Systems

Question 1

Draw the Electric Plant down to 4160v busses

Answer 1

Question 2

List loads on the L10 Bus

Answer 2

CW Pump C
MFP
Interbus LH-1-A
S/U supply to L11
S/U supply to L12

Question 3

List loads on the L11 Bus

Answer 3

CW Pump A
B33 Recirc Pump A (Fast)
Interbus LH-1-B
LF-1-A/C/E/H
(ACEHOLE)

Question 4

List loads on the L12 Bus

Answer 4

CW Pump B
B33 Recirc Pump B (Fast)
Interbus LH-1-C
LF-1-B/F/D/G

Question 5

List loads on the H11 Bus

Answer 5

RFBP A/C
CBP A/C
HWP A
CVCW Chiller A
TBCW Chiller A
LFMG A
SY Load Center

Question 6

List loads on the H12 Bus

Answer 6

RFBP B/D
CBP B
HWP B/C
CVCW Chiller B
TBCW Chiller B
LFMG B
U1 SA & IA Compressors
SW Pump A

Question 7

List loads on the XH busses
Which XH Bus is not diesel backed?

Answer 7

XH11:
CRD Pump A
NCC Pump A

XH12:
CRD Pump B
NCC Pump B
SW Pump B
XF-1-A

XH21: (Not diesel backed)
NCC Pump C
SW Pump D

Question 8

Regarding Aux Transfer Switch function:

What is the purpose of the Aux Transfer Switch?
Will the transfer still happen with the switch in “Off”?

Answer 8

Aux Transfer Switch will prevent powering an L bus from 2 seperate transformers, which would result in twice the fault current with a fault in the affected L bus.

With the switch in “Off,” the transfer still occurs.

Question 9

Regarding Fast Bus Transfer of L and H busses:

What causes a fast bus transfer to occur?
From which sources (primary or alternate) does a fast bus transfer occur?
What will happen when a breaker tries to transfer to a faulted bus?

Answer 9

Breakers auto transfer to alternate power supply if primary power supply goes down.
Breakers will not return to primary source if alternate source is subsequently lost.
Breaker will land in the trip free position.

Question 10

Regarding Stub Busses

What are stub busses?

What happens to stub busses on a LOOP? LOCA?

What happens to loads on the stub busses in these situations?

Answer 10

Diesel backed busses with not required but desired loads on them.

During a LOOP, stub busses stay tied to their source. During a LOCA, stub busses shed and will not be tied in until operators bypass with keylock switch.

In a LOOP, the stub bus loads react as follows:
CRD Pumps - Pumps trip, will remain off until operator intervention.
NCC Pumps - Pumps trip, will restart automatically when stub bus power returns.
SW Pump B - Pump trips, and will restart provided the control switch is in normal, the pump receives a LOOP signal, voltage is restored to the bus, and the pump discharge valve reposition sequence completes.

In a LOCA, these loads remain secured.

Question 11

Define LOOP, SBO, and TLAC

Answer 11

LOOP - Loss of Offsite power and at least one RHR powering DG is supplying its bus.
SBO - Loss of Offsite power with only HPCS operating.
TLAC - SBO with HPCS not operating.

Question 12

Regarding Loss of Offsite Power:

List conditions for degraded and lost voltage.

What protections do the Loss of Voltage and Degraded voltage signals provide?

What causes an EH bus Undervoltage signal?

What causes a divisional LOOP signal?
Explain how LOCA signal ties into this.

What will cause LOOP logic to initiate?

Answer 12

Degraded Voltage - < 3800v
Loss of Voltage - < 3000v

Loss of voltage prevents damage to running safety related equipment.
Degraded voltage ensures injection times and system alignments are accomplished.

< 3000v for 3 seconds, < 3800v for 4 mins, or < 3800v for 12 Seconds with a LOOP signal. This timer begins upon receipt of the undervoltage signal.

Bus undervoltage signal, Bus UF signal (59.1hz), or Divisional Test Switch to Test
AND
Opposite divisional bus UV < 75% (instant), or Opposite divisional bus UF (< 59.1hz).

Question 13

Which 480v Buses can be cross-tied?

Answer 13

F1A - F1B
F1C - F1D
F1E - F1F
F1G - F2G
EF1A - EF1B
EF1C - EF1D

Question 14

Explain how Div 3 480v differs from Div 1/2

Answer 14

Div 3 does not have load centers.
EF-1-E is comes straight from the transfomer to the MCC.

Question 15

Where is the Div 3 Transformer located?
Where are the Div 3 MCCs located?

Answer 15

EHF-1-E - CC 620’ inside the Div 2 Room

EF1E-1 - CC 620’
EF1E-2 - ESWPH 586’

Question 16

Where are the Non-Class 1E load centers located?

Answer 16

F-1-[A-F] -> TPC 647’
F-1/2-G -> SWPH 620’
F-1-H - ConstWPH 620’
XF-1-A - TPC 620’

Question 17

Where are busses L10,11,12 located?

Answer 17

TPC 620’

Question 18

Which Non-Class 1E MCCs have ABTs and which bus do they transfer to?

Answer 18

F1B08
F1C08
F1D08
F2A08
F2B11
F2C11

Transfer to XF1A

Question 19

List the conditions required for an ABT to autoshift from Normal Source.

Which ABTs are normal seeking, and how long until they return to normal source?

Answer 19

MCC bus voltage < 85% rated
Alternate power supply voltage and frequency > 90%
No lockout on the XF1A bus.

F1B08, F1C08, F1D08 are normal seeking and will return to normal source with power available for >30 minutes.

Question 20

What are the indications of a ground on a DC bus?

What action should be taken if a ground is discovered?

Answer 20

Positive or negative circuit ground light will extinguish.

If a ground is detected, loads should be secured to perform a ground isolation.

Question 21

Which DC load centers have reserve chargers?

Answer 21

All except for D1B

Question 22

List Safety Class DC buses and their locations.

Answer 22

ED1A & ED2A - CC 638’
ED1B & ED2B - CC 638’
ED1C & ED2C - CC/DG 620’ Inside the DG Panel

ED-2-C is in a room located at the exit of the RP Control Point

Question 23

How many cells in the Div 1 and Div 2 DC buses?

How many volts per cell?

What is the design basis of this voltage and quantity?

Answer 23

Div 1 - 60, Div 2 - 61
1.75V Per cell
Designed to maintain a voltage above 105v with a loss of charger for 2 hours and one cell < 1.75Vdc.

Cells are for batteries, not buses. Div 1 has the extra cell (RCIC).

Question 24

List all Non-Safety DC buses and their locations.

Which of these are diesel backed, and where do they get their normal power from?

DC busses and batteries have power available regardless of DG status.

Answer 24

D1A & D2A - Unit 1/2 TPC 620’
D1B & D2B - Unit 1/2 TPC 620’

D1A and D1B are diesel backed from F1D08 & F1B08 respectively. Their normal source is L12.

D1A and D1B are DC, not DG backed. (Their normal chargers are DG backed)

Question 25

List the major loads on BOP System A - D1A & D2A

Answer 25

Inverter DB-1-A for Vital Loads Dis Panel D1A06 Control Room Annunciators C34 Chart Recorder Upset Range Main Generator and Xfmrs Logic RFPT A Trip, reset, and test logic MFP Trip Logic Main Turbine Trip Logic Normal, Reserve, and Unit 2 Charger | These are smaller, less demanding loads, generally circuitry.

Question 26

List the major loads on BOP System B - D1B & D2B

Answer 26

Main Turbine EBOP RCIC Gland Seal Compressor Emergency Hydrogen Seal Oil Pump RFPT A and B EBOP MFP DC Lube Oil Pump Dist Panels D1B06 & D1B07 which include: BOP Switchgear breaker control power (Control power for all non-safety buses including stub busses) Emergency Lighting Feedwater Control 24vdc for DFWCS RFPT B Trip, reset, and test logic DG Fuel oil booster pumps LFMG Control and Interlocks Local annunciators Generator Field Breaker Control Circuitry. L10,11,12 and H11, 12 remote control/trip functions. Normal charger No reserve charger | These are larger loads like DC pumps. B for "Big"

Question 27

List the major loads of Div 1 and Div 2 DC system. | Make sure to differentiate any key differences between divisional busses

Answer 27

Normal Charger Reserve charge Divisional RHR valve control and indication RCIC System Valve Motors (Div 1 only) RCIC control and indication (Div 1 only) RCIC Logic (Div 1 only) ADS Logic Leak Detection Logic RPS Instrumentation RRCS Logic LPCS Logic (Div 1 only) LOCA Logic Remote Shutdown Logic Divisional Control Room Indication Divisional DG Controls and Field Flashing Divisional B33 Pump breaker control logic Divisional ATWS UPS Divisional Breaker Control Power Optical Isolators

Question 28

List the major loads on Division 3 DC System

Answer 28

Div 3 Generator Control Div 3 DG Field Flash control HPCS Logic Div 3 Breaker Control Power Div 3 Control room indicators Div 3 optical isolators.

Question 29

# ***Regarding the BOP inverter:*** What is the purpose of the static transfer switch? Are there any inhibitors on its functions?

Answer 29

Automaticall shift power supply from normal to alternate on the following: Overcurrent - Can auto switchback Undervoltage - Can auto switchback Continuity OOS - Manually reset Loss of power to battery - Manually reset - This switch will only occur after a 15 minute timer has elapsed and has detected that DB1A still has no normal or alternate source.

Question 30

# ***Regarding all Inverters*** What is the purpose of the static transfer switch?

Answer 30

The static transfer switch automatically shifts the inverter from the normal DC source to an alternate AC source.

Question 31

# ***Regarding BOP Inverter*** What are the purposes of the regulating and isolating transformers?

Answer 31

Regulating Transformer - Adjusts output voltage to maintain constant voltage during changes in load. Isolating Transformer - Eliminate electrical noise.

Question 32

What are the normal and alternate power supplies to the BOP Inverter?

Answer 32

Normal - D-1-A Alt - F1D08

Question 33

What are the loads on the ATWS UPS?

Answer 33

APRMs LPRMs NI Flow Instrumentation ERIS Das Cabinet

Question 34

What pumps water for the site fire water system? Discuss their controls and interlocks.

Answer 34

Jockey Pump - Auto start at 130# and Auto Stop at 150#. An autostart of the Motor or Diesel fire pumps will trip this pump and prevent it from starting. Motor Fire Pump - Auto start at 120# or control room pushbutton. Diesel Fire Pump - Auto start at 105#, loss of battery charger, or control room pushbutton. During a LOOP, the diesel fire pump starts due to loss of battery charger for 10 seconds.

Question 35

How is charcoal deluge actuated and why is it actuated this way?

Answer 35

Manual only, due to potential to overload floor.

Question 36

List all areas supplied by CO2 Fire Control

Answer 36

Recirc pumps DG Rooms TLO Storage Rooms TLO Purifier Rooms Computer Room Subfloor Control Room Subfloor Hose Reels

Question 37

What are the Master Control valves? What is their normal position? What position do they fail in?

Answer 37

Root valve from CO2 supply to selector valves in various locations of the plant. Normally closed. Fail open on loss of power.

Question 38

What are the Selector Control Valves? What are their normal positions? What position do they fail in?

Answer 38

Isolations for supplied areas/components of CO2 Fire Control. Normally Closed Fail Closed on loss of power.

Question 39

# ***Regarding the CO2 isolations for Drywell/Containment*** Explain logic of the containment outboard isolation valve, its normal position, and its isolation signal.

Answer 39

Must be opened manually. Normally closed. Closes on BOP LOCA/1.68# Drywell Pressure. With an alarm indicating a B33 Recirc pump fire, the Recirc pump selector valve is open for 40 minutes. In this time, the outboard containment isolation valve must be actuated for at least 1 minute, otherwise no CO2 will reach the Recirc pumps in the event of a recirc pump fire.

Question 40

List areas protected by Halon

Answer 40

SB 640' Telephone Battery Room Metrology Lab SB 605 TSC Radio Communication Room Computer Room

Question 41

Explain Halon Remote System Logic Panel Automatic System Actuation

Answer 41

Need 2 signals, 1 signal per zone.

Question 42

What is the purpose of the Bioshield?

Answer 42

Provide radiation and heat shielding

Question 43

What are the purposes of the Suppression Pool? What is its normal operating band, low level setpoint, and design temperature?

Answer 43

Provide water seal from containment to drywell. Provide heat sink for SRVs Provide means to suppress pressure transients from a DBA Source of water for ECCS Normal level - 17.8' - 18.5' Low level setpoint - 16.75' Design Temperature - 185F

Question 44

Purpose of the guard pipe penetrations and when are they required?

Answer 44

Surround high energy systems. They prevent containment overpressurization by directing pipe breakage back to the drywell. Required at > 275# or > 200F

Question 45

How are electrical penetrations in the containment sealed to prevent outleakage?

Answer 45

They are hermetically sealed with 28-30# of Nitrogen purge that prevent moisture intrusion and O-ring leakage.

Question 46

List the containment and drywell internal and external pressure limits

Answer 46

Internal Containment: 15PSIG Internal Drywell: 30PSIG External Drywell: -21PSID External Containment: -0.8PSID

Question 47

At what suppression pool temperature must the Reactor be shut down? At what temperature must it be emergency depressurized?

Answer 47

>110F >120F

Question 48

What is the difference between a Dedicated Air Lock Operator and an Airlock Monitor?

Answer 48

Dedicated Air Lock Operator is required to comply with tech specs and ensures only 1 door is open at a time. The monitor is required per Shutdown Safety and is only in place to bottle up containment.

Question 49

Effects of Loss of IA, LOOP, and LOCA on Containment Airlocks

Answer 49

Loss of IA - Electro-Mechanical locking pin does not engage. Door can be operated twice with the ammount of air available in the accumulators. LOOP - Control power is gone. Electro-Mechanical locking pin does not function. Can manually operate without power. LOCA - Bottom doors and upper outer door air isolates on BOP LOCA. Upper inner door air isolates on RHR LOCA

Question 50

Where does the area between the airlock seals vent to?

Answer 50

Annulus

Question 51

Explain the normal flowpath of the FPCC system

Answer 51

Skimmers Isolation Valves (Reactor Pools Only) Surge Tanks Pumps Heat Exchangers F/D Inlet Valves F/Ds F/D Outlet Valves Isolation Valves

Question 52

Describe the normal flowpath in RWCU

Answer 52

Suction from Loops and RPV Bottom Drain 2 Pumps in service RHX NRHX Filter Demins RHX Back to Feedwater system

Question 53

When should Supp RHR Fuel Pool Cooling be used? What restrictions are associated with this?

