Exam 2

Question 1

RCP

• Flowrate, Motor HP, Power Supply
• Flywheel purpose
• Anti-rotation device purpose. When does it actuate?
• CCW Cooling - What does it cool? CIS valves - what closes them?
  
  • Excess flow values & setpoints
• Interlocks

Answer 1

• 100,200 gpm @ 290 ft of head each, 7000 HP Motor - P/S A-3 PA0107, 0108, 0205, 0204
• Adds inertia to shaft to allow longer coastdown time for Decay Heat Removal. Takes ~4 minutes for pump to coastdown.
• Prevents idle RCP from water wheeling. 70 RPM
• CCW: Cools Thermal Barrier H/X, motor bearings, and motor air coolers.
  
  • CIS: Inlets: EG-HV-71,68 (outer); EG-HV-60,59 (In/Out); EG-HV-62/61 (In/Out). Closed on CIS-B (Hi-3 or manual CSAS)
  • Excess flow: If FT-13 thru 16 sense > 50 gpm BB-HV-13 thru 16 will individually close. If FT-62 senses > 206 gpm EG-HV-62 will close isolating all Thermal Barrier H/X’s.
• Will not start unless: Lift oil pump running and oil pressure > 600#

Question 2

PRT (OTN-BB-00004)

• PRT level restriction prior to degas
• Hydrogen precautions
• Concern for leakage when RCS pressure < PRT pressure
• Concern for draining PRT to CTMT Normal Sumps
• Time to cooldown PRT

Answer 2

• PRT Level > 19% until degassed to prevent PRT atmosphere from going into RCS.
• H₂ Precautions:
  
  • Maintain N₂ blanket to prevnt H₂/0₂ explosive environment.
  • [H₂] shall be < 4% prior to venting PRT to atmosphere.
  • PRT [O₂] content must be < 3% prior to putting H₂ on VCT.
• If Rx makeup water pressure > RCS pressure, water may leak into RCS via excess letdown line.
• If draining PRT to containment normal sumps, sump pumps cannot keep up and should only be done in emergency w/o verifying [H₂] < 4%.
• PRT Cooling: 1 hr by spraying makeup water, 8 hours by circulating w/ RCDT H/X.

Question 3

RVLIS

• RVLIS inputs & purpose

Answer 3

• RVLIS - Indicates Rx Vessel level based on D/P between Rx Vessel head & seal table. Adjusted for density based on T_H.

Question 4

COMS

• Purpose
• Controls
• Inputs

Answer 4

• Mitigates an overpressure at low temperature.
• COMS must be ARMED
  
  • Block valve opens when in ARM (cannot be closed unless COMS is blocked)
• Auctioneered Low WR Temperature used to calculate P_max & compared to channels WR Pressure. It’s used to actuate PORVs.

Question 5

Rod Banks & Groups/Speeds

Answer 5

Control Banks (25 Total)

• A: 4 (2/2) - 1 AC / 2 AC
• B: 8 (4/4) - 1 BD / 2 BD
• C: 8 (4/4) - 1 AC / 2 AC
• D: 5 (2/3) - 1 BD / 2 BD

Shutdown Banks (28 Total)

• A: 8 (4/4) - 1 AC / 2 AC
• B: 8 (4/4) - 1 BD / 2 BD
• C: 4 (one group) - SCDE
• D: 4 (one group) - SCDE
• E: 4 (one group) - SCDE

Speed

• Shutdown Banks: 64 SPM
• Control Banks:
  
  • Manual: 48 SPM
  • Auto:
    
    • -1.5° to -3°: 8 SPM
    • -4°: 40 SPM
    • -5°: 72 SPM

Question 6

RCS Inventory Balance (OSP-BB-00009)

• Frequency
• Acceptance Criteria
• Basic Steps

Answer 6

• Every 72 hours for 1 hour minmum.
• Acceptance:
  
  • Unidentified Leakage < 1 gpm
  • Identified Leakage < 10 gpm
  • Primary to Secondary Leakge < 150 gpd per S/G.
• Steps:
  
  • T_ave controlled within 1°F
  • Pressure stable ± 15 psig
  • Dilutions and borations avoided during test

Question 7

RCS WR Temperature

• Number
• Range
• What they provide inputs to.

