Saftey Injection(SI) Flashcards
What provides capability for Reactivity Control of Core on the Safety Injection system ?
-HPSI
-LPSI
-Safety Injection Tank(SITs)
How does the Safety Injection provide short term and long term Heat removal ?
-HPSI
-LPSI
-Shutdown Cooling system
-Containment spray
How does the Safety Injection provide Pressure & inventory control ?
-HPSI
-LPSI
-Safety Injection Tanks (SITs)
What does Safety Injection provider for containment ?
Iodine removal
How does Safety Injection provide RCS inventory control during Station Blackout ?
-HPSI
How does Safety Injection prevent hydrogen build up in containment post-LOCA ?
Uses containment spray to reduce hydrogen build up
What events will cause Safety Injection system to be used ?
-Loss of Coolant Accident(LOCA)
-Control Element Assembly Ejection Accident
-Loss of secondary coolant including uncontrolled steam release or loss of Feedwater
-Steam Generator Tube Rupture
What are the Active Injection Equipment ?
-HPSI pumps
-LPSI pumps
What is the Passive Injection Equipment ?
Safety Injection Tanks
What kind of water is injected by the Safety Injection into the RCS ?
Borated water
SIAS ensures acceptable consequences during what kind of emergency events ?
-Loss of Coolant Accident( LOCA)
-Control Element Assembly ejection accident
-Steam Generator Tube Rupture(SGTR)
-Main Steam Line Breaks(MSLB) inside containment
ESFAS initiates a SIAS to actuate Saftey Injection when which 2-out-of-4 signals are met ?
-PZR pressure low 1837psia
-Containment Pressure high 3psig
How much time do the Refueling Water Tanks contain to maintain full safety injection flow ?
Has enough borated water for 20 minutes of injection flow with all pump on both trains operating at runout with 10% margin
When a SIAS is generated how much time does it take to deliver borated water to the core ?
Within a maximum of 29 seconds after SIAS
Which RCS legs do the HPSI pumps inject borated water into ?
HPSI injects water into all 4 cold legs
Which RCS legs do the LPSI pumps inject borated water into ?
Injects borated water into 2 RCS cold legs
When will all 4 Safety Injection Tanks inject into the RCS ?
They will inject when RCS Pressure drops below Safety Injection Tank Pressure
What happens when Refueling Water Tank reaches 9.4% ?
-A Recirculation Actuation Signal is actuated
-Containment Recirc. Sump Isolation valves will automatically open to supply both trains of HPSI pumps
What valves automatically close when a RAS actuates? What valves must be manually closed on a RAS ?
-All safety Injection Pump Recirculation valves close
-RWT outlet valves must be manually closed by the control room following a RAS
Post LOCA initiation how long will it take to establish Long Term Core Cooling ?
2-3 hours Long Term Cooling will be Established
What flow paths does Long Term Cooling use ?
1.)Containment Recirc. pump supplies both train HPSI pumps
2.) HPSI pumps discharge flow is split 50% to 4 Cold Legs; 50% Hot Leg
How is the HPSI flow discharge split during Active Injection Long Term Cooling ?
The control room manually operates MOVs to split the flow 50/50 between the cold legs and hot leg by
Why is there a 50/50 split of flow between the 4 cold legs & the hot leg during Long Term Cooling ?
-Maintains subcooling
-Insures flushing to prevent boiling induced boron precipitation in Reactor Core, which could cause heat removal to be diminished
What happens to Safety Injection Pump Recirc. Valves during a RAS ?
All safety Injection Pump Recirculation valves are closed