TS 3.3.1 Reactor Protective System (RPS) Instrumentation - Operating

Question 1

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

Answer 1

Four

APPLICABILITY: According to Table 3.3.1-1

Question 2

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 ___

Answer 2

Measurement channels
Bistable trip units

ALSO automatic bypass removal feature for those trips with operating bypass

Question 3

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)

Answer 3

DNBR Margin, LPD margin, calibrated neutron flux power levels

Provide DNBR-Low and LPD-High pretrip and trip signals

Question 4

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”

Answer 4

Non-conservative

Question 5

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:

Answer 5

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)

Question 6

The RPS-VOPT can provide protection against core damage during the following events:

Answer 6

1 - Uncontrolled CEA Withdrawal from subcritical and Low Power (AOO)
2 - CEA Ejection (Accident)

Question 7

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?

Answer 7

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

Question 8

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:

Answer 8

1 - Loss of Condenser Vacuum
2 - CEA withdrawal from low power conditions
3 - CVCS Malfunction (AOO)
4 - Main FW System Pipe Break (Accident)

Question 9

Per LCO 3.3.1 every Function has an Applicability of Modes 1 and 2 EXCEPT for ___

Answer 9

Log Power Level - High

• Applicable in Mode 2 ONLY

Question 10

What is the NOTE for LCO 3.3.1?

Answer 10

Separate Condition entry is allowed for each RPS function

Question 11

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?

Answer 11

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(

Question 12

LCO 3.3.1 Condition B -
One of more Functions with 2 automatic RPS trip channels inoperable.

Required Actions and Completion Times?

Answer 12

B.1 - Place 1 channel in bypass and the other in trip (1 Hour)

Question 13

LCO 3.3.1 Condition C -
One or more Functions with 1 automatic bypass removal channel inoperable.

Required Actions and Completion Times?

Answer 13

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)

Question 14

LCO 3.3.1 Condition D -
One or more Functions with 2 auto bypass removal channels inoperable.

Required Actions and Completion Times?

Answer 14

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)

Question 15

LCO 3.3.1 Condition E -
Required Action and associated Completion Time not met.

Required Actions and Completion Times?

Answer 15

E.1 - Be in Mode 3 (6 Hours)

Question 16

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 ___

Answer 16

Analytical Limit and the Total Loop Uncertainty

Question 17

The Log Power Level - High Trip operating bypass is auto removed when log power decreases below ___

Answer 17

1E-4% NRTP

Question 18

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?

Answer 18

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

Question 19

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.

Answer 19

10 Minutes

Question 20

The SG Level-High RPS trip set point is set low enough to ensure a reactor trip occurs before the level reaches the ___

Answer 20

Steam dryers

Question 21

A CPC IS or IS NOT considered inoperable if CEAC inputs to the CPC are inoperable?

Answer 21

IS NOT considered inoperable

Question 22

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?

Answer 22

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

Question 23

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.

Answer 23

CR switches in “off” and “normal”

Question 24

Most trips are not required to be OPERABLE in Modes 3,4 and 5. Exceptions to this are:

Answer 24

1. Log Power Level - Protects Boron dilution and CEA withdrawal events
2. SG Pressure-Low - Protects MSLB in Mode 3

Question 25

For SG Level-Low (WR) process measurement circuit, which Functional Units must be Bypassed or Tripped when that circuit is inoperable or in test?

Answer 25

1. SG Level-Low (RPS)
2. SG #1 Level-Low (ESF)
3. SG #2 Level-Low (ESF)

Question 26

If 1 RPS channel is in trip and a 2nd channel is in bypass, a 3rd inoperable channel would ___

Answer 26

Place the unit in LCO 3.0.3

Question 27

Most Functions per LCO 3.3.1 and Table 3.3.1-1 are subject to what 4 SR tests?

Answer 27

1 - Channel Check
2 - Channel Functional Test
3 - Channel Calibration
4 - Response time testing

Question 28

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.

Answer 28

<15%

Question 29

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.

Answer 29

within 92 days prior to each startup

*92 days based on reliability analysis from CEN-327

Question 30

Why are neutron detectors excluded from RPS RESPONSE TIME SR’s and several other SR’s for LCO 3.3.1?

Answer 30

Because they are passive devices with minimal drift and the difficulty of simulating a meaningful signal