RPS Flashcards
LCO 3.3.1 “RPS Instrumentation” requirement
4 RPS trip units, associated instrument channels, and associated ZPM Bypass removal channels for each trip function shall be operable
LCO 3.3.1 “RPS Instrumentation” applicability
- High SUR - Modes 1-2. Trip may be bypasse when wide range power is < 1E-4%, or when thermal power > 13% RTP
- Loss of Load - Mode 1 when thermal power is >= 17% RTP
- All others are Modes 1-2, and Modes 3-5 with more than 1 full length control rod capable of being withdrawn and PCS boron concentration less than refueling boron concentration
- TM/LP, Low PCS Flow, Low S/G A Pressure, and Low S/G B Pressure trips may be bypassed when wide range power < 1E-4% RTP, and automatically removed when wide range power is >= 1E-4% RTP
LCO 3.3.1 “RPS Instrumentation” required action if 1 or more ZPM Bypass Removal channels inoperable
IMMEDIATELY remove the affected ZPM Bypasses, or declare the affected trip units inoperable
LCO 3.3.1 “RPS Instrumentation” required action if 1 or more functions with 2 RPS trip units or associated instrument channels inoperable
WITHIN 1 HOUR place 1 unit in trip
LCO 3.3.2 “RPS Logic and Trip Initiation” requirement
6 channels of RPS Matrix Logic, 4 channels of RPS Trip Initiation Logic, and 2 channels of RPS Manual Trip shall be operable
LCO 3.3.2 “RPS Logic and Trip Initiation” applicability
Modes 1-2
Modes 3-5 with more than 1 full length control rod capable of being withdrawn and PCS boron concentration less than refueling boron concentration
LCO 3.3.2 “RPS Logic and Trip Initiation” required action if 1 channel of Trip Initiation Logic inoperable
WITHIN 1 HOUR de-energize the affected clutch power supplies
LCO 3.3.2 “RPS Logic and Trip Initiation” required action if 2 channels of Trip Initiation Logic affecting the same trip leg inoperable
IMMEDIATELY de-energize the affected clutch power supplies
What is the logic required for RPS trips and pre-trips (alarms)?
- Trips - 2/4
- Pre-trips - 1/4
What is the purpose of the Variable High Power Trip (VHPT)?
- Protects against positive reactivity excursions during power operations, and while shutdown.
- Input comes from TMM Variable High Power output
What are the VHP pre-trip/trip setpoints?
- Min - 28.5%/30%
- Max - 105%/106.5%
- Variable - 13.5%/15% above power level when reset button is pushed
What is the purpose of the High Power Rate Trip?
Protects against an uncontrolled rod withdrawal or boron dilution while the reactor is critical, but at low power levels
-Input comes from wide range NIs (Channel A/C from NI-3, channel B/D from NI-4)
When is the High Power Rate Trip bypassed?
Below 1E-4% and above 15% power
What are the High Power Rate pre-trip/trip setpoints?
1.5 DPM/2.6 DPM
What is the purpose of the Low PCS Flow Trip?
Protects against fuel damage on a loss of coolant flow (DNB).
What are the Low PCS Flow pre-trip/trip setpoints?
97%/96%
What is the purpose of the S/G Low Level (A/B) Trips?
Protects against the loss of heat removal capability from the PCS
What are the S/G Low Level (A/B) pre-trip/trip setpoints?
31%/28%
What is the purpose of the S/G Low Pressure (A/B) Trips?
Protects against excessively high steam flow caused by a steam line break
What are the S/G Low Pressure (A/B) pre-trip/trip setpoints?
570 psia/512 psia
What is the purpose of the PZR High Pressure Trip?
Prevents operation when the reactor is generating more power than the secondary system is accepting
What are the PZR High Pressure pre-trip/trip setpoints?
2185 psia/2235 psia
What is the purpose of the TM/LP Trip?
Prevents the violation of minimum DNBR
What are the TM/LP pre-trip/trip setpoints?
Variable from TMMs or 1810 psia (whichever is higher)/variable from TMMs or 1760 psia (whichever is higher)