Control Building HVAC (HJ) Flashcards
If the ESF Switchgear Normal AHU (HJN-A03)discharge damper (HJA-M66) is OPEN and discharge damper (HJB-M66) is CLOSED, will the AHU start if given a start signal?
Yes, the ESF Switchgear Normal AHU (HJN-A03) will run if only one of its discharge dampers HJA-M66 or HJB-M66 is OPEN.
Conversely, the AHU will stop when both dampers go CLOSED.
The ‘A’ CR Normal AHU discharge isolation damper (HJA-M01) is OPEN and the ‘B’ discharge isolation damper (HJB-M01) is CLOSED. The RO goes to start the CR Normal AHU (HJN-A02); will the AHU start?
Interlocks exists that will prevent the CR Normal AHU (HJN-A02) from starting unless both of its discharge dampers (HJA-M01 & HJB-M02) are OPEN. In addition, a closure of either of these dampers will trip off the AHU. Dampers isolate on SIAS, LOP, CREFAS or CRVIAS. Fan trip: either discharge damper closed (M01A/M01B)
What ESFAS signal will start the ESF Switchgear Essentials?
SIAS or LOP
What will trip the Battery Room Ventilation Normal Exhaust Fans?
Battery Room Ventilation Normal Exhaust Fans (4)
* Takes suction on associated battery room
* Discharges directly to outside
* Power: NHN
* Start/Stop MCR HS (4)
* Auto trips:
o CO2 actuation in battery room
o Battery room essential fan running (high ∆P)
What will auto start/trip the Battery Room Ventilation Essential Exhaust Fans?
Battery Room Ventilation Essential Exhaust Fans (4)
* Same flow path as normal exhaust fans
* A (A-A, A-B) train fans aligned to Battery Rooms A/C
* B (B-B, B-A) train fans aligned to Battery Rooms B/D
* Power: PHA/PHB
* Auto start: SIAS or LOP
* Auto trip: high fan ∆P
o Could be caused by CO2 damper closing
o High pressure alarm in MCR
* B train has App. R controls
What will trip the ESF Switchgear Normal AHU?
ESF Switchgear Room Normal AHU (1)
* Assists Control Building Normal AHU in cooling DC equipment and ESF switchgear rooms.
* Cooled by WC
o TCV adjusts WC flow based on outlet air temp
* Power: NH
* Discharge dampers (2) isolate on SIAS or LOP
o Discharge splits to A and B train ESF equipment
* Start interlock: 1 of 2 discharge dampers open
* Trip: Both discharge dampers closed
How do the Control Room Essential AHU Outside Air Duct Isolation dampers fail on loss of power? What ESFAS signal causes these dampers (HJA-M02/3 & HJB-M02/3) to close?
Control Room Essential AHUs (2)
* Suction from MCR and outside (except CRVIAS), then to filter bank, cooling coils, to MCR.
* PGA/PGB
* Outside suction dampers (Electro-hydraulic)
o A/B train dampers in series to each fan
o Fail open on loss of power (PHA/PHB D panels)
o Auto open: SIAS, CREFAS or LOP (can be overridden)
o Auto close: CRVIAS (either train isolates both paths) (NO override)
o B train App. R controls
* AHU auto starts (from BOP-ESFAS):
o SIAS, CSAS, LOP (5 sec TD from sequencer)
o CRVIAS or CREFAS (No TD)
What will auto start the Control Room Essential AHU’s?
Control Room Essential AHUs (2)
o B train App. R controls
AHU auto starts (from BOP-ESFAS):
SIAS, CSAS, LOP (5 sec TD from sequencer)
CRVIAS or CREFAS (No TD)
What is the design basis for the Control Building HVAC?
- ≤ 5 rem whole body exposure during accident
- 30 day occupancy
What will auto close the dampers of the Control Building Normal Smoke Exhaust Removal Fan on the 140’ and 100’?
Control Building Normal Smoke Exhaust Removal Fan
* Capable of taking suction from all levels of the Control Building to evacuate smoke.
* Only one level of control building should be ventilated at a time (manually align flow path)
* Suction from outside air intake plenum
* Discharges to roof
* Fan controlled from B02 (no interlocks)
* 140’ level dampers:
oAuto close on LOP, SIAS, CRVIAS or CREFAS.
o No override
* 100’ level dampers:
o Auto close on LOP or SIAS.
o No override features for the dampers.
Dampers fail close on loss of power or air.
How does the DS system support Control Buildling HVAC?
DS supplies air washer water makeup
