LOIT 2020 exam prep > Exam 2 prep > Flashcards

Exam 2 prep Flashcards

Cberry notes for exam 2 (75 cards)

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1
Q

How is level maintained in the PZR?

What are the max and min setpoints when in REMOTE AUTO?

What are the associated Tave values for the max and min Lpzr programs

A
  • Level is maintained between 33%-53% based on Average Coolant Temperature
    • Average Coolant Temperature is proportional to Reactor Power
      • FAILURES IN TAVG INPUTS EFFECT LEVEL S/P! Not failures of Control Channel Power
    • S/P is never below 33% and never above 53% when in REMOTE AUTO
    • S/P changes from 33% to 53% linearly from 15%-100% power (Tavg)
      • ~ 568F to 586F Tavg (15%-100%)
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2
Q

What determines the PLCS setpoints when in Local AUTO?

A

The operator using the thumbwheel.

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3
Q

What is the AUTO letdown flow limited to by PLCS?

A

30-135 GPM

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4
Q

State the Lpzr deviation setpoints and what happens at each value.

A
  • +3% all backup heaters on, +2.5% all backup heaters off
  • +15% Normal Running CCP goes OFF, +14% Normal Running ON
  • -23% Standby CCP turns ON, -14% Standby turn OFF
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5
Q

State the alarms associated with Lpzr and any other associated actions.

A
  • 60% High level alarm (remember Tech Spec @ 56%)
  • 25% Low level alarm (Resets @ 27%)
    • THIS MATCHES WHEN HEATERS GET LOCKED OUT AND THEN BACK AVAILABLE (ALL HEATERS!)
  • Deviation alarms
    • +8.5% Hi level alarm in, +8.2% Hi level alarm is clear
    • -3.5% Lo level alarm in, -2.7% Lo level alarm is clear
      • THESE COME IN BASED ON SETPOINT REMOTE OR LOCAL
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6
Q

How would you determine what the setpoint should be if given a Rx power between 15-100%?

A
  1. Given Rx pwr - 15
  2. Ans/85
  3. ans*20
  4. Ans + 33
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7
Q

What happens to Lpzr setpoint on a RCS temp instrument that:

Fails HIGH

Fails LOW

Do temp instrument failures affect Lpzr setpoint in Local/Auto?

A

High: Lpzr setpoint goes to 53% and PLCS responds.

Low: Lpzr setpoint goes to 33% and PLCS responds.

NO

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8
Q

Actual Lpzr = 33%

Lpzr setpoint is shifted due to failure to 53%.

What happens in PLCS?

A

Remember:

Actual - Setpoint to get deviation. Do the “does this make sense?” check.

ie. Does it make sense that LD would go to maximum if actual Lpzr is already at the low end of the band? NO.
1. LD flow to minimum
2. STBY CHP DOES NOT START!!!! 33 - 53 = - 20%
3. PZR TRBL

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9
Q

Actual Lpzr = 53%

Lpzr setpoint is shifted due to failure to = 33%

How does PLCS respond?

A

Remember:

Actual - Setpoint = deviation. Do the “does this make sense?” check.

ie. Does it make sense that LD would go to maximum if actual Lpzr is already at the low end of the band? NO.

Deviation = 20%

  1. PZR TRBL
  2. LD flow to maximum
  3. NORMAL CHP stops

LD will be lost due to HI HI Regen Temp.

  1. All B/U heaters will energize (if < 2285psia) due to +3% deviation.
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10
Q

What will happen to PZR heaters on a LT-110X failure low if RCN-HS-100-3 is selected to BOTH?

To Y?

A

All PZR heaters will deenergize on <25% Lvl interlock.

Nothing.

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11
Q

What will occur on a loss of NNN-D11 with respect to Pressure and Level control?

A

NNN-D11

LIC-110 Master level controller loses pwr = output fails to 0; LCVs fail closed = LD lost

Normal and Stby CHG pps off, manual control available

“Y” level and pressure control channels lose pwr and output fails to 0

“Y” htr cutout channel fails = All htrs off if selected to Both or “Y”

Select channel “X” on HS-110 (level), HS-100-3 (level cutout), and HS-100 (pressure)

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12
Q

What will occur on a loss of NNN-D12 with respect to Level and Press control?

A

NNN-D12

TS-224-2 pwr loss causes 523 to close = LD lost

TIC-223 fails to 0 causing TV-223 to close

PIC-201 fails to 0 output = BPCVs close = LD lost

PIC-100 Master pressure controller loses pwr = output fails to 0

PIK-100 Spray controller loses pwr = output fails to 0 = spray valves close

“X” level and pressure control channels lose pwr (not LTs/PTs) and output fails to 0

“X” htr cutout channel fails = All htrs off if selected to Both or “X”

Select channel “Y” on HS-110 (level), HS-100-3 (level cutout), and HS-100 (pressure)

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13
Q

What happens to PPCS when the selected PZR press fails low?

