Development of Inspection Technique for CRDM Housing Canopy Seals

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EU-JRC Int Conf Amsterdam '98
Table of Contents

Primary Circuit and Internals Inspection

Development of Inspection Technique for CRDM Housing Canopy Seals

K. Sawaragi,, M. Taniguchi, Y. Tada, M. Kurokawa, Y. Araki, MHI, Ltd. Kobe, Japan

ABSTRACT

Lower canopy seal of thermo couple housing caused by oxygen induced SCC (IG - SCC ) in 1984.
Middle canopy seal of part length CRDM housing caused by chlorine induced SCC (TG - SCC ) in 1995.
Middle canopy seal of full length CRDM housing caused by chlorine induced SCC (TG - SCC ) in 1996.

To prevent leakage from CRDM housing canopy seal, Mitsubishi Heavy Industries have developed an ECT inspection technique and an automatic inspection system, and have performed periodical inspection to several plants in Japan since 1996.

The features of Mitsubishi's inspection system are as follows:

Specific cross-coil type ECT probe can detect 60% thickness SCC of axial, circumferential and oblique directions.
An automatic inspection system consist of four (4) kinds of inspection tool for upper, middle (full-length CRDM ) and lower canopy seals.

Primary Circuit and Internals Inspection

Publication Source: First International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurised Components , 20 - 22 October 1998, Amsterdam, Netherlands. Held by the Joint Research Centre of the European Commission.
Publisher: Woodhead Publishing Limited