2008 NRC Flashcards
(100 cards)
Operators are performing 2-OHP-4023-ECA-2.1, Uncontrolled Depressurization of All Steam Generators due to a steam leak inside containment along with failure of all SG stop valves to close.
Given the following plant conditions:
• Cooldown rate is stable at 155o F per hour.
• RCS cold leg temperatures are 340o F and lowering.
• Containment pressure is 8 psig and lowering.
• Narrow range Steam Generator levels indicate offscale low.
• Steam Generator AFW flow indicates 100x103 pph to each SG.
Which ONE of the following choices is correct for these plant conditions?
a. Adjust AFW flow to 60x103 pph on each Steam Generator.
b. Adjust AFW flow to 25x103 pph on each Steam Generator, AFTER at least one SG narrow range level is greater than 13%.
c. Adjust AFW flow to 25x103 pph on each Steam Generator.
d. Isolate AFW flow to ONLY three of the Steam Generators.
c. CORRECT. AFW flow is throttled to 25x103 pph on each Steam Generator if the cooldown rate is > 100oF per hour and level is less than 28% (Adverse Containment).
Given the following plant conditions on Unit 2:
• Reactor is at 100% power.
• All loop Tcolds are 540°F.
• All loop Thots are 606°F.
• Average of the 5 highest Core exit TCs is 620°F.
• A malfunction occurred with the pressurizer pressure control system resulting in an RCS pressure of 1915 psig without a change in reactor power.
Which ONE of the following describes the change from normal full power values to RCS subcooling based on the pressure transient?
Subcooling will:
a. lower to 11°F
b. lower to 22°F
c. rise to 58°F
d. rise to 91°F
a. CORRECT. Saturation Temperature for 1930 psia (1915 psig) is ~631°F. Comparing thermocouples to Tsat yeilds. 631°F - 620.00°F = 11°F. Pressurizer Vapor space temperature is 650 at 2235 psig.
During a Large Break LOCA, an evaluation of plant status is made during Step 11 of 1-OHP-4023-E-1, Loss of Reactor or Secondary Coolant. Part of this evaluation includes a check of ECCS pump compartment sump alarms and auxiliary building vent stack and area radiation monitors.
Which ONE of the following reasons describes the BASIS for checking these alarms and radiation monitors in this procedure?
a. Determine if local actions can be performed without excessive personnel exposure.
b. Determine if ECCS leakage exceeds that assumed in the Control Room dose analysis.
c. Determine if a transition should be made to address a LOCA outside of Containment.
d. Collect current radiation values to assist in Emergency Event classification.
c. CORRECT. Plant sump alarms and radiation monitors are both checked to identify leakage in the auxiliary building. This check is made to determine if the operator should make a transition to 1-OHP-4023-ECA-1.2, LOCA Outside Containment.
Given the following plant conditions:
• A Reactor Trip and Safety Injection have occurred.
• While implementing 2-OHP-4023-E-0, Reactor Trip or Safety Injection Step 10, it is determined that AFW flow can NOT be established.
• All SG NR levels are off-scale low.
• All SG WR levels are 58% and lowering.
• The crew has just entered 2-OHP-4023-FR-H.1, Response to Loss of Secondary Heat Sink.
• RCS Pressure is 175 psig and stable.
• Intact SG pressures are 475 psig and trending down.
Which ONE of the following describes the plant conditions and action required?
Steam Generators are:
a. required to provide secondary heat sink. Initiate Bleed and Feed per 2-OHP-4023-FR-H.1.
b. NOT required to provide secondary heat sink. Go to 2-OHP-4023-ES-0.0 Rediagnosis.
c. required to provide secondary heat sink. Remain in 2-OHP-4023-FR-H.1 to establish AFW Flow.
d. NOT required to provide secondary heat sink. Return to 2-OHP-4023-E-0.
d. CORRECT. Secondary heat sink is not required if SGs are at a higher pressure than the RCS. They act as a heat source. Crew returns to E-0.
Given the following plant conditions on Unit 1:
• A small break LOCA is in progress.
• Only one train of SI has actuated.
• RCS Pressure is 1290 psig.
• RCS Temperature is 703oF.
In order to prevent fuel damage from inadequate core cooling, what is the reason for maintaining a secondary heat sink?
a. To provide an alternate means of RCS pressure control.
b. Reflux boiling is the primary means of heat removal prior to voiding in the hot legs.
c. To ensure removal of RCS heat since the RCPs are expected to be running.
d. RCS pressure may remain so high that cooling from injection flow alone is inadequate.
d. CORRECT. Mass loss out the break is not sufficient to lower RCS pressure to a point where energy loss through the break along with injection flow is sufficient to address all decay heat removal requirements. The SG will aid in removing some of the excess decay heat.