A
  • PZR TRBL and PZR PRESS HI - LO
  • PPCS master to 0 output.
  • Spray valves will close.
  • Heaters will energize
  • Low Pzr press on B04
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14
Q

What will be the PPCS response to a selected PT that fails HIGH?

A
  • PZR TRBL
  • PZR PRESS HI - LO
  • Tur Bypass demand alarm
  • SBCS affected:
    • PT100x - Modulation signal biased down
    • PT100y - perm signal biased down.
  • Master ctrllr to maximum
  • Heaters to OFF
  • Spray full OPEN
    With no operator action, RCS will trip on LO DNBR.
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15
Q

What will happen to PLCS/PPCS on a loss of NKN-D41?

A

Alpha train non class heaters will lose control power.

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16
Q

What will happen to PLCS/PPCS on a loss of NKN-D42?

A
  • CHB-523 closes isolating letdown.
  • CHP auto control lost => all CHPs stop and are available in manual.
  • Loss of position indication: LCV, PCV, main spray.
  • PZR lvl control power lost => all htrs off on low lvl.
    • can manually operate bkrs
  • B train non class htr contrl power lost.
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17
Q

What will happen to PLCS/PPCS on a loss of PKA-M41?

A

IAA-UV-2 fails closed which will cause a loss of the following:

  • LD
  • Main spray
  • CBO shifts to RDT

Additionally, Aux spray valve 205 fail closed on LOP

AUX SPRAY IS NOT LOST.

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18
Q

Explain what happens on a TC/TH instrument failing HI at 100% power?

A

TC fails high, 100% power:
High Tave signal sent to PLCS resulting in maximum level setpoint.
No effect, PZR level already at maximum program value.
Operator selects unaffected Tave.

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19
Q

What will happen when a TC/TH instrument fails HIGH at 15 % power?

A

TC fails high, 15% power:
High Tave signal sent to PLCS resulting in maximum level setpoint.
“Pressurizer Trouble” annunciator alarms.
Letdown flow to minimum.
Operator takes local control of PLCS and shifts Tave to the unaffected
parameter.

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20
Q

What happens if a TC/TH instrument fails low at 100% power?

A

TC fails low, 100% power:

  • Low Tave signal sent to PLCS resulting in minimum level setpoint.
  • “Pressurizer Trouble” annunciator alarms.
  • Letdown flow to maximum.
  • “Normally running” charging pump stops (Tave must be selected to the faulted instrument for a Tcold failure).
  • Possible isolation of letdown due to the automatic closure of CHB-UV-515 upon receipt of a hi-hi regenerative heat exchanger outlet temperature.
  • B/U heaters energize if < 2285 psia (high pressure cutout for all PZR heaters).
  • Operator takes local control of PLCS and shifts Tave to unaffected parameter.
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21
Q

What will happen on a TC/TH instrument failure LOW at 15% power?

A

TC fails low, 15% power:

  • Low Tave signal sent to PLCS resulting in minimum level setpoint.
  • No effect, PZR level already at minimum value.
  • Operator selects unaffected Tave.
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22
Q

How will a failure of PNA-D25/ PNB-D26 affect PLCS and PPCS?

A

Panel PNA-D25 (PNB-D26)
PZR level transmitter RCA-LT-110X (RCB-LT-110Y) loses power / fails low.
All PZR heater breakers open if selected to the affected channel or “both” on RCN-HS-100-3.
Letdown to minimum if selected to the affected channel on RCN-HS-110.
Standby charging pump starts if selected to ‘X’ (‘Y’) channel on RCN-HS-110.
Operator will need to select channel ‘Y’ (‘X’) on RCN-HS-110 to restore PZR level control.
Operator will need to select channel ‘Y’ (‘X’) on RCN-HS-100-3 to restore PZR heater control.

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23
Q

What will happen to the PPCS and PLCS system on a loss of NNN-D11?

A
  • LD Ctrl valves fail closed
  • PLCS master fails to 0 output
  • Normal and STBY CHPs stop. manual is available.
  • Operator needs to select CH X on RCN-110, 100-3 and 100 to restore PZR HTR control
  • PZR lvl ctrl ch Y fails to 0(buffered signal) - All htrs OFF.
  • No output to lvl controller(has no effect - lvl controller has no power).
  • RNC PT 100Y fails low. NO htrs due to failed lvl ctrl.
  • Operator needs to select CH X to restore press control.
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24
Q

What happens to the PLCS and PPCS on a loss of NNN-D12?

