[CP] Containment Hydrogen Purge Flashcards
[CP]
2 subsystems of the CP system?
Purposes?
Refueling/Power Access Purge
Refueling Purge
– provides ventilation air for personnel comfort when the plant is shutdown during refueling operations and maintenance
Power Access Purge
– provides ventilation air to allow operator access for limited periods during power operation. Also controls pressure in the containment by periodically venting a portion of the containment air to plant vent
[CP]
What provides cooling to Refuel Purge AHU?
How is it controlled?
[NC] Normal Chilled Water
Automatically - maintains inlet air temperature at preset value
[CP]
When does [WC] provide cooling to Power Access Purge AHU?
High O/S Temp
[IA] interaction with [CP]?
Air for:
Dampers, valves, controllers, and CIVs
How is the system affected by a loss of IA?
Air operated dampers and valves fail closed, which will cause associated AHUs, AFU, supply or exhaust fans to trip
When is Refueling Purge Supply AHU operated?
Where is it located?
Mode 5/6
AB Roof
[CP]
How does the Power Access Purge Supply AHU do if O/S temp is too low?
Electric heating coils energize.
[CP] Power Access Purge Supply AHU controlled from?
Where is it located?
Control Room
AB Roof
[CP]
Why is there a heater installed up stream of the Power Access Purge Normal Exhaust AFU?
Prevents humidity from damaging charcoal filter down stream.
Concerning the Power Access Purge Normal Exhaust AFU, what is the purpose of the charcoal filter and second HEPA filter?
Charcoal filter removes fission product gases (mainly iodine) by adsorption
Second HEPA filter removes any carbon dust emitted from the charcoal filters
[CP]
Which [SQ] monitors Purge Discharge to Plant Vent?
RU-37/38
[CP] Auto functions for RU-37 and RU-38 with High Radiation?
CPIAS
What isolates [CP]? (2)
1 - CIAS
2 - RU-37/38 High Rad (CPIAS)
[CP] Two modes of Power Access Purge?
1 - Venting/Depressurization
2 - Power Access Purge
[CP] Purpose of Venting mode?
Depressurize CNTMT atmosphere during normal power operation or before power access purge
How is the CP system affected by a loss of Class 120 VAC?
Causes the CP system to shutdown and isolate from the containment
Power is lost to RU-37 (A Train) or RU-38 (B Train), which are used to generate CPIAS
How is the CP system affected by a loss of Non-Class 125 VDC?
Containment Refueling Purge AHU outlet dampers fail closed which will prevent operation of the AHU
Containment Power Access Purge AHU inlet damper fails closed which prevents operation of the AHU
Where does the containment purge system purge the containment atmosphere to? Where does the filtered and treated make-up come from?
plant vent stack
outside air
What is the flow path of the Containment Purge refueling purge subsystem?
outside air is drawn in through a single AHU with two fans. sends air through dampers and isolation valves to containment
two exhaust fans drawn air out of containment through dampers to the plant vent
some of the exhaust air flow goes through rad monitors with two external rad monitors as well
What does the containment purge refueling purge subsystem AHU consist of?
filter, heating and cooling coils two fans
In both of the containment purge subsystems, what happens when the exhaust rad monitors sense high radiation levels? The external rad monitors?
alarm
system isolates
[CP] Power access purge Flowpath?
O/S air
1 AHU
CNTMT Atmo
CNTMT Atmo
CIV
Heater
Exhaust AFU
Plant Vent w/ RU (internal and external)
What does the containment purge power access purge AHU consist of?
inlet damper
moderate & high efficiency filters,
coils,
fan
exhaust damper
[CP] Power access purge exhaust AFU
components (4)?
Where is it controlled from?
Location?
HEPA (Moderate)
charcoal,
HEPA filters
fan
Control Room
AB Roof
[CP] How many refueling purge exhaust fans are normally running while the system is in operation?
two, keeping containment at a slight negative pressure
What 2 systems operate together for containment clean-up? Power Access purge and ________________.
[HC] Pre-access Normal AFUs
