2010 NRC Flashcards
(100 cards)
Given the following conditions on Unit 2:
• The crew is responding to a Reactor Trip and has transitioned to 2-OHP-4023-ES-0.1, Reactor Trip Response, from 2-OHP-4023-E-0, Reactor Trip or Safety Injection.
• Following the transition the crew notes the following conditions:
• RCS Pressure is 2100 psig and lowering
• 2-NRV-152, indicating lights show an intermediate position
Which ONE of the following describes the actions the operator should take to address these conditions?
a. Close 2-NMO-152, PORV Block Valve, to stop discharge into the PRT.
b. Open Pressurizer Spray valves to depressurize the RCS and limit the loss of Reactor Coolant.
c. Turn on all Pressurizer Heaters to maintain RCS pressure.
d. Isolate air to containment to fail the Pressurizer PORV closed and stop the RCS mass loss.
a. CORRECT. Block valve is in series with the Pressurizer PORV. Closing the block valve will isolate the leak and prevent further depressurization of the RCS.
Given the following conditions on Unit 2:
• A reactor trip and safety injection have occurred.
• The crew is responding to a Small Break Loss of Coolant Accident (LOCA).
• All Reactor Coolant Pumps are tripped.
• The crew is depressurizing the Reactor Coolant System (RCS) in accordance with Step 13 of 2-OHP-4023-ES-1.2, Post LOCA Cooldown and Depressurization.
• A PORV is being used to depressurize the RCS.
As the depressurization occurs, which one of the following describes the expected trend of pressurizer level and the adverse operating condition that may initially occur as a result?
a. Lowering Pressurizer Level
Uncovering Pressurizer heaters.
b. Rising Pressurizer Level
Water solid conditions in the RCS and Pressurizer.
c. Rising Pressurizer Level
Upper head region voiding may occur.
d. Lowering Pressurizer Level
Upper head region voiding may occur.
c. CORRECT. The caution prior to commencing depressurization in ES-1.2 to refill the Pressurizer, states that a head void may occur as indicated by a rising Pressurizer level as water in transferred from the RCS to the Pressurizer.
Given the following conditions on Unit 1:
• A Large Break LOCA has occurred.
• Safety Injection has actuated.
Which ONE of the following describes:
1) How the Centrifugal Charging Pump suction swaps to the RWST when a Safety Injection is initiated, and
2) how the CHARGING PUMP SUCTION swapover to the containment sump is completed in accordance with 1-OHP-4023-ES-1.3, Transfer to Cold Leg Recirculation?
Note: VCT valves = QMO-451/QMO-452
RWST valves = IMO-910/IMO-911
a. 1) The VCT valves will start to close AFTER one of the RWST valves have traveled to the full open position.
2) The RWST valves will AUTOMATICALLY close after IMO-340, Charging Pp Suction from East RHR Hx has been opened.
b. 1) The VCT valves will start to close AFTER one of the RWST valves have traveled to the full open position.
2) The RWST valves will be MANUALLY closed after IMO-340, Charging Pp Suction from East RHR Hx has been opened.
c. 1) The VCT valves will start to close AS SOON AS one of the RWST valves start to open.
2) The RWST valves will AUTOMATICALLY close after IMO-340, Charging Pp Suction from East RHR Hx has been opened.
d. 1) The VCT valves will start to close AS SOON AS one of the RWST valves start to open.
2) The RWST valves will be MANUALLY closed after IMO-340, Charging Pp Suction from East RHR Hx has been opened.
b. CORRECT. The valves from the VCT will start to close when the valves from the RWST get fully open and after transfer to the containment sump the valves are placed in the A-Auto position.
Given the following conditions on Unit 2:
• Unit tripped from 29% power.
• RCP 21 breaker tripped open when the busses swapped.
Which one of the following describes the response of Thot and Tcold in Loop 1?
a. Tcold rises to approximately equal Thot.
b. Thot lowers to approximately equal Tcold.
c. Tcold lowers, Thot remains approximately stable.
d. Thot rises, Tcold remains approximately stable.
b. CORRECT. Loss of RCS flow in 1 loop, reverse flow in that loop will cause Thot to drop (no more forced circulation in that loop) to the Tcold value or slightly below.