A
  • PCV’s(201P/Q) fail closed due to loss of pwr to ctrlr.
  • Loss of LD due to CHB-523 closed
  • PZR lvl contrl ch X fails to 0. No heaters if in BOTH or X.
  • Must select Y ch on RCS-110 to restore PZR lvl control - only restores control to CHPs.
  • Must select Y ch on RCN-100-3 and 100 to restore PZR htr control.
  • PPCS master fails to 0 output - full prop heaters signal.
  • PZR Spray controller fails - Main SPray lost.
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25
What happens to PLCS/PPCS on a selected PZR level transmitter fail low?
1. "Pressurizer Trouble" annunciator. 2. "Pressurizer Level Hi-Lo" annunciator. 3. Letdown flow decreases to minimum. 4. "Standby" charging pump starts. 5. Heaters trip if selected to "Both" or failed level channel. 6. Actual PZR level increases until the unaffected level channel is selected. 7. Operator selects unaffected level channel for heater cutout and level control. 8. Low level indication on failed channel (B04).
26
What happens to PLCS/PPCS on a selected PZR level transmitter fails HIGH?
1. "Pressurizer Trouble" annunciator. 2. "Pressurizer Level Hi-Lo" annunciator. 3. Letdown flow increases to maximum. 4. "Normally running" charging pump stops. 5. Possible isolation of letdown due to the automatic closure of CHB-UV-515 upon receipt of a hi-hi regenerative heat exchanger outlet temperature. 6. Heaters energize if pressure (\< 2285 psia). 7. Actual PZR level decreases until the unaffected level channel is selected. 8. Operator selects unaffected level channel. 9. High level indication on failed channel (B04).
27
What happens to PPCS/PLCS on a non selected PZR pressure transmitter that fails HIGH?
1. "Pressurizer Trouble" annunciator. 2. "Pressurizer Pressure Hi-Lo" annunciator. 3. “Turbine Bypass Demand” annunicator. 4. SBCS affected: • If PT-100X - Modulation signal biased downward (controller demand generated). • If PT-100Y - Permissive signal biased downward (permissive light lit). 5. High Pressurizer pressure indication on B04. 6. No operator action.
28
What will happen to INDICATED Lpzr if the Variable leg develops a leak? the Reference leg develops a leak?
A leak in the variable leg will cause indicated level to LOWER. A leak in the reference leg will cause indicated level to RISE.
29
What is the output range on PIC-100 PPCS Master, that will control ONLY THE PROP HEATERS? SPRAY VALVE?
0% = (full prop heaters) to 33%(prop heaters OFF) 33%(SPRAY begins to open) to 50%(Spray FULL OPEN)
30
Explain the Setpoint override feature associated with the B/U heaters.
* Every backup heater has **Setpoint Override Feature** * This allows energizing backup heaters when PZR Pressure **\>2225 psia** * Take the handswitch to **OFF**…….**setpoint override light** comes on. Then go to **ON** and the **heater should energize** * Setpoint override will remain in for **10 seconds**. You cannot remove setpoint override until after 10 seconds. * When setpoint override is removed, it is locked out for **10 seconds.**
31
Will the LOW level and HIGH pressure cutouts still function when the backup heaters are taken to setpoint override?
YES!!!!!! Low level: \<25% Lpzr High pressure: \>2285 psia
32
What is the mission time for the UHS? What is required in order to meet this time?
* **26 day mission time**. Requires that the Spray Ponds be cross-connected **within 24 hours of the accident**
33
What is the SP system designed to maintain?
* System is designed to maintain **EW temperature to Essential Chiller ≤ 135F** during a design basis LOCA
34
State the events that will AUTO start the SP?
CLADS CREFAS/CRVIAS LOP AFAS DG running SIAS/CSAS
35
State the TS temperature and **usable** level associated with the SP. State the TS minimum CR indicated level.
* Spray pond temp **≤ 89F** * Spray pond level **≥ 12 ft of usable level**. Therefore actual level must be **≥13.5 ft** since we assume **1.5 ft** of water is **non-usable**. **Control room** indication **≥14 ft**
36
Where would one find CR indication of the SP upper and lower MOTOR bearing temperatures?
B07 multipoint recorders.
37
Which system has the lower system pressure and why? EW or SP?
EW To prevent radioactive release to the environment. SP is tube side. EW is shell side.
38
State what events would auto start the EW system?
## Footnote CALCS CREFAS AFAS LOP CRVIAS SIAS/CSAS
39
What will auto close EWA-145 and EWA-65 NC cross tie valves for A train?
