E-3 Series EOP's Flashcards
What are the FOP criteria for E-3? (S/G Tube Rupture)
- SI Reinitiation: Following SI termination, if either condition occurs, then manually establish ECCS as necessary to restore conditions AND go to ECA-3.1 (SGTR w/ Loss of Rx Coolant)
- Subcooling < 40F
-OR- - PZR level cannot be maintained >16%
- Subcooling < 40F
- Secondary Integrity: If any S/G# is lowering in an uncontrolled manner OR has completely depressurized, and affected S/G was not previously isolated using E-2, then go to E-2 unless needed for cooldown.
- Cold Leg Recirc: If RWST goes < 30%, go to ES-1.3 (Transfer to Cold Leg Recirc)
- AFW Switchover: If CST level goes <15%, then switch to alternate AFW supply.
- Multiple Tube Rupture: If any intact S/G level rises uncontrollably OR has abnormal radiation, then stabilize the plant and return to E-3, step 1.
- RHR Pump Restart: If RCS# lowers uncontrollably to <300#, then manually restart RHR pumps.
- Control Room Pressurization: Maintain one and only one pressurization fan running during subsequent recovery actions.
How is the amount of leakage into a Ruptured S/G contolled?
- The ruptured S/G is isolated from the intact S/G’s. This will allow for the ruptured S/G and RCS pressures to equalize.
- The RCS is then cooled down using an intact S/G. Lowering RCS pressure < ruptured S/G will cause leakage into the RCS.
What is the Ruptured S/G PORV setpoint changed to and why?
- Adjusted to 1040#
- Still provides pressure relief during an overpressure condition, but raising to a higher setpoint than the other S/G’s will minimize the radiological release.
What is the time commitment to isolating steam flow from the Ruptured S/G?
18 minutes
If offsite power is lost AFTER resetting SI, how is EDG load overload prevented?
Manually placing the Load Con Initiation switch (101-LCTA(B) to “Load Con” for the applicable train.
How is feed flow to the ruptured S/G controlled?
- Maintain feed flow until the ruptured S/G NR level is >13% then STOP feed flow.
Can a ruptured S/G that is also faulted be fed?
- No, feeding a faulted and ruptured S/G may cause a large cooldown, increase the amount of RCS to secondary leakage, and cause the S/G to overfill.
- The exception is if the faulted and ruptured S/G is the only S/G available for cooldown.
While performing E-3 (SGTR), why is RCS pressure checked to be >450# prior to initiating a cooldown?
- If pressure is <450#, the cooldown (performed rapidly as possible) could cause a PTS to the RCS and develop an ORANGE path on Integrity.
- Operators are directed to ECA-3.1, which limits the cooldown rate to prevent PTS.
If cooling down using Natural Circulation during E-3, how could a FALSE Integrity CSFST indication occur on the ruptured loop?
- The cooldown will cause ECCS flow through the ruptured S/G RCS loop to reverse. This will cause cold leg temps to lower to the point of FR-P.1 being met.
- Disregard the ruptured S/G RCS cold leg temp until after the cooldown/depressurization and SI is terminated.
What is the minimum differential pressure between the Ruptured and Intact S/G’s before ECA-3.1 must be entered?
- 250#
- About 250# is required at no-load temperature to stop RCS to secondary leakage while maintaining subcooling.
While using the PZR PORV to lower RCS pressure during E-3 the PRT rupture disc blows, causing high radiation levels in containment. Should the operator transition to E-1? (Loss of Rx or Secondary Coolant)
- NO
- Bases recommend continuing with E-3 to stop RCS to secondary leakage until otherwise directed.
What is the difference between a S/G Tube Leak and a SGTR?
- S/G Tube Leak: Leakage is within the capability of the CVCS system (One charging pump with letdown isolated).
- SGTR: Leakage is greater than the capability of the CVCS. SI will be required to maintain RCS inventory.
What is the maximum capability of the CVCS system in terms of a S/G Tube Leak?
One charging pump with maximum flow and letdown isolated.
What are the time critical actions during E-3? (SGTR)
- Isolate AFW to ruptured S/G -> 6 min of Rx Trip
- Isolate S/G -> 18 min of Rx Trip
- Initiate cooldown -> 4 min of isolating steam flow
- Initiate depressurization -> 3 min after the end of cooldown
- Terminate SI -> 2 min after depressurization
- Max time to termination of break flow -> 51 min
What are the concerns with overfilling a S/G during E-3? (SGTR)
- Liquid entering the main steam piping may exceed design loading causing a break.
- Water hammer of the steam piping and equipment.
- Turbine blade erosion.
- S/G Safeties and PORV’s are not designed to pass water. They may stick open or break.
What are the advantages and disadvantages of ES-3.1? (Post SGTR Cooldown Using Backfill)
Advantages:
- Minimizes radiological release.
- Facilitates processing of contaminated coolant.
Disadvantages:
- Adverse S/G chemistry effects on the RCS.
- Boron dilution event.
- Much slower at cooldown and depressurization.
What are the advantages and disadvantages of ES-3.2? (Post SGTR Cooldown Using Blowdown)
Advantages:
- Adverse S/G chemistry effects on the RCS.
- Boron dilution event.
Disadvantages:
- Storage and processing is limited.