Answer 53

When Lower Pools can not be maintained < 150F Unit must be in Cold S/D Applicable RHR system is INOP

Question 54

What is the upper pool temperature high limit and why?

Answer 54

< 110F in Modes 1,2, & 3 for SPMU to function as designed.

Question 55

FPCC system response to BOP and RHR LOCA, LOOP. What must be done in a LOCA or LOOP?

Answer 55

A BOP LOCA will isolate the containment isolation valve for the upper pools. An RHR LOCA and LOOP will isolate NCC to the FPCC HXs. ESW can be manually aligned to support cooling FPCC system. During a LOCA the FPCC F/Ds will isolate due to tank pressure ratings.

Question 56

Explain how upper pool inventory is maintained in the event of a system leak.

Answer 56

Siphon breakers on the upper pool prevent the siphoning of the pool through the return headers when a leak develops.

Question 57

Explain how system inventory and flow rates effect FPCC Surge tank

Answer 57

Inventory added - Tank level increases Invetory removed - Tank level decreases Flow rate increased - Tank level decreases Flow rate decrease - Tank level increases.

Question 58

FPCC pump trips

Answer 58

Surge tank level low 8.5"

Question 59

Location of Fuel Transfer Tube Day Tank Location of Fuel Transfer Tube Drain Pump Fuel Transfer Tube Drain Pump Autostarts/stops

Answer 59

IB 574' IB 574' Will start and stop based on level in auto. In start, will start if low level is clear.

Question 60

List the requirements for safe condition of fuel or core components

Answer 60

Properly seated in the reactor vessel Seated in designated storage location In IFTS carriage inclined in either CB or FB limit switch positions Fuel Prep machines fully submerged Properly seated in the designated location of the Hi-Storm

Question 61

How does a loss of RPS Bus B effect FPCC system?

Answer 61

The inboard containment isolation valve for the upper pool suction line is isolated. This will cause the upper pool to overflow if the upper pool return line is not isolated. | The inboard inlet isolation valve is a check valve and will not isolate.

Question 62

If SPCU is running, what systems can cause a trip of the SPCU Pump? What trips exist for the SPCU pump? What are the start permissives?

Answer 62

LPCS and RHR will cause a low flow trip if aligned to the full flow test return line. HPCS can cause a low flow trip due to sharing suction piping in the suppression pool. Low flow - 400 gpm for 5 seconds High Demin Inlet Temp - > 120F Permissives - Suction path 100% open.

Question 63

SPCU system response to BOP and RHR LOCA

Answer 63

SPCU suction isolations close on a BOP LOCA Demin outlet isolation closes on RHR LOCA

Question 64

Restrictions of using RHR B Loop as a SPCU return to SP

Answer 64

RHR B Must be declared inoperable.

Question 65

What systems does the SPCU system interact with and how?

Answer 65

HPCS - SPCU utilizes the HPCS suction piping. FPCC & SPCU can be aligned to each other to support cleaning. RHR - SPCU discharges into the test return lines back to the suppression pool. LPCS - If SPCU RHR A return path is used, LPCS shares that return path. Condensate - SPCU can be used to transfer water from the SP to the Hotwell or CST. WCT - SPCU can be used to transfer water from the SP to the WCT

Question 66

What does SPMU provide? Can it ever be overridden?

Answer 66

Additional heat capacity for cooling to the suppression pool. Yes, but NEVER IN A LOCA.

Question 67

Explain SPMU logic

Answer 67

1. LOCA Signal 30 Min Timer OR 2. SP Lo Lo (16.5") or Arm and Depress AND RHR LOCA signal or Test switch to Test.

Question 68

How is the 30 Min SPMU LOCA timer reset?

Answer 68

Taking the SPMU Auto/OFF keylock to off.

Question 69

What will cause the SPMU TRAIN A/B NOT NORMAL alarm to actuate?

Answer 69

If in Refuel and Mode switch is in Auto If NOT in Refuel and Mode switch in Off

Question 70

Will arm and depress of RHR LOCA switch cause the 30 min SPMU timer to actuate? Where does SPMU receive its signal for 30 min timer?

Answer 70

No The K110 relay in RHR LOCA logic. | The K110 relay is NOT the signal for the 30 minute timer!

Question 71

Where does AEGTS treated air exhaust to?

Answer 71

Train A - Unit 1 Plant Vent Train B - Unit 2 Plant Vent

Question 72

What system provides the motive force for Backup Drywell Purge?

Answer 72

AEGTS

Question 73

What is the purpose and flowpath of Backup Drywell Purge?

Answer 73

AEGTS fans drag air from the drywell through B/U Drywell purge piping. Backup drywell purge provides pressure relieving and control capabilities to support startup and heatup and mitigates pressure build up from air leaks.

Question 74

What will cause the backup drywell purge system to isolate?

Answer 74

Auto close CIVs on RHR LOCA - Can be overridden and will get an amber light. Auto close CIVs on High Drywell Gas Radiation - Can be overridden and will get an amber light.

Question 75

Explain how the AEGTS Electro Hydraulic Actuated Dampers Work

Answer 75

There are recirc and exhaust dampers that operate concurrently to regulate annulus pressure. The standby system is aligned to full exhaust. On a loss of power or hydraulics, recirc will fail closed, exhaust will fail open. | Consider the failure as "maximum vacuum"

Question 76

AEGTS Fan Auto Starts Which ones can be overridden? What are the effects of a LOOP on these fans?

Answer 76

RHR LOCA - Can be overridden and will get an amber light Low Flow Auto Start of STBY Fan (< 1500 cfm) - Can not be overridden They will momentarily shutdown, then restart with the D/G

Question 77

What are the trips and start permissives of the AEGTS duct heaters? When do they autostart?

Answer 77

Trip on loss of any permissive Permissives: No Hi Hi Htr trip (>225F) No Hi Htr Temp trip <166.2F fan discharge temp Exhaust fan running, and valid flow signal Heating coil thermostat circuit closed. Autostart on RHR LOCA. Can not directly override. Override by securing the applicable fan.

Question 78

How does the exhaust/recirc damper controller function? How does this controller fail and why does it fail that way?

Answer 78

0% - Full open exhaust, recirc closed - MAX VAC 100% - Full open recirc, exhaust closed. Fails to maximum vacuum (0%) to ensure all leakage is filtered before release to the environment.

Question 79

What is the Tech Spec atmospheric temperature limit in containment?

Answer 79

=< 95F

Question 80

How many AHUs are in the containment vessel and what cools them? How many fans per AHU? How many normally operate and whats the maximum amount allowed to operate?

Answer 80

6, cooled by CVCW 1 fan per AHU 4 Normally operate, but 6 can be operated for maximum cooling.

Question 81

Are the containment cooling system fan discharge dampers electric or pnuematic? How are they controlled? How do the Containment Cooling system fan discharge dampers fail?

Answer 81

Pnuematic Automatically actuate based on fan operating/secured, prevents reverse flow. Fail closed on loss of air or power to solenoid.

Question 82

How many AHUs operate in the drywell? How many fans per AHU? What cools them?

Answer 82

3 AHUs 2 fans per AHU Cooled by NCC

Question 83

How is the Containment Cooling system effected by LOCA?

Answer 83

CVCW Containment Isolations close on BOP LOCA. System will no longer cool.

Question 84

How is the Drywell Cooling system effected by LOCA?

Answer 84

DW AHUs are cooled by NCC and will isolate on an RHR LOCA. System will no longer cool. Drywell fans are powered by the Stub Bus and will lose power until power is restored by operators.

Question 85

# Regarding the 2 cooling coils in a drywell AHU: How is the operating cooling coil determined? What features provide redundancy?

Answer 85

The operating DW AHU coil is determined by a 3-way AOV selector. The valve fails to the B coil on loss of air. | The valve also fails to the B coil on loss of solenoid power.

Question 86

Where does Drywell AHU condensation drain to? Are there any alarms associated with these AHU drains?

Answer 86

Upper and Middle AHUs drain to the Drywell Equipment Drain Sump. Control room has an alarm for excessive flow provided by Leak Detection System. Low Drywell AHU drains to the Drywell Floor Drain Sump

Question 87

What atmospheric temperature is the lower Drywell Cooling AHU designed to maintain and why?

Answer 87

< 120 F on the RPV Skirt but > 80F to avoid brittle fracture.

Question 88

Drywell Cooling Fan auto starts and stops

Answer 88

Fan will autostart on running fan low flow if in standby. Standby fan will autostop when low flow condition clears. Running fan will not trip on low flow condition.

Question 89

Containment and DW Vent Exhaust damper trips and logic

Answer 89

Radiation Hi-Hi or downscale Inboard/Outboard logic BOP LOCA

Question 90

Explain the rotating red beacons for the DW purge surge tanks. What is the basis for this? When are they disabled? What actions must be taken if these beacons are illuminated?

Answer 90

Beacons will illuminate red if tanks are not full. If the tank is not full, it is possible that the DW purge lines are not completely filled with water, and this will create a nuetron radiation stream into containment. This alarm can be disabled when in Mode 4 or 5. Must contact the US and RO and notify them.

Question 91

Where does the CDWP system exhaust to?

Answer 91

Unit 1 Plant Vent

Question 92

Explain the modes of operation of CDWP system

Answer 92

Intermittent - 1 Containment purge supply fan and 1 CDWP Exhaust fan in operation. No drywell purge supply fans operating. Refuel - 2 Containment purge supply fans, 2 CDWP exhaust fans, 2 Drywell purge supply fans operating. DW Purge supply ductwork is drained. | Intermittent starts for 5 min in Flow mode, then switches to DP mode

Question 93

How many air operated isolation valves are in the CDWP system and how do they fail on loss of air, loss of power, and LOCA?

Answer 93

14 Air operated isolation valves. Fail close on loss of air and loss of solenoid power. Will isolate on BOP LOCA and Hi Hi radiation. | There are 4 radiation detectors in the Exh Plenum with INBD/OTBD logic. ## Footnote There is a 5th radiation detector, too that only activates the Containment and Drywell evacutation alarms.

Question 94

How does CDWP Vortex Damper modulate flow?

Answer 94

Vortex damper can modulate flow based on a preset flowrate or a Containment DP signal (There is a 5 min time delay on this signal). When the system supply fan damper switch is in normal, flowrate is controlled by the preset flowrate setting, then switches to the DP signal after the 5 minute delay.

Question 95

What is the purpose of the Combustible Gas Control System?

Answer 95

Maintain LOCA Hydrogen concentration < 4% (Lower Explosive Limit)

Question 96

What are the normal operating conditions and limitations of the Hydrogen Recombiner?

Answer 96

Minimum temp of 1150F Will ramp at 1225F and 2% Hydrogen Concentration Normal Operating Range 1225-1400F Maximum operating power < 75KW Must be shutdown if Hydrogen Concentration > 6%

Question 97

If the Hydrogen Recombiners are inoperable, what must be available?

Answer 97

One division of Hydrogen Igniters

Question 98

What locations are sampled for Hydrogen by the Hydrogen Analyzers?

Answer 98

Drywell Dome Containment Dome Drywell Head Above the Suppression Pool

Question 99

Explain the blue permissive light associated with the Hydrogen Analyzers

Answer 99

Light comes on after 3.5 mins to indicate a representative sample is achieved. After a shift, the sample is most accurate after 15 minutes due to purging of old sample.

Question 100

List trips of the Combustible Gas Mixing Compressors that are always active

Answer 100

RHR Breaker Open RHR Cooling Supply < 90% open Compressor discharge < 90% open C/S For compressor taken to stop

Question 101

Effects of a loss of power to Hydrogen Igniters

Answer 101

Igniters will not function and will not re-energize without operator action once power is restored. This is to ensure operator can verify Hydrogen concentration low enough to allow for starting.

Question 102

When must Hydrogen Igniters be operable? If the Hydrogen Igniters are inoperable, what must be available? What makes the Hydrogen Igniters inoperable? How many igniters are there per division?

Answer 102

Both Hydrogen Igniter systems must be operable in Mode 1/2. Both Hydrogen Recombiners and Mixing Compressors must be operable. =< 90% of hydrogen igniters not functioning per division. 52 in Div 1, 50 in Div 2 | <=90% of igniters cause inoperability.

Question 103

Describe the flow paths for the Containment Vacuum and Drywell Vacuum relief systems

Answer 103

Drywell: Containment -> Check Valve -> MOV -> Drywell Containment: Atmosphere -> Annulus -> MOV -> Check Valve ## Footnote Tip: You can physically operate either check valve from inside containment.

Question 104

Explain the Containment Vacuum Relief System MOV Logic

Answer 104

MOVs are normally open. They auto close on BOP LOCA as long as there is no vacuum in containment. They can not be closed if vacuum condition exists. They can not be opened if positive pressure exists in containment. They will always open if containment is under a vacuum and always close if containment is under pressure. ## Footnote The last two statements are only true if a LOCA signal exists.

Question 105

Explain the DW Vacuum Relief System MOV Logic

Answer 105

They are normally closed valves. They will open when a DW Vacuum condition exists. They will auto close on a BOP LOCA. If a vacuum condition exists, they will re-open and will actuate their override. At this point they must be manually closed to close, even if vacuum clears.

Question 106

How many Cont and DW Vacuum reliefs must be operable?

Answer 106

Containment - 3 shall be operable and 4 shall be closed. Modes 1,2,3, Movement of recently irradiated fuel Drywell - 2 shall be operable. Modes 1,2,3

Question 107

What are the consequences of leaving having 2 supply fans running in the FHB ventillation system?

Answer 107

Areas of the IB that are contaminated will become positively pressurized.

Question 108

FHB Ventillation response to a high airborne radiation alarm?

Answer 108

Sensed in the exhaust duct upstream of the exhaust plenum will trip the supply fans. Exhaust fans will continue to operate. Barometric dampers will pop open to provide air supply.

Question 109

Explain the FHB C Exhaust fan power supply setup

Answer 109

Powered by EF2D, which is powered by either EF1B or EF1D with a kirk key interlock in the access control area.

Question 110

List the control modes of DFWC

Answer 110

Low Flow Single Element Three Element Speed Control

Question 111

How does low flow control work? What restrictions are associated with low flow control?

Answer 111

Valve position controlled based on Level error and Low Flow Control Valve Flow Used when < 3% Prx Capacity is 1400 GPM Can not be used with MFP, as MFP control valve and this valve will not work well in unison.

Question 112

How does single element control work? When is it typically used? What restrictions are associated with Single Element

Answer 112

Controls MFP Flow Control Valve &/or RFPT Speed demand based on Level error only. Used when Prx is 3-15%. Must have a RFPT running/available and its controller in AUTO or a MFP running/available and its controller in auto. AND Reactor level signal GOOD AND RRCS FW Runback not active AND Operator disables transfer to 3 Element

Question 113

How does three element control work? When is it typically used? Why is three element preferred to single element in this range? What restrictions are associated with Three Element control?

