INES-event
INES 1

REACTOR SHUTDOWN BY TECHNICAL SPECIFICATIONS APPLICATION (UNUSUAL EVENT)

This event was intitated at 6:10 p.m. on May 9, 1992 when technicians, while performing the functional testing of pressure instruments of reactor recirculation pumps trip for ATWS, put one out of four switch selectors on "testing position" to verify the functional instrumentation operation and due to a mistake in the procedure application and communication deficiency between technicians, the trip logic was completed and a recirculation pump trip occurred. The operators reduced power to about 35% power according to technical specifications and following the abnormal procedures. At 7:35 pm the event was finished. In accordance with techspecs, the installation declared the event as unusual. All safety functions were fully available. This event was originally classified as "0" according to INES scale; but because of a similar event, which occurred on Nov. 27, 1991, due to a precedure error, this last event was upgraded to level 1.

Location: LAGUNA VERDE-1
Event date: Sat, 09-05-1992
Nuclear event report
Legenda & explanation