Given the following conditions on Unit 2:
• Reactor Coolant System (RCS) is in mid-loop condition
• The following indications are fluctuating on the running Residual Heat Removal (RHR): amps, flow, and discharge pressure
Which ONE of the following statements is correct regarding the standby RHR pump?
The standby RHR Pump should:
a. NOT be immediately started because air
entrainment could cause a loss of both RHR trains.
b. be immediately started because following a loss of
RHR flow, an RCS pressurization may occur precluding gravity feed makeup.
c. be immediately started because under certain loss of RHR conditions, core uncovery or core voiding can occur within 15 to 20 minutes.
d. NOT be immediately started because starting an idle RHR pump under mid-loop conditions could cause an unacceptable reduction in reactor shutdown margin.
a. CORRECT. The ARG provides a clear guidance which includes industry experience of why operation of an RHR pump operating with air entrapment should be evaluated because it could lead to pump damage. Starting the other RHR pump could transfer the problem to the other pump leading to a complete loss of the system.
Given the following conditions on Unit 1:
• Unit is operating at 100% power
• 1-NPP-151, PZR Press Channel 1, fails high
• The operator has taken manual control of Pressurizer pressure control and stabilized pressure at 2085 psig.
• Following completion of the procedure for response to a malfunction of a pressurizer pressure instrument, what will be the status of the CVCS/Charging system?
The ______ CCP will be INOPERABLE with the associated emergency leakoff valve deenergized in the ______ position.
a. East; open
b. East; closed
c. West; open
d. West; closed
a. CORRECT. Channel 1 affects QMO-225 for the East CCP. The Emergency leakoff is racked out in the open position to ensure minimum flow in the event of an SI.
Given the following conditions on Unit 2:
• The operators are implementing 2-OHP-4023-FR-S.1, Response to Nuclear Power Generation / ATWS
• Both Reactor Trip Breakers remain closed.
• The operators have completed steps of 2-OHP-4023-FR-S.1 through opening the MG Set output Breakers to shutdown the reactor.
Which ONE of the following describes the impact and potential consequences of the Reactor Trip Breakers remaining closed?
a. main steam line isolation signal will NOT occur to prevent excessive reactivity during the trip due to rapid RCS cooldown.
b. feedwater isolation signal will NOT actuate to prevent excessive reactor coolant system cooldown from the overfeeding of the steam generators.
c. main generator trip signal will NOT be generated preventing transfer of busses to reserve feed.
d. feedwater flow conservation signal will NOT occur to ensure equal distribution of water to the steam generators.
b. CORRECT. P-4 (Rx Trip Breaker Position) feeds the feedwater isolation signal. Either breaker being open will cause an isolation of flow to the SGs. However with neither breaker open, all FMOs and FRVs will remain open and Main Feedpumps will not trip. This will cause excessive flow to the SGs, which could lead to an overcooling of the RCS.
Given the following conditions on Unit 1:
• The Unit is operating at 75% power with all systems in automatic.
• Main Turbine DCS is in “MW IN” in preparation for turbine valve testing.
• Condenser vacuum is lowering.
Assuming no action has been taken by the crew, which ONE of the following describes the response of the rod control system to this event?
Control rods will automatically:
a. insert due to the rise in Tavg from the rise in steam flow.
b. insert due to the rise in Tavg from the lowering in steam flow.
c. withdraw due to the drop in Tavg from the rise in steam flow.
d. withdraw due to the a drop in Tavg from the lowering steam flow.
c. CORRECT. With the Main Turbine in “MW IN” control, the turbine valves are allowed to reposition to try to maintain Main Generator Load. As vacuum lowers, the turbine will become less efficient, causing more steam flow for the same MW output. As steam flow rises, RCS Tave will lower below Tref. With rods in AUTO, the rods will withdraw to minimize the Tave-Tref deviation.
Given the following conditions on Unit 1:
• Unit 1 was operating at 100% power when a condensate system transient caused both Main FW pumps to trip.