Answer 113

Adjusts RFPT Speed demand &/or MFP flow control valve position based on Level, Total Steam Flow, and Total Feed Pump Flow. Typically used above 15% Prx At least one RFPT running/available and its controller in AUTO or MFP runnin/available and its controller in AUTO AND Reactor level signal good AND RRCS FW Runback not active AND Steam Flow signal good AND Feed flow signal good AND Operator enables transfer to 3 element control.

Question 114

The reactor is at 40% power when the operator shifts from 1E to 3E. The output Steam flow/Feed Flow Error circuit is failed HIGH. What will happen when the transfer is enabled? What should the operator's actions be?

Answer 114

Initially, DFWCS would sense a high steam flow - feed flow error and increase feed rate significantly. This would cause a rapid rise in Reactor Level. The operator should take Manual control of the RFPTs IAW ONI-C34. If the operator transfers back to single element control with level significantly higher than required, the follow will happen: Recirc pumps are in fast speed. When transferred back to slow, feed flow may drop to < 3.43 mlbm/hr. If it does, the B33 cavitation interlock will trip and cause the recirc pumps to automatically downshift to slow speed.

Question 115

What are the two methods of controlling RFPT speed?

Answer 115

DCS Manual Potentiometer

Question 116

Which range of level detectors does the RFPT trip get its signal from? How many of these range detectors are there? How many are required for a trip? What else does this range input to on the DFWCS? How can these detectors effect the main turbine and RFPTs? What else are these detectors used for in regards to providing trips?

Answer 116

Narrow Range 3 detectors, 2 required for trip. Also inputs into L8 alarm circuit and Median Level Circuit. They provide the L8 trip to the main turbine and RFPTs. They also provide the L7/L4 alarm trips, the L4 B33 FCV runback trip, the L3 downshift, and setpoint setdown.

Question 117

How does 3 element control work? What instruments does it get its signals from?

Answer 117

3 Element control receives input from the narrow range level instruments, steam flow detectors, and feed flow (Feed flow venturis) to generate an error that adjusts RFPT speed and/or MFP flow control valve position to adjust level to its programmed setpoint.

Question 118

What is the median level circuit? What are automatic trips associated with failures in this circuit? | One bad signal, two bad signals, and three bad signals.

Answer 118

Median level circuit is part of three element control that determines which level to use in the program error. With 3 detectors, the median level is chosen for the program error level variable. One bad signal will be disregarded and the lower of the two good signals is used. Two bad signals will transfer to manual and the last signal from the Median Level circuit is propagated. With three bad signals, automatically transfers to manual and level signal forced to low scale of 165" and propagated.

Question 119

What level deviations cause trips in the DFWCS?

Answer 119

A signal > 8" from median level - CAD Alarm Any signal > 15" from any other level signal - RX CH ERROR HIGH alarm Two signals > 8" from mediau - System trips to manual control. One signal > 8" from median and another signal BAD/Bypassed - System trips to manual.

Question 120

Explain the program level circuit. What kind of shennanigans does this cause with level related trips?

Answer 120

Program level is 196" to 201". Level remains at 196" until approx. 45% Prx, at which point it increases linearly to 201" at 95% Prx. Certain trips are not based off of static reactor levels, like Reactor Level 4 Trip. These trips will vary in setpoint based on Prx.

Question 121

What inputs do the steam flow detectors have in the DFWCS?

Answer 121

Input to level programming circuit. Inputs to steam flow recorder. Input to 1E/3E level controller. Inputs to feed flow/steam flow mismatch.

Question 122

What will cause an auto transfer to 1E control when in 3E?

Answer 122

Loss of any steam flow transmitter Loss of 2 suction transmitters 2 suction transmitter with a 5% deviation Loss of recirc flow signal on running pump

Question 123

What are the suction flow transmitters? How do they work? What trips are associated with them?

Answer 123

Two flow transmitters on the suction side of each Feed Pump. With 2 good transmitters, flow is averaged to an output. If one transmitter is BAD or bypassed, only the good transmitter is used for output signal. DFWCS will remain in 3 element. With > 5% deviation in the transmitters or both transmitters fail, DFWCS will auto transfer to 1E control. With both transmitters failing, the FWP recirc valves will trip to 100% open as well.

Question 124

Explain the flow path from the MS Header through the main turbine

Answer 124

Stop Valves -> EQ Header -> TSV -> TCV -> HP Turb -> MSR -> Cross Around Piping -> CIVs -> LP Turbine -> Condenser

Question 125

What is the minimum flow requirements for the MFP and RFPT? How are the RFPT and MFP recirc valves controlled? What restrictions are on the operator when controlling in manual? What happens if a flow control transmitter fails?

Answer 125

MFP - 4000 GPM RFPT - 7000 GPM Normally controlled by the operator to maintain Feed flow in program band according to error. Operator may open the recirc valve further than program, but can not close further than demand signal. The recirc valve associated with the flow controller will fail open to 100% and the pump will shift from three element to one element control.

Question 126

What is the purpose of the TSVs? Which TSV has an internal bypass and what is its purpose? What is the purpose of the equalizing line in the TSV?

Answer 126

Quickly stop steam to the HP turbine in emergency or turbine trip situations. #2 TSV has an internal bypass used for chest warming and equalizing dp across all TSVs Allows even flow through TSVs regardless of how many TCVs are open

Question 127

What is Setpoint Setdown in DFWCS? What does it do? What is the purpose of this feature?

Answer 127

A hot button on the DFWCS display. Automatically initiates on a L3 Scram and any time you go below L3 after. For 10 seconds, it will maintain RPV level setpoint due to shrink (usually 196") and then lower the setpoint to 178". This prevents a level 8 trip from over feeding and cold water swell. At L8, all FWPs trip. It is undesirable to lose these pumps in a Scram if they are available for level control.

Question 128

# Regarding the Main Turbine System How many CIVs are there? What is the purpose of the CIVs?

Answer 128

6 CIVs. They protect the main turbine from overspeed (energy stored in the MSR) after trip.

Question 129

How is thrust bearing wear tracked? What setpoint will cause a main turbine trip?

Answer 129

Thrust bearing wear detector. Will trip when the sensed oil pressure drops to 8# and lowering.

Question 130

What are the start permissives of the turning gear? When will it auto start? What alarms come off the turning gear?

Answer 130

In reference to the recent OE where turbine rotor bowed: "Oh my god they never even looked." One Bearing Lift Pump (> 265 psig) Main Lube Oil Pressure (15 psig) Generator OP Bkr(610/611), disconnect S112, or S111 open Turning Gear CS not in off No quill shaft failure as sensed by EHC EHC Confirmation <100 rpm Low speed switch picked up (1.5 rpm) Auto starts at < 1.5 RPM shaft speed TURNING GEAR NOT RUN/NOT ENGAGE

Question 131

Normal Operating Parameters of Main Turbine and Turning Gear system What are the turbine oil temperature limits?

Answer 131

Condenser Vac < 5" HgA Turbine Oil Pressure (Bearing Header) 20-35 psig Turbine Oil Pressure (Shaft Oil Pump) 220-265 psig Main Turbine LO Temp 110-120F Turbine Bearing Vibration < 5 mils 80-95F oil supply when on turning gear 90F min supply when rolling 110F min when operating normaly

Question 132

List all Turbine Trips

Answer 132

RCIC Initiation Generator Lockout Thrust Bearing Wear Manual trips "Two fast" - Overspeed (110%, 1980 rpm) and B/U Overspeed (110.5%) "The High Threes (Like High Seas)" - Hi Rx Lvl (L8), Hi MSR level (1 - 195", 2 - 217.5"), Hi vibes (12 mils) "Loss 4 Words" - Loss of 125VDC (Active below 75% Turbine Speed), Loss of 24VDC, Loss of Stator Water Cooling (81C or 42.5 psig header pressure), Loss of Speed Sensors (Active when > 100 RPM) "5 B-Low" - Low Vacuum (8.1" HgA), Low EHC Pressure (1100psig), Low ETS Pressure (400 psig), Low MSOP d/c pressure (100 psig, active above 75% Turbine speed), Low Bearing Header Pressure (12 psig)

Question 133

Which turning gear interlocks does the Jog Pushbutton bypass?

Answer 133

Reverse Power Interlock and Turning Gear Oil Pump Discharge pressure

Question 134

What are normal causes of Turbine vibrations and the reasons associated with them?

Answer 134

Critical Speed - 1500 rpm - Harmonics of the turbine amplifies vibration. Packing Rub - Operation at low power, bypass steam, and packing adjusting to temperature can cause a temporary bow of the rotor resulting in imbalance. Oil Whip - When bearing is lightly loaded, formation and collapse of oil wedge can cause vibrations. Thermal Sensitivity - Magnitude and phase angle changes with load Mechanical Unbalance

Question 135

What is a quill shaft? What indications show that the quill shaft is functional?

Answer 135

A type of shaft coupling that spreads torque over a longer distance on adjoining components. Low speed switch picks up (1.5 rpm) EHC Confirmation < 100 rpm.

Question 136

How are TSV, TCV, Turbine Steam Drains, and CIVs positioned during turbine warm up?

Answer 136

TCVs are open, CIVs closed, all Turbine drains but 1 are closed, and #2 TSV poppet is thorttled to maintain pressure 60-100#.

Question 137

Explain how the turbine reacts to a change in reactor power.

Answer 137

For a power increase: Pressure Increase Voids collapse, adding reactivity Fuel temperature rises, adding negative reactivity TCVs respond to maintain constant reactor pressure Turbine load increases

Question 138

What are the three branches of the EHC circuitry? Which circuits are removed from the process when the system is placed in Bypass?

Answer 138

Speed, Load, Pressure Speed and Load circuits are bypassed.

Question 139

How is the turbine protected from overspeed? Which of these systems satisfies criteria in ORM for overspeed protection?

Answer 139

Mechanical Overspeed Trip Backup Overspeed Trip The mechanical overspeed trip satisfies the ORM requirements. This includes the TSVs, TCVs, Bypass Valves, and CIVs.

Question 140

What functions does the BOST provide? What is the BOST relationship to the Speed Control Unit? For any trips, what logic and setpoints are utilized?

Answer 140

The BOST provides turbine trips for the following: A backup to mechanical overspeed trip utilizing its own speed sensing, independent of the Speed Control Unit. Provides the arming for the Low MSOP discharge pressure trip, loss of 125vDC trip, and the loss of speed sensing trip. BOST is independent of the SCU. Overspeed - 110.5% in normal, 105% in standby. Utilizes 2 out of 3 logic. MSOP Discharge pressure Low - < 100# AND > 75% rated turbine speed. Loss of 125vDC AND > 75% rated turbine speed. Loss of Speed Sensing - Both speed sensing units out of service AND > 5.5% rated turbine speed.

Question 141

What is the wobbulator circuit?

Answer 141

When turbine speed is set to 1500 rpm, speed is varied between 1450 and 1550 rpm over a 12 minute cycle to minimize vibrations due to natural resonance of the turbine.

Question 142

How does the EHC system respond to a loss of one Speed Control unit? How will it respond to a loss of both speed control units? How will it respond to these situations with the Speed Control Unit in standby?

Answer 142

A loss of one speed control will cause the turbine to accelrate at twice the normal speed. With a loss of both speed control units, the turbine will trip if > 100 RPM. With the unit in standby, these functions are defeated and nothing will happen.

Question 143

What is Load Set? How is it determined and what is its normal value?

Answer 143

Load set is a value determined by the operator as the initial input for the Load Control Unit. It is controlled with a pushbutton on the panel and generally set to 120MW above the generator output.

Question 144

What is a Load Set Runback? What conditions will cause this? What are the setpoints for these conditions?

Answer 144

A signal override of the load set when certain conditions exist. Conditions: Loss of Stator Cooling - Either SWC outlet temp > 81C or SWC inlet pressure < 42.5 psig. This runback will cause a turbine trip if Generator Amps are >75% @ 2 mins or >25% @ 3.5 mins into the runback. Sync Speed Not Selected - 1800 RPM not selected (You only care about this during startup). Power Load Balance - Difference between tracking of Reheated Steam and Generator Current is >40%.

Question 145

How does the load set runback for stator water cooling work?

Answer 145

Load set reduces speed by 1% every 3 seconds. If the condition clears, the runback will stop. If not, the runback will continue until either the condition clears or TCV closure. During the runback, if the condition is still active at 2 minutes with > 75% generator load (approx 30,000 AMPS), or still active at 3.5 minutes with > 25% generator amps (approx 9,900 AMPS), the turbine will trip.

Question 146

What is a Load Limit Setback? What does it do? What is it designed to protect? What are its trip setpoints?

Answer 146

Protective circuit that inputs a reduced steam flow limit into the pressure control circuitry when its set value is eclipsed. It inputs a value into the Pressure Control Unit circuitry that causes the TCVs to close and the Bypass valves to open in order to reduce steam flow through the turbine. It sets back at a rate of 3% per second down to 75% rated steam flow. It is designed to protect the condenser from an overpressure condition. Setpoints are the same as the FCV Runback from B33: > 5.6" HgA with < 3 Circ Water pumps running OR #1 Bypass full open.

Question 147

What is the pressure regulator? What signal does it provide? How many channels does it provide? How can a failure of the pressure regulator effect the plant?

Answer 147

Circuit that calculates an error signal (3.33% per every 1 PSI) that outputs to the flow demand signal. There are two channels, a normal and alternate. If a pressure regulator channel fails, it will auto shift to the alternate channel. If the regulator is in test, it will not shift - instead the bypass valves will open. If the pressure regulator fails High, RPV pressure lowers. If low, RPV pressure rises. Can also fail as-is.

Question 148

#1 Bypass valve has an important feature that the other bypass valves don't. What is it?

Answer 148

#1 bypass valve provides the signal when full open for FCV Runback and Load Limit Setback.

Question 149

How many CIVs are there and how are they distributed? How do they normally work? What arrangement do they operate in and why do they operate this way?

Answer 149

There are 6 CIVs. The CIVs (Combined Intermediate Valves) are arranged on opposing sides of the low pressure turbines to emit steam for operation. They are normally full open or closed, and only throttle in an overspeed condition. They are paired in a Master/Slave arrangement that prevents a single LP turbine from being completely isolated from steam while other turbines still have steam emission. This prevents a significant overtorque condition on the turbine shaft.

Question 150

During steam chest warm up and shell warm up, how are the TSVs, TCVs, and CIVs arranged positionally? What allows for controlled warm up of this equipment?

Answer 150

The TSV is closed for both warm ups. The TCV is open for Shell warm up. The CIVs are closed for shell warm up and open for chest warm up. The #2 Poppit allows for this controlled warm up.

