Zach Stubby's Heavy Hitters - Secondary Systems Part 1 Flashcards

Question

What control signals (%, mA) open Steam Dump Banks 1/2/3/4?

Answer 1

I/P Supplies: →4 - 8ma or 0 - 25% signal to open Bank 1 0 - 100% →8 - 12ma or 25 - 50% signal to open Bank 2 0-100% →12 - 16ma or 50 - 75% signal to open Bank 3 0 - 100% →16 - 20ma or 75 - 100% signal to open Bank 4 0-100%

Answer 2

→loss of uPC1 - no arming signal for C-7; still available in Steam Pressure Mode →loss of uPC2 - no C-9, so no Steam Dumps

Answer 3

→trip open and arming circuits powered by uD2-3, not train related →if we lose uD2-3, we have no Steam Dumps

Answer 4

Load Reject Controller: →5°F deadband →Hi-1 10.6°F - all 6 Group 1 valves trip open (banks 1&2) →Hi-2 16.2°F - all 6 Group 2 valves trip open (banks 3&4) Plant Trip Controller: →no deadband →Hi-1 20°F - all 6 Group 1 valves trip open (banks 1&2) →Hi-2 40°F - all 6 Group 2 valves trip open (banks 3&4) There is no trip open circuitry for Steam Pressure Mode, only goes through I/P converter.

Answer 5

Steam Dumps are armed by meeting C-9 (condenser available) AND one of the following: →P-4, Train A only →C-7, load reject of 10% in 120 sec (PT-506 from uPC1) →Selector Switch in Steam Pressure Mode (ref pressure from PT-507, 200-1500 psig on PK-507 controller) Note: C-7 is reset by taking the Steam Dump Mode Selector Switch to "Reset"

Answer 6

→LOOP (no CWPs, so no C-9) →Main Steam Isolation (no steam moving through lines to Steam Dumps/Condenser) →ARVs would control RCS temp down to 561°F

Answer 7

→trip open in 3 sec →modulate open in 20 sec →close in 5 sec

Answer 8

→pot setting = (pressure - 200 psig)/130 →setpoint ↑, pressure ↑ (less steam flow), temp ↑, demand likely ↓ →higher temp results in negative ρ at EOL conditions but positive ρ at BOL when MTC is still +

Answer 9

→OFF RESET sends signal to protection solenoids to close venting air, which closes steam dumps →BYP INTLK removes Lo-Lo T-ave 553°F trip block to allow cooldown with Bank #1 valves ONLY

Answer 10

They will not open in any Mode.

Answer 11

→T-ave Mode will remain in Load Reject Controller and not swap over →RCS temp stabilizes at 562°F (5°F above 557°F)

Answer 12

→normal is SSW if CST Level <6%, unit is in ERGs, and with Shift Man approval →if SSW is unavailable, then provisions provided to fill CST with Fire Protection water

Answer 13

→FSBV closes on AFW Pump Start →U2 AFW connects to MFW before CTMT penetration, same line used by FSBV and AFW to feed SG

Answer 14

→designed to cool down RCS from 557°F to 350°F for RHR use →can provide normal cooling load up to 7% RTP

Answer 15

570 gpm at a maximum developed head of 1370 psig

Answer 16

→minimum flow recirc line with orifice 200gpm →close on >200gpm →open <227gpm →fail open on loss of air or power →normally maintained open in standby →common line back to CST →valves have an accumulator to allow 2 strokes for 30 mins (from same air accumulator as MDAFW Pump flow control valves)

Answer 17

Each associated flow control valve provided with a safety class air accumulator sized for five full cycles, plus leakage and steady state consumption for 30 minutes (same accumulator as recirc valves).

Answer 18

→normally open AOVs →fail open on loss of air or power →PV‐2453A & 2453B for train A to SGs 1 & 2 →PV‐2454A & 2454B for train B to SGs 3 & 4 →air accumulators for 5 full cycles for 30 minutes (shared accumulator with pump min flow valve) →on start of MDAFW Pumps, M/A stations trip to auto and go 100% open →after 10 sec time delay, manual operation can be selected →each feed line has an orifice to limit flow to 700 gpm

Answer 19

→1145 gpm at 4075 rpm and a maximum developed head of 3236 ft (1433 psig) →overspeed occurs at 4750 ± 50 rpm (116% rated speed) →overspeed mechanism will reset itself at 3000 rpm →Trip & Throttle Valve will need to be locally reset →on loss of air or electrical power, turbine speed governor will fail to max speed

