INES-event
INES 0

UNSCHEDULED SHUTDOWN DUE TO STEAM LEAKAGE FROM AN OUTLET PIPE OF A HIGH PRESSURE TURBINE

A small steam leakage was discovered nearby a former bearing stand of a high pressure turbine at about 7:30 am on 18 October 1992 when Fugen was going on full power operation. It was found out by a field investigation that the steam leakage occurred near an instrument pipe for a pressure detector of an outlet pipe of the high pressure turbine. The reactor was shut down by normal operating procedure and a generator was cut off from the grid system at 2:10 to investigate causes of the leakage and to repair the affected part.
After the shutdown, the investigation of the affected pipe was carried out and a small penetrating hole (about 8 x 4mm) was confirmed at a gamma-plug welded at the outlet pipe to stop a hole from which a radioactive source was inserted to examine the welding part of the pipe during the construction period of Fugen (1976). However the integrity of the outlet pipe was kept. The causes for the penetrating hole are suspected to be erosion-corrosion due to factors such as relatively high wetness in the steam, material and of the gamma-plug.

Location: FUGEN ATR
Event date: Sun, 18-10-1992
Nuclear event report
Legenda & explanation