Question 151

What do generated trip signals for the turbine utilize to actuate trips on the TSVs and TCVs? What component causes the fast acting close of the TCVs to actuate?

Answer 151

The Disc Dump Valve will dump hydraulic pressure and cause the valves to close due to heavy spring pressure. The Fast Acting Solenoid provides a bleed path that relieves hydraulic pressure and causes the TCV to close rapidly.

Question 152

Describe the flow path through RWCU

Answer 152

Suction from 2 recirc loops and the RPV bottom drain 2 Pumps normally in service RHX NRHX 2 F/Ds RHX Feedwater

Question 153

What is the purpose of circulating RWCU from the bottom head drain?

Answer 153

Prevents thermal stratification.

Question 154

# Regarding a RWCU isolation signal The RWCU CIVs closure predicates a delay for the rest of the isolation. What is the duration of this delay and what is it for?

Answer 154

32 seconds to allow for the CIVs to close with a reduced differential pressure across them.

Question 155

The leak detection signal for the RWCU system has a bypass. Which RWCU system trips are bypassed by this switch?

Answer 155

All except for L2, SLC initiation, and NRHX Demin outlet temperature.

Question 156

List the RWCU Leak detection trips and setpoints

Answer 156

LVL 2 - 130" SLC initiation High Delta Flow (>59 GPM for 10 mins) Loss of Power to E31 for > 1 second High RWCU Equipment Room Temp High Steam Tunnel Temp 156F NRHX Demin Outlet 140F

Question 157

List the RWCU Pump Trips and Setpoints. List any unique attributes of a trip if it has any.

Answer 157

CIV Close < 90% Open Thermal Overload High Stator Temp 275F High Thermal Neck Temp 180F Low Flow < 70 GPM for 3 seconds. This trip is delayed for 120 seconds during the initial pump start. If the pump control switch is taken to start again, the 120 second timer will restart.

Question 158

What are the auto close signals for the RWCU Blowdown line and basis behind them?

Answer 158

Upstream Pressure < 5 PSIG to prevent a leak from vacuum draining the system. Downstream Pressure > 140 PSIG due to downstream piping not rated for higher pressure.

Question 159

Explain the discrepancy in differential flow while performing a blowdown of the RWCU system to the main condenser or rad waste.

Answer 159

The blowdown line won't register flow until blowdown flow is > 35 gpm. When performing a blowdown, differential flow will indicate higher than actual until the blowdown flow exceeds 35 gpm.

Question 160

With both RWCU pumps operating, what will happen when a CIV closes?

Answer 160

Both pumps will trip.

Question 161

What will happen if an operator positions both the blowdown line to the condenser and rad waste isolations open?

Answer 161

Vacuum on main engine will be broken and can damage waste collection tank.

Question 162

What are the normal and alternate power supplies for RPS A & B?

Answer 162

A Normal - MG Set from F1B08 A Alternate - F1C08 B Normal - MG Set from F1C12 B Alternate F1D12

Question 163

With a loss of L11, what will happen to the RPS system when in a normal lineup? What will happen because of this?

Answer 163

RPS B normal supply does not have an ABT and RPS B will lose power. This temporary loss of power to B RPS will input a half scram and an inboard NS^4 isolation.

Question 164

What are the trip setpoints for the RPS MG sets?

Answer 164

Overvoltage 140V Undervolt 60V Underfrequency 54 hz

Question 165

What is the purpose of the EPA breakers? How are they arranged? What are the trip setpoints for the EPA Breakers? What are the consequences of an EPA breaker trip?

Answer 165

Protects the MSIV solenoids, scram solenoids, and RPS relays from voltage issues. They are arranged 2 per circuit in series. Overvoltage 132VAC Undervoltage 108VAC Underfrequency 57hz If an EPA breaker trips, the RPS bus will lose power. This will cause a half scram and a BOP isolation for the applicable division.

Question 166

What is the difference between the Scram and Backup Scram? How do backup scrams function?

Answer 166

Scram signal opens scram pilot valves that vent CRD system to the scram discharge volume and cause the CRDs to rapidly insert. The Backup scram signal vents the air header that controls the scram pilot valves to allow them to fail open in the event that they do not receive a proper signal. This is a redundancy mechanism. Backup scram valves, unlike scram valves, are DC powered and energize to actuate.

Question 167

What is the normal position of the Scram Discharge Pilot valves and how do they reposition in the event of a scram?

Answer 167

Normally open, they close when a scram signal is inserted to bottle up the SDV.

Question 168

What are the lights above the 4 SCRAM arm and depress buttons? If a single light is out above each switch, what does that indicate? If both lights are out above a single switch, what does that indicate?

Answer 168

The lights are for the scram signals for that applicable rod group. Illumination indicates that a scram signal is not present. If a single light is out on each channel, a half scram is inserted. If both lights are out above a single channel, that is a failure of equipment and a full scram on a single channel, 1/4 of the rods are inserted.

Question 169

List the Modes of Operation, the mode switch position for each mode, and any requirements associated with them.

Answer 169

Mode 1 - Power Ops - Run - Usually 8-10% Prx Mode 2 - Startup - Startup/Refuel - 0-10% Prx Mode 3 - Hot S/D - Shutdown - > 200F with all RPV bolts tensioned. Mode 4 - Cold S/D - Shutdown - < 200F with all RPV bolts tensioned. Mode 5 - Refuel - Refuel or Shutdown - One or more RPV bolts untensioned.

Question 170

What is the TSV Closure scram setpoint, when is it bypassed, and basis?

Answer 170

3 TSVs < 95% open based on 1st stage shell pressure of 212 psig. Bypassed at < 38% RTP as indicated by 1st stage shell pressure (212 psig) Bases is anticipated pressure increase and resultant power increase, prevents MCPR from being exceeded.

Question 171

What is the TCV Closure scram setpoint, when is it bypassed, and basis?

Answer 171

ETS hydraulic oil < 530 psig. 3 TSVs < 95% open based on 1st stage shell pressure of 212 psig. Bases is anticipated pressure increase and resultant power increase, prevents MCPR from being exceeded.

Question 172

What is the SDV high level setpoint, when is it bypassed, and basis? What consequences can occur if the SDV scram is not given enough time clear before the scram is reset?

Answer 172

> 67% full Bypassed with mode switch in Refuel or S/D with keylock in bypass. Scram when you can. The air header takes a few minutes to repressurize and drain the SDV. If mode switch is placed in run before SDV is drained low enough, another Scram signal will insert.

Question 173

What is the MSIV isolation scram setpoint, when is it bypassed, and what is the basis?

Answer 173

3 MSIVs < 92% open. Bypassed when mode switch not in run. Based on the anticipated pressure incrase and resulting power increase.

Question 174

What is the Drywell pressure high scram setpoint, when is it bypassed, and what is the basis?

Answer 174

1.68# in drywell Never bypassed This is a LOCA condition

Question 175

What is the High Rx Pressure scram setpoint, when is it bypassed, and what is the basis?

Answer 175

1065# Never bypassed. Protect the vessel.

Question 176

What is the Reactor Level Low scram setpoint, when is it bypassed, and what is the basis?

Answer 176

Level 3 - 178" Bypassed with MS in S/D and L3 Keylock bypass switches in bypass. Recirc line break analysis, ensures fuel PCT < 2200F

Question 177

What are the APRM scram setpoints?

Answer 177

APRM Neutron flux high - 118% -- terminate MSIV closure event and protect vessel. APRM Neutron flux high NOT in Run - 15% APRM Simulated Thermal Power High (Flow Biased) - 0.628wr + 61% (normal) 40.6% (single loop) -- Protect against slow thermal transients, protect fuel, MCPR < limits. APRM INOP - < 14 LPRM inputs, high/low voltage, card out of file, not in operate (Standby)

Question 178

What are the IRM Scram setpoints?

Answer 178

IRM Neutron flux high - 120/125 units Protects against rod withdrawal errors. IRM INOP - Low/High voltage, card out of file, not in operate, Loss of power. All bypassed in RUN

Question 179

What algorithms do the OPRMs use to provide scram signals? Which scram signal is pertinent to analysis? What is the bases of this signal? When are OPRM scram signals enabled?

Answer 179

Period, amplitude, growth. Only period is analyzed, it keeps MCPR within limits. Enabled when > 23.3% Prx and < 63.5% flow.

Question 180

What are the SRM scram setpoints, and why are they disabled?

Answer 180

Upscale (2x10^5 CPS) and inop. They are bypassed with shorting links because they are only used on a fresh core. With SRM trips active, all coincidence protection is defeated.

Question 181

What is the High Reactor Water Level scram setpoint and basis, and when is it bypassed?

Answer 181

Level 8 - 219" Feedwater controller failure, maximum demand. Ensures MCPR SL is not violated due to the static volume increasing collapsing of voids adding reactivity. Bypassed when not in run.

Question 182

What are the TS Safety limits?

Answer 182

With steam dome pressure < 686 PSIG or Core flow < 10% rated core flow: Limit Thermal power to =< 23.8% RTP With Steam dome pressure >= 686 PSIG AND Core flow >= 10% MCPR shall be >= 1.07.

Question 183

RPS Bus A loses power. What lights are illuminated above the arm & depress Scram switches?

Answer 183

All right lights extinguish.

Question 184

List the loads off the MS Equalizing header

Answer 184

2nd stage MSR RFPT A/B Offgas Preheaters Steam Seal Evaporators Steam Jet Air Ejectors

Question 185

How many SRVs are there? How many are ADS valves? How many are Low-Low set valves?

Answer 185

19 total, 8 ADS, 6 Low-Low set

Question 186

What is the purpose of the SRV line vacuum breakers?

Answer 186

They open when steam condenses in the SRV line to the suppression pool. This prevents a vacuum condition that would siphon a leg of water that would subsequently become a massive water hammer that would destroy the SRV piping if another SRV lift occurred.

Question 187

What redundancies does the SRVs have to reduce the risk of them not operating? | Make sure to discuss power, air, and fail-safe redundancy.

Answer 187

SRVs have two DC powered solenoids, one from each division. Either solenoid can cause an actuation itself. SRVs also have air accumulators. The 8 ADS valves and the lowest Low-Low set (51D) have 2 air accumulators supplied by Safety Related Instrument Air. The remaining have a single accumulator supplied by instrument air. The SRVs also have a safety mode that will open regardless of power or air supply.

Question 188

What does the red light on the SRV switch indicate? When does it illuminate?

Answer 188

Indicates there is pressure in the tail-pipe, meaning the valve has recently lifted or is leaking by. Illuminates at 30 psig in the tail pipe.

Question 189

When taking remote control of SRVs at the remote shutdown panel, which valves can be controlled? How will taking control of these valves effect operation of the SRVs?

Answer 189

F051C, D, & G can be taken to remote control. If only one division of these valves is taken to remote, the valve features can still actuate on the other division. If both divisions are in remote control, then all automatic features (except for Safety) of these valves will not function. The remaining SRVs will still function as normal.

Question 190

The reactor has undergone a transient that caused a pressure increase to 1120 PSIG. How many SRVs lifted? Currently, Reactor Pressure is 940 PSIG. How many SRVs remain open?

Answer 190

10 SRVs lifted in relief mode. 1 at 1103 psig, 9 at 1113 psig. There is two SRVs still open. The F051C and D remain open and will reset at 936# & 926# respectively. The remaining low-low set valves reset at 946#.

Question 191

How many SRV actuations are available in the accumulators utilizing Instrument air? What about SRIA?

Answer 191

1 actuation per SRV in a loss of air event. The SRIA supplied valves have 2 actuations in their accumulators.

Question 192

What are the purposes of the Flow Restrictors and where are they located?

Answer 192

Limit DP across dryer and RPV internals. Limit blowdown to < 150% in the event of a MSL break. They are in the MSLs upstream of the INBD MSIVs

Question 193

How do the MSIVs work? How are they operated? What system provides the motive force to open them? What provides the motive force to shut them? What happens to the MSIVs if their control switches are taken to test?

Answer 193

Two solenoids with electrical signal provided by RPS energize to hold valves open. Only one solenoid is needed to maintain the valve open - these solenoids are de-energized in the event of a scram signal from their parent channel. They can be operated manually with control switch. Instrument air provides the motive force, once the air pressure signal is high enough the valves will open against spring force. When air is dumped from the valve, springs overcome the loss of force and shut the valve. When the valve is taken to test, instrument air bleeds off the bottom part of the actuator. The MSIV will slowly close.

Question 194

What pressure in the instrument air system will cause the MSIVs to become inoperable? At what pressure will they begin to drift closed?

Answer 194

90# 48#

Question 195

How does the MSIV NS^4 isolation signal work?

Answer 195

There are 4 channels for the MSIVs, and each line has an instrument from each channel. MSIVs use 1 out of 2 taken twice logic. A trip on 2 channels in ANY MSL will cause all 4 MSIVs to close.

Question 196

What are the MSIV NS^4 isolation setpoints?

Answer 196

Low MSL Pressure - 807# Low Condenser Vacuum - > 21.5HgA Reactor Water Level Low - L1, 16.5" High MSL Flow - 254 psid High Turbine Building Temp - 145.8F High ST Temp - 156F or 152.5F

Question 197

With SRVs cycling on ADS, what actions should the operator take to protect containment?

Answer 197

The operator should manually cycle SRVs at different azimuths to prevent localized heating of the suppression pool.

Question 198

How many pumps are in the Main Turbine Lube Oil system? List each pump and its motive force (power supply or shaft attached). Which pumps operate below rated Turbine speed (1800 RPM)

Answer 198

6 Main Shaft Oil Pump - Attached Oil Driven Booster Pump - Attached Motor Suction Pump - F1D08 Turning Gear Oil Pump - F1D08 Emergency Bearing Oil Pump - D1B Bearing Lift Pumps - F1D08

Question 199

What is the purpose of the Oil Driven Booster Pump?

Answer 199

To provide suction oil to the Main Shaft Oil pump at 1800 RPM

Question 200

What is the purpose of the Motor Suction Pump? When will it auto-start? How does this pump's control switch indicate its operating state?

Answer 200

Provides NPSH to the Main Shaft Oil Pump when the Oil Driven Booster Pump is unavailable. Auto starts at a low MSOP suction pressure of < 10#. When operating, indicates red as normal. When in Auto and not operating, indicates red light. When in Off, no light indiciation.

Question 201

# Regarding the main turbine lube oil system: On a loss of oil header pressure, which pump is the first to start? What are the auto-start signals of this pump? How does this pump's control switch indicate its operating state?