Answer 20

→powered from 125VDC uED1‐1 →local panel shows valve position T&TV and turbine speed →SI on Train A removes control power to local panel →prevents the following remote indication and control (on MCB): →indication of turbine speed →turbine overspeed light indication →no annunciator for turbine overspeed →T&TV position indication →cannot trip the turbine from the control room →turbine will still start and come up to speed, just without indication →can locally trip pump OR close steam supply valves from MCB to stop the turbine →power to local control panel can be restored after SI on Train A is reset by depressing OPEN push button 2452H on CB‐09 →this restores full functionality of the turbine

Answer 21

Each associated flow control valve provided with a safety class air accumulator sized for five full cycles, plus leakage and steady state consumption for 30 minutes

Answer 22

→each SG has ONE handswitch that controls BOTH the MDAFW & TDAFW MOV isolation valves →MOVs powered from opposite train from FCVs →opposite train power supplies ensure that we can still isolate flow to an SG on loss of one train

Answer 23

→500,000 gal tank →53% (244,000 or 249,100 gals, depending on reference given) reserved for AFW per revised TS 6-30-2011 →10-inch line to suction of both MDAFW pumps →a second 10-inch line to suction of TDAFW pump →CST minimum volume (53%) ensures that water is available to maintain the RCS in Hot Standby for 4 hours followed by a cooldown to 350°F at a rate of 50°F/hr for 5 hours

Answer 24

BLA →B - Blackout-OL opens MS supply valves #1, B Train; #4, A Train →L - Lo-Lo Level 38% U1, 35.4% U2 in 2 SGs (2/4 Level Transmitters) →A - AMSAC "There's no T in turbine."

Answer 25

BLAST →B - Blackout (Train related) →L - Lo-Lo Level 38% U1, 35.4% U2 in 1 SG (2/4 Level Transmitters) →A - AMSAC →S - SI in conjunction w/ SI Sequencer →T - Trip of both Main Feed Pumps

Answer 26

→SG Blowdown isolates →SG Sampling isolates →CST discharge valves HV-2484/2485 (Makeup/Reject Valves) close →Split Flow Bypass Valves (U2 only) close →Motor Driven AFW flow control valve trip to Auto 100% open

Answer 27

1) Manually reset the overspeed trip linkage by physically repositioning the trip linkage. The overspeed device plunger mounted on top of the turbine bearing casing should drop back into the plunger housing. 2) Depress clutch lever to engage handwheel. Clutch must remain depressed through steps 3 and 4 below. 3) Turn handwheel CW until the latch mechanism is fully engaged. 4) After latch mechanism is fully engaged, turn handwheel CCW until actuator is fully up. 5) Release the clutch lever. Note: the turbine on the TDAFW pump must be at rest for 15 seconds before resetting governor speed setting

Answer 28

→130 gpm on mini flow line →limited to 20 min to prevent pump damage

Answer 29

→supplied by Main Steam lines #1 & #4 before MSIVs →normally closed AOVs with accumulators to allow isolation on loss of air →accumulators allow isolation within 30 mins + 7 more hrs to keep valves closed →valves fail open to ensure turbine acceleration to rated speed in 85 sec

Answer 30

Do not exceed 800 gpm flow on any MDAFW Pump.

Answer 31

Three AFW trains shall be operable in Modes 1-3. If three AFW trains are inoperable: →initiate action to restore one AFW train to operability immediately. →LCO 3.0.3 and all other LCO Required Actions requiring Mode changes are suspended until one AFW train is restored to operable status (LCO 3.0.4b is NOT applicable) Note: SR 3.7.5.2 verifies developed head of each AFW pump. For TDAFW Pump, it is NOT required to be performed until 24 hours after ≥ 532 psig in the steam generator.

Answer 32

During power operation morpholine is used for pH control.

