Week 6 Flashcards
- Unit 1 tripped from 100% full power.
- SIAS, CIAS, MSIS, and AFAS-1 have initiated.
- The RCS is in forced circulation.
- Steam Generator #1 pressure is 750 psia and dropping rapidly.
- Steam Generator #1 level is 8% WR and dropping rapidly
- Steam Generator #2 pressure is 940 psia and slowly lowering.
- Steam Generator #2 level is 37% WR and slowly lowering.
- Auxiliary feedwater flow is > 2000 gpm to steam generator #1.
- Auxiliary feedwater flow is 0 gpm to steam generator #2.
WHICH one of the following actions correctly addresses the existing symptoms?
A. Stop feeding SG #1 and ensure feedwater flow is restoring level in SG #2.
B. Throttle and balance flow to each steam generator.
C. Stop feeding SG #1 and allow SG #2 to feed in RTO.
D. Allow maximum flow to SG #1 until level is greater than 10% WR.
A. Stop feeding SG #1 and ensure feedwater flow is restoring level in SG #2.
- An ESD has occurred due to a steam line break inside containment.
- The Operating crew has just entered in the ESD procedure.
- Containment pressure peaked and is stable at 9 psig
- Containment temperature is 186°F.
- PZR level is 12% and rising.
- RVUH is 100%.
- RCS subcooling is 112°F
- SG 1 is at 24% WR (increasing) and being fed from AFW at 505 gpm.
- SG 2 is below the indicated level.
- Both HPSI pumps are injecting into the RCS.
Based on these conditions, the operator should…
A. throttle HPSI immediately.
B. maximize feedflow to SG 1 and throttle HPSI when PZR level reaches 15%.
C. throttle HPSI when PZR level reaches 15%.
D. maximize feedflow to SG 1.
C. throttle HPSI when PZR level reaches 15%.
- The reactor has tripped.
- An ESD has occurred on SG #1.
- SG #1 has just reached dryout.
The following indications are available to the Secondary Operator: •Loop 1 T-cold 392°F •Loop 1 T-hot 480°F •Loop 2 T-cold 460°F •Loop 2 T-hot 488°F
Which one of the following pressures indicates the pressure that SG # 2 should be reduced to?
A. 465 psia.
B. 225 psia.
C. 610 psia.
D. 565 psia.
B. 225 psia.
- Pressurizer pressure 1650 psia and decreasing
- Subcooled margin is 95°F and increasing
- No activity in the Containment or Steam Plant
- A single event is in progress with no other complications
The most likely diagnosis for this condition is:
A. ESD
B. LOCA
C. LOOP
D. SGTR
A. ESD
During an ESD, why should safety injection be throttled as soon as the throttle criteria is met?
A. Prevents excessive cooldown.
B. Minimizes erosion damage to the injection valves.
C. Minimizes the time SI pumps are running on mini-flow.
D. Minimizes the possibility of pressurized thermal shock.
D. Minimizes the possibility of pressurized thermal shock.
- Pressurizer pressure is 2290 psia and slowly increasing.
- Tc is 572°F and slowly increasing.
- Subcooled margin is 45°F and lowering (getting worse).
- No indications of activity in the Containment or Steam Plant.
The most likely diagnosis for this condition is:
A. Uncomplicated Reactor Trip.
B. Steam Line Break (ESD) outside containment.
C. Feedline break (ESD) outside containment.
D. Large Break LOCA.
C. Feedline break (ESD) outside containment.
- The faulted S/G is isolated and the unisolated S/G is at 38% WR and slowly lowering.
- All Reactor Coolant Pumps (RCPs) are secured.
- RCS is subcooled (>34°F using CET’s).
- Pressurizer level is 36% and stable.
- 100% in the Upper Head is indicated by RVLMS.
What parameter is inadequate for throttling HPSI?
A. steam generator level.
B. subcooling margin.
C. pressurizer level.
D. Safety Injection flow.
A. steam generator level.
- A ESD has occurred due to a steam line break on SG 2 inside containment.
- The operating crew is in the process of performing the SPTAs.
- Containment pressure is at 10 psig and rising.
- Containment temperature is in excess of 200°F.
- PZR level is 12% and rising.
- RCS temperature is rising.