* **Low level (@ 17”) in EW Surge Tank** closes the **“A” train** NC to EW cross tie valves * SIAS actuation signal - can be overridden.
40
What other method of cross tying NC and EW exists besides EWA-145 and EWA-65?
Manual valves that will cross tie the bravo EW train.
41
What is the Ref head pressure control valve? Why does it exist?
* Prevents STACKING in the condenser * Limits cooling water flow rate during LOW LOAD Conditions
42
State the main steam components that have N2
MSIVs have N2 accumulators ADVs - 16 hr N2 backup with N2 supply and accumulators. D/C FWIVs N2 is the motive force with an 8 hour N2 backup
43
State the number of MSSVs and setpoints.
5 per steam line for a total of 20: 1 @ 1250 psig 1 @ 1290 psig 3 @ 1315 psig
44
At what D/P can the MSIVs be proceduraly opened?
\< 100 psid
45
What happens when MSIV switch is taken to Exercise?
Causes the valve to go slowly to 90% open then automatically back to 100% open using Hydraulic pump
46
What is the power supply to MSIVs?
* **Normally directly off “A” and “B” PK Battery** * **Alternately** off the PK Bus * LOSS OF POWER (Batt. completely disch): **valves fail closed**
47
Describe how IA being lost can affect MSIVs?
* On loss of IA: the valves are designed to remain “AS IS” * **Capable of FAST closing** * If Air Reservoir Pressure goes away then the valve **FAILS AS IS** * White SEIS @ reservoir pressure **@ 85 psig**
48
How do MSIV bypass valves respond to a loss of IA or power?
Fail closed on both.
49
Concerning the ADVs, how will the valves respond to a loss of PNA or PNB? How will a loss of PNC or PND affect ADVs?
* Controller Power * **PN “A” and PN “B” only** * Loss of PN “A” or PN “B” **2 ADVs inop (fail closed)** * **DO NOT** fall for losing PN “C” or PN “D”. This has no effect on ADVs
50
How will the ADVs respond to a loss of PKA-D?
* Permissive power * **PK “A”, “B”, “C”, “D”** * Loss of ANY PK Bus **2 ADVs inop (Fail Closed)** * Permissive separated by Train * **PK A & C only 2 ADVs INOP** * **PK A & D(or B) all 4 ADVs INOP**
51
What effect will losing IA have on ADVs? How long, if at all, will the ADVs be available for following a loss of IA?
* Loss of Air * ADVs have **nitrogen accumulators** * Designed for **16 hour** Station Blackout Coping Strategy ALSO (not on top of) **4 hours at HOT STANDBY plus 9.3 hours to reach SDC entry conditions.** * On a Loss of IA the ADV’s will fail closed **once nitrogen accumulator pressure runs out.**
52
How will a loss of power and or a loss of air affect the D/C FWIVs? What provides the motive force for the D/C FWIVs? Why is there a backup system if IA is lost?
* IA reposition servos for going open or closed **N2 provides motive force** * Back-up N2 system **provides 8 hours** of valve operation if **N2 system is lost**……allows AFN to supply the SGs * LOSS OF POWER **(PK)** * **FAIL OPEN** * LOSS OF AIR and N2 **FAIL CLOSED**
53
How do the Econ FWIVs fail on loss of power or loss of air?
* **Economizer Feedwater Isolation Valves** * LOSS OF POWER (Battery completely discharged) * **Fail Closed** * LOSS OF AIR * **No change (capable of Fast Closing)**
54
State how the AS cross tie is operated for the supplying Unit and the other Units.
* ASN-V015 is open for the supplying unit. ASN-V014 is kept open for Unit’s not carrying the X-tie header
55
State which loads are supplied by the 50psig section of AS. Where do the Aux bldg AS loads drain to?
* BAC, Gas Stripper, and EVAP * Steam loads in the Aux and Radwaste Bldg drain to Aux Steam Receiver Tank
56
What is the function of RU-7? WHat happens on a HI RU-7 alarm? What occurs with respect to RU-7 monitored drains on a loss of AIR? What cools the Aux Steam Vent Condenser?
* RU-7 is the Rad Monitor for Aux Steam Receiver tank effluent * If **RU-7 high alarm is received** auto directs effluent to RW TDS system and not the Main Condenser * LOSS OF AIR * Fails to direct effluent to LRS * Aux Steam Vent Condenser cooled by NC
57
What will occur on a loss of NC with respect to AS or Loss of Receiver Transfer pumps?
* **Results in flooding the HA Ventilation** * If a high level alarm for receiver tank is received both pumps should be running
58
State the power supplies to the non class channels of Excores and how they are calibrated.
* Non- Class Excores * Powered by: * **NNN-D11** (Control/SU Channel 1) **& NNN-D12** (Control/SU Channel 2) * Calibrated: * **Calibrated to match JSCALORC** (norm) **& NKBDELTC** (alt)
59
State the purpose of BDAS and when it is required to be in service. How is BDAS placed in test mode and what is the consequence?