Unit 2 Reactor Startup is in progress with Reactor Power at 2E-8 amps and rising.
Given the following conditions on RCP 23:
• Calculated #2 Seal Leak Rate is 1.6 gpm.
• Lower Bearing water temperature is 200°F and rising.
• Motor Bearing temperature is 174°F and stable.
• Seal Leakoff temperature is 179°F and rising.
• Seal Injection Flow is 10 gpm.
• Vibrations are at 16 mils and stable.
Which ONE of the following operator actions MUST be taken based upon these conditions?
a. Manually trip the reactor, Enter 2-OHP-4023-E-0, Reactor Trip or Safety Injection, perform immediate actions, then trip the No. 3 RCP.
b. Initiate reactor shutdown per 2-OHP-4021-001-003, Power Reduction and trip the No. 3 RCP after the reactor is shutdown.
c. Do NOT trip the reactor. Trip the No. 3 RCP and be in Hot Shutdown in 1 hour.
d. Do NOT trip the reactor. Trip the No. 3 RCP and close the No. 1 seal leakoff valve.
b. CORRECT. The #2 seal is failing and will require a controlled shutdown to remove the pump from service. Reactor trip is not required, since all other parameters are within limits of the procedure and fold-out page.
While responding to a LOCA, a transition to OHP-4023-ECA-1.1, Loss of Emergency Coolant Recirculation, was performed due to a loss of emergency coolant recirculation.
Given the following conditions:
• RWST level is 18% and lowering.
• Containment Pressure is 2.5 psig
• All ECCS pumps are running.
• Both CTS pumps were stopped.
• RCS Pressure is 940 psig.
Make up is being added to the RWST and ECCS is reduced to one train of SI flow.
Which ONE of the following describes the reason for these actions?
a. Restore RWST level so Containment Spray can be started.
b. Prevent damage to vital equipment by saving one ECCS train.
c. Establish conditions to allow restart of RCPs.
d. Delay the time to RWST depletion.
d. CORRECT. Makeup is added to the RWST to extend time the ECCS pumps can take suction from the RWST and supply core cooling. Reducing to one train of ECCS flow (1 CCP, SI, & RHR) delays the time to RWST depletion.
Unit 2 Reactor power is at 100%. Given the following plant conditions: • QRV-251 Charging Flow Controller is in MANUAL since Automatic control has failed. • PRZ level is stable at program level. • Charging and letdown are balanced. Which ONE of the following describes the impact on the plant if a transient causes power to be lowered to 30% while 2-QRV-251 remains in MANUAL? a. Charging flow will RISE. b. Charging flow will LOWER. c. PRZ level will LOWER. d. PRZ level will RISE.
c. CORRECT. With QRV-251 Charging Flow Controller in Manual Charging flow will remain constant. As the RCS cools down, the Pressurizer Level will lower as the water contracts.
Given the following plant conditions on Unit 2:
• A loss of all AC power has occured.
• The crew has just completed the immediate actions of 2-OHP-4023-ECA-0.0, Loss Of All AC Power.
Why does the procedure place a priority on checking for isolation of the RCS?
This action:
a. minimizes the RCS inventory depletion and maximizes the time until core uncovery.
b. ensures all RCS leak paths are isolated, thus preventing core uncovery.
c. maintains sufficient pressurizer level for proper control of the heaters and sprays for RCS pressure control.
d. prevents potential for rupturing the PRT due to excessive opening of the pressurizer PORVs.
a. CORRECT. The step for RCS isolation ensure that the only leakage path is by way of the RCP seals. This action minimizes the RCS leakage and extends the time until core uncovery.
Given the following plant conditions on Unit 2: • The unit was operating 100%. • A loss of 250 VDC Train A occurs. Initially, CRID 1 and 2 power supply will be \_\_ (1)\_\_ aligned to \_\_(2)\_\_. a. 1) automatically 2) a 600 VAC vital bus. b. 1) manually 2) a 600 VAC vital bus. c. 1) automatically 2) CRP-3. d. 1) manually 2) CRP-3.
a. CORRECT. Auto transfer will occur to the vital bus on a loss of the normal 250VDC feed to the inverter.
Unit 2 was operating at 100% when a Large Break Loss of Coolant Accident occurred thirty minutes ago.
