RC-C-4921, SSPS Hardware & RPS-ESFAS Signals

Question 1

What does placing the SSPS Input error inhibit switch to the TEST position do to SSPS (specifically the circuity required to actuate ESFAS)

Answer 1

• Removes ground from the circuit in the logic bay

“Normal” Operation (Switch not in TEST)
Signal -> Input bay -> Contact closes -> Logica bay Ground -> Output bay -> Master -> Slave

Question 2

What does placing the SSPS Output mode select switch to the TEST position do to SSPS (specifically the circuity required to actuate ESFAS)

Answer 2

• Power will not be provided to slave relays (allows testing of Master Relays without actuations)

“Normal” Operation (Switch not in TEST)
Signal -> Input bay -> Contact closes -> Logica bay Ground -> Output bay -> Master -> Slave

Question 3

With the SSPS Output Mode Select Switch in TEST, will the red SI switches work?

Answer 3

• No. Red switches actuate master relays. Since there is no power for slave relays, SI Switches will not work

Question 4

With the SSPS Input error inhibit switch in TEST, will the red SI switches work?

Answer 4

• Yes. However, automatic SI will not work since signals are not being sent down stream of the logic bay.

Question 5

What does the SSPS Mode 5 & 6 switch do?

Answer 5

• Maintains OPERABILITY of the CVI signal as well as SR, Audio Count Rate, and Containment Evacuation alarm. All other ESFAS signals are out of service (Output mode select in TEST)

Question 6

What is the difference between the UV and Shunt trip features of the Reactor Trip Breakers

Answer 6

• UV trip comes directly from the logic cabinets and will occur upon a loss of 48 VDC
• Shunt trip is in parallel with UV trip (i.e., they both actuate trip coil)
• During SSPS testing Control Power fuses are removed (250 VDC) from breaker, but UV coil still trips breaker