EOP Flashcards
What is adverse containment?
5 psig
10E5 R/hr
During ELAP Unit PRZ and SG temps verified below 196.8*F
If rad levels exceed 10E5 R/hr and eventually come back down, do you still have to use adverse containment values?
YES, until evaluated for integral dose
What is the order of priority of the Critical Safety Functions?
Subcriticality
Core Cooling
Heat Sink
Integrity
Containment
Inventory
Which CSFs require continuous monitoring?
Red or Orange
What are the fission product barriers?
Fuel Cladding
RCS
Containment
E-Plan
What are the methods of heat removal for a SBLOCA?
ECCS Flow / Breaker Flow
AFW / SGs
Why is a CL Break considered the worst scenario for a SBLOCA?
More mass is lost prior to ECCS flow equaling break flow. The cross under loop seal must be clear before steam can be vented from the break
What are indications of a faulted SG?
Tave lowers
Rx Power Rises
Possible turbine load lowering
SF > FF
What are indications of SGTR?
SJAE / GSLO Rad monitors high
SG Level rising uncontrollably
PRZ Pressure and Level Lowering
What are indications of a LOCA?
Containment Rad Monitor & Dew Point rising
PRZ Level and Pressure lowering
What is the SI Termination Criteria found in ES-1.1
Subcooling > 40*F
Heat Sink by SG level >13% OR > 240K ppm
RCS Pressure stable / rising
PRZ Level 16% (20%)
What does meeting your SI termination subcooling criteria tell you?
Adequate core cooling and secondary heat sink
What does meeting your heat sink SI termination criteria tell you?
Ensure subcooling will be maintained following termination
What does meeting your RCS Pressure SI Termination criteria tell you?
Ensures subcooling will be stable / rising and SI flow is effective in raising RCS Inventory
What does meeting your PRZ Level SI Termination Criteria tell you?
Sufficient RCS Inventory
Only valid if RC is subcooled
Ensures ability to maintain pressure following termination
Why do RCPs need to be tripped on a phase B?
Loss of CCW flow to RCP LO Coolers
Where do you transition from in E-0 if a Rx Trip is not successful?
FR-S.1
What is the order of diagnostic transitions in E-0 and why ?
E-2, easy to find/fix and can mask other issues
E-3, stops offsite dose. Lots of TCAs
E-1, auto actions can handle it
In E-0, why do we lower AW to < 450K pph?
Limits overcooling the RCS
In E-0, why is the minimum AFW 240K pph until the minimum SG water level is maintained?
ENsures enough FW flow for decay heat removal. Also, min # for Heat Sink CSF Status Tree
What are the entry conditions for ES-0.0, Rediagnosis?
ALL of the following:
SI is I/S or Required
E-0 has been exited
E-Series procedure in progress
What must be done after a reactor trip for each control rod not fully inserted?
Borate 160 (150) ppm for each rod
If in ES-0.1, Reactor Trip Response, what do you do if you get an SI?
Return to Step 1 of E-0
Why would you transition from ES-0.2, Natural Circ Cooldown to ES-0.3, NC Cooldown w Steam Void?
If CST Inventory is low
After LOOP when a high rate of planned Cooldown and depressurization is required due to reduced CST inventory
What removes most of the heat from the head on NC?
CRDMs
In ES-0.3, Natural Circ Cooldown with Steam odd, when should you not try to start an RCP?
If cooling had been previously lost
In ES-0.3, NC Cooldown w steam void, why is it required to raise PRZ Level to 84% prior to starting a RCP?
Ensures PRZ level doesn’t lower causing a loss of subcooling when the RCP is started due to void collapsing / lowering PRZ level
What are the benefits of restarting RCPs?
Enhances core heat removal
Improves RCS Pressure and Temp Control
Improves PRZ Level Control
Which RCP is the most effective?
3 bc it has the most dP
What are the 3 factors affecting spray flow?
Vessel and RCS piping DP
Coolant Velocity head at spray flow scoop located at spray flow penetration in CL
PRZ Level
What are the indications of NC?
Subcooling ? 40*F
Stable or Lowering:
- SG Pressures
- CETCs
- RCS HL Temps
RCS CL Temps at saturation temp for SG Pressure
What should be done if NC cannot be verified?
Raise steam dump flow
For a SBLOCA, why is 1300# trip criteria?
Ensures RCPs are stopped before the break is uncovered so no additional mass is lost
Why is CCW to RHR adjusted to 5,000 gpm during CL Recirc?