Answer 33

Shrink: →caused by events that suddenly decrease steam flow (rapid load decrease, RCP trip, control valve closure) →feedwater flow > steam flow →SG riser level decreases due to decreasing void fraction →downcomer flow temporarily decreases to equalize downcomer/riser pressures →less moisture is being returned to downcomer due to reduced steam flow →SG level goes down →will continue until conditions stabilize and steam/feed flow are balanced

Answer 34

Swell: →caused by events that suddenly increase steam flow (steam break, rapid load increase) →steam flow > feedwater flow →SG riser level increases due to increased void fraction →more moisture is entrained in the steam exiting the tube bundle →downcomer flow temporarily decreases to equalize downcomer/riser pressures →more moisture is returned to the downcomer due to increased moisture entrainment →SG level goes up →will continue until conditions stabilize and steam/feed flow are balanced

Answer 35

→Primary: 2485 psig and 650°F in RCS →Secondary: 1285 psig and 600°F

Answer 36

→7 Venturi nozzles at SG outlet →little flow restriction during normal operation (low ΔP, 2-3 psid) →flow measurement for SGWLC →limits steam flow in the event of a steam break; limits size of break to 1.388 sq ft →protects against DNB/fuel integrity from cooldown rate/positive reactivity addition →protects containment integrity by limiting rise of containment pressure and temperature for IRC steam break →reduces thrust forces on main steam line →limits stresses on SG internal components like tubesheet (RCS boundary)

Answer 37

→tap off main steam lines 1 & 4 before MSIVs →Fail open AOV's →upstream check valve prevents backflow from feeding steamline break →u-HV-2452-1 Train A from SG 4 (uED1-1) →u-HV-2452-2 Train B from SG 1 (uED2-1) →valves have accumulators that allow for maintaining valve closed for 7 hrs, plus 30 mins to allow for closing manual isolation Open on 'BLA': →Blackout (OL) →Lo-Lo SG Level on 2/4 SGs (2/4 detectors per SG) →AMSAC

Answer 38

MSIV's Auto Close on: →CNTMT Hi-2 (2/3) at 6.2 psig →Lo Main Steam Line Pressure of 605 psig (rate compensated, blockable when < P-11) →Main Steam Line Negative Rate - 100 psig per sec with 50 sec Time Constant (enabled when Lo MSL Pressure blocked) →Manual 1/2 handswitches →Control transfer of MSIV from MCB to RSP Note: MSL Isolation also closes the before MSIV drip pot isolation AOVs, and a manual closure of an MSIV will close its associated upstream drip pot valve

Answer 39

→provide minimum capacity to modulate an ARV 15 times over 4 hours →1 full stroke and 14 modulations each equal to 10% of the valve full open capacity

Answer 40

→not credited for overpressure protection; used for cooldown purposes (during SGTR) →prevent safeties from lifting →valve normally set to open @ 1125 psig but may be varied depending upon plant conditions (sat pressure/130 = pot setting) →takes about 15%-20% output on controller to open valve initially due to pilot plug, but once open can be throttled below this point →two required for adequate cooling capacity for U1; one required for U2 →considered operable if they can be manually cycled from the CR

Answer 41

→can be operated from MCB or RSP →control must be transferred to RSP via junction boxes and Amphenol connectors; junction boxes located in ARV Accumulator room

Answer 42

→U1 ARVs provided with OPEN/OFF keyed switch, used to fully open ARV using separate solenoid powered from opposite train →switches required per analysis for D-76 generators to prevent overfill of generator during a tube rupture in conjunction with a loss of a single train of power →analysis requires 2 SGs for max cooldown. (U1 D-76 SGs have smaller steam space volume therefore would fill up faster during the tube rupture) →U2 ARV only has single solenoid supplied from 1 train

Answer 43

Geiger-Mueller Tube: →outside of pipe, upstream of safeties →can detect 2.5 gpm primary to secondary tube leak →leak detection based upon 1% fuel failure →also labeled as "Main Steam Line Monitors" (u-RE-2325 thru 2328) N-16 Scintillation Detector: →just upstream of MSIVs (downstream of safeties) →can 1.0 gpd with a range of 1.0 to 150 gpd →Red Alarm at 15 gpd →N-16s aren't accurate below ≈40% power →also labeled as "Steam Generator Leak Rate Monitors" (u-RE-2325A thru 2328A)

Answer 44

Setpoints: →1185 psig →1195 psig →1205 psig →1215 psig →1235 psig Other Info: →ASME code overpressure protection for SGs →for any one safety valve, the relieving capacity may not exceed a maximum design flow rate of 970,000 lbm/hr (≈25% SG rated steam flow) →prevent steam line pressure from exceeding 110% of its design pressure of 1185