Answer 7

• 1 T_H & 1 T_C per loop.
• 0° - 700°F
• Input to:
  
  • COMS
  • RVLIS
  • Subcooling Monitor
  • MCB Indication/Recorders

Question 8

Power/Logic Cabinet Urgent Alarms

Answer 8

Power Cabinet (Low Low RPM)

• Loose or missing card
• Logic error
  
  • Zero current ordered to both Stationary and Movable gripper coils @ same time
• Regulation Failure
  
  • Sampling resistor current not expected
• Phase Failure
  
  • SCR Bridge not operating properly.
• Multiplex error
  
  • More than 1 group of rods in 1 power cabinet try to move at once.
• Power cabinet non-urgent occurs when one instrumentation power supply fails. If caused by main power supply, attempted rod motion will cause urgent.

Logic Cabinet (LIPS)

• Loose or missing card
• Input to slave cycler incorrect
• Pulser failure
• Shutdown Bank C,D,E circuit failure.
• Logic Cabinet urgent failure prevents all auto and manual rod motion.

Urgent Failures:

• Failure alarm locks selected group, energizing both SGC & MGCs.
• “Inhibit signal prevents all rod motion from that cabinet.
• Rx Trip causes regulation and logic errors.

Question 9

Shutdown Bank Withdrawal (OTG-ZZ-0001A)

• Precautions
• Prerequisites

Answer 9

Precautions

• Avoid activities that could cause distractions in MCR.
• SR NIs operable per T/S 3.3.1
• Reactivity Management SRO must be designated.
• If counts ↑ x4 withdrawal suspended and rods inserted.
• If critical is acheived befroe S/D banks withdrawn enter OTO-ZZ-00003 for loss of SDM & initiate immediate boration.

Prerequisites

• CRS Permission
• Ensure 2 SR NIs operable
• If following refuel, request engineering for ICRR Plot Support
• Designate Reactivity Management SRO.
• Ensure reactivity management brief has been completed.

Question 10

Rod Control Logic Cabinet Components

• Purpose of:
  
  • Pulser
  • Master Cycler
  • Bank Overlap Unit
  • Slave Cyclers
• Bank Overlap Thumbwheels

Answer 10

• Pulser supplies output pulses to master cycler. (# of output pulses is 6x # of input pulses)
• Master Cycler is a reversible counter that correctly sequence the groups within the rod banks.
• Bank Overlap Unit is a counter that keeps a record of control bank operation, and determines the proper sequence of bank operation for the overlap scheme.
• Slave Cyclers generate the required sequence of current orders to the CRDM coils for rod motion.

Bank Overlap Thumbwheels:

• S1: 115
  
  • A: 115
  • B: 0
• S2: 228
  
  • A: 228
  • B: 113
• S3: 230
  
  • B: 115
  • C: 0
• S4: 343
  
  • B: 228
  • C: 113
• S5: 345
  
  • C: 115
  • D: 0
• S6: 458
  
  • C: 228
  • D: 113​

Question 11

MCB Startup Reset Switch​

Answer 11

• Resets [POSSUM]:
  
  • ​Pulse to Analog Converter to 0
  • Bank Overlap unit to 0
  • MCB Step Counters to 0
  • Slave Cycler
  • Urgent Alarm Circuits
  • Master Cycler

Question 12

PZR Spray Valves

• Setpoints
• Flowrate and basis
• Bypass valves
• Connection to RCS Loops
• RCP Requirements