Prevents pump Runout if 1 pump fails
When is RHR Spray placed in service?
50 mins (allows decay heat removal) - 70 mins (containment peak pressure)
What are the 10CFR100 Limits at the site boundary?
25 REM Whole Body, 300 REM Thyroid for 2 hours
While in ES-1.1, SI termination, what if you are unable to maintain 40*F subcooling and PRZ LeveL?
Go to E-1 bc there must be another issues. If you just add another CCP back on, you’d meet the SI Termination Criteria again
For a Faulted SG, when will you have a SI?
Upstream of the MSIVs for a steam break or downstream of check valve for a feed break.
In E-2, faulted SG Isolation, why will AFW have to be periodically reduced to maintain SG Levels after RCS Temp is stabilized?
Lowering Decay Heat Levels
In E-2, Faulted SG Isolation, why do we control AFW Flow?
Prevent SG Dryout
Minimize RCS Cooldown
Prevent SG Overfill
Control RCS Temp after Cooldown is stopped
During E-3, SGTR, why do we want to terminate SI?
Helps control primary to secondary leakage
What could be a potential problem if the SG is overfilled during a SGTR?
Rupture of MS Line from weight of the water
Damage to PORVs, Safeties and TDAFP
During a SGTR, what is the affected SG PORV set point changed to and why?
1040 psig to minimize the release
Why do we ensure the ruptured SG level reaches 13% before isolated AFW to it?
To ensure SG Tubes are covered, which will prevent depressurization
What does the UFSAR assume for a SGTR?
Operator actions are taken to isolate ruptured SG efficiently
What are the advantages and disadvantages of ES-3.1, Cooldown using backfill?
+ Minimizes radiological releases and allows processing of RCS
- Potential boring dilution, secondary chemistry effects on RCS, Slow
What are the advantages and disadvantages of using ES-3.2, Cooldown using blowdown?
+ Minimizes radiological releases, NO boron dilutions or chemistry effects
- storage / processing capabilities, spreads contamination, SLOW
What are the advantages / disadvantages of using ES-3.3, cooldown using steam dump method?
+ FAST
- Contamination / radiation, potential water hammer on secondary components.
When would you transition back to E-2 from ECA-2.1, Uncontrolled depressurization of all SGs?
If any SG pressure boundary is restored, except while performing SI Term steps 10-20
During ECA-2.1, what is AFW lowered to and why?
25K per SG to prevent boiling dry and minimize thermal shock effects if FF is later raised
What is the minimum DP that should be maintained between the ruptured and intact SGs?
250#
When would you enter ECA-3.1, SGTR w loss of RC, subcooled recovery?
Cannot isolate ruptured SG from any intact SGs
Faulted and Ruptured SG
Min DP cannot be maintained
SGTR w LOCA
When would you transition from ECA-3.1 to ECA-3.2, SGTR w Loss of RC, saturated Recover?
RWST level is low with NO corresponding rise in Containment water level
What are the immediate actions for FR-S.1?
- Trip Rx
- Insert Rods > 48 spm
- Manually actuate AMSAC
- Trip Turbine
- ATWS Runback
- MSICs close
What is the purpose for tripping the turbine in FR-S.1?
Prevents excessive cooldown and conserves SG Water
Why do you NOT trip RCPs if power is >5%?
Provides core cooling and keeps fuel integrity in tact
Is an ATWS worse at BOL or EOL?
BOL due to less temperature feedback
Why is RCS pressure checked less than PRZ PORV setpoint in FR-S.1?
ensures ability to emergency borate
What is the minimum AFW flow during ATWS?
450K LBLOCA until 13% NR Level
How could an unneeded SI complicate an ATWS?
FWI and MFPs will trip which will mean SGs could dryout
What are the possible ways to lose subcriticality during an ATWS?
Dilution
Cooldown
Rods do not fully insert
Is it necessary to have adequate SDM to exit from FR-S.2?
No, however a boration is expected to be continued after the transition to ensure adequate SDM
What containment pressures put you into a red and orange path for Containment CSF?
Red - 12 psig
Orange - 2.8 psig
While in ECA-1.2, LOCA Outside of containment, what is the indication that your leak has been isolated?
RCS Pressure Rising
Why does ECA-1.1, Loss of emergency coolant recirc, direct depressurizing the SGs to 670 psig?
To prepare for a controlled accumulator injection to keep the core covered
What are the assumptions concerning the LBLOCA analysis?
