List the PPS parameters that will cause actuation
- VOPT
- High Log Power
- High LPD
- Low DNBR
- High PZR Pressure
- Low PZR Pressure
- Low SG Pressure
- Low SG Level
- High SG Level
- High Containment Pressure
- High-High Containment Pressure
- Low RCS Flow
- Low RWT Level
List the instrument, setpoint(s), actuation(s) and design bases associated with the VOPT actuation.
- Safety channel NIs
- Fixed ceiling @ 110%, Variable ceiling @ 9.7% above current with a rate of change of 10.6%/min
- Trips reactor
- Prevents core damage from uncontrolled CEA withdrawal or CEA ejection.
List the instrument, setpoint(s), actuation(s) and design bases associated with the High Log Power actuation.
- Safety channel NIs (middle detector)
- > .01% power
- Trips reactor
- Protects fuel cladding and RCS pressure boundary during unplanned criticality during shutdown.
List the instrument, setpoint(s), actuation(s) and design bases associated with the High LPD actuation.
- Originates in CPCs
- 21kW/ft
- Trips reactor
- Protects against fuel CL melt during peaks from several different transients.
List the instrument, setpoint(s), actuation(s) and design bases associated with the Low DNBR actuation.
- Originates in the CPCs
- <1.34
- Trips reactor
- Protects against core damage in hot channel due to several transients. Is primary trip.
List the instrument, setpoint(s), actuation(s) and design bases associated with the High PZR Pressure actuation.
- PT 101A-D (NR)
- > 2383 psia
- Trips reactor
- Protects RCS PZR SL during loss of condenser, CEA withdrawal at low power, CVCS malfunction, MFW pipe break.
List the instrument, setpoint(s), actuation(s) and design bases associated with the Low PZR Pressure actuation.
- PT 102A-D (WR)
- <1837 psia (variable)
- Trips reactor, SIAS, CIAS
- Assists ESF to trip reactor during LOCA, CEA ejection, MSLBs.
List the instrument, setpoint(s), actuation(s) and design bases associated with the Low SG Pressure actuation.
- PT 1013A-D & 1023A-D
- <960 psia (variable)
- Trips reactor, MSIS, AFAS Lockout possible
- Protects against rapid RCS cooldown.
List the instrument, setpoint(s), actuation(s) and design bases associated with the Low SG Level actuation.
- LT 1113A-D & LT 1123A-D
- 44.2 (maybe 44.3%) (WR) trips reactor
- 25.8% (WR) initiates AFAS
- 20.3% (WR) DAFAS initiation input
- Prevents RCS overpressurization due to loss of heat sink
List the instrument, setpoint(s), actuation(s) and design bases associated with the High Containment Pressure actuation.
- PT 351A-D (NR)
- > 3 psig
- Trips reactor, SIAS, CIAS, MSIS
- Prevents containment overpressurization during MSLB, LOCA
List the instrument, setpoint(s), actuation(s) and design bases associated with the High High Containment Pressure actuation.
- PT 352A-D (WR)
- > 8.5 psig (actually 8.06 psig)
- CSAS
- Prevents containment overpressurization during MSLB, LOCA
List the instrument, setpoint(s), actuation(s) and design bases associated with the Low RCS Flow actuation.
- PD 115A-D & 125A-D
- <12.49 psid floor, 17.2 psid below current with .115 psi/sec ramp. (typ. is 25 psid, therefore floor will govern)
- Protects against RCP sheared shaft (would not be detected by RCP speed)
List the instrument, setpoint(s), actuation(s) and design bases associated with the Low RWT Level actuation.
-LT 203A-D
-<9.4%
-RAS
-Prevent ECCS pump loss
(do not activate early to ensure adequate volume in containment)
List the instrument, setpoint(s), actuation(s) and design bases associated with the High SG Level actuation.
- LT 1114A-D & 1124A-D (NR)
- > 91%
- Trips Reactor, MSIS
- Protects turbine from moisture carryover
Which PPS actuations receive signals from CPCs?
- Lo DNBR
- High LPD
What are the matrix power supplies and what happens if one were to fail?
- PNA, PNB, PNC, PND
- A single failure of above will trip (2) RTSG breakers, no reactor trip.
How do initiation circuits interface with matrix relays and how do they trip the reactor?
- The relays at the bottom of the matrix ladders are associated with individual contacts in the initiation circuits.
- If any of the (6) contacts in an initiation circuit is opened, the K relay is de-energized which opens & closes contacts (shunt & UV) in the associated RTSG, opening that breaker.
What is the control power source for the RTSGs and what happens if one were to fail?
- PKA, PKB, PKC, PKD
- A single RTSG associated with that power source would open, no reactor trip.
Describe the High LPD/Low DNBR operational bypass.
The bypass may be manually input below 10-4% power to defeat trips from abnormal CEA alignment during startup. Bypass is automatically removed above 10-4% power.
Describe the Low PZR Pressure operational bypass.
Allows RCS heatup/cooldown. Defeats RPS & ESFAS actuation. Is manually input below 400 psia and is automatically removed above 500 psia.
Describe the Hi Log Power operational bypass.
May be manually bypassed above 10-4% power, and must be done before 10-2% trip. Is automatically removed at 10-4% on power reduction.
What is the hierarchy for the trip channel bypass interlock?
Priority is given alphabetically and only 1 channel may be bypassed. (if C is bypassed and A is taken to bypass, C will come out of bypass and A will be in bypass)
Describe operation of the Test PB for the bistable status indicators.
Depressing the button will illuminate all (3) lights. Releasing will only extinguish the BYPASS light. RESET must be pressed and will extinguish the P & T lights if conditions are clear.
What parameters can be lowered via reset PB?
-Low PZR Pressure
(drops trip 400 psia below RCS pressure, 10s delay to press again)
-Lo SG Pressure
(drops trip 200 psia below SG pressure, 10s delay to press again)