Answer 12

• Setpoints
  
  • Start Opening: Controller setting + 25 psig (2260 psig nominal)
  • Full Open: Controller setting + 75 psig (2310 psig nominal)
• Flow Rate:
  
  • 450 gpm each.
  • Sized to prevent PORV actuation on 10% setp load change.
• Bypasses:
  
  • Manual valve allows 0.5 gpm thru spray outlet for chemical mixing (boron) and limits thermal stress.
• Connection to RCS Loops: PCV-455 B ← Loop 1 T_C; PCV-455C ← Loop 2 T_C
• RCP Requirements:
  
  • Loop 1 or 2 RCP must be running to drive flow (D/P between spray line and surge line in Loop 4)
  • Most effective if loop 4 RCP is running (due to lower static pressure in Loop 4 hot leg/surge line w/ RCP running)

Question 13

PZR (code) Safety Valves

• Number
• Setpoint
• Flowrate
• Basis

Answer 13

• Number: 3
• Setpoint: 2460 ± 49 psig
• Flowrate: 420,000 gpm each
• Basis: Prevents exceeding design pressure following 100% load loss to turbine with no dumps or rods.

Question 14

RCP Seals

• For each seal: How it works, flowrates & Leakoff Paths
• # 1 Seal ΔP limitation
• Standpipe makeup

Answer 14

• Seal #1:
  
  • Controlled leakage seal.
    
    • Leakage controlled by ensuring gap b/w seal ring and runner is held constant by balancing hyrostatic forces.
  • Seal injection from CVCS flows into space b/w #1 seal & bearing @ 8 gpm.
  • 3 gpm flows past #1 seal (5 gpm into RCS) and into the VCT (per pump).
  • DO NOT EXCEED 200 psid across the seal.
• Seal #2:
  
  • ​Face rubbing seal.
  • Backpressure from #2 seal forces flow into VCT.
  • On loss of injection becomes film riding.
  • Allows 3 gph to RCDT.
• Seal #3:
  
  • Face rubbing w/ double dam.
  • Backpressure from #3 seal forces water to RCDT.
  • Standpipe leaks 400 cc/hr to RCDT and another 400 cc/hr to CTMT Normal Sump
• Standpipe Makeup:
  
  • _​_BB-LCV-178 thru 181 auto makeup from RMWST to maintain 26.6” - 41.5”.
  • Can be manually controlled at RL021.

Question 15

PZR PORVs

• Lift setpoint & minimum system pressure
• How they operate
• Solenoid power supply & PORV designators
• Flow rate
• Block valve power supplies & designators

Answer 15

• Lift Setpoint:
  
  • 2335 psig (nominal)
    
    • Variable for COMS.
  • Minimum 125 psig system pressure to operate
  • Reseats 2315 psig.
• How:
  
  • ​Solenoid opens → Opens pilot → system pressure opens main valve
• Designators/Power Supply:
  
  • BB-PCV-455A (‘A’ Train): NK51
  • BB-PCV-456A (‘B’ Train): NK44
• Flowrate: 210,000 gpm each
• Block Valve Designators/Power Supplies:
  
  • BB-HV-8000A (‘A Train): NG01B
  • BB-HV-8000B (‘B’ Train): NG02B

Question 16

PZR Setpoints

• Design parameters
• Program level Range
• Level Setpoints

Answer 16

• Design:
  
  • _​_5%/min load ramp, 10% instant load change, 50% load reject w/ auto rod control & steam dumps w/o Rx Trip, No SI from Rx & Turbine Trip
  • 1800 ft³ prevents water hammer thru safeties during loss of load w/ high Pressurizer Level and auto rods/dumps.
  • Will not empty on Rx/Turbine Trip.
• Program Level: 25% - 56.17% from 0 - 100%. Corresponds to T_ave 557° - 585.3°F
• Setpoints:
  
  • _​_92% Rx Trip
  • 70% High level Alarm
  • L_programmed +5%: High Deviation, energizes backup heaters.
  • L_programmed - 5%: Low Deviation
  • 17% Isolates Letdown & Trips PZR Heaters

Question 17

Pressure Control

• Heater Banks: What each do, power supplies, power consumption
• PZR Pressure Controller: Potentiometer setting, range, what it controls.