Answer 45

minimum N2 pressure ≈ 1839 psig

Answer 46

Mode 1: →all 4 bypasses locked closed Modes 2, 3, or 4: →only 1 MSIV bypass valve can be opened at a time to satisfy CNTMT Isolation requirements →other three bypass valves locked closed and associated MSIVs are closed →bypass valve is opened 1/4 turn at a time →once DP is ≤15 psid, MSIV can be opened

Answer 47

→air driven hydraulic pump to open →N2 to close →designed to stop flow within 5 sec →on trip signal, hydraulic solenoids **energized to open** and dump fluid, and N2 closes valve →loss of power to air solenoid for hydraulic pump fails open, causing the MSIV to open if hydraulic bleed solenoid valves have failed closed →ensuring uD2 is aligned to battery charger prevents MSIVs from opening (operators are dispatched on an SI to align BCuD24 so that air solenoid remains closed) Note: MSIVs designed to close w/in 5 sec to... →prevent uncontrolled blowdown of more than one SG →minimize RCS cooldown →maintain CNTMT temp and pressure w/in limits following an MSL break inside CNTMT

Answer 48

→fail closed AOVs →close when MSIV given closed signal →can be manually opened

Answer 49

→main turbine operation time without MSRs in service should be minimized - limited to 300 hrs/yr →without MSRs, increased erosion of the LP turbine blades will occur →if MSRs to be shut down, BOTH right and left MSRs should be shut down simultaneously to maintain a balanced steam flow →MSRs may be taken out of service if steam flow is adjusted so that the max generator output is 1130 MWE (97%) →single MSR operation NOT allowed

Answer 50

→steam flows from HP turbine exhaust to moisture separator chevron section →shell drain collects removed moisture and drains to shell drain tank →shell drain tank drains to Heater Drain Tank via level control system →3 MSR safeties - lift at 181 psig, 184 psig, and 187 psig →main turbine HP stop valves should not be opened during MSR pre-warming to prevent cross connecting main steam and aux steam Note: when pre-warming the MSRs, ΔT between tubesheets of left and right MSRs shall not >25°F

Answer 51

→pressure ≥80 psig →if not met, ARV is inoperable →immediate entry into TS 3.7.4

Answer 52

→62,150 lbm/hr →allows plant to maintain hot standby for 4 hrs, then cool plant from no load T-ave (557°F) to 350°F (RHR cut-in) in 5 hrs at 50°F/hr before exhausting CST inventory

Answer 53

saturation pressure/130 = number of turns

Answer 54

→Unit 1: 67% →Unit 2: 64% →controlled by SGWLC →Level Dominant System, but steam flow/feed flow mismatch will overcome level dominance

Answer 55

→Unit 1: 38% →Unit 2: 35.4% →causes Rx Trip →causes AFW Auto Start (1/4 SGs for MDAFWPs, 2/4 SGs for TDAFWP)

Answer 56

→Unit 1: 84% →Unit 2: 81.5% →P-14: →MFPs trip →turbine trips →Feedwater Isolation signal →2/3 detectors on any 1 SG (ch 1 not used SGs 1&4; ch 2 not used SGs 2&3)

Answer 57

**→Manual** **→SI** from either train (also trips Main Turbine and causes FWI) **→Low Turbine Bearing Oil Pressure** - U1 ≤5.5 psig, U2 ≤4 psig; (2/3) 2 sec TDPU **→Low Pump Bearing Oil Pressure** - U1 ≤10psig, U2 ≤7 psig; (2/3) 2 sec TDPU **→Low Vacuum Aux Condensers** (2/3) ≤17.5" Hg on 2 detectors OR <21" Hg on one detector and 17.5" Hg on another detector; 2 sec TDPU **→Low MFP Suction Pressure ≤190 psig** (2/3); 30 sec TD MFP A, 45 sec TD MFP B; staggered trip **→Low MFP Suction Pressure ≤170 psig** (2/3); 4 sec TD (trips both simultaneously) **→Thrust Bearing Wear** ≥32 mils (2/3) **→Electrical Overspeed** ≥5600 rpm (2/3) **→Mechanical Overspeed** ≈5720 rpm (5663-5773 rpm, 5720 ± 57 rpm or ±1% tolerance) **→P-14 SG Hi-Hi Level** (2/3 on any one SG); also trips Main Turbine and causes FWI

