INES-event
INES 1

CRACK IN CONTROL ROD HOUSING

During the refueling of the plant a visual inspection of the CRDM (control rod drive mechanims) housings a crack in the housing number 36 was discovered. The housing is in reserve without control rod and it is in peripherical position. The crack has 20 mm length and axial orientation pass through the wall of the mechanism and is located 30 cm over the head of the vessel.
With additional ultrasonic inspection another crack has been detected in the same housing, on the opposite side, no passing through the wall of housing.
Additional inspection on two more housings reveals another no passing axial crack in the housing number 31.
The causes of the event are unknown.

Location: JOSE CABRERA-1 (ZORITA)
Event date: Tue, 18-01-1994
Nuclear event report
Legenda & explanation