SBLC Flashcards
What is the purpose of the SBLC System?
Provides a backup system to bring the Rx to shutdown condition from any time independent of CRD System. (Per UFSAR, control pH at or above 7 during LOCA)
Why is SBLC NOT a backup for RPC Scram?
Due to the time necessary to initiate and inject full contencts
What are teh design bases for SBLC system?
- Used to maintain Torus pH at or above 7 following LOCA with significatn fission product release to ensure iodine will be retained in Torus w/ Rx at 100% power wtih equilibrium Xenon and rods in normal pattern
- Equivalent concentration of Boron of 600ppm at 68F in core (918ppm in less than 100 minutes to bring Rx from full power to 1% dk or more sub-critical)
- Designed to provide for additional margin of 25% boron to compensate for possible losses and imperfect mixing
What must the boron concentration be maintained at to achieve design concentration in core following injecton?
14% by weight at 40gpm to achieve 918ppm boron in less than 100minutes (3605 gallons of mixture)
During Hot Shutdown and Cold Shutdown Conditions, how much SBLC injection is required to bring to stable condition?
Hot: Injected to tank level of 39%
Cold: Injected to tank level of 14%
What is the saturation temperature of the Boron solution and what temperature is required to maintain it in liquid form?
saturation temperature of 62F - causes crystalization if lower
Kept above 83F (TS) and tank set at 95F
What positive reactivity effects must SBLC overcome?
Elimination of Steam Voids Moderator Temp drop to 125F Deduced doppler effect Decreased rod worth as boron competes with rods Xenon Decay
What MCR indications are there for SBLC?
5 lights - Flow, Squib, Pump 1, Pump 2
Discharge Pressure
Tank Level
1-vlv (Normally LO)
What are the 3 primary test flow paths?
Clean Demin from test tank pumped back to test tank
Clean Dmn from test tank Pp and inject to Rx
Mn Tnk pumped to Test Tank
What is capacity of Boron Storage Tank?
5250 gallons
What is the purpose of the SERVICE AIR sparger?
Provides thorough mixing of solutions
What provides power to SBLC Tank Heater?
Normal Setpoint?
Trip?
Powered by MCC 29-1 (38-1)
Normally set at 95F
Trips at level <15% (19.5”)
What is the purpose of the SBLC Tank Bubbler and what supplies it?
Bubbler used for level indication - supplied using Instrument Air
What is the total flow and pressure for the SBLC Pumps?
Total Flow of 80gpm (40gpm per Pp) at 1330psig
Design flow is 40gpm PER pump at 1500psig
What are the power supplies for the SBLC Pumps?
2A - MCC 28-1/ 2B - MCC 29-1