Purge and Ventilation Flashcards
What is supplied by the Radwaste Area HVAC System?
Aux Bldg ventilation, including East/West Safeguards
Function/purpose of the Radwaste Area HVAC System?
- Supply suitable environment for equipment and personnel
- Air flows from high radioactivity to low radioactivity
- Exhaust air goes through a HEPA filter
- Exhaust > Supply to maintain a negative pressure
V-10, Radwaste Area Supply Fan, interlocks
- Supply dampers open/closed when ventilator is started/stopped
- V-14A/B that is in standby trips when V-10 trips
- V-10 trips on high rad on radwaste area rad monitor
V-14A/B, Radwaste Area Exhaust Fans, interlocks
- Associated damper opens/closes when fan is started/stopped
- If air flow < 25%, standby fan will start
- Exhaust dampers modulate to maintain set pressure in exhaust plenum
PO-1809, East/North Corridor Supply Damper, function
Closes on high rad to isolate the header that is most likely the source of high rad, as this header supplies both safeguards rooms and radwaste rooms 590 Aux Bldg
Why is 1 V-14 required to be operating?
Needed for adequate sampling of rad monitors and to prevent potential contamination of personnel using fume hoods in the chemistry sample area
What are the Radwaste Area HVAC requirements when the equipment hatch is open?
V-10 and V-14A/B should be on
What are the Radwaste Area HVAC requirements when transferring V-6A/B Main Exhaust Fans?
V-10 and V-14A/B need to be stopped before transferring to prevent backflow through the filters, causing a radioactive release
What is the order for starting fans in the Radwaste Area HVAC System?
- place rad monitor in service
- start a V-14
- start V-10
What is the order for stopping fans in the Radwaste Area HVAC System?
- inform chemistry before stopping V-14A/B
- stop a V-14
- stop V-10
- stop remaining V-14
V-69, Aux Bldg Addition Fuel Handling Area Supply Fan, interlocks
- supply damper opens/closes when fan starts/stops
- if V-69 trips, standby V-70A/B will trip (unless it’s running)
- V-69 trips on high rad
Fuel Handling Fan and Damper Emergency Trip handswitch positions
NORM - allows starting V-69 and V-70A/B
TRIP - trips V-69 and V-70A/B
What is supplied by the Aux Bldg Addition Radwaste Area HVAC System?
Cools/heats rad waste processing areas of the aux bldg
V-67, Aux Bldg Addition Radwaste Area Supply Fan, interlocks
- supply damper opens/closes with fan start/stop
- if V-67 trips, V-68A/B that is in standby trips
- high rad condition trips V-67
V-68A/B, Aux Bldg Addition Radwaste Area Exhaust Fans, interlocks
- exhaust damper opens/closes with fan start/stop
- if suction pressure drops to 1.5” water, with supply fan V-67 off, V-68A/B in standby will start
What is the purpose of the Penetration and Fan Room HVAC System?
Supplies filtered outside air to the area where the main feed and main steam piping penetrate containment
What temperature does the Penetration and Fan Room HVAC System maintain the main feedwater penetration area?
100 F
What temperature does the Penetration and Fan Room HVAC System maintain the main steam penetration area?
110 F
What temperature does the Penetration and Fan Room HVAC System maintain the fan room area?
120 F
V-78, Penetration and Fan Room HVAC System Supply Fan, operation
- suction damper opens/closes on fan start/stop
- fan starts at 90 F and stops at 70 F
- high rad condition @4 mR/hr trips V-78
V-79, Penetration and Fan Room HVAC System Exhaust Fan, operation
- exhaust damper opens/closes on fan start/stop
- fan starts at 90 F and stops at 70 F
- high rad condition @4 mR/hr trips V-78
V-78/79, Penetration and Fan Room HVAC Supply/Exhaust Fans, fan controls
3 position handswitch MAN/OFF/AUTO
MAN - both fans start and associated dampers open
OFF - both fans stop and associated dampers close
AUTO - fans and dampers operate off of temperature
What is the purpose of the Containment Purge System?
Ventilate containment when shutdown in Modes 5 and 6
What are the interlocks associated with V-46, Air Room Supply Fan?
- when the fan starts, the suction damper and air room damper open
- fan trips on CHP/CHR
What is the purpose of the air room damper opening when the air room supply fan starts?
Damper opens to allow air to circulate through the entire containment, not just the air room
Containment Purge supply and exhaust dampers operation
- fail closed
- close on CHP/CHR
What is a precaution associated with the RGEM System during containment purge?