Answer 17

• Heater Banks:
  
  • A Bank: Backup, 700 KW from PG21
  • B Bank: Backup, 700 KW from PG22
  • C Bank: Variable, 400 KW from PG24
• PZR Pressure Controller:
  
  • 1700 - 2500 psig, 10 turn potentiometer => 80 psig/turn
  • 2235 psig nominal setting => 6.7 turns (nominal) setting
  • Controls:
    
    • Variable Heaters ± 15 psig
    • Spray starts opening + 25 psig; Spray full open + 75 psig
    • Backup on - 25psig; Backup off -17 psig

Question 18

RCS Chemistry

• What chemicals are added to RCS? Why?
• What are the RCS T/S Chemistry requirements?

Answer 18

• Li₇OH: pH Control
• H₂: Oxygen scavenging (hot)
• Zinc: Prevents crud deposition
• N₂: Prevents O₂ absorption in VCT when H₂ not being used.
• Boron: Chemical Shim
• Hydrazine: Oxygen scavenging (Cold)
• H₂O₂ (Hydrogen Peroxide): Causes chemical shock leading to crud burst (prior to refuel).

T/S

• [O2] < 0.1 ppm (1.0 transient) every 72 hrs
• [Cl-] < 0.15 ppm (1.5 transient) every 72 hrs
• [F] < 0.15 ppm (1.5 transient) every 72 hrs
• [H2] - every 72 hrs

Question 19

PRT

• List the inputs
• Alarm Setpoints (Hi level, Lo Level, Hi Temp, Hi Press)

Answer 19

Inputs

• 2 PORVs
• 3 Safeties
• RHR Suction Relief
• RCP Seal Return Relief (140°F)
• CVCS Letdown Relief
• Excess Letdown
• Reactor Makeup Water
• N₂

Alarms

• Hi Level: 81%
• Lo Level: 64%
• Hi Temp: 115°F
• Hi Press: 6 psig

Question 20

RCS Leakage

• State the differential allowable RCS Leakage Rates

Answer 20

• No pressure boundary leakage
• 1 gpm unidentified leakage
• 10 gpm identified leakage
• 150 gpd leakage thru any one S/G

Question 21

RCP Components and Cooling

• State the purpose & Operation of:
  
  • Thermal Barrier Heat Exchanger
  • Flywheel
  • Anti-reverse rotation device
• Which system(s) cool RCP components? Which do they cool?
• RCP power supplies and ratings

Answer 21

• Thermal Barrier H/X: Backup cooling supply to seal package
• Flywheel: Increases inertia of RCP shaft to increase coastdown time to approximately 4 minutes to aide in decay heat removal.
• Anti-Reverse Rotation Device: Pawls lower into contact w/ ratchet plate @ < 70 rpm, locks ratchet plate (flywheel) prior to shaft reversing direction. Reduces starting current by preventing reverse rotation.
• Cooling:
  
  • CCW cools the motor air coolers, motor bearing oil coolers, and thermal barrier H/X
  • (CVCS) Seal injection cools seal package and pump bearing
• Power Supplies:
  
  • ‘A’ RCP: PA0107
  • ‘B’ RCP: PA0108
  • ‘C’ RCP: PA0205
  • ‘D’ RCP: PA0204
• Pump Ratings
  
  • _​_100,200 gpm @ 290 ft
  • 7000 HP, 6 Pole, 1200 RPM induction motor

Question 22

NI Fuses and Misc. Switches

• High Flux @ S/D Block Switch
• SR & IR Level Trip Bypass Switch
• Power mismatch bypass switch
• Rod Stop Bypass
• Upper/Lower Section Defeat Swtiches
• Comparator Channel Defeat Switch
• Startup Rate Select

Answer 22

• Block MCB & CTMT Alarm
• Bloc SR Hi Flux / IR High Flux & Rod Stop
• Removes a PR from auctioneering circuit to rod control and FRBV’s
• Removes a failed detector from comparator & clears PR upper/lower deviation alarms
• Removes channel from current comparator preventing alarm from channel
• Selects which channel feeds SUR.

