TS 3.3.1 Reactor Protective System (RPS) Instrumentation - Operating Flashcards
3.3.1 RPS Instrumentation - Operating
LCO 3.3.1 ___ RPS trip and bypass removal channels for each Function in Table 3.3.1-1 shall be OPERABLE
Four
APPLICABILITY: According to Table 3.3.1-1
The RPS is segmented into four interconnected modules: Measurement channels Bistable trip units RPS Logic Reactor Trip circuit breakers
LCO 3.3.1 addresses ___ and ___. It also addresses ___
Measurement channels
Bistable trip units
ALSO automatic bypass removal feature for those trips with operating bypass
For LCO 3.3.1, the CPC’s provide outputs to drive display indications (___ ___ ___) and provide ___ and ___ pretrip and trip signals (from TS Bases 3.3.1)
DNBR Margin, LPD margin, calibrated neutron flux power levels
Provide DNBR-Low and LPD-High pretrip and trip signals
For LCO 3.3.1, regarding Bistable Trip Units…
“A channel is inoperable if its actual set point is ___ with respect to its Allowable Value”
Non-conservative
Each RPS set point is chosen to be consistent with the functions of the respective trip. The basis for each trip set point falls into 1 of 3 general categories:
1 - To ensure that the SLs are not exceeded during AOOs
2 - To assist the ESFAS during accidents
3 - To prevent material damage to major plant components (equipment protective)
The RPS-VOPT can provide protection against core damage during the following events:
1 - Uncontrolled CEA Withdrawal from subcritical and Low Power (AOO)
2 - CEA Ejection (Accident)
In Modes 3,4, or 5, with RTCB’s open or the CEAs not capable of withdrawal, the Log Power Level - High trip DOES or DOES NOT have to be Operable?
DOES NOT have to be Operable
- Indication and alarm functions required to indicate a boron dilution event are addressed in LCO 3.3.12 BDAS
The PZR Pressure - High trip provides protection for the high RCS Pressure SL. With PZR Safeties and MSSV’s, it provides protection against over pressurization of the RCPB during the following events:
1 - Loss of Condenser Vacuum
2 - CEA withdrawal from low power conditions
3 - CVCS Malfunction (AOO)
4 - Main FW System Pipe Break (Accident)
Per LCO 3.3.1 every Function has an Applicability of Modes 1 and 2 EXCEPT for ___
Log Power Level - High
- Applicable in Mode 2 ONLY
What is the NOTE for LCO 3.3.1?
Separate Condition entry is allowed for each RPS function
LCO 3.3.1 Condition A -
One or more Functions with one automatic RPS trip channel inoperable.
What are the Required Actions and Completion Times?
A.1 - Place channel in bypass or trip (1 Hour) AND
A.2 - Restore channel to OPERABLE status (Prior to entering Mode 2 following next Mode 5 entry(
LCO 3.3.1 Condition B -
One of more Functions with 2 automatic RPS trip channels inoperable.
Required Actions and Completion Times?
B.1 - Place 1 channel in bypass and the other in trip (1 Hour)
LCO 3.3.1 Condition C -
One or more Functions with 1 automatic bypass removal channel inoperable.
Required Actions and Completion Times?
C.1 - Disable channel bypass (1 Hour) OR
C.2.1 - Place affected auto trip channel in bypass or trip (1 Hour) AND
C2.2 - Restore bypass removal channel and associated auto trip channel to OPERABLE status (Prior to entering Mode 2 following next Mode 5 entry)
LCO 3.3.1 Condition D -
One or more Functions with 2 auto bypass removal channels inoperable.
Required Actions and Completion Times?
D.1 - Disable bypass channels (1 Hour) OR
D.2 - Place 1 affected auto trip channel in bypass and place the other in trip (1 Hour)
LCO 3.3.1 Condition E -
Required Action and associated Completion Time not met.
Required Actions and Completion Times?
E.1 - Be in Mode 3 (6 Hours)
The general relationship among PVNGS trip set point terms is as follows:
The calculated limiting set point is determined within the plant specific set point analysis and is based on the ___ and the ___
Analytical Limit and the Total Loop Uncertainty
The Log Power Level - High Trip operating bypass is auto removed when log power decreases below ___
1E-4% NRTP
When indicated Log power channel is failed HIGH (>1E-4%), the auto Hi-Log power trip bypass removal feature in that channel CAN or CANNOT function?
Cannot Function
- Both auto DNBR-LPD and Hi-Log Power bypass removal features are affected by a failed Log power channel and should therefore be considered INOPERABLE
The SG Level-Low RPS trip set point ensures that there will be sufficient water inventory in the SG at the time of the trip to provide margin of at least ___ minutes before AF is required to prevent degraded core cooling.
10 Minutes
The SG Level-High RPS trip set point is set low enough to ensure a reactor trip occurs before the level reaches the ___
Steam dryers
A CPC IS or IS NOT considered inoperable if CEAC inputs to the CPC are inoperable?
IS NOT considered inoperable
For LCO 3.3.1, Each CPC channel contains 6 processor modules. Failure of which module makes a CPC channel inoperable per LCO 3.3.1?
ONLY CPC Processor Module failure. Aux CPC Processor Module failures do NOT make the CPC channel inoperable.
- CEAC 1/2 and CPP 1/2 area addressed in LCO 3.3.3
Compliance with LCO 3.3.1 Condition C.1 is met by placing the ___ and ___ for the Hi-Log power and DNBR/LPD bypasses respectively.
CR switches in “off” and “normal”
Most trips are not required to be OPERABLE in Modes 3,4 and 5. Exceptions to this are:
- Log Power Level - Protects Boron dilution and CEA withdrawal events
- SG Pressure-Low - Protects MSLB in Mode 3
For SG Level-Low (WR) process measurement circuit, which Functional Units must be Bypassed or Tripped when that circuit is inoperable or in test?
- SG Level-Low (RPS)
- SG #1 Level-Low (ESF)
- SG #2 Level-Low (ESF)
If 1 RPS channel is in trip and a 2nd channel is in bypass, a 3rd inoperable channel would ___
Place the unit in LCO 3.0.3
Most Functions per LCO 3.3.1 and Table 3.3.1-1 are subject to what 4 SR tests?
1 - Channel Check
2 - Channel Functional Test
3 - Channel Calibration
4 - Response time testing
Per LCO 3.3.1, SR 3.3.1.6…
When power is ___ the CPCs do not use the excore generated signals for axial flux shape information.
<15%
Per LCO 3.3.1, SR 3.3.1.12…
SR 3.3.1.12 is applicable only to operating bypass functions and is performed once within ___ prior to each startup.
within 92 days prior to each startup
*92 days based on reliability analysis from CEN-327
Why are neutron detectors excluded from RPS RESPONSE TIME SR’s and several other SR’s for LCO 3.3.1?
Because they are passive devices with minimal drift and the difficulty of simulating a meaningful signal
