Secondary Containment (T22) Flashcards
What is the normal configuration for SEC coolers?
During normal ops on both units
1 SEC cooler is running in CRD diagonal (cools running CRD pump), in RCIC room & in HPCI room.
All other SEC coolers are secured
Auto start initiates “SEC Auto Initiation Signal Present” P650 / P657
What auto starts the CRD diagonal coolers?
CRD diagonal: In AUTO both auto start on High CRD room temp: A (95°F) & B (100°F)
What auto starts the RCIC diagonal coolers?
RCIC diagonal: In AUTO both auto start on RCIC initiation (E51F045 open) or High RCIC diagonal temp: A 100°F & B 100F (105F)
What auto starts the HPCI room coolers?
HPCI room: In AUTO both auto start on HPCI initiation (E41F001 open) or High HPCI room temp: A 100°F & B 100F (105F)
What auto starts the SE CS/RHR diagonal coolers?
SE CS/RHR diagonal: In AUTO both auto start on
CS ‘B’ (A) running or RHR ‘B or D’ (‘A or C’) running or High SE diagonal temp: A (135°F) & B (140°F)
What auto starts the NE CS/RHR diagonal coolers?
NE CS/RHR diagonal: In AUTO both auto start on
CS ‘A’ (B) running or RHR ‘A or C’ (‘B or D’) running or High NE diagonal temp: A (135°F) & B (140°F)
What is the purpose of Secondary Containment?
Minimizes the ground level release of airborne radioactive materials and provide for the controlled, filtered, and elevated release of the Rx Bldg atmosphere under accident conditions.
Resulting exposures are kept to a practical minimum and are w/in the guideline values given in 10 CFR 20 & 50.67
What components/buildings comprise Secondary Containment?
Secondary Containment consists of: Rx Bldg Refueling floor SBGT Main Stack Rx Bldg HVAC system
What is the normal pressure maintained inside Secondary Containment? When is the alarm?
In order to ensure that any leakage is into the building, secondary containment is designed to be maintained at a slightly negative pressure:
-.20” H2O relative to the building exterior
Alarm -0.18” H2O (0.0” H2O)
What are the two groups that Secondary Containment is divided into?
HVAC systems open in SC to outside environment contain double isol valves w/ position-indicating lights in the MCR.
ECCS systems (RHR Service Water, CST line, etc.) designed to engineered safeguard standards and criteria
What are the three zones of Secondary Containment?
U1 Rx Bldg – Zone I
U2 Rx Bldg – Zone II
U1 & U2 Refueling Floor – Zone III
*Easy way to remember, U1 = 1, U2 = 2, U1 + U2 = 3
What are the isolation signals for Secondary Containment?
A/B inboard & C/D outboard
Low RWL -35”
Hi Drywell Pressure 1.85 #
Hi Rx Bldg Vent Rad (K609) 18 mR
Hi R/F Vent Rad (K611) 18 mR
U2 Only:
U2 R/F Vent Hi Rad
(K634) West dryer/Sep pool 6.9 mR
(K635) East dryer/Sep pool, FP 5.7 mR
*All the same setpoints as Group 2 isolation, except for RWL at -35” instead of +3” for a Group 2.
What conditions must be met for Secondary Containment integrity to exist?
ALL MUST BE MET:
Containment is intact
SBGT is operable
At least one door in each access to the secondary containment is closed
The sealing mechanism associated w/ each penetration is operable
Secondary containment integrity maintained at all times EXCEPT when which conditions are met?
ALL MUST BE MET:
Rx is in Modes 4 or 5
No core alterations are being performed
No irradiated fuel is being moved inside the secondary containment
No ongoing OPDRVs (Operation with Potential to Drain the Rx Vessel)
What is the response to a Secondary Containment isolation signal?
Supply & exhaust fans TRIP & ventilation dampers close for:
U1 RB Zone I
U2 RB Zone II
U1 & U2 RF Zone III
U1 SBGT STARTS & takes suction on U1 Rx Bldg & Refueling Floor
U2 SBGT STARTS & takes suction on U2 Rx Bldg & Refueling Floor
