-
During normal full power operation of Unit Two the following alarms and indications are noted:
SERVICE AIR PRESS LOW alarm Sealed In
RB INSTR AIR RECEIVER 2A PRESS LOW Not in Alarm
RB INSTR AIR RECEIVER 2B PRESS LOW Not in Alarm
Instrument Air header pressure 100 psig
Service Air header pressure 100 psig
Which one of the following actions is required in accordance with 0AOP-20, Pneumatic System Failures?
A. Start SBGT.
B. Close the manual Noninterruptible Isolation Valves.
C. Close the Service Air isolation valves, PV-706-1 and PV-706-2.
D. Close the Reactor Building Isolation Dampers.
C. Close the Service Air isolation valves, PV-706-1 and PV-706-2.
As service/instrument air pressures lower, a series of actions are required per the AOP. 105# SA - Service Air Isolation Vlvs 706-1 &2 are ensured closed. With these conditions, Service air alarm would come in at 107# and should have isolated at 105#. With indication on the service air header still at 100# indicates that this action has not occurred, and the action should be taken.
-
Unit Two has a small line break in the drywell. Conditions are as follows:
RPV Level 35" (N026NB)
RPV Pressure 980 psig
Drywell Pressure 6 psig
Div I and II PNS Pressure 125 psig
Div I and II B/U Nitrogen System 115 psig
Based on these conditions and without the use of any overrides, the continuous
Pneumatic supply to the SRVs is from:
A. PNS only.
B. Backup Nitrogen only.
C. either PNS or Backup Nitrogen.
D. Neither PNS nor Backup Nitrogen.
B. Backup Nitrogen only.
A LOCA signal exists from low RPV level. The LOCA signal closes RNA isolation valves (group 10) to the drywell. The signal is also sent from RNA isolation valve logic to open the backup nitrogen valves. Backup Nitrogen is considered to provide acontinuous supply as long as header pressure in either division remains above 95 psig.
-
Unit 2 is in MODE 3 following a seismic event and plant scram.
Unit 2 conditions are:
Reactor level 55 inches
Reactor pressure 500 psig
Drywell pressure 9 psig
Division I PNS Header pressure 93 psig
Division II PNS Header pressure 98 psig
Which one of the following describes the status of the Backup Nitrogen Isolation Valves?
A. Div I Nitrogen Backup Isolation Valves, RNA-SV-5482 is open.
Div II Nitrogen Backup Isolation Valves, RNA-SV-5481 is open.
B. Div I Nitrogen Backup Isolation Valves, RNA-SV-5482 is open.
Div II Nitrogen Backup Isolation Valves, RNA-SV-5481 is closed.
C. Div I Nitrogen Backup Isolation Valves, RNA-SV-5482 is closed.
Div II Nitrogen Backup Isolation Valves, RNA-SV-5481 is open.
D. Div I Nitrogen Backup Isolation Valves, RNA-SV-5482 is closed.
Div II Nitrogen Backup Isolation Valves, RNA-SV-5481 is closed.
B. Div I Nitrogen Backup Isolation Valves, RNA-SV-5482 is open. Div II Nitrogen Backup Isolation Valves, RNA-SV-5481 is closed.
-
Which one of the following identifies the signal(s) that will initiate the Backup Nitrogen System, including the reason for the Backup Nitrogen System?
A. Low Reactor Building Instrument Air header or Core Spray LOCA signal.
Ensures operability of ADS valves and Inboard MSIV's.
B. Core Spray LOCA signal ONLY.
Ensures operability of ADS valves and Inboard MSIV's.
C. Low Reactor Building Instrument Air header or Core Spray LOCA signal.
Ensures operability of ADS valves and the Hardened Wetwell Vent Valves.
D. Core Spray LOCA signal ONLY.
Ensures operability of ADS valves and the Hardened Wetwell Vent Valves.
C. Low Reactor Building Instrument Air header or Core Spray LOCA signal. Ensures operability of ADS valves and the Hardened Wetwell Vent Valves.
- Following a core Spray LOCA and containment isolation signal, the PNS supply to the DW will be isolated.
- The Backup Nitrogen System would supply pneumatics to SRV Accumulators, the Reactor Building to Suppression Chamber Vacuum Breaker Isolation Valves, and the Hardened Wetwell Vent Isolation Valves
|
|
