Exam 2 Flashcards

Question

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

Answer 1

* _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)

Answer 2

* _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"

Answer 3

* _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

Answer 4

* 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.

Answer 5

* 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.

Answer 6

* _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

Answer 7

* **_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!!

Answer 8

* _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.

Answer 9

* 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%

Answer 10

* 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)

Answer 11

* _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

Answer 12

* 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.

Answer 13

* 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.

Answer 14

* 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

Answer 15

* 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