E-0 Series EOP's Flashcards
What conditions should be established prior to restarting a RCP?
- RCP Bus energized
- RCP cooling (CCW and Seal Injection)
- Thermal Barrier Cooling high D/P alarms clear
- # 1 Seal D/P >200
- # 1 Seal Leakoff greater than RCS dependent value.
- Bearing lift pump running for 2 minutes.
What conditions can rule out steam void formation in the Rx Vessel Upper Head?
With RVLIS <100%, all of the following is met:
- RCS# < 1725#
- Core has remained covered
- Accumulators have NOT injected
Why is it preferred to postpone RCP restart until after a void in the upper head is vented?
- PZR level may lower off-scale low and lead to loss of pressure control and letdown isolation.
- Could transfer non-condensable gases to transfer to other places in the RCS and impede heat transfer.
- Non-condensable gases in other parts of the RCS could cause erratic/erroneous indications.
- Non-condensable gases transferred to the PZR could make pressure control harder. (Hard Bubble formation)
Define Natural Circulation
Flow within the RCS caused by temperature induced density gradients and differences in elevation between the heat source and the heat sink.
What are the physical conditions required to support Natural Circulation? (SUP-011)
- There must be a heat source and heat sink.
- Heat sink must be at a higher elevation than the heat source.
- A flow path exists between the heat source and sink.
- Density gradients caused by temperature differences between the two must exist.
What parameters confirm formation of Natural Circulation? (SUP-011)
- Subcooling >40F
- S/G #’s stable or lowering
- RCS hot leg temps stable or lowering
- CETC temps stable or lowering
- RCS cold leg temps at saturation temp for the S/G’s
What are the SI Termination Criteria?
- Subcooling >40F
- Secondary Heat Sink verified (NR level >13% in at least one S/G OR total feed flow >240k pph)
- RCS # stable or rising
- PZR level >16%
What is the name of procedure E-0?
Rx Trip or SI
What is the name of procedure ES-0.0?
Rediagnosis
What is the name of procedure ES-0.1?
Rx Trip Response
What is the name of procedure ES-0.2?
Natural Circulation Cooldown
What is the name of procedure ES-0.3?
Natural Circulation Cooldown with Steam Void in Vessel
What is the name of procedure ECA-0.0?
Loss of ALL A/C Power
What is the name of procedure ECA-0.1?
Loss of All A/C Power Recovery Without SI Required
What is the name of procedure ECA-0.2?
Loss of All A/C Power with SI Required
What are the Major Actions for E-0?
- Verify auto actions initiated by the safeguards system
- Identify the appropriate EOP network procedure for recovery. (E-2, E-3, then E-1)
- Shut down unnecessary equipment and continue to identify appropriate recovery procedure.
What are the Major Actions for ES-0.1? (Rx Trip Response)
- Ensure primary system stabilizes at no-load conditions.
- Ensure secondary system stabilizes at no-load conditions.
- Ensure necessary components have power.
- Maintain/Establish forced flow.
- Maintain stable plant conditions.
What are the Major Actions for ES-0.2? (Natural Circulation Cooldown)
- Permit cooldown and depressurization of the RCS at the fastest rate possible WITHOUT forming voids in the vessel head.
What are the Major Actions for ES-0.3? (Natural Circulation Cooldown w/ Steam Void in Vessel)
- Permit cooldown and depressurization of the RCS at the fastest rate possible while allowing formation of voids in the vessel head.
What are the FOP criteria for E-0? (Rx Trip or SI)
- RCP Trip: If either condition occurs, trip all RCP’s
- CIS phase B
-OR- - RCS # <1300# AND a CCP or SI pump running
- CIS phase B
- AFW Switchover: If CST level lowers to <15%, then switch to alternate supply.
- Cold Leg Recirc: If RWST level lowers to < 30%, then go to ES-1.3 (Transfer to Cold Leg Recirc)
- Faulted S/G Isolation: Isolate AFW flow to a SINGLE affected S/G if:
- Single S/G # lowers uncontrollably or is completely depressurized.
-AND- - Secondary heat sink is established
- Single S/G # lowers uncontrollably or is completely depressurized.
- RCP Bus Trip Criteria: if either condition occurs, open affected RCP bus RAT supply:
- Annunciator 119(219) or 120(220) drop 69
-AND- - Any associated bus phase voltage < 110 volts
- Annunciator 119(219) or 120(220) drop 69
What is the basis for controlling AFW flow to between 240K lbm to 450K lbm?
- Lower end is enough flow to ensure adequate heat sink available to remove decay heat.
- Higher end is low enough flow to reduce excessive cooldown.
What things are checked for a FWI?
- Both MFP’s tripped
- MFP discharge valves closed
- FRV’s closed
- Feed Isolation Valves closed
Why does E-0 (Rx Trip or SI) only allow isolating feed flow to ONE faulted S/G?
Isolating more than one S/G may not meet minimum flow requirements for heat sink and would subsequently create a RED path on Heat Sink.
What criteria will require transition to FR-S.1 (Response to Nuclear Power Generation/ATWS) from E-0?
Rx Trip criteria not met, and RNO criteria not met after manually tripping the Rx.