Question 23

BDMS

• Operation
• Setpoint
• How to block
• When can you block BDMS?

Answer 23

• SR counts are averaged over one minute & compared to previous nine one-minute samples. If most recent exceeds any of the previous nine one-minute samples by 1.7x it sends a signal to the SSPS system to CVCS to:
  
  • Open BG-LCV-112D/112E (RWST Source for Charding)
  • Close BG-LCV-112B/112C (VCT Source for Charging)

** Either train signal will align both valves

• Blocked by depressing block switch SE-HS-11 & SE-HS-12 (train specific) → causes 57B: SR Flux Doubled Byp/Blocked
• Per T/S 3.3.9, BDMS can be blocked:
  
  • During subcritical physics testing.
  • M2 < P-6 and M3 during & prior to control bank withdrawal
  • M3 during and just prior to shutdown bank movement.

Question 24

Core Exit Thermocouples

• How many, number of junction boxes
• Range
• OTA-RK-56B: RCS < 50°F Subcool
• OTA-RK-56A: RCS Saturate

Answer 24

• 50, 2 junction boxes, reference junctions monitored by RTDs.
• 0°-700°F linear, can be used up to 2500°F for trending during accident.
• CETCs use in EOPs for SI Termination Criteria

Question 25

MIDS

• Uses of MIDS
• Fission Chambers
• How fission chambers positioned in core, including interlocks
• How data used (where does it go?)

Answer 25

• Uses:
  
  • Calculate Fuel Burnup Distribution
  • Detect/verify rods out of position
  • Calibrate NIs for ΔI (Axial Offset)
• Detector positioned by cable driven drive motor into thimbles located in seal table into 58 locations in core. Position selected via a 6-path transfer device which feeds detector to one of 4 15-path transfer devices. → withdrawal limit switch stops detector from being pulled into drive wheel.
• Data used in:
  
  • QPTR
  • Excore NI Calibration
  • Hot Channel Factor Measurements
  • PDMS (Beacon)

Question 26

Lower/Upper Head and Misc. Internal Components

• Upper head penetrations & purpose
• Lower head penetrations & purpose
• Upper sealing & leak detection
• Purpose of:
  
  • Lower Core Plate
  • Upper Core Plate
  • Former & Baffle Plates
  • Secondary Core Support Assembly

Answer 26

• Upper (59 Total):
  
  • 53 CRDM
  • 4 incore T/C assemblies
  • 1 Rx Vessel Head Vent (RVHVS)
  • 1 Rx Vessel level Indication System (RVLIS)
• Lower (58 Total):
  
  • Incore instrumentation thimbles.
    
    • Extend 12” into vessel
• Sealing:
  
  • _​_Sealed by two O-Rings attached to head.
  • Leak Detection provided by tell tale drain b/w inner and outer o-rings that drains to RCDT w/ temp alarm @ 160°F (BB-TI-401).
    
