N-16 System Flashcards
List the three critical functions of the N-16 System.
- Measure neutron levels.
- Acts as heat sink to cool PALM U-Cup Seal
- Provide pressurized water source to fill ATR vessel level transmitter, standing leg, and associated impulse lines.
What is the function of neutron level detection from the N-16 system?
Data is supplied to the Lobe Power Calculation and Indication System to determine power offset and display power split information to the RO.
What N-16 lobe powers are required for plant startup?
NE
SE
NW
SW
C
C/2
Draw the N-16 system.
What are the two supplies to N-16?
BPD and LDW
What is the function of PRV-18-186?
PRV-18-186 regulates BPD pressure from 300 psig to 100 psig for supply to PRV-8-136.
What is the function of PRV-8-136?
Lowers suction pressure to N-16 pumps from 100/120 psig to 20 psig.
What is the function of N-16 strainers M-134/135?
80 mesh strainers that strain suction source to N-16 pumps.
What is the design flow and pressure for the N-16 pumps?
18 GPM @ 510 psig
What is the function of PRV-18-7?
PRV-18-7 provides recirculation flow from N-16 discharge at 6 GPM/250 psig to ensure stable system pressure.
What is the function of PCV-18-9?
Pressure control to N-16 station 11 at 12 GPM/400 psig
What is the N-16 flowrate to PALM test seals when in use?
1.5 GPM
Describe flow distribution through N-16 station 11.
Flow at station 11 is divided and metered into 10 individual streams of 1.15 GPM.
Where does station 11 effluent from the reactor go?
N-16 water from the beta counting chambers is routed to the gland seal water feed tank.
When is BPD used as source to N-16?
Preferred source during reactor operation.
When is LDW used as source to N-16?
- If BPD flow transmitter FT-18-29 is OOS
- During outages when PCS is depressurized and BPD isolated
- BPD water activity is too high
Where is FT-18-29 BPD to N16 Total Flow Transmitter located?
BPD Corridor (Second Basement)
Where is N-16 PRV-18-186 located?
South wall of the HDW Room.
What is the fail position of PRV-8-136?
PRV-8-136 fails closed.
Describe M-130/131 N-16 Pumps.
Single stage, gear-driven centrifugal inline pumps
30 GPM@470 psig
Normal 18 GPM@510 psig
Describe N-16 pump cooling.
Pump oil sumps are cooled with raw water supplied from the canal HX raw water supply (return to canal HX discharge)
Describe impact of abnormally high or low flow through N-16 pumps.
- <18 GPM - causes excessive vibration and pressure surging
- > 30 gpm - causes substantial drop in output pressure (potential motor overload)
What is the purpose of the LDW line backflow preventers concerning N-16 system?
Prevents contamination of the LDW supply piping from N-16.
What is the purpose of the suction strainers in the N-16 system?
Prevent particulate matter from entering the fine flow control valves of station 11.