Answer 58

Loss of uD2 will prevent an electrical trip of the MFPs due to loss of the control system. Quickly shut down the MFPs if: →radial bearing metal temp >225°F →any other bearing metal temp >215°F →any oil temp >215°F →radial bearing vibration >5 mils

Answer 59

→Hi-Hi S/G Water Level (P-14), resettable

Answer 60

Feedwater Isolation Signal (FWI) closes the following valves: →u-FCV-510 through 540 Flow Control Valves →u-LV-2162 through 2165 Flow Control Bypass Valves →u-HV-2134 through 2137 Feedwater Isolation Valves →u-HV-2185 through 2188 Feedwater Isolation Bypass Valves →2-FV-2193 through 2196 Feedwater Pre-Heater Bypass Valves (U2 only) →2-FV-2181 through 2184 Feedwater Split Flow Bypass Valves (U2 only) Valves Close in Order To: →prevent excessive RCS cooldown →prevent uncontrolled SG filling →limit mass addition to CNTMT in event of DBA

Answer 61

→reduce power to <98.6% if lost →LEFM is a high accuracy flow measuring device which uses acoustic energy pulses to determine the final feedwater mass flow, and is used in calorimetric

Answer 62

Feed Water Isolation Valves (u-HV-2134/2135/2136/2137) →hydraulically opened, nitrogen to close, 2040 psig minimum pressure to be operable →pressure less than 2040 may result in exceeding surveillance stroke time →provided with train related solenoids to dump hydraulic pressure and close valves within 5 secs →hydraulic pumps powered from: uEB1-3 for SGs 1 and 3, uEB2-3 for SGs 2 and 4 → **maintain ≥90°F at all times per IPO-002, based on fracture toughness (TR 13.7.38)**

Answer 63

→in Auto, valves throttle to maintain 5,000 gpm suction flow (MFP trip reset will open if in Auto) →driver card failure enables a separate solenoid which causes the valve to open at 4,275 gpm and close at 6,625 gpm →at normal power this would keep it closed →fails open on loss of air →fails closed on loss of signal →fails closed on MFP trip if both HP and LP steam supplies are shut

Answer 64

Feed Pump Discharge Valves HV-2109/2110 Interlocked with MFP status →auto opens on feed pump turbine start signals →auto close on a trip of the feed pump turbine OR closure of both HP and LP steam valves →trip signal overrides start signal →can auto open after trip signal reset

Answer 65

Water Hammer Interlocks are satisfied when: →no Feedwater Isolation signals present →FWIBV full open for 50 minutes →IRC feedwater temp >250°F for 10 minutes AND feedwater ΔT across cntmt penetration <10°F →total feedwater flow is >500,000 lbm/hr per SG →admin limits: SG pressure >605 psig and NR level >5%

Answer 66

Water Hammer Interlocks met causes the following: →allows opening FIV (will auto open if in Auto after Open) →once FIV open, FIBV/FPBV auto close and FSBV auto opens

Answer 67

Water Hammer Interlocks are removed by any of the following: →Feedwater Isolation Signal is received →both FWIV and FWIBV go full closed →FSBV doesn't have open signal and total FW flow to SG is <475,000 lbm/hr →total FW flow to SG decreasing to <475,000 lbm/hr in conjunction with either IRC feedwater temp decreasing to <250°F OR ΔT across cntmt penetration increasing to >10°F

Answer 68

→any MDAFWP auto start signal →Feedwater Isolation →Water Hammer Interlocks not met Note: during normal, 100% power, split flow bypass is approx. 15% of total flow.

Answer 69

To open FWP flush bypass valves (HV-2122 & 2124): →both FWPs tripped (both HP and LP steam valves closed) →both FWP suction valves (HV-2321 & 2323) closed.

Answer 70

→2 AC oil pumps and 1 DC oil pump →1 AC pump normally in service →AC pumps are dual stage - 1st stage supplies 55 psig header; 2nd stage supplies 200 psig header

Answer 71

→standby AC pump starts at 175 psig header pressure on the 200 psig header →DC pump auto starts at 25 psig bearing header pressure →only supplies 55 psig bearing header; bypasses lube oil coolers and filter

Zach Stubby's Heavy Hitters - Secondary Systems Part 1 Flashcards

(95 cards)