Answer 201

Turning gear oil pump. Auto starts on MSOP Discharge pressure < 190# or LO Cooler Inlet < 15#. When operating, indicates red as normal. When in Auto and not operating, indicates red light. When in Off, no light indiciation.

Question 202

What is the purpose of the Emergency Bearing OIl Pump? What powers it? What will cause it to auto start?

Answer 202

Provide oil supply during a LOOP or low header pressure condition. Powered by D1B. Auto starts on MSOP Discharge Pressure < 180#, TGOP < 10#, or TLAC.

Question 203

What is the purpose of the Bearing Lift Pump? When is the bearing lift pump typically operated? What is the basis of this operating range? What are the start permissives? When will it trip? How does this pump's control switch indicate its operating state?

Answer 203

Supply oil to the journal bearings for TGOP operation. Typically operated at < 900 rpm. After this point, the oil wedge is formed and will maintain itself. Start permissives - TGOP > 10# AND > 6# oil header suction source. Trips on < 6# suction pressure (must be reset after trip). Green light on - Insufficient discharge pressure < 265#. Blue Light on - Sufficient suction pressure, trips reset, and CS in Auto. Red Light - Lift pump is running. It is possible to have red and green lights on simultaneously.

Question 204

How does a LOOP effect the operation of the Main Turbine LO System? How does a LOCA effect it?

Answer 204

During LOOP MT will trip. As MSOP pressure lowers due to shaft speed lowering, electric driven pumps will sequentially start when their auto start setpoints are reached. Eventually MT coasts to a stop. During a LOCA there is no immediate effect on the system. The alternate power supply to F1D08 is removed until operator intervention restores the stub buses, so if there is a LOOP following a LOCA prior to restoration of the stub bus, the Emergency Bearing Oil Pump will supply the necessary pressure to the turbine bearing until the turbine coasts to a stop.

Question 205

What is the upper temperature limit for all lube oil exiting a bearing?

Answer 205

< 180F

Question 206

What cools the MTLO coolers?

Answer 206

Service Water

Question 207

List all pumps in the RFPT LO System. What are there power supplies?

Answer 207

Main Oil Pumps & Aux Oil Pumps - Non-Class 480V Emergency Oil Pump - D1B

Question 208

List the auto starts of the RFPt Main and Aux Oil Pumps.

Answer 208

A - < 201# B - < 200#

Question 209

List the auto starts of the RFPT Emergency Oil Pump How is the pump secured after an auto start?

Answer 209

Low filter outlet pressure of < 28# or Loss of power to main pumps Pump must be manually secured after an auto start.

Question 210

What cools the RFPT LO Coolers? What is the effect on a loss of this system?

Answer 210

Cooled by TBCC. Bearings will not get cooled due to loss of cooling.

Question 211

What issues in the RFPT LO System will cause a trip of the RFPTs?

Answer 211

Bearing oil pressure < 4#

Question 212

How does a LOOP effect the RFPT LO System? How does a LOCA effect it?

Answer 212

RFPT Main and Aux oil pumps are not diesel backed. Pumps will trip and Emergency pump will operate to provide oil for coast down only. LOCA has no direct effect on this system.

Question 213

Describe the pump arrangement for the MFP. Describe the redundancies in their power supplies.

Answer 213

MFP has two pumps, an AC pump and a DC pump. The AC pump has no redundancy. It is non-safety 480v powered with no auto starts or trips. The DC Pump is powered by D1B.

Question 214

Explain the auto starts associated with the MFP DC LO pump

Answer 214

It auto starts on flow < 6 gpm on the AC pump or low bearing oil pressure < 8#. It will secure itself at > 6 gpm.

Question 215

What cools the MFP LO Coolers? What are the effects of a loss of this system on the MFP LO System?

Answer 215

Cooled by TBCC LO temp will rise but there are no trips or alarms associated with MFP LO.

Question 216

Explain the effects of a LOOP on the MFP LO System? What effects does a LOCA have?

Answer 216

During a LOOP, the MFP loses power (L10). The MFP AC Pump also loses power. The DC pump will auto start on one of its autostart signals until the pump coasts to a stop. A LOCA has no effect on the MFP LO System.

Question 217

Describe the flow path for the Lube Oil Purification System

Answer 217

Drain from resevoir Precipitate compartment Filter compartment Storage compartment Pump Polishing filter Return to MLO resevoir

Question 218

What happens to Scram time as RPV Pressure lowers?

Answer 218

It increases.

Question 219

# Regarding the CRDH system What are the consequences of a failed Flow Control Valve?

Answer 219

Cooling water flow is severely restricted and CRD temperatures increase.

Question 220

What is Rod Density? How is it calculated?

Answer 220

Total number of control rod notches inserted into the core divided by number of notches available.

Question 221

What is the normal water supply to the CRD system? What is the alternate supply? How is the alternate supply initiated?

Answer 221

Normally supplied by condensate downstream of the FDs and before the CBPs Alternate is from the CST There is a check valve and alternate supply line that taps off the make-up line from the CST. When Normal supply fails or is secured, the check valve will open and supply CST water to the CRD pumps.

Question 222

# Regarding the CRD system How is the PCV operated? Is it motor operated or pnuematic? What is the supply for its operation? What position does it fail to? What maintains differential pressure between the vessel and the CRD system?

Answer 222

PCV is throttled to a set position to establish differential pressure initially. Motor operated, from non-class 480v. Fails as-is. The FCV automatically repositions to maintain a constant flow, thus maintaining a constant DP.

Question 223

What is the purpose of the Stab valves in the CRD system? How many are there? Are they motor operated or pnuematic? How do they fail? What flow rates are associated with them? What system redundancies prevent stab valve failure from creating excessive rod speeds? Describe their operation.

Answer 223

Stab valves maintain drive water pressure 260 psid above reactor pressure. There are 8 stab valves, with 2 per drive water header. They are air operated valves. They fail closed on loss of power/air. Each stab valve is capable of passing 4 gpm when open. An in-line relief that opens at 550 psid and relieves downstream of the PCV will prevent stab valve failure from creating excessive rod speeds. During an insert signal, 2 stab valves will close. During a withdraw signal, 1 stab valve closes. This directs water into the drive header where the differential pressure will move the control rod.

Question 224

What are the effects of a Scram signal on the CRD system?

Answer 224

Scram signal is inserted depressurizing the charging header. The flow element for the FCV is downstream of the charging header. This will create a high flow signal as the majority of CRD water is directed to the lower pressure area (to the HCUs). This causes the FCV to fully close, preventing flow from reaching the drive water and cooling water headers. The system will remain in this condition until the scram is reset and the HCUs are allowed to return to repressurize.

Question 225

# Regarding the CRD system: What happens to the FCV on a loss of air?

Answer 225

Fails closed.

Question 226

# Regarding the CRD system What is the purpose of the pressure equalizing valves in the exhaust header?

Answer 226

They lift to repressurize the exhaust header following a scram. This prevents high D/P across the operating CRDMs and limits rod speed.

Question 227

# Regarding the CRD system What are the directional control valves? How many are there per control rod? What indications would a failure of a directional control valve provide? What does this mean?

Answer 227

Directional control valves reposition to allow flow through the drive header to insert or withdraw control rods. There are 4 directional control valves per control rod. A failure of a directional control valve would indicate drive flow of 0 . This means the HCU is hydraulically locked.

Question 228

What is the Scram Discharge Volume? What happens to it during a scram? What consequences exist if these functions do not occur?

Answer 228

Omega shaped volume meant to receive bleed off from the reactor when inserting control rods with a reactor scram. During a scram, its vent and drain valves trip shut to capture the discharge from the scram. If these valves do not isolate, there is a direct path venting reactor water to the suppression pool.

Question 228

What mech component supports the CRDM as it settles?

Answer 228

Collet Fingers

Question 229

What is the purpose of the CRD Housing Support Structure? | Also referred to as "Shoot out steel"

Answer 229

Strongback that prevents ejection of a control rod any more than 3 inches (equal to one notch) in the event of a CRD housing failure.

Question 230

What feature will allow the control rods to fully insert if all methods of delivering charging water pressure for the Scram failed? How high must reactor pressure be to allow this feature to function?

Answer 230

Ball check valve in the mechs. Must be > 600#.

Question 231

Describe the drive piston construction of a CRD Mech. What does this design facilitate?

Answer 231

Piston has two separate surface areas above an below (called the p-under and p-over areas). This difference in surface area creates a difference in force with the same pressure, allowing the mech to drift inwards in the event of an HCU failure.

Question 232

# Regarding CRD Mechs What are the collet fingers? What happens if they fail when retracted?

Answer 232

Collet fingers are clasps that latch in to notches to prevent rods from moving further out of the core than commanded. If the collet fingers fail when retracted the control rod will drift out of the core.

Question 233

# Regarding CRDM construction What is the velocity limiter? What safety feature does this provide and why is it important?

Answer 233

The base of the rod, which is shaped like a parachute to limit speed to < 3.11ft/sec in the event of a rod drop accident. This prevents a high reactivity insertion rate by limiting hte control rod velocity. It is shaped so that during a scram, the insertion rate is not significantly affected.

Question 234

What actions are required if two or more Scram accumulators are inoperable with > 600 psig steam dome pressure? What actions are required if one accumulator is inoperable with < 600 psig steam dome pressure? With more than one accumulator inoperable with < 600 psig steam dome pressure?

Answer 234

Within 20 minutes from discovery, restore charging water header pressure to > 1520 psig. Verify charging water header pressure > 1520 psig. Scram immediately.

Question 235

What are the power supplies for CRD pumps? How do these pumps function in a LOOP? LOCA? What start permissives exist for these pumps? what trips exist for these pumps?

Answer 235

Stub busses During a LOOP, the stub bus will re-energize when the diesels pick up their busses. The CRD pumps must be manually restarted. During a LOCA, the stub busses are stripped from their normal EH supplies. CRD pumps can not be restored until the operator re-energizes the stub busses. Permissives: Suction pressure > 25" HgA Pump oil pressure not low Trips: Low suction pressure < 25.8" HgA Low oil pressure < 3 psig Undervoltage Overcurrent

Question 236

How is oil supplied to the CRD pumps? How are these pumps powered? What trips, permissives, and autostarts are associated with these pumps?

Answer 236

Attached and Auxiliary lube oil pumps. Attached are shaft driven, auxiliary are powered by F1C08 and F1D08 Shaft driven pump has no logic. Trip on oil pressure > 9 psig and rising. Permissive to start < 9 psig. Auto start on < 5 psig AND respective pump breaker closed.

Question 237

How does the CRD OTBD CIV fail? How does this valve position during a LOCA?

Answer 237

Fails as-is. Stays as-is during LOCA.

Question 238

What is rated total core flow? What is rated FDW flow? What is the recirculation ratio and what is its value?

Answer 238

104 mlbm/hr 16 mlbm/hr Recirculation ratio is the amount of times water passes through the moisture seperator before it goes into the MS system. 6:1

Question 239

Explain the effect of a recirculation pump downshift or trip on the reactor.

Answer 239

The decrease in flow causes an increase in void formation. This increases RPV level and reduce reactivity.

Question 240

What are the indications of a failed jet pump? What is the major potential consequence associated with this failure?

Answer 240

Drop in reactor power Drop in total core flow Drop in core plate D/P Failure of a jet pump could cause a loss of refloodable volume due to increased blowdown area in the event of a LOCA.

Question 241

For B33 recirc pumps, what provides the NPSH in slow and fast speed?

Answer 241

Height of the downcomer in slow. Height of the downcomer + subcooling of the feedwater in fast.

Question 242

What are indications of inner, outer, and both seal failures in the B33 Recirc pumps? What actions are required when seal temperature exceeds 210F?

Answer 242

Inner seal failure - Outer seal pressure increases. Increases staging flow through 2nd PBD coil (Staging Flow Hi Alarm) Outer seal failure - Decreased pressure in #2 seal. Outer seal leak detection line Hi Flow Alarm. Both seals failed - Leakage past the outer seal (leak detection Hi Flow Alarm). If the seal temperature exceeds 210F, operator is required to trip pump.

Question 243

What is a FCV runback? What are the setpoints to actuate it? When is it active? If a signal is generated to perform a FCV on A Recirc FCV, will B Recirc FCV run back as well?

Answer 243

Flow control valves run back to 17% indicated FCV position, equivalent to 48% of rated flow, 58 mlbm/hr. RFPT Trip AND RPV L4 or Condenser vacuum > 5.6" HgA AND either < 3 cw pumps running OR #1 Steam Bypass Valve full open. Active in Fast speed only. No, not unless a signal is generated on B Recirc FCV as well. Each FCV has its own channel.

Question 244

What is the Automatic Flow Demand Limiter? What is its purpose? What indications show that its in control? What instrumentation provides the signal for the AFDL? What is the maximum amount of protection it can provide?

Answer 244

Circuit that takes control of FCV position and runs back flow in the event that a power setpoint is reached. It allows flow to be increased over 100% rated core flow at end of cycle and provides protection for high APRM flux conditions. Annunciator "AFDL IN CONTROL" on P680 will alarm. APRM A & E feed into the flux estimator which provide its input signal. Max AFDL override is 40% of the flow demand signal. This equates to roughly 45% change in valve position.

Question 245

A APRM upscales and the AFDL IN CONTROL annunciator actuates. FCVs begin to close and the operator takes APRM A to Bypass. What are the effects of this action?

Answer 245

As soon as APRM is bypassed, AFDL will no longer be in control. FCVs will return to their normal position and a power excursion will be imparted due to insertion of reactivity.

Question 246

# Regarding Reactor Recirc System List shifts and trips of the HPUs

Answer 246

Shifts: Pressure Low (<1650#) Low oil resevoir level OC/UV Warm Oil (>145F) Velocity Error HPU Trips: Pressure low with other HPU in Maint. Oil Empty 60 Gal OC/UV with other in maint. High Oil Temp >150F

Question 247

Draw or explain the electrical diagram for B33 pump power supplies

Answer 247

Question 248

What are the cavitation interlocks? What does each interlock protect? What protective action do these interlocks take?

Answer 248

Low Total FW Flow - < 3.43 mlbm/hr for 15 seconds. Protects the FCVs. Steam Dome/Pump Suction DP - <10F for 15 seconds. Protects the recirc pumps and jet pumps. They trip the 5 Bkrs on the pumps and automatically downshift to slow

Question 249

What is the low level downshift interlock? What protective action does this interlock take? What are the bases behind this interlock?

Answer 249

Automatic downshift to slow speed at Reactor L3 (178") Trips the 5 Bkrs, downshifts to slow speed. Primary basis: Downshift provides temporary level increase due to increase in voids. Secondary basis: Prevent jet pump cavitation and minimize velocity head effects on wide range level instrumentation.

Question 250

What is the EOC RPT Interlock? What protective actions does this interlock take? What is the basis for this trip?