* Required **within 1 hour of entering Mode 3** w/ flux in the S/U range * 3.3.12 : **2 Channels in Modes 3, 4, 5, 6** * Depressing the **FLUX/SETPOINT** button **3 times w/in 3 seconds** causes BDAS to enter test mode and is **inoperable**
60
State the type, alarms and when it is energized as it relates to the S/U channels
* Type: * **Each S/U Channel contains two BF3 PROPORTIONAL** (region) **detectors** * Provides a High CPS alarm at 10,000 CPS to remind the operator to turn off high voltage * **Energized @ 2x10-6% log power** * Done by selected HV PERMIT button on the NI drawer and S/U Channel on B04
61
What type of detectors are the Control Channels?
* **Control Channel are uncompensated IONIZATION** (region) **detectors**
62
What type of detector is the Safety Channels? What indications do they provide?
* **Safety Channels** * Type: * **3 stacked U-235 fission chambers** * Center channel: **Provides log power (indication at RSP\*)** **All 3 are used to determine LINEAR POWER**
63
Which detector is used for the HI LOG POWER trip? What is the setpoint? When can it be bypassed?
Center safety channel. 10E-2% at 10E-4%
64
What will happen if the LOG CALIBRATE switch is taken out of OPERATE?
* **If the log calibrate switch is taken out of the OPERATE position the high log power bypass will be removed (BAD WRONG)**
65
What detector is used to generate the VOPT trip signal? What are the setpoint?
* **Comes from the safety channels.** (Remember must have 2 of 4 safety channels to have it actually trip) * Fixed: 110%, Variable: 9.7% above steady state power, Rate of change ≥ 10.6%/min
66
What is the purpose of the QSPDS system?
Safety related equipment that provide indications of approach, existence of and recovery from INADEQUATE CORE COOLING
67
What is displayed always on the QSPDS? What determines whether RCS or Upper Rx Vessel Head SCM is displayed?
* **Temp Sat Margin of RCS (always)** * Displays the more limiting of either (**RCS or Upper Reactor Vessel Head saturation margin)**
68
Where do the RVLMS HJTCs enter the core?
* HJTC: * They come in from the top of the core through unused CEA channels through the grey lock hubs. * **Each assembly (A & B Channel) contains 8 HJTCs**
69
State the RVLMS levels and their relative sections.
* Upper Head: * 1 – 67% * 2 – 41% * 3 – 16% * 4 – 0% * Plenum * 5 – 73% * 6 – 47% * 7 – 21% * 8 – 0%
70
How do the HJTCs provide vessel level indication? When is the plenum level not valid?
* For each HJTC there **is a heated and unheated HJTC** * Indicates a **void** when the **difference** between the heated and unheated is **200F** **OR** when an **unheated** reaches **700F** * When reading the display ACTUAL water level is somewhere between the detector that indicates a void and the next one down that indicates no void * **When RCPs are running the plenum indication IS NOT valid**
71
State the operating characteristics concerning the CETs. How are parameters displayed that are out of range? What is shown when a parameter exceeds its setpoint?
* 61 total located at the top of the in-core instrument strings. * Indicate temperature between **200F-2300F.** * Out of range detectors show **question marks instead of temp** **Orange backlighting** indicates a parameter exceeds setpoint
72
state the purpose of the refrigerant head pcv bypass valve and its normal configuration.
allows bypassing refr. head pcv during high heat loads and degraded ew pump performance when cooling the pc hx's. 720 gpm through the condensers is necessary to accommodate a design basis accident in the middle of the summer with EW temp @ 132F normally locked closed.
73
How is an approach to ICC indicated in QSPDS?
Loss of subcooling Lowering vessel level Increasing CET temperatures as fuel is uncovered
74
How is the recovery from ICC displayed by QSPDS?
Lowering CET temperatures as the fuel is rewetted. Rising Rx vessel level. Transition from superheat/saturation conditions to subcooled conditions.
75
Why is cladding temperature of great importance in QSPDS? How is cladding temperature measured?
Cladding temperature is the parameter most likely associated with fission product release. It cant be directly measured. So we use CET at core exit. CET and Ppzr are used to calculate amount of superheat, which is directly related to the amount of fuel uncovered. The abs value of superheat is not important, but the TREND.
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