Containment Spray System(NS) Flashcards
What is the purpose of the Containment Spray System?
- Remove thermal energy from containment atmosphere in the event of a LOCA.
- Maintains containment pressure below the design limit of 15psig after all the ice has melted in the ice condenser and steam generated in the core continues to enter the containment
- Remove fission product iodine from the post accident containment atmosphere
What is the normal suction path alignment for the Containment Spray System?
The Containment Spray pumps are normally aligned to the FWST when in standby
When will we ever spray the Containment from the FWST?
NEVER
What features provide for protection against accidental actuation of Containment Spray?
- The spray header isolation valves are normally closed
2. Multiple redundant instruments are used for containment pressure
How many Containment Spray Pumps are there, What is the flow rated of one Containment Spray Pump, and what provides cooling to their motors?
- There are 2 containment spray pumps per unit, one per train
- Design flow rate is 3400gpm at 168psig
- KC provides motor cooling for the containment spray pumps
What is the power supply to the Containment Spray Pumps?
ETA/ETB
What is the design/purpose of the Containment Spray Heat Exchangers?
- There are two NS heat exchangers per unit, one per train
- Vertical shell and tube
- Borated water used to spray flows through the shell
- RN flows through the tubes
What system provides cooling to the Containment Spray Heat Exchangers, and how is it aligned?
- The nuclear service water system provides cooling
2. RN has to be manually aligned
What is the maximum Nuclear Service Water flow through the Containment Spray Heat Exchangers, and why?
- Maximum RN flow through the heat exchanger is 4650gpm
2. Flow is limited to prevent vibration induced stress in the tubes
How many spray headers are there in Containment?
- There are 4 spray headers from the Containment System, two per train
- There are 2 additional spray headers from the Residual Heat Removal System.The ND spray headers are not connected to the NS system
Where are the motor operated valves in the Containment Spray System?
The motor operated containment isolation(2 per train) valves are located outside of containment, and are manually opened for to actuate spray
How is water returned from Containment Spray to Lower Containment?
The refueling cavity drains(6 drains)are normally open, and they allow water from containment spray to flow back to the lower containment
What is the general rule about the Containment Spray Pump Suction Valves?
Only one source of water can be aligned at a time to the spray pump suction
What is required to open the Containment Spray Suction Valves from the Containment Sump(NS-1B and NS-18A)?
- The FWST suction valves must be closed(NS-20A and NS-3B)
2. The NI valves from the containment sump must be open(NI-185A and NI-184B)
What is required to open the Containment Spray Suction Valves from the FWST(NS-3B and NS-20A)?
The containment spray suction valves from the containment sump(NS-1B and NS-18A) must be fully closed