Given the following current plant conditions:
• All Control Rods are inserted.
• RCS Pressure is 40 psig.
• Pressurizer Level is 0%.
• All equipment has functioned as designed.
• RCS Subcooling is 0°F.
• Containment Radiation levels are in alarm and slowly rising.
• Containment Pressure is 4 psig and slowly lowering.
Which ONE of the following describes the status of automatic Containment Isolation?
a. Phase A was DIRECTLY actuated by a High Containment Pressure Signal, and Phase B was DIRECTLY actuated by a High-High Containment Pressure Signal.
b. Phase A was DIRECTLY actuated by the Safety Injection Signal and Phase B was DIRECTLY actuated by a High-High Containment Pressure Signal.
c. Phase A was DIRECTLY actuated by the Safety Injection Signal and Phase B has NOT actuated.
d. Phase A has NOT actuated and Phase B has NOT actuated.
b. CORRECT. Phase A has actuated on the Safety Injection Signal and Phase B has actuated on High-High Containment Pressure Signal.
Which ONE of the following describes the procedural actions in response to addressing a leaking Pressurizer (PRZ) PORV?
a. 1. All PORV block valves are initially closed to lower tailpipe temperature.
2. One PORV block valve is opened at a time.
3. Leakage is determined by a rise in tailpipe temperature after each PORV block valve is re-opened.
b. 1. PORV block valves are closed one at a time.
2. Temperature on the tailpipe is monitored by the operator.
3. Leakage is determined by a lowering of tailpipe temperature after each PORV block valve is closed.
c. 1. PORV block valves are closed one at a time.
2. Temperature on the Pressurizer Relief Tank (PRT) is monitored by the operator.
3. Leakage is determined by a lowering PRT temperature after each PORV block valve is closed.
d. 1. All PORV block valves are initially closed to stabilize Pressurizer Relief Tank (PRT) temperature.
2. One PORV block valve is opened at a time.
3. Leakage is determined by a rise in PRT temperature after each PORV block valve is re-opened.
a. CORRECT. The procedure requires that all PORV Block Valves be initially closed. Once tailpipe temperature is lowering, the block valves are opened 1 at a time to check for a rise in tailpipe temperature.
Unit 1 Reactor has been holding at 30% for the last hour due to Chemistry.
Given the following plant conditions:
• West Main Feedwater pump is stopped.
• East Main Feedwater pump is operating.
• AFW pumps are aligned for automatic operation.
• AMSAC is aligned in NORMAL.
The East Main Feedwater pump trips and a manual Reactor Trip is initiated.
The current conditions exist:
• Narrow Range Steam Generator levels lowered to 33%.
• Steam Dumps indicate 10% open.
Which ONE of the following statements correctly describes the AFW pump status after the Reactor Trip with no further operator actions?
a. The Motor Driven and Turbine Driven AFW pumps have NOT started.
b. The Motor Driven AFW Pumps have auto started but the Turbine Driven AFW pump has NOT started.
c. The Turbine Driven AFW Pump has auto started but the Motor Driven AFW pumps have NOT started.
d. The Motor Driven and Turbine Driven AFW pumps have all auto started.
b. CORRECT. The Motor Driven AFW pumps will auto start on the loss of both Main FW pumps but the Turbine driven AFW pump will not.
Given the following plant conditions:
• An AEO has reported a major air leak in the plant air system.
• The crew is implementing 2-OHP-4022-064-001, Control Air Malfunction.
Which ONE of the following pressures would require the SRO to direct a manual Reactor Trip and enter 2-OHP-4023-E-0, Reactor Trip or Safety Injection?
a. Plant Air header pressure lowers to 79
b. Plant Air header pressure lowers to 84
c. Control Air header pressure lowers to 79
d. Control Air header pressure lowers to 84
c. CORRECT. 02-OHP-4022-064-001, Control Air Malfunction directs a reactor trip if Control Air Pressure is <80 psig.
Given the following plant conditions on Unit 2:
• A Loss of All AC Power has occurred.
• The crew is performing the actions of 2-OHP-4023-ECA-0.0, Loss of All AC Power.
• The operators have been unable to restore power.
