Event details:
While performing a routine reactor pulse for surveillance purposes, the signal input cable to one of the power monitoring safety channels was disconnected, making the associated high power scram not functional. The pulsing procedure requires disconnecting this cable for preoperational testing, but states that the instrument input be returned to its normal operating status prior to actually performing the operation. Contrary to the procedure, this was not done and the reactor was operated at 2 watts for 7 minutes without that required safety channel operating. A second safety channel was fully operational during that time. The high power scrams are not required during pulse mode operations. The disconnected cable was subsequently discovered and reconnected.
The licensee informed the
NRR Program Manager (Morlang).