E-1 Daily Quiz Flashcards
List the four phases of a LBLOCA?
Blowdown
Refill
Reflood
Long Term Recirc
When does ECCS injection reach the intact loops?
Reflood Phase
What does the accident analysis 10.CFR.50.59 state?
Some fuel damage may occur
None of the ECCS acceptance criteria will be exceeded
Why is the TCA for transfer to cold leg recirc 5 min?
Ensure Peak Clad Temp not exceeded
How much time must pass prior to placing RHR Spray in service?
50 Min to ensure decay heat can be removed from CCPs and SI pps
What is the threshold for a SBLOCA?
Greater than the capacity of the charging system
What is the threshold for a LBLOCA?
Below shutoff head of RHR pumps (>400gpm)
Why are RCps tripped during a LBLOCA?
Loss of CCW on Phase B
Three phases of SBLOCA?
blowdown
reflood
long term recirc
What must be done if a SG is found to be depressurizing during E-1 step 2 and cannot be isolated due to equipment failures?
Consider it isolated and move on in E-1
What is the purpose of checking any SG pressure lowering or RCS pressure rising in E-1 Step 9?
To determine if faulted SG is still blowing down and loop through procedure again to determine if SI can be terminated
What is the basis for accumulator isolation with RCS pressure <150psig?
Accumulator water has already injected and all that remains is N2
What must the crew do if a Red path is identified while transferring to ES-1.3?
Complete portions of ES-1.3 until it tells you to begin monitoring status trees again
While responding to a LOCA RCS pressure is above RHR pump head but lowering. Should the RHR pups be stopped?
No, pressure may lower below their shutoff head at some point
While performing E-1 what conditions must be satisfied to allow CTS pumps to be stopped?
Ctmnt pressure <2psig
When would hot leg recirc be utilized following a SBLOCA and why would it not normally be used?
If sub cooling was not restored use it
If sub cooling is restored concentrated boric acid in the core would not occur
Why must SI pumps be stopped during alignment to hot leg recirc?
Dead head the pump, mini flows closed during cold leg recirc alignment
Where do the ECCS pumps discharge during hot let recirc?
RHR and SI to hot legs
CCP to cold legs
What must be done if only one SI pump recirc valve will close while swapping to cold leg recirc?
Only one required they are in series
What is the basis for splitting CCW trains in ES-1.3?
Prevent pump runout if one were to trip
Under what conditions would the SI pumps not be aligned for cold leg recirc?
If RCS pressure is above their shutoff head
What are the restrictions for placing hydrogen recombiners in service?
6 hours after event with hydrogen concentration between 0.5 and 4%
Requirements for SI termination
Subcooling >40
Heat Sink
RCS Pressure stable or rising
PRZ level
Why is RCS pressure checked after stopping a CCP during SI termination?
To detect a SBLOCA
What must you do if PRZ level cannot me maintained after establishing normal Charging in SI termination?
Realign the BIT and go to ES-1.2 Post LOCA cooldown
What happens during a SBLOCA that causes the core to recover after being uncovered for a period of time?
Loop seal clears
What are the two heat removal methods during a SBLOCA? Which one is also effective during a LBLOCA?
ECCS/Break flow and SGs
ECCS flow, SG are a heat source
When does natural circ stop and reflux cooling begin?
When the steam generation rate in the core exceeds the condensing capacity of the SGs
What is reflux cooling?
Condensed steam flows back the hot legs to the core
Affects of leaving the RCPs running during a SBLOCA
Increased mass loss keeping two phase mixture at the break.
Increased heat transfer until shutdown
Why do we trip RCPs at 1300psig?
Prior to break uncovery if done afterwards would not prevent the increased mass loss
What makes a SBLOCA in the cold leg worse?
Loop seal must clear before steam can be vented from the break
What indication is unique to a PRZ steam space break
PRZ level rising
When does the 1300psig RCP trip not apply?
Operator induced cooldown
Following direction to start RCP
SI from non power condition
When is PRZ level not a valid indication of RCS inventory?
When subcooling doesn’t exist because of head voiding
Conditions that would force you to ES-1.2 from E-1 and ES-1.1?
No RHR injection
Pressure lowering following stop of first CCP
PRZ level cannot be maintained with normal charging
RCS Pressure less than SI Pump shutoff head
What conditions will allow stopping an ECCS Pump during flow reduction of ES-1.2 when only PRZ level requirements are met?
Hot leg temps less than 340 F and RHR in service
If RCS pressure drops to just above RHR head following a LOCA can the cooldown be initiated in ES-1.2 at the first encounter?
No, cool down must remain less than 100 degrees in any 60 min period
In ES-1.2 why do we continue to monitor subcooling greater than 40 degrees?
To determine if ECCS flow reductions can be performed
What is the subcooling trend following stopping of one ECCS pump during flow reduction?
Sub cooling will lower but should remain above minimum. It will then increase due to the cooldown.
Preferred RCP to restart during ES-1.2? What effects spray flow?
3
Highest DP
PRZ level
Coolant velocity
Adverse conditions from depressurizing RCS to refill the PRZ with no RCPs running?
Voiding in the head
Major action categories of ECA-1.1?
Attempt to restore equipment
Conserve RWST
Cooldown
Minimum Subcooling
What actions are performed to minimize break flow?
Depressurize to minimum subcooling
What is the basis for depressurizing the SGs to 670psig in ECA-1.1?
Perform a controlled injection of accumulators to keep the core covered
What conditions must exists for operators to leave the loop of the first 25 steps of ECA-1.1?
RWST <11% stop and lockout RHR/CTS pumps
What must be performed if recirc equipment is restored in ECA-1.1?
Return to procedure step in affect
E-Plan classification for ECA-1.2 Loca Outside Containment?
SAE
How do we determine if ECA-1.2 LOCA Outside containment efforts were successful?
RCS Pressure Rising
How many CTS pumps are required in ECA-1.1 based on containment pressures?
<8 psig none
>8 psig one
>12 psig two