- RCS subcooling is 112°F.
- SG 1 is at 45% WR and being feed from AFW at 300 gpm.
- HPSI flow to the RCS is acceptible per appendix 2.
Based on these conditions, the operator should:
A. Start all available charging pumps.
B. throttle HPSI immediately.
C. immediately reduce RCS pressure to lower subcooling to less than 100°F.
D. increase heat removal on SG 1 to stabilize Tc
D. increase heat removal on SG 1 to stabilize Tc
- A steam leak occurs in the Turbine Building.
- A manual reactor trip is initiated.
- The turbine trip isolates the steam leak.
- T-cold for both loops indicate 555°F.
- The crew is performing the SPTAs.
- SBCS is functioning properly.
- No ESFAS actuations have occured
Based on these conditions, the Control Operator should…
B. continue the cooldown to a Tcold of 500°F.
C. initiate an MSIS and stabilize temperature using ADVs.
D. allow the RCS to heat up to its normal post trip band of 560° to 570°F Tcold.
A. stabilize RCS temperature at its present value with SBCS in manual.
- An overcooling transient occurred which dropped plant temperature uncontrollably to 470°F.
- RCS temperature and pressure have been stablized on the left side of the 200°F subcooled line of Standard Appendix 2.
Which of the following actions is appropriate?
A. Cool down and repressurize the RCS.
B. Cool down and maintain RCS pressure constant.
C. Depressurize and maintain RCS temperature constant.
D. Heat up and repressurize the RCS.
C. Depressurize and maintain RCS temperature constant.
Which one of the following plant parameters is an indication that an excessive steam demand event is occurring? Assume the S/G is not dried out.
A. Lowering RCS temperature with increasing containment pressure.
B. Increasing reactor power with increasing RCS temperature.
C. Lowering RCS temperature with increasing pressurizer level.
D. Lowering RCS temperature with increasing pressurizer pressure.
A. Lowering RCS temperature with increasing containment pressure.
- An excessive steam demand event is in progress with a S/G safety valve open.
- S/G #2 has been determined to be the affected S/G.
Is there a concern with continuing to feed the affected S/G following an ESD event?
A. No, it will minimize the rebound effect.
B. Yes, it will fill the S/G and cover the tubes.
C. Yes, it will cause the RCS to cool down further and affect reactivity.
D. No, it will minimize the need for auxiliary feedwater.
C. Yes, it will cause the RCS to cool down further and affect reactivity.
- The reactor has tripped.
- An MSSV has stuck open on SG 1.
- SG 1 is at 32% WR.
- SG 1 is at 930 psia.
- SG 2 is at 43% WR.
- SG 2 is at 1060 psia.
- LOOP 1 Tc 538°F, Th 559°F.
- LOOP 2 Tc 556°F, Th 559°F.
With no operator action, which of the following describes the status of SG feedwater?
A. AFA and AFB are feeding both SGs.
B. Neither SG is receiving feedwater
C. AFA and AFB are feeding SG 1 only.
D. MFW is feeding both SGs in RTO at greater than 250 gpm.
B. Neither SG is receiving feedwater
- Unit 1 is operating at 82% power.
- All systems are in normal lineup when the generator trips due to a loss of field.
- SBCV #4 is OOS.
- CEA’s are not selected for large load reject.
Based on these conditions, the operating crew should:
A. immediately select CEAs for large load reject and manually initiate a cutback.
B. start a rapid shutdown per 40OP-9ZZ05, Power Operations.
C. trip the reactor.
D. insert CEAs in manual sequential.
C. trip the reactor.
- Unit 1 is operating at rated power.
- A Main Turbine trip occurs.
- A RPCB fails to automatically actuate.
- The Primary Operator IMMEDIATELY depresses the following two pushbuttons simultaneously:
- “DROP SUBGRPS”
- “LOSS OF FEEDPUMP”
Comparing the plant response to this action versus how the plant would have responded if the “LARGE LOAD REJECT” pushbutton has been depressed, which of the following is accurate?
The actions taken would result in…
A. a larger rise in pressurizer pressure.
B. more CEAs dropped on the RPCB.
C. fewer CEAs dropped on the RPCB.
D. a smaller rise in pressurizer pressure.
A. a larger rise in pressurizer pressure.