Some zirc-water reaction is expected
ECCS flow to the faulted loop and the accumulator injection for that loop spills to containment
RHR pumps must not be aligned for spray prior to 50 mins after the onset to ensure decay heat levels are within the heat removal capability of 1 CCP and 1 SI pump
Core safety could be challenged if RHR and CTS flow is interrupted for more than 5 mins while transferring over to CL Recirc
What is the EOP basis for tripping the turbine in FR-S.1 when there is a loss of MFPs but no reactor trip?
Maintain/Extend SG Inventory
When should you not restart RCPs for ES-1.2, Post LOCA Cooldown and Depressurization?
When all seal cooling has been lost long enough that maximum RCP seal parameters have been exceeded. Instead, cool the RCS to reduce temp of the water flowing thru the pump seals
This removes the potential thermal shock damage to the seals
While in ES-1.2, Post LOCA Cooldown and Depressurization, you’re doing ECCS flow reduction. You’re ready to stop the first CCP. RCS Subcooling exactly meets subcooling table requirements. After you stop the pump, what do you expect?
Subcooling will lower to the minimum required value then recover with the cooldown
In ECA-1.1, Loss of Emergency Coolant, what is the basis for cooling the RCS at a maximum cooldown rate (after a LOCA outside containment that has not been isolated)
The cooldown rate will minimize offsite releases due to the event by reducing the need for supporting systems and equipment
If we have inadequate core cooling, what could happen?
Core uncovers
Fuel damage could occur
What are the red path entries into FR-C.1?
5 highest CETs all > 1200*F
RVLIS NR < 46% with all 5 highest CETs > 757F with no RCPs running and SC < 40F
What’s the most effective strategy of FR-C.1?
Establish ECCS Flow
What are the 4 Major Action Categories of FR-C.1?
Establish ECCS Flow
Rapidly Depressurize SGs to Depressurize RCS
Start RCPs
Open all RCS Vent Paths to containment
What is the purpose of rapidly Depressurize go SGs in FR-C.1?
Allows accumulator and RHR pump injection
In FR-C.1, when would you not start a RCP?
If SG depressurization was ineffective due to loss of heat sink bc creep failure of the SG tubes
In FR-C.1, would you start RCPs without support conditions?
YES! Start 1 RCP at a time until CETCs are < 1200*F
What do CET temps of 757*F indicate?
Superheated core exit
Why is a 1” SBLOCA the worst scenario for FR-C.1?
Loop seal never clears, so steam mass loss rate out the break isn’t reduced.
What is indicative of superheated conditions?
High CETCs
What is indicative of core uncovery?
Low RVLIS
What is significant about 46% RVLIS level?
COre covered…. 3.5 ft from bottom of core
Why are RCPs stopped in FR-C.1 after SGs are Depressurize to 160 psi?
Loss of #1 seal requirements
Why are RCPs so important in FR-C.1?
They provide forced 2 phase flow to prevent inadequate core cooling
In FR-C.2, if all RCPs are running, what must be done?
Stop #3 for later use
What are the Major Action Categories for FR-H.1?
Attempt to restore FF to SGs
Initiate RCS Bleed and Feed
Restore and verify Heat Sink
Terminate RCS Bleed and feed
When would the secondary heat sink not be required?
LBLOCA
RCS Temp <350*F bc RHR can be used
What must be done during FR-H.1 if NO CCPs are available?
Stop all RCPs and initiate feed and bleed immediately to Depressurize to SI pressure
How can you tell if secondary heat sink has been restored?
Lowering RCS Temps and rising SG Level
What are the feeding guidelines after bleed and feed initiation per FR-H.1 FOP if CETCs are rising?
- Feed any SGs that are NOT dry at max Rate
- If ALL SGs are dry, feed 1 SG at max rate. When CETCs lower, check for fault or rupture. IF it is, then establish FF to INTACT SG at < 50E3 ppm
What are the feeding criteria after bleed and feed initiation in FR-H.1 if CETCs are stable or lowering?
Feed any SGs that are not dry as necessary to restore NR level
If all SGs are try, then feed 1 SG at a time less than 50E3 ppm.
What is considered a dry SG?
WR < 17%
If SI termination criteria is not satisfied in FR-P.1, what should be done?
Start RCP to mix ECCS flow w RC to minimize thermal stresses not he vessel and then soak for 1 hr
What is looked at for SI Termination criteria in FR-P.1?
