40EP-9EO06 Loss of all Feedwater (LOAF) Flashcards
What are the major mitigating steps for LOAF
- Stop all RCP’s (stop heat input)
- Isolate SG liquid outputs (conserve inventory)
- Restore feed to at least 1 SG
- Evaluate c/d to SDC or stay in HSBY
For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the Reactivity Control SFSC
- < 2x10-4% ↔ or ↓
- All FSCEA inserted OR borating > 40gpm OR SDM established
For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the Maintenance of Vital Auxiliaries SFSC
- At least 1 PB
- same train as PB: PKA, PKC, and PNA OR PKB, PKD, PNB
- Bus Plus
For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the RCS Inventory Control SFSC
- Lpzr 10-65%
- ≥ 24°F subcooling
- RVUH ≥ 16%
For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the RCP Press Control SFSC
- P/T limits
For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the Core Heat Removal SFSC
- Th < 650°F
- Max Quadrant CET < 650°F
For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the RCS Heat Removal SFSC
- Tc ↔ or ↓
For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the Containment Isolation SFSC
- CNTMT press < 2.5 psig
- No valid CNTMT or 2° RU alarms or rise
For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the CNTMT Temp and Press Control SFSC
- < 117°F
- < 125°F during a LOOP
- < 2.5 psig
During 40EP-9EO06 Loss of all Feedwater (LOAF), what actions are taken to help conserve SG inventory?
- Close SG BD CIV’s
- Close SG Sample CIV’s
During 40EP-9EO06 Loss of all Feedwater (LOAF), what are the possible methods to restore feedwater?
- AFA local reset or local operation
- AFB local brkr operation
- AFN local brkr operation OR swap control power (from D panel to batt chrgr)
- Re-align AFA/AFB suct. to RMWT
- Restart MFP’s
Establish Low press source:
- Condensate pump (off-site power required)
- Fire Pump (<100 psia)
When would you re-align AF pump suctions from CST to RMWT and why do you do it then?
- < 9’ in the CST
- Provides 20 minutes to swap
During 40EP-9EO06 Loss of all Feedwater (LOAF) if you are unable to re-establish feed what are you required to do?
- go to FRP
During 40EP-9EO06 Loss of all Feedwater (LOAF), when establishing a low pressure source how is the CDR controlled?
- 100°F/hr CDR can be exceeded
- Feed has priority over CD
During 40EP-9EO06 Loss of all Feedwater (LOAF), what should be considered PRIOR to establishing a low pressure source of feed?
- Going to FRP
- Using MVAC recovery
- Power AF from opposite side power
During 40EP-9EO06 Loss of all Feedwater (LOAF), when should a fire pump be used as a feed source?
- ONLY if timely recovery of higher press feed source is improbable
During 40EP-9EO06 Loss of all Feedwater (LOAF), how are the usage of AFA/ AFB/ AFN different if there is also a LOOP?
- LOOP condensate pumps stop
- AFN usage delayed IF AFA/ AFB available
- MFW piping needs sufficient time to cool to minimize water hammer
During 40EP-9EO06 Loss of all Feedwater (LOAF), if CW flow to the main condensers is lost what actions are required?
Why are these actions required?
- Close MSIV’s and bypasses
- Blowdown select switch to OFF
- Close Steam trap isolation 1135/1136
- Prevents over pressurization of condenser
What are the indications of SG dryout? When is a SG considered to be in a dryout condition?
- EOP consider SG’s at dryout when below 0% WR on any CR indicator
Actual Dryout:
- SG press decays rapidly
- Loop ▲T↓ as Tc ↑ to Th
How long until core uncovery occurs following LOAF and SG Dryout?
- 1 Hour
During 40EP-9EO06 Loss of all Feedwater (LOAF), how is Feedwater restoration different if a SG has dried out?
- if 1 or more SG have dried out feed only 1
- Feed SG with inventory
- If both are dry feed last to go dry
Following SG Dryout, what is the max feed rate and why?
- ≤ 1000 gpm (≤ 0.5 E6 lbm/hour)
- Reduce damage due to stress on SG from cold feedwater