    • If leakage detected, OTs enter containment to valve in good seal, and operation can continue on one seal.
• Lower Core Plate:
  
  • _​_Supports fuel directly and distributes coolant via 4 holes under each assembly.
• Upper Support Plate:
  
  • _​_Aligns & supports fuel and rod guide tubes.
• Former and Baffles
  
  • _​_Outline periphery of core to make cylinder into square for fuel assemblies.
• Secondary Core Support Assembly:
  
  • _​_Designed to catch lower internals assembly and fuel following failure of core barrel flange.
  • Max displacement ~ 1.25”

Question 27

Subcooling Monitor

• Parameters used & number
• All instruments for each train of SCMM
• T/S LCO 3.3.3 PAMS requirements for CETC

Answer 27

• Parameters:
  
  • _​_2 WR T_H RTDs
  • 2 WR T_C RTDs
  • 1 RCS WR Pressure (PT-403, PT-405)
  • 25 CETC
  • 3 T/C Reference Junction RTDs
  • 2 NR P_PZR
• ​Calculated T_sat based on lowest pressure and compares to highest RTD & TC.
• T/S 3.3.3:
  
  • Requires 2 channels with 2 CETC each per quadrant of core.
  • 4 total per quadrant
  • Modes 1-3
  • Monthly OSP-SH-00001

Question 28

Rx Vessel Construction / Flowpaths

• Design limitations / parameters
• Nozzle sizing & features
• Explain the flowpaths thru the vessel & % + purpose

Answer 28

• 40 year lifetime, 2500 psia (2485 psig), 650°F, hydro pressure 3125 psia
• Inlet nozzles are 27.5” diameter & tapered to reduce velocity entering Rx Vessel.
• Outlet nozzles are 29” diameter and have bosses on inside surfaces that maet w/ outlet nozzles & lower internals to minimize bypass flows.
• Flow: 96% for heat removal, 4% bypass flows:
  
  • Nozzle Bypass (1%): Water that flow from inlet to outlet due to small clearance b/w core barrel & outlet nozzle bypass.
  • Control Rod & Instrument Thimble Bypass (2%): Water goes into CR guide thimbles and instrument thimble @ bottom of fuel elements and flows out w/o removing heat.
  • Baffle Wall Bypass Flow (0.5%): Water passing up between inner perimeter of baffle wall and fuel elements.
  • Head Cooling Bypass Flow (0.5%): T_C water passing up thru ports in the core barrel support and upper internals to cool head plenum.

Question 29

Pressurizer and Pressure Control (OTN-BB-00005)

• Aux spray and spray ΔT requirements
• Min Pressurizer Level
• RCS/PZR boron effects from heater operation
• RCS Degas (OTN-BB-00006)
  
  • [O₂] limits
  • VCT pressure limit w/ RCPs secured

Answer 29

• Aux spray actuation w/ ΔT > 320°F limited 10 cycles
• Aux spray line emeergency use only with ΔT > 300 °
• Spray ΔT shall not exceed 585°F
• L_PZR > 17%
• B/U Heaters in service w/ RCS C_B near peak value causes RCS boration/dilution different from predicted.
• [O₂] shall be < 3% when [H₂] > 4% to prevent explosion
• When RCPs are secured, VCT pressure < 5psig to minimzie gas buildup in head.

Question 30

RCS WR Pressure

• BB-PT-403 / 405 / 406 inputs & purpose

Answer 30

• BB-PT-405 (Red) & 403 (Yellow)
  
  • _​_Off Seal Table
  • Input to:
    
    • RVLIS
    • Subcooling Monitor
    • COMS
    • RHR Suction Interlock
      
      • BB-HV-8702 A/B: PT-403
      • EJ-HV-8701 A/B: PT-405
• BB-PT-406:
  
  • Indication Only

Question 31

OTΔT and OPΔT

• Inputs to each
• Penalties
• How runback works

Answer 31

• OTΔT - 122.6% Nominal
  
  • ​Inputs:
    
    • T_ave
    • P_PZR
    • ΔI
  • Lowers If:
    
    • T_ave > 585.3°F
    • T_ave Rising
    • P_PZR lowering < 2,235 psig
    • ΔI out of band
  • Rises If:
    
    • T_ave Lowers
    • P_PZR Rises > 2,235 psig
    • T_ave < 585.3°F
  • Runback: 133% for 2.3s, waits 27.7 seconds.
• OPΔT - 110.73% Nominal
  
  • ​Inputs:
    
