40AO-9ZZ09 RPCB LOFP

Question 1

What are the entry conditions for RPCB LOFP?

Answer 1

• Alarms indicating LOFP

- Unexplained drop in FWP disch press or speed

Question 2

What are RPCB LOFP Exit criteria?

Answer 2

Condition 1:

• Power stable, going to raise power
• CEA > TIL
• AOP direct to ZZ05

Condition 2:

• Power stable, maintain power
• CEA > TIL
• AOP directs to ZZ05

Condition 3:

• Power Stable
• CEA > TIL
• CEA overlap restored
• AOP direct to ZZ04 or ZZ07 (change modes)

Question 3

During Reactor Power Cutback (LOFP) 40AO-9ZZ09 what is Rx Trip Criteria?

Answer 3

• ≥ 74% MFP trips and RPCB fails to actuate (Auto and Man.)
• CEA deviates from subgroup >6.6” and any reg group < TIL
• Both MFP Trip
• SGWL approaches trip setpoints (≤44.2% NR, ≥91% WR)
• CPC ASI (pt 187) ±0.45 trending 0.5
• Turbine Load ≤ 410 MW and vacuum >5” HgA or >4”HgA for 1 hour

Question 4

What are the MFP trips?

Answer 4

Overspeed - > 6350 RPM
Low Suction Press - < 245 psig (B 10 sec A 15 sec)
High disch. Press - > 1750 psig
Low Vacuum - > 13.5” HgA
Low Control Oil Press. - < 75 psig
High Thrust Brng press - > 40 psig
Low BRNG Oil Press. - < 4 psig

Question 5

How does a Loss of NNN-D15 affect the MFP’s?

Answer 5

• A MFP controls Fail CLOSED

- No auto RPCB

Question 6

How does a Loss of NNN-D16 affect the MFP’s?

Answer 6

• B MFP control vlvs Fail CLOSED
• No Auto RPCB
• Both MFP’s lose stop vlv Indication

Question 7

How is RPCB LOFP different than RPCB LLR?

What is the concern with incorrect Manual actuation during RPCB LOFP?

Answer 7

• Quick Open Block sent to SBCS for LOFP

- MAN LLR during a LOFP results in HIGHER steam Demand with LOWER feed

Question 8

How do you clear a SETBACK signal following a RPCB?

Answer 8

• Cleared once input from RPCS is no longer present (Auto Act. OOS adn Test/Reset)
• Load Limit Pot turned CCW until clear

Question 9

At what power do you remove RPCB from Service?

Answer 9

< 70%

Question 10

If a RPCB LOFP fails to auto actuate what actions are you allowed to perform manually?

Answer 10

≥ 74%

• Press LOFP and Drop Subgroup buttons
• Trip Rx if both auto and manual fail

<74 %

• Manually insert CEA to match Rx/Turbine power
• If setback - Runback has not lowered turbine load, manually adjust pot unitl ≤ 65% (890MW)

Question 11

Following a RPCB how long is the allowance for LCO 3.1.7 PDIL’s?

Answer 11

• PDIL may be violated for 2 HOURS following RPCB

- Tracking still required

Question 12

Following a RPCB when restoring CEA overlap, what group is adjusted to what position?

Answer 12

If Reg Group 3 is > 95”

• Use MG
• Withdraw Reg Group 4 to 95” BELOW REG GROUP 3
• Use 10” pulls
• Wait 1 minute between pulls
• If power ↑ > 1% adjust next pull to be < 1%
• Maintain ±3°F Tavg/ref

Question 13

Following a RPCB if power CANNOT be stabilized due to Xe or it is desired to reduce power, at what power level do you stabilize at?

Why?

Answer 13

< 12%

• CPC canned value
• ↓ condenser tube errosion
• DCCV swapover
• Tilt and ASI LCO not applicable < 20%