- Contamination could spread through the secondary.
What are the advantages and disadvantages of ES-3.3? (Post SGTR Cooldown Using Steam Dump)
Advantages:
- Fastest method.
Disadvantages:
- Contamination spread through the secondary.
- Increased exposure to personnel and the public.
- Processing costs high.
What are the major actions for E-3? (SGTR)
- Identify and isolate the ruptured S/G.
- Cooldown to establish subcooling.
- Depressurize to restore RCS inventory.
- Terminate SI to stop RCS to S/G leakage.
- Prepare for cooldown to cold shutdown.
What are the major actions for ES-3.1? (Post SGTR Cooldown Using Backfill)
- Prepare for cooldown to cold shutdown.
- Cooldown and depressurize to RHR system conditions.
- Cooldown to cold shutdown.
What are the major actions for ES-3.2? (Post SGTR Cooldown Using Blowdown)
- Prepare for cooldown to cold shutdown.
- Cooldown to RHR system conditions.
- Depressurize to RHR system conditions.
- Cooldown to cold shutdown.
What are the major actions for ES-3.3? (Post SGTR Cooldown Using Steam Dump)
- Prepare for cooldown to cold shutdown.
- Cooldown to RHR system conditions.
- Depressurize to RHR system conditions.
- Cooldown to cold shutdown.
When do the RCP trip criteria of E-3 (SGTR) Step 1 no longer apply?
The criteria no longer apply after an OPERATOR induced cooldown has been initiated.
Note: even if directed back to step one in the procedure the RCP’s are NOT stopped if an operator induced cooldown has been initiated.
What actions must be taken if any ruptured S/G cannot be isolated from at least one intact S/G while performing E-3?
Transition to ECA-3.1 (SGTR with Loss of Rx Coolant - Subcooled Recovery Desired)
What actions must be taken if no intact S/G is available for cooldown while performing E-3?
- Cooldown using the faulted S/G
OR - Transition to ECA-3.1 (SGTR with Loss of Rx Coolant - Subcooled Recovery Desired)
What actions must be taken if a PZR PORV cannot be closed while performing E-3?
Transition to ECA-3.1 (SGTR with Loss of Rx Coolant - Subcooled Recovery Desired)
What is the minimum D/P that should be maintained between the ruptured S/G and intact S/G’s? What actions can be taken to maintain it and what actions must be done if it cannot be maintained?
- 250# D/P
- Initiate RCS cooldown <100F in any 60 minute period.
- If minimum D/P cannot be maintained, transition to ECA-3.1 (SGTR with Loss of Rx Coolant - Subcooled Recovery Desired)
What are the methods for depressurization AND order of preference for the FIRST depressurization in E-3?
- Normal spray
- PZR PORV
- Aux Spray
What are the methods for depressurization AND order of preference for the SECOND depressurization in E-3?
Trick question, only Normal Spray is used.
If RCS subcooling drops below 40F due to operator action should FOP actions to manually start ECCS pumps and transition to ECA-3.1 (SGTR with Loss of Rx Coolant - Subcooled Recovery Desired) be taken?
- NO!
- Restore subcooling using the normal system lineup. Do not take FOP action unless the normal system lineup cannot restore subcooling.
What is the cooldown rate while performing any of the ES-3 series procedures?
Maintain <100F in any 60 minute period.
While performing any of the ES-3 series procedures, what is the NR level band in the ruptured S/G maintained at and why?
- > 20% to 62%
- > 20% ensures that the tubes remain covered and the RCS won’t depressurize into the steam space of the S/G.
- 62% allows enough volume to provide cooling to the S/G without overfilling.
While performing any of the ES-3 series procedures, what is the pressure band in the ruptured S/G maintained at and why?
- > 420# to <1010#
- > 420# ensures adequate NPSH to the RCP’s
- <1010# ensures adequate margin to S/G PORV relief setpoint.
What are the methods of depressurization AND order of preference while performing any of the ES-3 series procedures?
- Normal Spray
- Aux Spray
- PZR PORV
What must be completed prior to performing a cooldown using ES-3.2 (Post SGTR Cooldown Using Blowdown) or ES-3.3? (Post SGTR Cooldown Using Steam Dump)
Dose assessment completed AND results are ACCEPTABLE.
Why must the Ruptured S/G pressure be lowered while performing either ES-3.2 or ES-3.3 series procedures?
The ruptured S/G will act as a PZR for the RCS. Pressure must be lowered in conjunction with RCS pressure to minimize RCS to S/G Leakage.
What Tube Leak rate will require a Rx Trip?
Per 4022-002-021: Leak rates between 50-100gpm require a Rx Trip.
What Tube Leak rate will require a Rx Trip & SI?
Per 4022-002-021: Leak rates >100 gpm will require a Rx Trip & SI.
Define “Uncontrolled Level Rise”
Level continues to rise with all feedwater to the S/G isolated.
How can a SGTR cause a PTS concern if RCP’s are secured?
Loop flow stagnation will occur in the ruptured loop, pooling of cold ECCS injection due to lack of mixing with bulk RCS coolant could cause over cooling of the vessel.
If more than one S/G is ruptured, how do you determine the target temp for the cooldown in E-3?
Use the LOWEST ruptured S/G pressure.
