During routine surveillance testing on Unit 1 'B' Train Solid State Protection System, per FNP-1-STP-33.2B, the 'B' Train Rx Trip Breaker Failed to trip when a trip signal was sent from one of the manual function test push buttons. Indicated voltage did go to zero, but the
Reactor Trip Breaker did not open. Per the testing sequence, the
shunt trip for this breaker was being blocked at this time. A timeout was taken to determine the best course of action. Following discussions with Shift Manager, Duty manager, Emergency Director, and Electrical Maintenance supervision, it was decided to determine if the breaker would trip via the
shunt trip mechanism. The surveillance testing was continued, and the 'B'
Reactor Trip Breaker opened when the test signal was again inserted with the
shunt trip unblocked. The 'B'
Reactor Trip Breaker was replaced with a new breaker, and was subsequently tested sat per applicable sections of the surveillance test procedure.
- This event did not result an any offsite radiation release, and did not pose a threat to the general public.***
The licensee informed the NRC Resident Inspector.
