Growth model of circumferential outer diameter stress corrosion crack in retired steam generator tube of kori 1 nuclear power plant

Growth model of a circumferential outer diameter stress corrosion crack (ODSCC) in a retired steam generator tube of the Kori 1 nuclear power plant was proposed based on extensive destructive examinations of the pulled tubes of Alloy 600 from the Kori 1 plant. A small ODSCC grows in a lateral direction as well as a forward direction until it meets a neighboring ODSCC which also grows in a lateral direction as well as a forward direction. And then, the two ODSCCs which meet on the same circumferential plane are consolidated into a single ODSCC. By repeating such a consolidation process with time, it seems that the apparent growth rate of an ODSCC in the lateral direction is much faster than that in the forward direction. Growth model of a circumferential ODSCC from a retired steam generator tube of the Kori 1 plant reveals that many ODSCCs are initiated and grow in both directions independently until they meet and finally they are consolidated.