SSPS Flashcards
What does the Bistable Test Switch in test do?
- Gives SSPS a trip signal for both trains
- Used to place bi-stable in “Trip” (if it fails in its non trip direction)
What does the RPS Bypass Switch in bypass do?
- Prevents getting a trip signal
- Puts power to logic bay regardless of input, allowing you to test the input drawer (using bistable test switch) without chance of causing an actuation.
(keyed switch)
What powers Train A Slave Relays?
CRID I
(120v AC)
What powers Train B Slave Relays?
CRID IV
(120v AC)
What power failure will prevent an actuation of ESF equipment?
- A loss of either CRID I or CRID IV (Train Specific) will prevent an ESF actuation
- (Master and Slave Relays are normally de-energized. Loss of a supplying CRID won’t allow the SLAVE Relays to energize on a trip)
Where does the SSPS General Warning come from?
Logic Cabinets
What will cause an SSPS General Warning?
- Bypass Bkr Closed
- Output mode selector switch in test
As well as: - Loss of 48v DC or 15v DC (CRID lost)
- Input Error inhibit switch in INHIBIT
- Multiplexer switch in INHIBIT
- Any circuit board removed except isolation boards
- Permissive switch out of OFF
- Memories switch out of OFF
- Grounded return fuse blown
A loss of which SSPS power supplies will cause a Rx trip?
Both 15v DC pwr supplies
OR
Both 48v DC pwr supply
How do the Trip Coils on the RTBs cause the Reactor Trip Breakers to trip?
Energize to trip
How do the UV Coils on the RTBs cause the RTB to trip?
Deenergize to Trip (loss of 48v DC)
does NOT need control power
How do the Rx Trip switches trip the Rx?
Either Rx Trip Switches will energize both Rx Trip and Bypass Breaker Trip Coils (all 4)
What does the Shunt Coil do for the RTB?
Energizes the trip coil
(RTBs only, they are not on the Rx Trip Bypass Bkrs)
uses control power
If both Rx Trip Bypass Bkrs are closed in at the same time, what will happen?
Trips both Bypass Breakers
If you put bistable test switch to test, what happens?
Trips (actuates) bistables with the exception of CTS
(CTS bistables are bypassed. They are energize to actuate)
What is provided power directly from the SSPS Input Bays?
Input Bay Direct Feeds
What are the Input Bay Nondirect feeds powered by?
Protection racks
Is the General Warning light visible with the Logic Cabinet door closed?
Yes, it is visible on the Logic Bays
Which RTB and Rx Trip Bypass Bkrs are tripped by Train A SSPS?
- Rx Trip Bkr A
- Rx Trip Bypass Bkr B
Which RTB and Rx Trip Bypass Bkrs are tripped by Train B SSPS?
- Rx Trip Bkr B
- Rx Trip Bypass Bkr A
What will happen if you get a General Warning on Both Trains of SSPS?
Reactor will trip
What does the Isolation Amplifier do?
Ensures failure in control system does not cause the same issue in the protection system
If the Output Mode Selector Switch is taken to test, what happens?
Disables all slave relays for an entire train
(by replacing 120 vAC power with 15 vDC)
What does the Input Error Inhibit Switch do?
Keeps logic cards from sensing a change in input. The signals will NEVER get to the logic cabinet, which allows testing.
SI Switch for that Train WILL work
What does the MULTIPLEXOR DO?
Only goes to status lights, alarms, PPC
What are the inputs to OTΔT? What does it protect from?
RCS ΔT, Tavg, AFD and Pzr Pressure
(Protects from DNB)
What are the inputs to OPΔT? What does it protect from?
RCS ΔT and Tavg
(Protects from KW/ft)
No P in OPΔT!!!
What’s the only ESFAS trip that cannot be reset with a trip signal still standing?
Steamline Isolation
What is the high level flowpath for SSPS from a signal in the field to the pump and valve actuations?
If CRID 1 is lost, what is the significance for SSPS?
Train A Slave Relays are lost, so auto actuations for that train won’t work. Train A SI Switches will NOT work. Pumps and valves can be aligned manually
If CRID 4 is lost, what is the significance for SSPS?
Train B Slave Relays are lost, so automatic ESF actuations won’t happen. Train B SI switches will NOT work. Pumps and valves would have to be aligned manually
The following conditions exist:
- Containment pressure instrument Channel #1, 2-PPP-303 (PT-937) declared inoperable.
- Required actions per 2-OHP-4022-013-011 Containment Instrumentation Malfunction have been completed.
- Required Technical Specification Actions have been taken for Channel #1, 2-PPP-303 (PT-937)
What is the REMAINING coincidence for the SAFETY INJECTION ACTUATION and CTS ACTUATION?
SI = 2/3
CTS= 2/3
(The CTS Actuation Bistable is placed in the BYPASSED condition to prevent inadvertent actuation. This changes the remaining channel coincidence to 2/3 instead of the previous 2/4. Only 3 channels (Channels 2, 3, & 4) feed the SI Actuation This channel does NOT feed SI so the SI coincidence remains at 2/3)
Given the following plant conditions:
- Unit 2 is at 100% power
- Containment pressure instrument Channel #3, 2-PPP-301, declared inoperable
- Required actions per 2-OHP-4022-013-011 CONTAINMENT INSTRUMENTATION MALFUNCTION have been completed
CRID 2 has just lost power.
Explain the impact on the Safety Injection system.
Train ‘A’ and ‘B’ Safety Injection actuation logic were satisfied. Both Trains equipment will automatically actuate.
Will the Manual SI Switches work if the Output Mode Selector Switch is in TEST?
No! Must be done manually if required.
Will the Manual SI Switches work if the Input Error Inhibit Switch is in INHIBIT?
Yes!
Does a loss of 250 vDC control power result in a Reactor Trip? Why or why not?
YES!
The trip is a result of loss of DC power to the underfrequency relays that sense a Low Frequency condition that requires a reactor trip.
What happens if you lose CRID 1 and 2?
Both Train A 48 and 15 vDC power supplies go away. Reactor trips
What does the Mode 5 and 6 switch do?
Maintains 120 vAC to slave relays for CVI relays, even with the Output Mode Selector Switch in Test.
What is the normal source of power to the Rod Control Logic Cabinets?
120 vAC stepped down from 260 vAC Rod Drive MG Set Output