Answer 250

EOC RPT Downshifts RCPs to slow speed when either TCV fast closure or TSV < 90% open. Only active at > 38% Prx as indicated by 1st stage shell pressure. Trips the 3 and 4 bkrs, which in turn trip the 5 bkr. This interlock is in place because at the EOC the initiating conditions will add reactivity faster than the control rods can insert negative reactivity. The downshift will supplement negative reactivity addition.

Question 251

What causes a Recirc pump downshift in the Redundant Reactivity Control System? What causes them to trip in this system? What is the basis of these trips?

Answer 251

RPV Pressure > 1083# will cause the 3 and 4 bkrs to trip, which will trip the 5 bkr. If RPV Pressure > 1083# and APRM not in downscale after 25 seconds, the pumps will trip completely. Pumps will also trip at L2 (130"). These are in case of an ATWS.

Question 252

What are the seven common start permissives for the Reactor Recirc Pumps?

Answer 252

Suction > 90% open Discharge > 90% open FCV in minimum FCV in Manual Thermal shock interlocks met 5A/B bkrs racked in with control power available. No incomplete sequence timer.

Question 253

# In regards to the B33 system What is the thermal shock interlock?

Answer 253

Temperature Delta between steam dome and bottom of vessel < 100F. Temperature delta between steam dome and recirc suction line < 50F Temperature delta between recirc lines < 50F

Question 254

Explain the starting sequence for the Recirc pumps in slow speed. What permissives are required besides the 7 common?

Answer 254

Pumps are started in fast. Once pumps reach 95% of rated speed, 5 bkr trips and pump coasts down. At approx. 26% speed, pump aligns to the LFMG and runs in slow. Also need FDW Flow < 3.43 mlbm/hr, Low power bypass sw in normal, LFMG available.

Question 255

During a pump shift, what circuit monitors the shift and what actions occur if the shift fails?

Answer 255

Incomplete Sequence Relay circuit. If the transfer exceeds 40 seconds, the 1 and 5 bkrs are tripped.

Question 256

What permissives are required for a shift to fast speed from slow speed besides the 7 common permissives?

Answer 256

Flow > 3.43 mlbm/hr No EOC RPT or RRCS setpoints No cavitation interlocks Auto Transfer sequence not energized Above L3 (178")

Question 257

What are the effects on Reactor Recirc system with a loss of ED1A/ED1B

Answer 257

The applicable pump will trip if running in fast. Bkrs 3 and 4 get their control power from Divisional DC. The 5 Bkr would sense that they are open even though they would remain closed. If in slow, there woul dbe no effect.

Question 258

Immediate actions for recirc pump trip in Modes 1 and 2

Answer 258

Scram the reactor.

Question 259

List the flowpaths with the stator water cooling system.

Answer 259

Main flowpath: Stator windings Secondary flowpath: Rectifiers Tertiary flowpath: Deionizer

Question 260

What actions should be taken if stator water cooling conductivity reaches 9.9 micromohs/cm^3

Answer 260

Turbine must be tripped.

Question 260

How many stator water cooling pumps are there? What are the auto starts of the stator water cooling pumps? Will the pumps continue running after the condition clears?

Answer 260

2 126.1# primary or 115.5# backup on running pump. Yes, the pump seals in with the initiating signal and control switch must be taken to off to reset.

Question 261

What cools stator water cooling? How many coolers are there and how are they arranged? How is temperature modulated through these coolers? What is the system response for a failure of the temperature modulator?

Answer 261

TBCC 2 coolers in series. A 3-way TCV bypasses around the HXs to modulate temperature to approx 38C. If the TCV fails, it will fail to the max cooling position.

Question 262

What causes a SWC runback?

Answer 262

Cooling water inlet pressure low < 42.5# Cooling water outlet temperature high > 81c

Question 263

Explain the process of a stator water Load Set Runback

Answer 263

Load set is typically 120 MW above generator output. When a stator water runback initiates, this load set will dial back at a rate of 1% every 3 seconds. Once Load Set with the runback becomes the low value, TCVs will being to close while bypass valves open. A main turbine trip will occur if generator load is not reduced to < 75% in 2 minutes OR < 25% in 3.5 minutes. In all likelihood the runback will not clear and the operator is reuqired to Scram the reactor when the 3rd bypass valve begins to open to maintain margin.

Question 264

What system monitors for leaks in the SWC system detected? What else does this system provide?

Answer 264

Stator Leak Monitoring System (SLMS) Monitors in-leakage of hydrogen to the SWC system as well to validate stator winding hydraluic integrity.

Question 265

# Regarding the Stator Water Cooling System What is the purpose of the pressure control valve? What are the mechanical stops for this valve installed for?

Answer 265

PCV maintains pressure of the SWC system at least 3# below generator casing pressure to prevent hydrogren in-leakage (3 psid). Mechanical stops installed to ensure both sufficient flow to purge gas bubble formation while maintaining pressure low enough to no exceed required value at rated load.

Question 266

How are vessel external temperatures monitored? What will cause them to alarm and why?

Answer 266

RTDs on top head flange, shell flange, bottom head flange. Will alarm at < 85F due to brittle fracture concerns.

Question 267

List calibration conditions for Shutdown Range level instrumentation

Answer 267

165" - 570" 120F RPV Temp 0 PSIG 90F in Drywell

Question 268

List calibration conditions for Upset Range level instrumentation

Answer 268

165" - 350" Sat. Water/Steam mixture 1025 PSI RPV Norm DW Temp

Question 269

List calibration conditions for Normal Range level instrumentation.

Answer 269

165" - 230" Sat Water/Stm 1025 PSI RPV Norm DW Temp Jet Pump Flow

Question 270

List calibration conditions for Wide Range level instrumentation

Answer 270

5-230" Sat Stm/Water 1025 PSI RPV Normal DW Temp 20 BTU/lbm Subcooling No Jet Pump Flow

Question 271

List calibration conditions for Fuel Zone level instrumentation

Answer 271

50" to -150" Sat mixture 212F RPV 212F DW No flow 0 PSI RPV

Question 272

# Regarding B21 Level Instrumentation Explain Level Notching Phenomenon

Answer 272

With CRDH Ref Leg Purge out of service, level instruments notch up during depressurization due to non-condensable gasses coming out of solution in the reference leg. This causes various anamolies that will caues indicated level to be higher than actual.

Question 273

List all trips and actions associated with the various level set points.

Answer 273

Question 274

# Regarding the RRC System What is an ARI? How is it actuated? How long until an ARI can be reset?

Answer 274

Alternate Rod Insertion - 4 valves per division vent the scram air header to open scram valves. ARI Signal energizes DC solenoids that open block and bleed valves. 30 Seconds

Question 275

How long does an RRCS trip seal in?

Answer 275

12 Minutes

Question 276

What causes an RRCS Recirc Pump downshift?

Answer 276

RPV > 1083#

Question 277

What causes an RRCS Recirc pump trip?

Answer 277

RPV > 1083# and APRMs not in downscale after 25 seconds. or L2 (130")

Question 278

# Regarding the RRC System What causes a Feedwater Runback? What happens in a feedwater runback?

Answer 278

RPV > 1083# and APRMs not in downscale after 25 Seconds RFPT and MFP level controllers shift to manual and run back to minimum.

Question 279

How many rods can be bypassed by the rod pattern controller? What does this allow the operator to do?

Answer 279

Up to 8 rods can be bypassed. This allow sthe rods to be manipulated without interlocks - very dangerous. Use consequence bias.

Question 280

How does rod pattern controller limit rod position? When is this controller active governing rod position? What kind of rod blocks does it insert? What is the basis of this feature?

Answer 280

RPC does not have specific notch limits, it has bank limits. Its active when power is below the LPSP (< 19% Prx) based on turbine 1st stage pressure. It will provide both insert and withdraw blocks. Protects against a rod drop accident.

Question 281

When does the rod withdrawal limiter take control? What does the rod withdrawal limiter protect from? What are the withdraw limits associated with it and when are they active?

Answer 281

Above the LPSP. Protects the plant from exceeding MCPR due to rod withdraw error. From LPSP to HPSP (>19% and < 66.7%) 4 notch limit. Above HPSP 2 notch limit.

Question 282

What are the rules for Rod Position Substitution?

Answer 282

Can not use substituted data. No more than 1 rod per gang may have a substitution When good data is received, it replaces substitute data. Shall not substitute over good data.

Question 283

What will a faulty position indication probe cause?

Answer 283

Channel Disagree and Data Fault

Question 284

What will cause a Rod Drift alarm?

Answer 284

Rod moves to a position RACS did not anticipate. Rod passes by an odd read switch without a command.

Question 285

What is the Rod Gang Drive Cabinet? What does it check? What can it bypass and how many of them can it bypass? What are precautions of bypassing?

Answer 285

Analyzer that scans all 177 rods to validate scram valve positions, SRI switch position, and HCU status. Can bypass 1 HCU at a time. Bypassing will prevent all information from bypassed HCU from being sent back. Bypassing a drive will prevent it from moving UNLESS that drive is selected in a gang, in which case it will move with the gang.

Question 286

List all Select Rod Blocks

Answer 286

Rod Select Clear pb not depresed One rod selected and withdrawn in Refuel mode Rod selected and driving Analyzer comparison or self test malfunction

Question 287

List all Insert Rod Blocks

Answer 287

Position substitution violation Rod Pattern Sequence Violation (from RPC)

Question 288

List all APRM rod blocks and when they are bypassed.

Answer 288

APRM Downscale - Bypassed Not in Run APRM Upscale (12%) - Bypassed in Run APRM Upscale Flow Bias - Bypassed not in run APRM Inop - Never bypassed Flow Channel Upscale - Bypassed not in run

Question 289

List all IRM Rod blocks and when they are bypassed.

Answer 289

IRM Downscale - Bypassed in IRM R1 and in Run IRM Hi Flux - Bypassed in Run IRM INOP - Bypassed in Run IRM Detector Wrong Position - Bypassed in run

Question 290

List all SRM Rod Blocks. When are they bypassed?

Answer 290

SRM Downscale < 0.7 CPS SRM Upscale 1x10^5 CPS SRM Inop SRM Wrong Position < 100 CPS and not full in Bypassed with MS in Run, IRM R8, or SRM bypassed. Wrong position & downscale bypassed on IRM R3.

Question 291

List the following rod block trips and when they are bypassed: Rx Mode Switch SDV Lvl Hi SDV Keylock in B/P Refuel platform Rod Pattern Controller

Answer 291

SDV Level Hi - 12 Gallons, never bypassed SDV Keylock -> MS in S/D or Refuel & SDV in Bypass -> Bypassed in S/U or Run Mode Switch -> Mode Sw in S/D -> Bypassed other than S/D Refuel Platform - R/F Bridge over core & Grapple > 550 lbs. -> Bypassed other than Refuel RPC -> Sequence violation, 4 notch limit, or 2 notch limit, bypassed based on LPSP & HPSP.

Question 292

How do OPRM inputs work?

Answer 292

Question 293

When are OPRMs enabled? What actions must be taken if in the OPRM trip enabled region and the Immediate exit region is entered?

Answer 293

>23.3% RTP and < 63.5% Flow

Question 294

What happens to the APRM Recirc Flow Unit Flow Biased Scram Setpoint if the Flow Channel Summer output fails to 0?

Answer 294

Rod block becomes 56% & Half scram becomes 61%

Question 295

What power the LPRMs, APRMs, and OPRMs? What are the consequences of cycling the breaker on this power supply?

Answer 295

ATWS Inverter Cycling these breakers is the preferred method of inserting a scram if the control room is uninhabitable as it will not close the MSIVs.

Question 296

How is the Turbine Generator synched to the grid?

Answer 296

Out of phase closure is prevented with relays. Breaker lockouts must be reset Synchroscope selected Match Volts In phase moving slow in the fast direction near 12 o'clock position. At this point relays will allow for synching to grid.

Question 297

What does the exciter do? What provides the voltage for the exciter?

Answer 297

Exciter flashes the initial field over a span of 10 seconds to turn the generator into an actual generator. Field flash voltage is provided from D-1-B

Question 298

What is the purpose of the power rectifier? What cools it? How many power rectifiers are there and how many are required to be online at 100% power?

Answer 298

Rectifier converts AC to DC for use in the field current. Cooled by Stator Water Cooling There are 5 on the turbine and 4 are required to be online.

Question 299

How is the generator field established initially and how is it maintained?

Answer 299

Field is initially flashed over a 10 second span by the exciter. Once the field is established, the exciter secures and field current is supplied by output slip rings through the Generator Field Breaker, which goes through a rectifier to make the generator field.

Question 300

What does the voltage regulator control? How many voltage regulators are there and how do they work?

Answer 300

Voltage regulator controls reactive power. There is an AC voltage regulator that automatically controls voltage. There is also a DC voltage regulator. This regulator is manual and maintains constant generator excitation.

Question 301

What conditions will cause a transfer from AC (Automatic) to DC (Manual) voltage regulation? What precautions should be taken in regards to DC regulator setpoint vs. automatic regulator output?

Answer 301

Voltage unbalance Exciter field overcurrent (Instantaneous) Exciter field overcurrent (Time delay) Maximum excitation limit (>5 seconds) Generator field breaker open or racked out Exciter field breaker open or racked out. The DC regulator should be periodically matched to avoid excessive transients in reactive voltage on a swap to manual control to prevent a sudden change in field strength.

Question 302

List the protective circuits of the AC Voltage Regulator

Answer 302

Exciter Field Current Limiter Maximum Excitation Limiter Exciter Minimum Voltage Limiter Underexcited Reactive Ampere Limit (URAL) V/Hz Regulator

Question 303

What does the Underexcited Reactive Ampere Limit protect from and how is this accomplished?

Answer 303

The URAL limits how underexcited the generator can operate (the generator can only lead so much before operation is challenged). It protects from pole slippage, which could cause significant damage.

Question 304

What does the Maximum Excitation Limiter protect the generator from? What actions does it take to enact this protection?

Answer 304

Protects the generator from excess excitation which would cause overheating conditions. Takes over AC Regulator signal and applies 100% rated excitation. If no response in 5 seconds, transfers to the DC regulator. If no response in 10 seconds, trips the Generator Field Breaker.

Question 305

What does the De-Excite circuit protect and how does it accomplish this?

Answer 305

Backs up the field breaker trip to remove generator excitation. Trips when exciter field breaker trips, grounding the voltage regulator.

Question 306

What is the Generator Core Monitor used for? How can the operator determine if a warning light on the GCM is valid?

Answer 306

Generator Core Monitor pulls air samples from inside the Hydrogen cooled areas and monitors for insulation breakdown. With a warning light in, a filter is inserted into the monitoring process. If the sample reading returns to a normal value, then the alarm is valid and actions must be taken.

