INES-event
INES 0

REACTOR TRIP DUE TO TROUBLE OF DISCONNECTOR SWITCH IN SWITCH YARD

Ulchin-1 was operated at full power and Ulchin-2 had been completed 75% reactor physics test. One of disconnector switches in switch yard of both units had problems with melted contact point. Disconnector switch was grounded and actuated transformer protection relay. Finally, generator trip caused reactor trip in both units.
Justification: as full safety functions were available, the event is rated at level 0 as per user's manual, part III, Table II, A1.

Location: ULCHIN-1
Event date: Tue, 23-11-1993
Nuclear event report
Legenda & explanation