Less Restricitive
SC > 90*F and RVLIS Level
What is the operator error assumption made in FR-P.1 to make a PTS concern possible?
SI termination is delayed 30 mins
In FR-P.1, how long do you soak and when does the clock start?
1 hr when temps is stable
What is the cooldown limit in FR-P.1 after the soak?
50*F/hr
How can you exit FR-P.1 without any actions?
RCS Pressure < 300# and RHR Flow > 400 gpm
LBLOCA
Is a cooldown or heatup more limiting for RCS Integrity and why?
Cooldown bc of tensile stress on the inner wall
What’s the worst case PTS accident and why?
3” SBLOCA when both RCS forced flow and NC are lost and cold RWST water streams to vessel belt line welds.
What is the cooldown rate in FR-P.1?
100*F per hour
WHat should have happened before implementing FR-P.2, yellow path?
SI should have been terminated
When would you not perform FR-I.1?
SI is in service and needed
In FR-H.1, what must be done if less than 2 PORV flow paths are open or CETCs are rising?
Use additional vent paths…. NSOs
What is the preferred order of the secondary heat sink sources?
AFW own unit
AFW cross tie
MFP
Condensate
What’s key to determine if you have Nat Circ?
Large Delta T
What are the benefits of feed and bleed?
Minimize core uncovery and prevent inadequate core cooling
When is an ATWS worse?
BOL due to less feedback from a smaller MTC
During an Emergency Remote Shutdown, how is Pressurizer Pressure Controlled?
On Safeties….. PRZ Block Valves should be closed
What is the minimum that must be done before evacuating the control room?
Rx and Turbine should be tripped
Should equipment placed I/S by EOPs be stopped by SACRGs?
Only if SACRG stops it or TSC recommends it
What would be a RED path on FR-Z.1, Response to High Containment Pressure?
> 12 psig
What would be an orange path on FR_Z.1, Response to High Containment Pressure?
> 2.8 psig
When would RHR Spray be placed in service per FR-Z.1? Why this time?
50 mins after the accident with < 2 CTS Pumps I/S.
Low enough decay heat for 1 CCP and 1 SI Pump to handle
What are the normal sources of water that are accounted for in FR-Z.2, Response to Containment Flooding?
RCS
RWST
Accumulators
Ice Bed Melt
LOCA / Secondary Break
What are the modes of applicability for ECA-0.0?
Modes 1-4
While attempting to restore power during ECA-0.0, which pump switches would you not take to PTL?
ESW to ensure EDG Cooling
When would you transition out of ECA-0.0 without getting power back?
CETs > 1200*F, go to SACRG-1
How many SDGs must be running in ECA-0.0 to start recovery actions?
2
What would meet entry into the ECA-0.1 recovery path? (SI not required)
SC > 40*F
PRZ Level > 16 (20)%
ECCS Pumps not providing Flow
What’s the criteria for entry into ECA-0.2, SI Require recovery?
SC <= 40*F
PRZ Level <= 16 (20)%
ECCS Pumps providing Flow
What happens if steam voids for in the SG U-tubes during ECA-0.0 ?
NC will stop bc steam is preventing fluid flow (poor heat transfer)
What’s the purpose of Secondary Depressurization in ECA-0.0?
Minimizes inventory loss thru RCP Seals to extend time to core uncovery
During ECA-0.0, why would we not re-establish Seal Injection Flow after a prolonged lack of flow?
Prevents cracking he seals or warping the shaft
If CCW is lost for an extended period of time due to a loss of power, how do we re-establish cooling to the RCPs?
Performed a cooldown, to cool the seals
During a loss of all AC Power, ECA-0.0 directs the operators to do what to control CR Temperature ?
Open cabinet doors within 30 mins
While recovering from a loss of all AC Power, why may a BAT Pump be use to pressurize the CCP Suction?
High VCT Temp
NPSH
Where would you transition to when complete with ECA-0.1, Loss of All AC Power Recovery without SI Required?
ES-0.2, Nat Circ Cooldown
Where would you transition to when complete with ECA-0.2, Loss of All AC Power Recovery with SI Required?
E-1, Loss of Reactor or Secondary Coolant
What is the difference between a small and intermediate break in E-2?
Small Break - MFW System maintains SG Level
Inter Break - Rx trip will occur ~ 5 mins
Why will AFW need to be reduced as time passes after a faulted SG Depressurizes all the way?
Lower decay heat levels