Question 307

List the Generator Field Breaker Trips

Answer 307

Primary or Secondary Lockout energizes High V/Hz ratio sensed (Time delays) - 1.10 V/Hz (45 seconds) - 1.18 V-Hz (2 seconds) Max Excitation exceeded (Time delayed) Generator Breaker Control Switch to Trip Local Trip Pushbutton

Question 308

In the generator capability curve below, describe the following: What do the pressure curves represent? What is the limiting issue from lines A-B? What is the limiting issue from lines B-C? What is the limiting issue from lines C-D?

Answer 308

The pressures on the curves represent the hydrogen volume pressure cooling the stator. For A-B, curve is limited by field heating. For B-C, curve is limited by armature heating. For C-D, curve is limited by armature core end heating.

Question 309

What is the most severe transient for reactor pressure that the plant could face and what does it challenge?

Answer 309

Generator load reject with no bypass valve action. Challenges MCPR.

Question 310

What condenser condition would require a turbine trip at low loading of < 375 MWe?

Answer 310

Vauum > 5" HgA

Question 311

For the graph below, determine if the following parameters are acceptable: Generator lagging 50 MVARS Generator output 1200 MWe Hydrogen Pressure 45 PSIG

Answer 311

No, these conditions fall outside the acceptable parameters of the Generator Capability Curve

Question 312

What are the consequences of feedwater flow failing high?

Answer 312

Challenges L8 Reactor Scram condition Power increase due to subcooling and static head collapsing voids.

Question 313

Explain the flow path for long cycle cleanup

Answer 313

With one HWP online for short cycle cleanup -> to the HST -> One RFBP -> External Drain Cooler -> #5 Heaters -> FW Pump Bypass -> #6 Heaters -> Bypass of #6 Heaters -> Throttle return to HP Condesner.

Question 314

How does DFWCS sense if a RFPT is available?

Answer 314

Senses if there are no low hydraulic header pressure trip signals and the discharge valve is 90% open.

Question 315

The operating RFBPs tripped on low HST level. What actions must be done to the RFBPs in recovery from this event?

Answer 315

RFBPs must each be manually started prior to placing in standby. This will clear the trip signal and prevent water hammer.

Question 316

What is the purpose of the external drain coolers?

Answer 316

Provide subcooling for the 5 heaters drains to prevent flashing to steam in the DC heater.

Question 317

What are the two methods of supplying steam to the RFPTs? When is each method used?

Answer 317

Steam is supplied to the RFPTs from the MS Equalizing Header and from cross around piping. During initial startup, the RFPT will utilize MS EQ HDR steam to operate. When cross around piping pressure becomes sufficient, the high pressure control valve will throttle closed and the low pressure control valve will throttle open to control RFPT speed.

Question 318

How do RFPT trips work?

Answer 318

Each RFPT has its own trip system. A trip will lower hydraulic pressure to < 75 psig and cause fast closure of both stop valves. There are 4 ways to trip: Remote (Control Room) Local Manual Trip Lever Electrical Trip Solenoid Overspeed (Mechanical)

Question 319

List the start permissives for the RFBPs

Answer 319

HST Lvl > 47 1/16" Seal Pressure > 110# Suction/Discharge Valves > 90% Open No electrical Lockout

Question 320

List the RFBP Trips and Setpoints

Answer 320

HST Level < 47 1/16" HST Confirmatory < 104 1/16" Suction/Discharge < 90% Open Motor Overcurrent

Question 321

List the RFBP Auto Starts

Answer 321

Start Permissives must be met Any RFBP Trip Low MFP NPSH < 15# Low RFPT NPSH < 12#

Question 322

List this RFPT trips

Answer 322

Turbine overspeed 110% Low Aux Cond Vacuum 11.5" RPV Lvl Hi 219" Loss of all RFBPs RCIC Initiation (Time delay 4.5 mins if > 95% power) High Discharge Pressure RFP Suction Valve not Full Open Low Bearing Oil Pressure Thrust Bearing Wear Manual trip PB Local trip lever

Question 323

List the MFP Start Permissives

Answer 323

Suction Valve > 80% Open RPV Lvl < L8 LO Pressure > 6# No Lockout

Question 324

List the Trips and Setpoint of the MFP

Answer 324

Suction Valve < 80% Open RPV L8 219" Low LO Pressure Low NPSH < 5# for 14 seconds Lockout

Question 325

List the auto starts of the MFP

Answer 325

Loss of 1 RFPT & remaining RFPT LPSV is open Loss of both RFPTs

Question 326

When will the RFBP recirc valves automatically open? How are they closed?

Answer 326

HST to RFBP discharge differential pressure > 320# Must be closed by operator.

Question 327

When do RFPT discharge valves auto close?

Answer 327

RFPT Trip

Question 328

What causes an automatic opening of the RFPT and MFP recirc valves?

Answer 328

For the RFPTs, if any RFP trips in manual, will auto open. Will also auto open if flow demand < 7000 gpm. For MFP, if the MFP trips in manual, the recirc valve will auto open. Will also auto open if flow demand < 4000 gpm.

Question 329

What restrictions are automatically enforced regarding positioning of the MFP and RFPT recirc valves?

Answer 329

Valves can be opened for more flow if desired. Can not be closed further than the minimum flow positions for the applicable pump (7000 gpm RFPT, 4000 gpm MFP).

Question 330

With a train of the 1 & 2 heaters lost, what are the generator load limits and bases for these restriction? Why are they different?

Answer 330

If RFPTs are supplied by the MS EQ Hdr, limit to 1125 MWe. If RFPTs are supplied by extraction steam, limit to 1188 MWe. Prevents undue loading and overstressing of any turbine parts. The delta between the limits is because extraction steam reduces the stresses involved by reducing the stage pressures, pressure drops, etc.

Question 331

With 2 trains of 5 heaters lost, what are the generator load limits and bases for these restrictions? Why are they different?

Answer 331

If RFPTs are supplied by main steam, 938 MWe. If supplied by extraction steam, 1000 MWe. This is to prevent overloading of FW heaters 6A and 6B.

Question 332

What restrictions on reactor power must be enacted for a loss of 1 train of 1/2 heaters? How does this restriction change if 2 trains are lost? What is the basis for these restrictions.

Answer 332

Reactor power must be lowered to within the limits allowed by 18,000 gpm condensate flow. If a second train is lost, this restriction lowers to 9,000 gpm. This is to minimize flow induced vibrations in feedwater heater tubes.

Question 333

If 2 trains of 3 heaters are lost, what restrictions must be placed on reactor power? What is the basis for this restriction?

Answer 333

Reactor power must be lowered to within the limits allowed by 11,900 gpm condensate flow. This is based on bypass line flow limitations.

Question 334

With two trains of the same 5 or 6 heater lost, what restrictions must be placed on reactor power? What is the basis for this restriction?

Answer 334

Reactor Power must be lowered to within the limits of 18,400 gpm Feedwater Flow. This is due to bypass line flow limitations.

Question 335

When will a RFBP NOT autostart on a trip of another RFBP? What happens instead?

Answer 335

If the trip was due to HST Level low. All RFBPs trip.

Question 336

How does a loss of IA effect the feedwater system?

Answer 336

Feedwater recirc valves fail open. Seal injection valves fail open. MFP FCV freeze circuitry actuates at 70 psig IA. RFP Seal drain tank drain to condenser fails closed.

Question 337

How does a LOOP effect the feedwater system?

Answer 337

RFBPs are lost. RFPT Lube Oil AC pumps lost and RFPTs trip. DC LO pumps auto start. MFP is not operable (loss of L10) Seal water injection pumps de-energize. MOVs fail as is.

Question 338

How does a loss of vacuum effect the feedwater system?

Answer 338

At 11.5" HgA in the Aux Condenser, RFPTs trip.

Question 339

How will a MSL Break effect the Feedwater system?

Answer 339

RFPTs will coast down as steam is voided from the MS system. Feedwater flow decreases to zero but the MFP does not auto-start because no trip signal exists on the RFPTs. If operator does not start the MFP and begin feeding, HPCS and RCIC will initiate at L2.

Question 340

What does the feedwater leakage control system do? Where does it get its water supply from?

Answer 340

Prevent leakage outside of containment via feedwater lines following a LOCA. Basically a valve gland sealing system that uses clean water. Div 1 gets its water from the LPCS/RHR A Waterleg pump. Div 2 gets its water fromt he RHR B/c waterleg pumps.

Question 341

What are the loads of the CCCW system?

Answer 341

ECC Pump room, Computer room, Control Room Emergency Recirc, Control Room, MCC, SWGR and Misc, and Controlled Access Ventilation systems.

Question 342

What trips the CCCW system? What are the CCCW System auto-starts?

Answer 342

C CCCW Pump- LOCA or LOOP, Not diesel backed. A & B CCCW Pumps - LOOP, restart in 35 Seconds if in STBY. For Auto starts -> LOCA, in-service pump will remain in service if running. Starts at 35 sec if in Standby.

Question 343

What causes the CVCW CIVs to close?

Answer 343

BOP Isolation, no override

Question 344

What cools CCCW? What cools CVCW?

Answer 344

ECC Cools CCCW A/B NCC Cools CCCW C NCC Cools CVCW

Question 345

Explain the recycle interlock. How is it different for CCCW than for CVCW and TBCW?

Answer 345

After a trip, the system prevents restart for a set amount of time to protect the compressor motor. CCCW has a 20 minute delay and is bypassed in LOOP and LOCA The others have a 15 minute delay.

Question 346

How many branches of SRIA are there? What is the normal pressure band for the SRIA system? What operability requirements are covered by SRIA? What loads are on each branch? What system can provide makeup to SRIA if no other means are available to maintain system pressure?

Answer 346

There are two branches of SRIA. Maintained between 160 and 170 psig. If SRIA is below 150#, ADS valves are inoperable. If SRIA Receiver B is < 90#, OTBD MSIV Leakage criteria is not met. A Side has 4 ADS Valves and the lowest LLS Valve B Side has 4 ADS valves (Two of them LLS), and supplies OTBD MSIV Closure assist. Instrument air can be bridged to the B side to repressurize to 120#

Question 347

If the HPCS Injection valve is closed, how is SLC operability effected? What about Alternate Boron Injection?

Answer 347

SLC is not effected becuase it injects downstream of the HPCS injection valve. Alternate Boron Injection is not available because it injects upstream of that isolation.

Question 348

SLC A is initiated, what effect does this have on the RWCU system?

Answer 348

SLC A is Div 1 so the OTBD CIV for RWCU would isolate. This would cause the RWCU Pumps to trip.

Question 349

SLC is initiated on both divisions. The SLC A and SLC B pressure gauges both indicate pump operation. Is this sufficient to determine if SLC is operating as designed? If yes, why? If no, then how would proper operation be verified?

Answer 349

No, because the gauges for both pumps tap off the same system cross connect line. In order to determine if both pumps are operating properly, a flow rate must be determined. A single pump is only capable of approx. 43 gpm, so dividing level change by time will determine how many pumps are operating.

Question 350

What is the minimum required temperature in the SLC storage tank? What is it normally maintained at? What does this prevent?

Answer 350

> 70F Heaters cycle 75-85F This is to prevent precipitating boron out of solution.

Question 351

SLC is initated but no discharge pressure is seen after the keylocks are taken to start. Have the pumps failed to start?

Answer 351

Not necessarily, there is a delay to start waiting for suction valve to open.

Question 352

SLC is initiated and the continuity light on A squib valve does not extinguish. What are the consequences of this failure?

Answer 352

There are not really any consequences because 1 squib valve is rated for 100% flow and the systems are cross connected.

Question 353

What is the only valve in the IFTS system that is motor operated?

Answer 353

The transfer tube drain isolation.

Question 354

# Regarding the IFTS system What does the Versa Blocking Valve do?

Answer 354

Prevents opening bottom valve if transfer tube is not drained. Can not be defeated.

Question 355

Describe the IFTS auto transfer sequence

Answer 355

* Initially: Fuel in Carriage, Bridge away from Upender area, Flap Vlv Open, Bottom Vlv Closed * AUTO RUN START * Upender Inclines * Xfer to Fill/Drain position in fast speed and stops * Flap Closed * Drain Opens and drains to lower pool level * Bottom Opens * Drain Closed * Xfer to FHB in fast speed in then slow in until carriage bottoms out * Winch provides 3” slack until “AT FUEL BLD” light * Upender Vertical – unload/load * IFTS Drain Tank water is pumped to FPCC Surge Tanks, and returned to upper pools

Question 356

List interlocks associated with the F11 and F15 bridges. What do these interlocks do?

Answer 356

Refuel Interlock - Can not remove a fuel bundle from the RPV unless all rods are full in. - Removes power from the fuel hoist motor. Bridge Reverse Stop 1 - Hoist loaded and there is a control rod withdrawn. - Cannot move bridge over the RPV. Bridge Reverse Stop 2 - Mode switch NOT in R/F, or more than one rod selected, or more than one rod withdrawn. - Cannot move bridge over the RPV. Safety Travel Interlock - RF Bridge entered a restricted area. - Power interrupted to RF bridge, Trolley, and Fuel Hoist.

Question 357

What is considered a safe fuel storage location?

Answer 357

Properly seated in a designated storage location. Properly seated in IFTS carriage with Upender inclined. Seated in the fuel prep machine in its full down position. Properly seated in the designated location of the HI-STORM Cask Properly seated in the MPC for spent fuel dry storage. Properly seated in the reactor vessel (only if all refueling interlocks are available)

Question 358

What does the HPCS system seal-in reset pushbutton do? How does it effect the system when initiating conditions still exist?

Answer 358

Breaks the seal in and stops initiating signal. If L2 is not clear, it will not do anything. If Drywell Pressure is not clear, it will reset the initiating signal.

Question 359

What is the low speed stop for the RFPTs?

Answer 359

3300 RPM

Question 360

List the serviced loads of the following stages of extraction steam:

Answer 360

Question 361

What is the purpose of the Positive Assist Check Valves on the Extraction Steam system?

Answer 361

Prevent turbine overspeed following a turbine trip.

Question 362

Explain what happens with heaters regarding high level automatic actions.

Answer 362

Receiving Drains close Alternate drains on the heater with the high level open. Extraction steam supply isolats - Except for the 1/2 heaters, condensate isolates on those.

Question 363

Immediate actions for ONI-N36, Loss of Feedwater Heating

Answer 363

While core flow > 58 mlbm/hr, reduce reactor power using FCVs to: - < 96% Prx or - Less than or equal to power level prior to loss of feedwater heating.

Question 364

How do heater drains fail on loss of power/air?