• The turbine and reactor failed to trip automatically.
In accordance with the immediate actions of 1-OHP-4023-FR-S.1, Response to Nuclear Power Generation/ATWS, the operators will:
1) Manually trip the Reactor, if it fails to trip insert control rods.
2) Manually actuate AMSAC.
3) Manually trip the Turbine, if it fails to trip, then runback the turbine.
Which ONE of the following describes the bases for these immediate actions in 1-OHP-4023-FR-S.1?
The safeguards systems are designed assuming that the only heat being added to the RCS is from _______ . For an ATWS event with a loss of normal feedwater, a Turbine trip within 30 seconds will ________ .
a. fission product decay and RCP heat;
prevent challenging the Pressurizer PORV’s.
b. fission product decay and RCP heat;
maintain S/G inventory.
c. 5% power;
maintain S/G inventory.
d. 5% power;
prevent challenging the Pressurizer PORV’s
b. CORRECT. Per FR-S.1 Background Document, the assumed heat generation is from decay heat and RCP heat. Turbine is tripped to maintain SG water inventory.
Given the following conditions on Unit 2:
• A loss of all AC Power occurred due to severe weather conditions and failure of emergency diesel generators to start and supply safeguard buses.
• The operating crew is carrying out actions of 2-OHP-4023-ECA-0.0, Loss of All AC Power.
• The operators are at a point where they are to commence cooldown and depressurization of the steam generators to 190 psig.
Based on these conditions, which ONE of the following statements describes the reason why a secondary depressurization is directed?
a. To prevent a challenge to the Core Cooling Safety Function Status Tree which is being monitored for implementation.
b. To remove stored energy in the steam generators to limit the potential of challenging RCS integrity.
c. To remove available energy in the steam generators and thus minimizing any challenges to the containment structure if a Faulted S/G were to occur.
d. To minimize RCS inventory loss through the RCP seals, which maximizes time to core uncovery.
d. CORRECT. The primary concern is a loss of RCS inventory with no way to recover level. This could lead to core uncovery. The SGs are depressurized to lower RCS temperature and pressure to slow the loss of inventory.
Given the following conditions on Unit 2:
• Unit has just tripped due to a Loss of Offsite power.
• Both EDGs started and energized the required loads.
• All equipment responded as designed.
The following conditions exist:
• Containment parameters are normal
• Average core exit thermocouple (CET) temperature is stable.
Which ONE of the following combination of RCS pressure and average CET temperature verifies the MINIMUM required subcooling to AVOID Safety Injection per 2-OHP-4023-ES-0.2, Natural Circulation Cooldown?
a. 600 psig, 590oF
b. 500 psig, 460oF
c. 450 psig, 430oF
d. 375 psig, 400oF
d. CORRECT. 2-OHP-4023-ES-0.2 , Foldout Page (FOP) needs >40oF of subcooling, or requires that a SI be actuated. Tsat fo 400 psia (375 psig + 15 psi) is 444.6oF. Based on the conditions provided, 44.6oF of subcooling exists, exceeding the 40oF requirement.
Given the following conditions on Unit 1:
• Unit is operating at 60% power
• Pressurizer Level Control is in MANUAL
• Pressurizer LEVEL CTRL SELECTOR switch is in the Channel 2-3 position
• CRID 3 power supply fails
Assuming no operator action, which ONE of the following statements describes the effect of this failure on the CVCS and PZR level control system?
a. QRV-251, CCP Disch Flow Control fails OPEN
Letdown Isolates
Actual Pressurizer Level Rises
b. QRV-251, CCP Disch Flow Control fails CLOSED
Letdown Isolates
Actual Pressurizer Level Rises
c. QRV-251, CCP Disch Flow Control fails CLOSED
QRV-200, Charging Header Pressure Control Valve fails OPEN
Actual Pressurizer Level Lowers
d. QRV-251, CCP Disch Flow Control fails OPEN
QRV-200, Charging Header Pressure Control Valve fails CLOSED
Actual Pressurizer Level Lowers
a. CORRECT. Loss CRID 3 causes a Loss of PZR level Channel NLP-153 which will result in an indicated low Pressurizer level. This will cause the PZR Level control to Close QRV-112 and Open QRV-251. (Note that QRV-251 will also fail Open & QRV-112 will Close from Loss of CRID 3 per OHP-4021-082-008 Table 3. i.e. - either NLP-153 failing or loss of power causes same effects)
Which ONE of the following describes the reason for disabling AMSAC, de-energizing DCS Inverters, and stopping all DC powered Turbine Oil Pumps in 2-OHP-4023-ECA-0.0, Loss of All AC Power ?
