なる各種の機器・部品を使用し、ITER保守装置の駆動源を模擬して設計、製作、8kgfの重り(模擬負荷)を指令信号によりモータで回転,制御する装置である。ガンマ線照射下での連続動作試験は、平均線量率を3.6kGy/h、目標積算線量を30MGy以上とし、2000年3月から開始した。試験では、動作時のモータ電流及び主要部の温度データの取得,故障事象の把握,個々の機器・部品の外観変化を観察した。試験は途中に分解点検をはさみ、2段階に分けて実施した。その結果、第1, 第2各段階での装置停止時までの積算線量は47.6MGyと23.9MGy、運転時間はそれぞれ13,200時間と6,640時間となり、ITER真空容器内線量率(0.5kGy/h)から求められる保守装置の耐放射線性を十分に満たすことがわかった。なお、停止の原因は、第1段階では減速機に充填したグリースの硬化、第2段階では電線の絶縁劣化に起因した。本報告書では、耐放射線モータ駆動装置の設計条件、基本仕様をはじめ、照射試験、分解点検の結果等について述べる。

The components in the vacuum vessel of ITER (International Thermonuclear Experimental Reactor), e.g. blanket and divertor, are replaced using the dedicated remote handling systems. The environment conditions inside the vacuum vessel during the operation are temperature of 50$$^{circ}$$C, gamma ray radiation and air or inert gas atmosphere at 1 atm. ; therefore multiple elements are required as durability of the remote handling systems. In addition, the remote handling system it is desired to be able to operate over a long time. The radiation resistance motor driving equipment, which comprises parts with different radiation resistance levels, was designed simulating mechanisms of the ITER remote handling systems. The equipment being the servomotor, turns the weight (dummy load) of 8 kgf and controls, and continuous running test under high gamma ray irradiation was started from March, 2000. Irradiation conditions on the test were the dose rate of 3.6 kGy/h, the target accumulation dose of 30 MGy at the minimum. The irradiation test was performed two stages which was divided by overhaul of the equipment. The achieved accumulation dose and running time in these stages were approximately 47.6 MGy/13,200 hours and 23.9 MGy/6,640 hours, respectively. As a result, it has been confirmed that sufficient radiation resistance of the equipment, which is required from the latest dose rate of 0.5 kGy/h inside the vacuum vessel was achieved. In this report, we describe design conditions of the equipment and the results of the 1st and 2nd irradiation tests and the overhaul after the 1st irradiation test.

Access

:

- Accesses

InCites™

:

Altmetrics

:

[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.