Which ONE of the following describes the actions required for the safeguards equipment and why?
a. The control switches for the safeguards equipment are placed in Pull-to-Lock to prevent a potential bus overload when power is restored.
b. The control switches for the safeguards equipment are placed in Pull-to-Lock to prevent the possibility of an uncontrolled cooldown and depressurization of the RCS when power is restored.
c. The control switches for the safeguards equipment are verified to be in automatic alignment on the 4KV bus(es) that get power back so if SI is required, it will occur without operator action.
d. The control switches for the safeguards equipment for ONE train are placed in Pull-to-Lock and the control switches for the other train are verified to be in automatic. This ensures alignment for injection without operator action.
a. CORRECT. All major loads on the bus are stripped prior to energizing the bus to prevent excessive loading as pumps initially start.
Given the following plant conditions on Unit 2:
• The unit was operating at 12% power.
• Reserve Aux Transformer 201AB was supplying Buses 2A and 2B.
• Reserve Aux Transformer 201CD was supplying Buses 2C and 2D.
An electrical transient occured on the Grid.
During the transient the following values were reached:
Electrical Bus
• Parameter 2A 2B 2C 2D
• Frequency (Hz) 57 57 59.7 59.7
• Local Voltage (VAC) 4100 4100 4200 4200
• CR Indication (VAC) 118.2 118.2 121.1 121.1
• Ann. 207, Drop 10, RCP BUSSES UNDER FREQ TRIP is LIT
Which ONE of the following describes the expected status of the reactor trip breakers and the Reactor Coolant Pumps?
Note: Assume no operator action.
a. Reactor Trip Breakers remain Closed
All 4 RCPs remain running.
b. Reactor Trip Breakers Trip Open.
All 4 RCPs remain running.
c. Reactor Trip Breakers Trip Open.
All 4 RCPs trip off.
d. Reactor Trip Breakers remain Closed
ONLY 2 RCPs remain running.
b. CORRECT. The RCPs no Longer trip on Underfrequency (Recent Plant Modification)
The crew was operating Unit 2 at 100% when High secondary radiation and lowering PRZ level caused the crew to suspect a SG tube leak or rupture.
Which ONE of the following describes the THRESHOLD condition for initiating a reactor trip and safety injection per 02-OHP-4022-002-021, Steam Generator Tube Leak?
The THRESHOLD is when Pressurizer level can not be maintained with __(1)__ CCP(s) in service and letdown __(2)__ .
a. 1. one
2. in service
b. 1. one
2. isolated
c. 1. two
2. in service
d. 1. two
2. isolated
b. CORRECT. The procedure directs the operator to maximize charging flow and reduce/then isolate letdown. If PZR level can NOT be maintained in this configuration it is a rupture.
Given the following plant conditions:
• Both Units are in Mode 1.
• Engineering has determined that a relay has failed that will prevent the SI auto-start of the U1 East Essential Service Water (ESW) pump.
• All of the other U1 East ESW Pump start signals will function as designed.
• The Unit 1 East ESW discharge crosstie valves are de-energized in the open position while maintenance replaces the motors on the valves.
Which ONE of the following describes the operability and Technical Specification (TS) applicability associated with these conditions?
a. All ESW related trains are still OPERABLE because Unit 1 East ESW pump can still be manually started, and a service water TS LCO action statement would NOT be entered.
b. Only Unit 1 East ESW Train is INOPERABLE and a service water TS LCO action statement would be entered because the auto start is required to be operable.
c. All ESW related trains are still OPERABLE because the Unit 1 East ESW pump will start automatically if the discharge pressure falls below 40 psig and a service water TS LCO action statement would NOT be entered.
d. Both Unit 1 East and Unit 2 West ESW Trains are INOPERABLE and the ESW TS LCO action statements for both units must be entered because the crossties are open.
d. CORRECT. If the crossties are open then the LCO action statement also applies to Unit 2.
Given the following plant conditions:
• The plant was at 80% power and stable at EOL.
• A fault caused a continuous rod withdrawal.
• The rod motion was stopped after 20 steps by placing the Rod Control to MANUAL.
• The reactor did NOT trip.
What were the final effects of the fuel temperature and moderator temperature coefficients when the plant had stabilized?
a. The fuel temperature and moderator temperature coefficients have added positive reactivity
b. The fuel temperature and moderator temperature coefficients have added negative reactivity.
c. The fuel temperature coefficient added negative reactivity and moderator temperature coefficient have added positive reactivity.
d. The fuel temperature coefficient added positive reactivity and moderator temperature coefficient have added negative reactivity
b. CORRECT. Both the MTC and FTC are negative at EOL.
Given the following plant conditions:
• A Small Break LOCA occurred 12 hours ago.
• Containment pressure is 1.2 psig.