a. Allow turbine oil systems to be de-energized and drain to the main turbine lube oil tank.
b. Prevent inadvertent actuation of control systems and auto start of pumps.
c. Extend the DC battery life for N Train and BOP batteries.
d. Limit overheating of cabinets and pump motor overload.
c. CORRECT. ECA-0.0, Step 17 Note states that DC Loads are shed to extend the life of the DC batteries associated with the loads.
Given the following conditions:
• An accidental spill of the Monitor Tank has occurred in the Aux Building.
• Radiation levels in the area of the spill are 40 mRem per hour at 30 cm.
• Contamination levels based on smear on the floor around the tank are 1.2 x104 dpm/100 cm2 beta-gamma.
Which ONE of the following describes how the area will be posted in accordance with PMI-6010, Radiation Protection Plan?
a. Radiation Area ONLY.
b. Contamination Area ONLY.
c. Radiation Area AND Contamination Area.
d. High Radiation Area AND Contamination Area.
c. CORRECT. This area should be posted as a radiation area (>5 mrem in 1 hour and <100 mrem/hr) and a contamination area (>1000 dpm/100 cm2).
Given the following condition:
• 1-MRV-213, Unit 1 SG11 PORV, was locally isolated due to excessive leakby.
Which ONE of the following describes the status of the SG11 PORV Radiation Monitoring and the reason?
a. Channel MRA-1601 is Unavailable. Technical Requirement actions are NOT required since all of the other SG PORV monitors are operable.
b. Channel MRA-1601 is Inoperable. Technical Requirements actions are required since PORV isolation renders the radiation monitoring function Inoperable.
c. Channel MRA-1601 is Unavailable. SG11 Radiation Monitoring is still Operable since MRA-1602 is still functioning.
d. Channel MRA-1601 is Operable. Isolation of the SG PORV does NOT affect radiation monitor operability.
b. CORRECT. TRO 8.3.8 requires 1 Channel per loop to be Operable. The SG PORV Monitor is required to be declared Inoperable if the PORV is closed or isolated. Declaring the SG PORV Radiation monitor inoperable requires that Function 2.b Action C be applied.
Given the following conditions on Unit 2:
• Unit was operating at 100% power when a malfunction of the Control Air system occurs.
• The Control Air header rapidly depressurizes and cannot be restored.
Which ONE of the following describes the correct operator response?
Immediately trip the Reactor and implement:
a. 2-OHP-4023-E-0, Reactor Trip or Safety Injection.
2-OHP-4022-064-002, Loss Of Control Air Recovery, may be performed concurrently after transitioning to 2-OHP-4023-ES-0.1, Reactor Trip Response.
b. 2-OHP-4023-E-0, Reactor Trip or Safety Injection.
2-OHP-4022-064-002, Loss Of Control Air Recovery, is NOT needed since the EOP network may be performed without reliance on Control Air.
c. 2-OHP-4023-E-0, Reactor Trip or Safety Injection.
2-OHP-4022-064-002, Loss Of Control Air Recovery, may NOT be performed until completion of 2-OHP-4023-ES-0.1, Reactor Trip Response.
d. 2-OHP-4022-064-002, Loss Of Control Air Recovery, until restoration of Control Air from any source.
Perform 2-OHP-4023-E-0, Reactor Trip or Safety Injection steps as time allows.
a. CORRECT. OHI-4023, Abnormal/Emergency Procedure User’s Guide allows Abnormal Procedures to be implemented concurrently with Non-Accident (ES-0.1, 0.2 or 0.3) Emergency Procedures after the immediate actions are complete at US discretion.