If RGEMS or any of its channels becomes inoperable during containment purge, then grab samples are required every 12 hours, and these samples are required to be analyzed for gross activity within 24 hours
LCO 3.7.13 “Engineered Safeguards Room Ventilation (ESRV) Dampers” requirements
2 ESRV Damper trains shall be operable
LCO 3.7.13 “Engineered Safeguards Room Ventilation (ESRV) Dampers” applicability
Modes 1-4
LCO 3.7.13 “Engineered Safeguards Room Ventilation (ESRV) Dampers” required actions in less than 1 hour
If 1 or more ESRV Damper trains are inoperable, then IMMEDIATELY initiate action to isolate the associated ESRV Damper train
What is the purpose of the Engineered Safeguards Room HVAC System?
Maintains safeguards rooms cool for equipment cooling
What HVAC system supplies/exhausts air to/from the Engineered Safeguards Room HVAC System?
Radwaste Area HVAC (V-10 and V-14A/B)
What is safety related in the Engineered Safeguards Room HVAC System?
- coolers
- SW piping and control valves
- dampers, damper positions, and isolation signals
What are the Safeguards Rooms Cooling Fans V-27A/B/C/D power supplies?
V-27A/C - MCC-1
V-27B/D - MCC-2
V-27A/B/C/D controls
HAND - starts fan
AUTO - fan starts at 85 F room temperature
STANDBY - fan starts at 90 F room temperature
PULL TO LOCK - stops fan and disables start
How do the Engineered Safeguards Rooms supply and exhaust dampers operate?
- fail closed
- close on high rad signal, isolating fresh air to/from the room. Air within the room is then just circulated through the cooler to maintain room temperature
How do you reopen ESS Room dampers after a high rad condition?
Have to push the “Radwaste Area High Rad Isolation Reset” push button
Which ESS Room Cooler Fans are safety related?
V-27B/C
What needs to be done if an ESS Room rad monitor is inoperable?
Close the dampers for that room
At what temperature are ESS components inoperable?
< 42 F
LCO 3.7.12 “Fuel Handling Area Ventilation System” requirement
The Fuel Handling Area Ventilation System shall be operable with 1 fuel handling area exhaust fan aligned to the emergency filter bank and in operation
LCO 3.7.12 “Fuel Handling Area Ventilation System” applicability
- during movement of irradiated fuel assemblies in the fuel handling building when irradiated fuel assemblies with < 30 days of decay time are in the fuel handling building
- during movement of a fuel cask in or over the SFP when irradiated fuel assemblies with < 90 days of decay time are in the fuel handling building
- during core alterations when irradiated fuel assemblies with < 30 days decay time are in containment with the equipment hatch open
LCO 3.7.12 “Fuel Handling Area Ventilation System” required actions in less than 1 hour
If the Fuel Handling Area Ventilation System is not aligned or in operation OR is inoperable, then IMMEDIATELY stop movement of fuel assemblies, stop core alterations, and stop movement of a fuel cask in or over the SFP
What is the purpose/function of the Fuel Handling Area Ventilation System?
- supplies heated/cooled air to the SFP area to permit personnel access and to control airborne radioactivity in the area
- limits site boundary dose rates during a fuel handling or cask drop accident
V-7, Fuel Handling Area Supply Fan, interlocks
suction damper opens when fan starts
D-977/978, Fuel Handling Area Exhaust Dampers, controls
Only 1 in service at a time
REFUEL/NORMAL handswitch
REFUEL - directs flow through a charcoal filter
NORMAL - directs flow through normal HEPA filter
What is the required Fuel Handling Area Ventilation System lineup when in REFUEL mode?
ensure the supply fan V-7 is off, and only 1 exhaust fan V-8A/B on, so as not to exceed the capacity of the charcoal filter
What are the V-8A/B Fuel Handling Area Ventilation System Exhaust Fans power supplies?
V-8A - MCC-7
V-8B - MCC-8
What is the purpose/function of the Main Exhaust System?
collects ventilation exhaust from containment and aux bldg ventilation, monitors it via RGEM, and exhausts it out the stack
What are the power supplies for V-6A/B, Main Exhaust Fans?
V-6A - LCC-12
V-6B - LCC-12
What are the interlocks associated with V-6A/B?
fan won’t start until its associated damper is open
What is the standby feature associated with V-6A/B?
non running fan will start if running fan trips
What happens to V-6A/B after a load shed?
- fans won’t automatically restart due to the fans not being considered for EDG loading
- in order to restart the fans, a relay must be reset on the back side of LCC-11/12
Main Exhaust Dampers design features
- fail closed
- when V-6A/B is taken to start, damper opens. once damper is open, the fan will start
- open on exhaust plenum pressure of 2” and rising
SOP notes and precautions associated with Main Exhaust Fans
- if both V-6A/B are off, then all other plant ventilation should be secured
- only 1 V-6 shall be in operation at a time