• Containment air temperature is 215ºF.
• OHP-4023-FR-Z-3, Response to High Containment Radiation Level, is entered.
Which ONE of the following verifications is a major action category of OHP-4023-FR-Z-3?
a. Both Containment Recirculation Fans are running.
b. Upper and Lower Containment Ventilation Fans are running.
c. Containment Ventilation Isolation has occurred.
d. Control Room Ventilation System is in ISOLATE.
c. CORRECT. Step 1 of the procedure ensures that CVI has occured.
Given the following plant conditions on Unit 2:
• A LOCA occurred thirty minutes ago.
• Containment Pressure has risen to 5 psig.
• The crew has completed steps of 2-OHP-4023-ES-1.3, Transfer to Cold Leg Recirculation, to align RHR/CTS suctions to the recirculation sump and the CCP/SI suctions to RHR Discharge.
• ONLY the Train A CCP, SI, RHR, and CTS pumps are operating.
• The next step of 2-OHP-4023-ES-1.3 directs the crew to “Check if RHR Spray is Required”.
Based on the indications above, which ONE of the following would best describe the required action AND the reason for the decision?
a. Place RHR spray in service NOW since ALL of the requirements are met.
b. Place RHR spray in service ONLY after RHR has injected for 50 minutes to ensure adequate core cooling.
c. Do NOT place RHR spray in service because the RHR pump suction is NOT aligned to the RWST.
d. Do NOT place RHR spray in service because ONLY one RHR pump is operating.
b. CORRECT. RHR is required if only 1 CTS pump is operating. After RHR has injected for 50 minutes the core is sufficiently cooled to allow RHR to be diverted to support spray functions.
Given the following plant conditions on Unit 1:
• The unit is at 100% power.
• Pressurizer Level Control selector is in the 1-2 position.
• Pressurizer Level Channel 1 (NLP-151) fails low.
Which ONE of the following describes the reason that Charging Flow and/or PZR Level control are placed in Manual in accordance with OHP-4022-013-010, Pressurizer Level Instrument Malfunction?
If NO operator action is taken following the channel failure:
a. charging flow will lower and PRZ level will lower until heaters are de-energized.
Rx Trip will occur on OTDT from the lowering pressure.
b. charging flow rises and PRZ level rises.
PRZ PORVs will open as the steam space is compressed.
c. charging flow will lower and PRZ level will lower until heaters are de-energized.
PZR pressure will lower to Rx Trip setpoint.
d. charging flow rises and PRZ level rises.
PRZ level will rise to a Hi Lvl Rx Trip setpoint.
d. CORRECT. Charging flow rises and PRZ level rises (due to charging flow and loss of letdown). PRZ level will continue to rise to a Hi Lvl Rx Trip.
Given the following plant conditions on Unit 1:
• A Small Break LOCA has occurred.
• Offsite Power was lost on the reactor trip.
• The actions of 1-OHP-4023-ES-1.2, Post LOCA Cooldown And Depressurization, are in progress.
• Both CCPs are running with suction aligned to the RWST.
• Both RHR Pumps are stopped in Neutral.
• Both SI Pumps are running.
• The crew is ready to depressurize the RCS to refill the Pressurizer.
Which ONE of the following is the FIRST method available to the operator to commence the RCS depressurization?
The operator will open:
a. One PZR PORV to vent the PZR.
b. All Pressurizer PORVs to vent the PZR.
c. The PZR Aux Spray Valve to spray down the PZR steam space.
d. One PZR Normal Spray Control valve to spray down the PZR steam space.
a. CORRECT. Since normal spray is not available (RCP Busses De-energized from loss of offsite power), the next choice is to use one PZR PORV.
Given the following plant conditions on Unit 2:
• The unit is at 100% power
• One Control Rod in Bank D Group 1 was found stuck at 190 steps.
• While aligning the remainder of the rods in Bank D to 190 steps an additional Control Rod in Bank D Group 2 was found stuck at 210 steps.
• It has been determined that both rods are mechanically bound.
In accordance with Technical Specifications, which ONE of the following describes the action required within one hour?
a. Determine that Shutdown Margin requirements are satisfied.
b. Determine that QPTR requirements are satisfied or enter the applicable action statement.
c. Verify all peaking factors are within acceptable limits.
d. Align the remainder of rods in the affected banks within 12 steps of the stuck rods.
a. CORRECT. Technical Specifications 3.1.4, Rod Group Alignment Limits, Condition A, requires SDM verification within 1 hour.