Given the following conditions:
• A Main Transformer fire has occurred on Unit 1.
• The Unit 1 Reactor and Main Turbine/Generator have been tripped.
• The Turbine AEO has reported that the Main Transformer deluge system has actuated.
• The Outside Tour AEO has reported that all three fire water pumps are running.
The reported status of the Fire Water System is ____________ for this event. The Main Transformer deluge system ___________ expected to automatically actuate once the Main Generator is tripped, ___________ fire water pumps are expected to be running.
a. abnormal; is; but only 2
b. abnormal; is not; but 3
c. normal; is; and 3
d. abnormal; is not; and only 2
a. CORRECT. For any given actuation of the fire system, the maximum number of pumps running should be 2. All three pumps running are an indication of a piping rupture. The deluge valve will not automatically actuate until the main transformer is de-energized.
Given the following conditions on Unit 2:
• Reactor Power is at 100% when a fire occurs in the Control Room Cable Vault.
• A large amount of smoke accumulates in the Control Room,
• The Shift Manager determines that the main control room must be evacuated in accordance with 2-OHP-4025-001-001, Emergency Remote Shutdown.
Which ONE of the following describe the operation of the Emergency Diesel Generators (EDGs)?
a. Start both EDGs prior to control room evacuation.
Locally control EDGs from LSI panels as required.
b. Trip both EDG HEAs prior to leaving control room.
Restore EDGs per 2-OHP-4025-R-15, if required
c. Leave EDG control switches as is.
Locally Trip and Isolate EDGs in accordance with 2-OHP-4025-LTI-3, if required.
d. Leave EDG control switches as is.
Locally control EDGs from LSI panels as required.
c. CORRECT. EDGs are left as is. Trip, Isolation, and restoration is performed following evacuation per appendix R procedures.
Given the following conditions on Unit 1:
• Unit is in Mode 3.
• The 4160 VAC distribution system is being supplied by the Reserve Auxiliary Transformers (RATs).
• Due to a system disturbance, indicated voltage on the safeguards buses drops.
The following conditions now exist:
• T11A Voltage Indication is 112 Volts
• T11B Voltage Indication is 114 Volts
• T11C Voltage Indication is 113 Volts
• T11D Voltage Indication is 114 Volts
Which ONE of the following describes the FINAL plant response if voltage remains at these values for an extended period?
a. All safeguards busses will be energized by their respective EDG.
b. T11A and T11C busses will be energized by their respective EDG.
c. T11A and T11B busses will be energized by its respective EDG.
d. Only T11A bus will be energized by its respective EDG.
c. CORRECT. An Undervoltage condition of 113 V will energize 62-1 T11A. After a 111 Second delay it will open T11A9 and T11B1 causing T11 A and T11B to lose power. This will cause the EDG to start and energize T11A and T11B.
Given the following conditions on Unit 1:
• Reactor power is 100%.
• West CCP is in operation with the East CCP in standby.
• West CCW pump is tagged out for maintenance.
Which ONE of the following describes the immediate operator actions required for a loss of Bus T11D:
a. Trip reactor because the RCP seals will overheat without Component Cooling flow.
b. Trip reactor because there is NO charging flow to replace letdown.
c. Initiate a controlled shutdown because the Charging pump will overheat without Component Cooling flow.
d. Initiate a controlled shutdown because the RCP seals will overheat without charging flow.
a. CORRECT. Per Loss of CCW procedure, Trip Reactor and Then trip RCPs.
Given the following conditions on Unit 2:
• Reactor is at 100% power.
• All control systems are in normal alignment.
• Letdown flow is aligned with a flow of 120 gpm at QFI-301.
The following parameters are now noted on the CVCS system:
• Seal Return Flows are 3 gpm per RCP
• Charging flow is 137 gpm and rising.
• 2-QTA-160, Regen HX Outlet Temp - Letdown, has lowered 5°F from its steady state value.
• VCT level is 33% and lowering.
• PZR level is 55% and lowering slowly.
• RCS temperature is 574°F and stable.
