40EP-9EO06 Loss of all Feedwater (LOAF)

Question 1

What are the major mitigating steps for LOAF

Answer 1

• 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

Question 2

For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the Reactivity Control SFSC

Answer 2

• < 2x10-4% ↔ or ↓

- All FSCEA inserted OR borating > 40gpm OR SDM established

Question 3

For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the Maintenance of Vital Auxiliaries SFSC

Answer 3

• At least 1 PB
• same train as PB: PKA, PKC, and PNA OR PKB, PKD, PNB
• Bus Plus

Question 4

For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the RCS Inventory Control SFSC

Answer 4

• Lpzr 10-65%
• ≥ 24°F subcooling
• RVUH ≥ 16%

Question 5

For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the RCP Press Control SFSC

Answer 5

• P/T limits

Question 6

For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the Core Heat Removal SFSC

Answer 6

• Th < 650°F

- Max Quadrant CET < 650°F

Question 7

For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the RCS Heat Removal SFSC

Answer 7

• Tc ↔ or ↓

Question 8

For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the Containment Isolation SFSC

Answer 8

• CNTMT press < 2.5 psig

- No valid CNTMT or 2° RU alarms or rise

Question 9

For 40EP-9EO06 Loss of all Feedwater (LOAF), what is the CNTMT Temp and Press Control SFSC

Answer 9

• < 117°F
• < 125°F during a LOOP
• < 2.5 psig

Question 10

During 40EP-9EO06 Loss of all Feedwater (LOAF), what actions are taken to help conserve SG inventory?

Answer 10

• Close SG BD CIV’s

- Close SG Sample CIV’s

Question 11

During 40EP-9EO06 Loss of all Feedwater (LOAF), what are the possible methods to restore feedwater?

Answer 11

• 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)

Question 12

When would you re-align AF pump suctions from CST to RMWT and why do you do it then?

Answer 12

• < 9’ in the CST

- Provides 20 minutes to swap

Question 13

During 40EP-9EO06 Loss of all Feedwater (LOAF) if you are unable to re-establish feed what are you required to do?

Answer 13

• go to FRP

Question 14

During 40EP-9EO06 Loss of all Feedwater (LOAF), when establishing a low pressure source how is the CDR controlled?

Answer 14

• 100°F/hr CDR can be exceeded

- Feed has priority over CD

Question 15

During 40EP-9EO06 Loss of all Feedwater (LOAF), what should be considered PRIOR to establishing a low pressure source of feed?

Answer 15

• Going to FRP
• Using MVAC recovery
• Power AF from opposite side power

Question 16

During 40EP-9EO06 Loss of all Feedwater (LOAF), when should a fire pump be used as a feed source?

Answer 16

• ONLY if timely recovery of higher press feed source is improbable

Question 17

During 40EP-9EO06 Loss of all Feedwater (LOAF), how are the usage of AFA/ AFB/ AFN different if there is also a LOOP?

Answer 17

• LOOP condensate pumps stop
• AFN usage delayed IF AFA/ AFB available
• MFW piping needs sufficient time to cool to minimize water hammer

Question 18

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?

Answer 18

• Close MSIV’s and bypasses
• Blowdown select switch to OFF
• Close Steam trap isolation 1135/1136
• Prevents over pressurization of condenser

Question 19

What are the indications of SG dryout? When is a SG considered to be in a dryout condition?

Answer 19

• 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

Question 20

How long until core uncovery occurs following LOAF and SG Dryout?

Answer 20

• 1 Hour

Question 21

During 40EP-9EO06 Loss of all Feedwater (LOAF), how is Feedwater restoration different if a SG has dried out?

Answer 21

• if 1 or more SG have dried out feed only 1
• Feed SG with inventory
• If both are dry feed last to go dry

Question 22

Following SG Dryout, what is the max feed rate and why?

Answer 22

• ≤ 1000 gpm (≤ 0.5 E6 lbm/hour)

- Reduce damage due to stress on SG from cold feedwater