Answer 364

Normal drains fail closed, alternate drains fail open - except for the 1s, both normal and alternate fail open.

Question 365

List the shutoff head and rated pressure/flow for the LPCS pump.

Answer 365

S/O head - 450 psig 6110 gpm at 128 psig

Question 366

What is the purpose of the waterleg pump in the LPCS system? What systems does this pump supply? What are the implications of this pump being secured?

Answer 366

Keeps lines filled thus minimizing injection time and preventing water hammer. Supplies LPCS, RHR, and FWLCS Div 1 If pump is secured, systems it supplies will be considered INOP until filled/vented.

Question 367

Explain the logic sequence for the LPCS Min Flow Valve What is its standby position?

Answer 367

Auto Open - when flow < 1350 GPM & Pump Bkr Closed Auto Close - Flow > 1380 GPM for 5 seconds. When system is in standby condition, min flow valve is open.

Question 368

Explain how LPCS system valves position during a LOCA signal. How can positioning change of these valves change based on reactor pressure?

Answer 368

Injection valve opens only if "blue light permissive" is in. Test return closes. Min flow valve stays open if flow < 1350 gpm. This will happen if reactor pressure is sufficient as to prevent LPCS from establishing minimum flow into the vessel.

Question 369

Explain the blue light permissive

Answer 369

When blue light is on, pressure sensed downstream of the injection valve is < 600#. If the blue light is on, the valve may be opened manually, and will automatically open if an RHR LOCA signal is sensed. For 15 minutes after the INITIAL illumination of the blue light, the operator may manually open the valve - even if the light extinguishes. The injection valve will NOT automatically open if the blue light is extinguished, even if the event falls in this 15 minute grace window.

Question 370

Explain the precautions of the LPCS system regarding the suppression pool suction valve.

Answer 370

There are no automatic operating features associated with this valve. The LPCS pump will operate even if this valve is shut. The pump can destroy itself in this situation, so the operator must be careful to ensure that it is open when the pump is running.

Question 371

Explain how power supply to the LPCS pump behaves during LOOP and LOCA conditions.

Answer 371

During a LOCA, the LPCS pump will delay 15 seconds before starting in due to bus loading concerns. If a concurrent LOOP/LOCA, this delay will be bypassed if power is restored within 19 seconds of the initiating signal. If power is restored after the 19 second window, the 15 second delay is in effect again. If a LOOP comes in after a LOCA, the LPCS pump breaker will ride the bus, and will return to operation as soon as EH11 power is restored.

Question 372

Describe the effects of overriding the HPCS pump OFF when an initiating signal is present. When will the pump restart without operator input?

Answer 372

Overriding the HPCS OFF during an initiating condition will prevent further automatic initiation of the HPCS pump. The pump will not restart until either: a) The pump logic is reset or b) Power is lost and subsequently restored to the EH13 bus.

Question 373

Describe the effect of overriding the HPCS Injection Valve in the closed position with an initiating signal. When will the valve automatically reposition without operator input?

Answer 373

Overriding the HPCS injection valve will prevent any further automatic operation of the valve. The valve will remain overridden until the logic is reset with the Seal-In reset pushbutton. The logic for this valve is DC powered and will remain in-tact through a loss of power to the EH13 bus.

Question 374

Describe the requirements for depressing the HPCS "Seal-in Reset" & "RX WT RLVL HIGH SEAL IN RESET" pushbuttons. What does each pushbutton accomplish?

Answer 374

Seal in reset will not do anything unless above L2 (130"). This button will reset all of HPCS logic and lockout the drywell initiating signal until the drywell falls back below the initiating signal set point. This will prevent DW initiating signal even if button depressed below the L2 setpoint. The RX WTR HIGH LEVEL SEAL IN RESET will reset lockout of the HPCS Injection valve if it closed on L8, allowing further operation of the valve. Depressing this button with the initiating signal still present will cause the valve to auto-open.

Question 375

Explain how power supply to the HPCS pump behaves during LOOP and LOCA conditions.

Answer 375

During a LOCA condition, the HPCS pump will delay starting by 10 seconds for bus loading concerns. For a concurrent LOOP/LOCA, the pump will start immediately upon restoration of the EH13 bus provided power is restored within 15 seconds of the initiating condition. If power is restored after that point, the delay will occur. If there is a loss of power condition on the EH13 bus when the LOCA condition exists, the pump breaker will ride the bus and the pump will start immediately upon restoration of power.

Question 376

Explain how the HPCS CST suction and Supp Pool suction isolations are normally positioned and how they operate. How are the valves interlocked to each other?

Answer 376

The normal flow path is the CST suction, but the system is credited based on the suppression pool volume. During a LOCA, if both valves are not full open, the CST suction isolation valve will automatically open. If either valve is open, they will remain in their current positions. The suppression pool suction isolation will automatically open if the SP level > 18'4" or CST level is < 98000 gallons. If the suppression pool suction isolation is open, the CST suction isolation valve will not open with the control switch taken to open. If the CST suction isolation is open, taking the suppression pool suction isolation to open will also cause the CST suction isolation to close.

Question 377

Explain the interlocks associated with the HPCS test return to CST isolation valves.

Answer 377

On a LOCA, both valves close. The suppression pool suction isolation valve can not be open with these valves open. If the suppression pool suction isolation indicates open, these valves will auto close.

Question 378

Describe the HPCS logic for minimum flow.

Answer 378

Min flow valve opens if flow < 725 gpm & pressure > 145#. Min flow valve closes if > 725 gpm OR < 145#.

Question 379

How is hydrogen seal oil pressure controlled?

Answer 379

Pressure Regulator that maintains seal oil pressure 8# greater than hydrogen pressure.

Question 380

What is the float trap? What happens if the float valve fails open? Closed?

Answer 380

Seals generator from outside air with float valve. If float valve fails closed, oil backs up into hydrogen. If float valve fails open, rapid depressurization of the generator casing.

Question 381

Effect of a LOOP on Hydrogen Seal Oil

Answer 381

Main SOP de-energizes momentarily. ESOP starts when pressure < 90#. MSOP re-energizes when deisels pick up XF-1-A

Question 382

Where all can seal oil be supplied from? On the tertiary source, what is the pressure in the oil header and what pressure in the casing can it maintain?

Answer 382

MSOP, ESOP, Bearing Oil Header Bearing oil header is 16#, so it can maintain 8# hydrogen pressure in the casing.

Question 383

What levels does RCIC initiate and secure automatically at?

Answer 383

L2 130" & L8 219"

Question 384

Describe the power supplies for RCIC electrically operated equipment.

Answer 384

All components are DC powered from ED1A except for the vacuum breaker CIVs, Steam Supply CIVs and Bypass, and the GS Compressor which is D1B

Question 385

What are the limitations with RCIC involving a loss of ED1A

Answer 385

System will not automatically initiate and must be manual-local controlled.

Question 386

How is RCIC flow regulated? What is the flow range RCIC can provide? Explain how the ramp function works regarding speed control.

Answer 386

RCIC flow is controlled by its speed via the governor valve. Can provide 230-725 GPM. Ramp function is the initial starting process of RCIC. Initially, governor is wide open and RCIC will speed up quickly until hydraulic pressure builds up and allows the governor to function. From this point, the governor will significantly dial down on RCIC pump speed over a 12 second window to its set flow rate.

Question 387

What is the purpose of gland seal compressor for RCIC? What components does it service? When does it auto start? What is it powered by?

Answer 387

Provide sealing to keep radioactive steam out of the space. Seals the turbine seals, TTV stem, and Governor Stem. Autostarts on L2. Powered by DB

Question 388

The RCIC Steam Shutoff Valve (F045) receives its automatic operating signals from what instruments? What is the open permissive for this valve?

Answer 388

Steam shutoff receives its open and shut signals from the wide range level instruments. Requires the turbine exhaust to suppression pool isolation valve to be open.

Question 389

What causes the RCIC min flow valve to open or close?

Answer 389

Open: Flow < 120 GPM & > 125# discharge pressure. Close: > 180 GPM OR Steam Shutoff closed (F045).

Question 390

Describe the automatic operation of the RCIC Injection valve.

Answer 390

Auto opens on RCIC initiation if the F045 is open. Auto closes if either the F045 or TTV are shut.

Question 391

Describe the interlock for the RCIC CST suction isolation valve regarding the suppression pool suction isolation valve. What causes this valve to auto open or close?

Answer 391

The suppression pool suction isolation must be taken to close prior to the CST suction isolation reaching full open or the CST/Sup Pool interlockw ill cause the CST suction isolation to close automatically. Open: RCIC initiation if the SP suction isolation is not open. Close: SP suction isolation reaches full open.

Question 392

What causes the RCIC Test Return to CST isolation valves to close?

Answer 392

RCIC Initiation or SP suction is open.

Question 393

What will cause the RCIC SP Suction isolation to automatically open or close? What permissives to open does this valve have?

Answer 393

OPEN: High SP Level or CST Level Low Close: DIV 1 RCIC Isolation Requires the test return to CST lines to be closed.

Question 394

What will cause an RCIC divisional isolation?

Answer 394

Hi RCIC Room Temp - 143F Hi Steam Tunnel Temp - 156F (29 min delay, can be bypassed). Hi RHR Room Temp - 157F Hi Steam Flow Steam Supply Pressure Low - 60# Hi Exhaust Diaphragm Pressure - 10#

Question 395

What happens if the operator depresses the RCIC Isolation push button with no isolating condition? Which division has the manual isolation pushbutton?

Answer 395

Nothing, condition required to actuate. Div 1

Question 396

Explain the RCIC Initiation Turbine and RFPT Trip Logic

Answer 396

If RCIC initiates and power > 95%, the reactor will scram in 4.5 minutes unless the TTV is tripped. If power is < 95% OR the High Power RCIC Setpoint switch is set to DISABLE, the reactor will immediately scram.

Question 397

Which RCIC automatic features are enabled when RCIC is in Remote Shutdown Control?

Answer 397

Just the overspeed trips.

Question 398

List the RCIC turbine trips

Answer 398

Mechanical Overspeed > 120% High Exhaust pressure > 25# Low Pump Suction Pressure RCIC Isolation signal on either division Remote Trip PB

Question 399

When is RCIC required to be operable?

Answer 399

> 150# steam dome pressure

Question 400

# Regarding the Leak Detection system What constitutes identified and unidentified leakage?

Answer 400

Leakage to the equipment drain sump is identified, to the floor drain sump is unidentified.

Question 401

# Regarding the leak detection system How do the fill up and pump out timers work? Which sumps have these timers?

Answer 401

Fill up timer starts when the sump pump stops- if the pump starts before the timer expires it alarms. Pump out timer starts when the pump starts. If the pump is still running (it utilizes a level switch to de-energize) then then it will alarm. All sumps except the DW FDS have these timers.

Question 402

What cools the DW and containment sumps?

Answer 402

NCC

Question 403

What isolations trigger off the MSL delta temperature monitors? How many of these monitors are there?

Answer 403

None, it is only for alarms. There are 8.

Question 404

Which RCIC isolation signals can be bypassed?

Answer 404

Only the room temp isolations.

Question 405

What signals cause an RHR Sampling Isolation?

Answer 405

L3 178" DW Pressure > 1.68# Hi RHR Room temperature

Question 406

What signals cause an RHR SDC isolation?

Answer 406

L3 178" RPV > 135# Hi RHR Room temperature

Question 407

How are all RWCU isolation signals bypassed?

Answer 407

A single bypass switch.

Question 408

Explain ECCS Leak Detection. Which systems are paired with each other?

Answer 408

ECCS Leak detection measures DP between two established points inside of the vessel to determine if there is a piping failure in the downcomer region. RHR A LPCI injection nozzle and LPCS Spray Sparger are paired. RHR B and RHR C Injection Nozzles are paired HPCS and Above Core Plate pressure sensing are paired.

Question 409

Explain the effect of a loss of one E31 NUMAC

Answer 409

MSIV Half Isolation Divisional CIV isolation RCIC isolations due to room temperatures and steam tunnel not functional If in SDC, Divisional SDC isolation.

Question 410

Explain the effects of a loss of an RPS bus on NS4 isolations. How does this change for a loss of the divisional EH bus?

Answer 410

If an RPS bus is lost, will get all applicable divisional isolations (INBD/OTBD). If an EH bus is lost, isolation will initiate as soon as power is restored.

Question 411

Which isolations are not effected by NS4?

Answer 411

RHR LOCA isolations RCIC Isolations

Question 412

List all NS4 Isolation Types and their setpoints

Answer 412

Balance of Plant 1.68# Drywell, L2 130" RWCU Isolation Too many to list and already listed in another card RHR SDC Isolation L3, RPV Pressure > 135#, RHR Room Temp RHR Sampling Isolation L3, RHR Room Temp, 1.68# Rx Plant Sampling Isolation MSL HI HI, L2

Question 413

Purpose of the D17 system

Answer 413

Monitors airborne(D17) and gaseous effluent(D17) activity in the plant (samples, detects, indicates, records) and initiates actions to limit release

Question 414

# In regards to D17 monitors What do they sample for? | P-I-G

Answer 414

Particulate Iodine Gas

Question 415

Which ventilation systems only sample for gas?

Answer 415

IB & AEGTS exhaust

Question 416

What causes the D19s to automatically start?

Answer 416

High on associated channel D17s. BOP LOCA

Question 417

List D17A Liquid Process Monitors

Answer 417

ESW A ESW B NCC RW to ESW SW to ADHR Manhole #20

Question 418

List D17A Gas Sample Monitors

Answer 418

OG Pretreat OG Post Treat

Question 419

List the D17 monitored areas and what trips are associated with each. Which D17s do not have particulate and iodine sampling?

Answer 419

No P/I highlighted in yellow

Question 420

List the three modes of operation for Isophase Bus Duct Cooling. Which modes are controlled from the field? When is each mode used?

Answer 420

Normal - Generally used Once Through Mode - Used when TBCC unavailable for cooling coils, controlled from the field. Self Cooling Mode - Used when fans are not available, controlled from the field.

Question 421

# Regarding Isophase Bus Duct cooling How many bust duct cooling fans are there? What will cause a trip in the system? What happens due to the trip?

Answer 421

2 100% Capacity fans Trip on low flow or high outlet air temp of 185F Trip will start standby fan on a 45 second time delay. Delay is for suction damper stroking. If the problem still exists, system will cycle between fans.

Question 422

What are the limits for Isophase Bus Duct Cooling self cooling mode?

Answer 422

100C Conductor Temp or 20000V

Question 423

How do the Isophase Bus Duct Hydrogen Analyzers work?

Answer 423

Analyze up to the H2 LEL (4%) on a 0-100% scale. 100% indicated is 4% H2 concentration.