    • T_ave
  • Lowers If:
    
    • T_ave > 585.3°F
    • T_ave rising

** OPΔT ONLY LOWERS!!

Question 32

NR Temps (T_C, T_H, T_AVE, ΔT)

• ​Each temp’s range
• Function of auctioneered high T_ave
• Function of auctioneered ΔT
• Annunciator:
  
  • 66C-69C: Loop 1-4 T_avg HI Dev
  • 66D-69D: Loop 1-4 T_avg LO Dev
  • 65C: Auct T_avg HI
  • 65D: T_ref/T_auct HI
  • 65E: T_ref/T_auct LO
  • 66A-69A: Loop 1-4 ΔT HI Deviation
• Annunciator 66B-69B: Loop 1-4 ΔT LO Deviation

Answer 32

• T_H: 530° - 650°F; T_C: 510° - 630°F; T_avg: 530° - 630°F
• Auct High T_ave: Rod Control, Steam Dump Control, Pressurizer Level Controller
• Auct High ΔT​: Rod Insertion Limit
• Annunciators:
  
  • T_avg HI Dev: T_avg > 3° above Auct HI T_avg, WHEN defeated
  • T_avg LO Dev: T_avg > 3.5° below Auct HI T_avg for remaining loops.
    
    • If T_avg fails high, other 3 loops alarm will alarm until defeated.
  • Auct T_avg HI: Auct T_avg > 588.3°F
  • T_ref/T_auct HI: T_ref - T_auct > 3°F
  • T_ref/T_auct LO: T_ref - T_auct < -3°F
  • ΔT HI Dev: ΔT > 7.41% higher than Auct. HI ΔT for remaining loops WHEN defeated.
  • ΔT LO Dev: ΔT > 7.41% lower than Auct. HI ΔT fro the remaining loops.
    
    • If ΔT fails high, other 3 loops alarm until defeated.

Question 33

PZR Master Pressure Controller

• How the Pressure Channel SS works (BB-PS-455F)
• Potentiometer operation & PZR Range of Controller
• Operation of Master Pressure Controller

Answer 33

• Upper Selected → Master Controller (BB PK-455A)
• Lower Selected → Alarms
• 10 Turn Potentiometer, 1700 - 2500 psig range → 80 psig/turn
• In Auto → normally 50% → Variable Heaters energized @ low power
  
  • As P↑, output ↓
• In Manual → move controller the direction you want it to go.
  
  • For Boron equalization, turn on B/U Heaters and manually set controller to 40%

Question 34

PZR Level Controller

• Which LT can be selected on BB LS-459D? (Lvl Control Selector)
• Upper Selected Controls
• Lower Selected Controls

Answer 34

• LT-459 & 461 can be upper, 460 & 461 can be lower
• Upper:
  
  • Control → BG-LCV_124(121) charging controller
  • ± 5% Deviation alarms
  • 17% Letdown isolation (BG-LCV-459 only)
• Lower:
  
  • Hi Alarm (70%)
  • 17% Letdown isolation (BG-LCV-460 only)

Question 35

Rod Movement (1 Step) Sequence of Events

• Withdrawal
• Insert

Answer 35

• Withdraw:
  
  • _​_SGC starts ON @ 4.4A
  • SGC current ↑ to 8A, MGC Turns ON
  • SGC turns OFF
  • Lift Coil Turns ON (Lifts Rod)
  • SGC Turns ON
  • LC & MGC OFF
  • SGC ↓ current to 4.4A
• Insert:
  
  • _​_SGC starts ON @ 4.4A
  • SGC current ↑ to 8A, LC turns ON
  • MGC turns ON
  • SGC turns OFF
  • LC turns OFF (Drops Rods 1 Step)
  • SGC turns on @ 8A
  • MGC turns OFF, SGC ↓ 4.4A