Which ONE of the following describes the effect on the unit and the action required to address the conditions?
a. RCS leakage is from the letdown line between the orifices and the letdown containment isolation valves. Isolate Letdown.
b. RCS leakage is from the charging line on the RCS side of the regenerative heat exchanger. Isolate Charging and Letdown.
c. RCS leakage is from the letdown line on the CVCS side of the regenerative heat exchanger. Initiate an investigation to determine if the leak is isolable.
d. RCS leakage is from the charging line on the CVCS side of the regenerative heat exchanger. Isolate Charging and Letdown.
b. CORRECT. If Regen Hx Outlet temperature is lowering, then more charging flow is going through the Regen Hx. This means the leak is downstream of the RHX in containment. Since Charging flow increased from a normal value of 132 GPM to 137 GPM with no other changes the leak rate is approximately 5 GPM and will required isolation of the charging header to isolate the leak.
Given the following conditions: • QRV-200, RCP Seal Backpressure Valve, is operating at 30% open. Assuming QRV-251, Charging Line Flow Control Valve is NOT adjusted, IF QRV-200 fails to 60% open, THEN: Charging Pump RCP Seal Charging Flow to Discharge Press Injection Flow Regen Hx a. Lowers Rises Lowers b. Rises Lowers Rises c. Rises Rises Lowers d. Lowers Lowers Rises
d. CORRECT. QRV-200 will cause a lower backpressure on the CCP discharge and seal injection line, resulting in lower CCP discharge pressure and less flow to the RCP seals. In addition this action will raise charging flow.
Given the following conditions:
• Unit 2 is in Mode 4 during cooldown per 2-OHP-4021-001-004, Plant Cooldown from Hot Standby to Cold Shutdown
• West RHR Pump and Heat Exchanger are operating, aligned to the cooldown path through injection lines to Cold Legs Loops 2 & 3
• RCS temperature is 300°F and stable
• RCS pressure is 335 psig and stable
The air supply line to IRV-320, West RHR Hx Outlet Valve, breaks, causing a complete loss of Instrument Air to the valve.
Which ONE of the following describes the effect on the plant and the action that could be taken to mitigate the transient?
a. RHR Flow through the West HX will be lost. Throttle open IRV-311 RHR HX Bypass to maintain greater than 3000 gpm RHR flow.
b. RHR Flow through the West HX will be lost. Stop the West RHR pump immediately to prevent overpressurizing letdown.
c. RHR Flow through the West HX will rise. Throttle ICM-111, RHR Discharge to Cold Leg 2 & 3 and IRV-311 RHR HX Bypass to prevent overcooling the RCS.
d. RHR Flow through the West HX will rise. Throttle ICM-321, West RHR Injection to Loops 2 & 3 and IRV-311 RHR HX Bypass to prevent overcooling the RCS.
d. CORRECT. IRV-320 fails open on loss of air. This will raise RHR flow through the HX. ICM-321 can be throttled closed to reduce total RHR flow and IRV-311 can be throttled open to allow more flow to bypass the HX in order to control RCS cooldown.
Given the following conditions:
• Unit 2 has experienced a loss of both CCW pumps in MODE 3
• NEITHER Unit 2 CCW pump can be restarted.
• CVCS crosstie from Unit 1 is NOT available.
• BOTH Unit 2 CCPs are running because a CCP swap was in progress.
• 2-OHP-4022-016-004, Loss of Component Cooling Water, is in progress.
Which ONE of the following describes the procedural requirements for CCP operation based on these conditions?
a. Immediately stop both CCPs.
b. Immediately stop one CCP; stop the second CCP within 1-1/2 minutes of the event.
c. Stop BOTH CCPs within 1-1/2 minutes of the event.
d. Immediately stop one CCP; run the second CCP as long as it continues to operate.
d. CORRECT. 02-OHP-4022-016-004 has a note prior to step 4 that describes the possible damage that may occur to a CCP on the loss of CCW. The note and procedure directs that one CCP be saved until CCW is restored. The other pump should be run as long as possible to allow time to align Seal injection crosstie.