Question 36

DRPI

• How many steps per LED
• How many LEDS for SD? For Control?
• Accuracy of DRPI: Normally, Loss of Data A, Data B, & T/S 3.1.7
• Rod Position Urgent Failure Indications/Causes
• Rod Position Non-Urgent Failure Indications/Causes
• Rod Position Deviation Causes

Answer 36

• 6 steps per LED
• Shutdown Bank:
  
  • Bottom, next 3 are 6 steps each, next (middle) on from 24 to 210 steps, last 4 are final 6 step increments (210, 216, 222, 228), and GW - 10 total
• Control Bank
  
  • Bottom, 38 in 6 step increments from 0 to 228, GW - 40 Total
• ±4 steps, +10/-4, -10/+4, ±12 from step counter
• Flashing GW LED, Rod bottom LED; error in data, >6 steps Δ in data, sum of data > 228 steps.
• Error in A or B LEDs, Flashign GW LED; Purity/Data Errors, Accuracy Mode switch not in A & B, Rod Dev Cards disagree or cards removed.
• Any SD rod < 210 steps; Control Bank Rod > 12 steps Δ from any rod in that bank; RPI Urgent Alarm.

Question 37

RCP Operation (OTN-BB-00003)

• Seal Leakoff operation < 100 psig RCS Pressure/Seal Injection to secured RCPs
• Cooling RCP radial bearing and RCS temperature requirement
• Precautions of seal injection not provided by NCP or if CCP is inoperable
• RCP starting limitations following RCS Cooldown or heatup
• Seal Injection throttle valve D/P limitations
• RCP motor start/stop cycling limitations

Answer 37

• Seal leakoff vavles should be closed w/ P_RCS < 100 # and Seal injection maintained to prevent crud migration.
• CCW established to Thermal Barrier H/X or Seal Injection established > 160°F to cool bearing.
• If T> 220°F & CCP inoperable, seal injection should be from NCP. If NCP doesn’t provide seal injection, both CCW trains should be operating w/ service loop from train w/ non-operating CCP.
• Starting Limits:
  
  • If starting RCP after cooldown by RHR > 20°F w/ no RCP running - draw bubble first
  • If RCPs stopped > 5 mins during H/U & T_RCS > T_{seal injection} - draw bubble first.
  • If T_RCS < 275°F, T_SG shall be < 50°F above T_C prior to starting RCP.
• Max D/P of 1700 psid (erosion) across seal injection throttle valves.
• Stop/Starts:
  
  • If motor did not acheive full speed → no restart for 30 mins
  • 2 starts allowed if RCP comes to stop between
  • 3 starts allowed if RCP has run 20 mins or been idel for 45 mins
  • If 3 starts/attempts in 2 hour period, 4th may be made after 1 hr idle.

Question 38

RCS Fill and Vent (OTN-BB-00001)

• Definitions Of:
  
  • Limited Inventory
  • Lowered Inventory
  • Reduced Inventory
• Max RHR Flow during vacuum fill
• RCS P/T limits on venting

Answer 38

• Limited: RCS Level < 110” but > 64” w/ fuel in RV
• Lowered: RCS Level at or below flange w/ fuel in RV
• Reduced: RCS Level < 64” (<3’ below flange) w/ fuel in RV
• 2000 gpm max during vacuum fill to prevent vortexing RHR.
• T < 175°F or Press < 100 psig

Question 39

Manual RCP Trip Criteria (OTO-BB-00002)

Answer 39

• Frame vibs > 5 mils (If 3-5 mils & > 1 mil/hr = Trip)
• Shaft vibs > 20 mis (If 15-20 mils & 2 mil/hr = Trip)
• Seal Leakoff < 0.8 gpm or > 6 gpm
• # 1 Seal & Bearing inlet temp > 230°F
• Motor bearing temps > 195°F
• Motor stator temps > 311°F
• CCW lost to RCP motors > 10 minutes
• Seal injection and CCW to Thermal Barrier H/X > 6 minutes