- Containment sump vlvs OPEN - SI mini-flows CLOSE - LPSI STOPS

Safety Injection Flashcards by William Shockley

What is the purpose of the SI system

Inject borated water into the core for cooling during
emergencies
Recirc and cool RCS while S/D
CS provides press/temp protection to containment

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What is the purpose of SDC system

reduce RCS from 350F to 125F
Cool the plant to cold S/D following LOCA or SLR
Supplement SFP cooling
xfer water between RFP and RWT

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What is the purpose of CS system

Reduce CNTMT temp/press
Limit leakage of airborne activity from CNTMT
Remove iodine from CNTMT atmosphere
Remove heat from CNTMT in recirc mode

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What is the ECCS design criteria

Peak cladding temp <2200*F
Max cladding oxidation <17% of original thickness
Max H2 produced <1% if all cladding reacted
Maintain coolable geometry
Capable of long term cooling and decay heat removal

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What is the ECCS design criteria

Peak cladding temp <2200*F
Max cladding oxidation <17% of original thickness
Max H2 produced <1% if all cladding reacted
Maintain coolable geometry
Capable of long term cooling and decay heat removal

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To be able to meet its mission SI is designed and built to be

Seismically qualified
Meet single failure and separation criteria
Independent
Redundant
Meet environmental qualifications

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What is the functional design requirements for RWT volume

20 minutes full SI flow, all pumps, plus 10%

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What is the design basis of the SDC system

Cool RCS to 135*F in 27.5 hours
Maintain 75*F/hr cooldown rate
Capable of long term cooling
1 train can maintain RCS <200*F in <36 hours

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What is CNTMT design temperature and pressure

300*F

60 psig

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What is the design basis for CS CNTMT pressure control

Reduce pressure from peak to 1/2 peak value in less than 24 hours

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When can CS be aligned to SDC

<200*F

<250 psia

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What is the difference between the HPSI injection path and the LPSI injection path

HPSI injects to all for cold legs, LPSI only injects to 2

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What manual action must be taken following a RAS

Manually close RWT outlet vlvs 530/531

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What causes a RAS

RWT level 9.4%

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What occurs on a RAS

Containment sump vlvs OPEN
SI mini-flows CLOSE
LPSI STOPS

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What action should be taken as early as possible if a RAS is expected and why

Refill RWT with borated water: HUT, batching, SFP

- Alleviates concerns with RAS sump blockage

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When and why do we shift to Hot leg injection (long term cooling) with SI system

2-3 hours after injection begins

- Minimize/prevent boron precipitation

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What is the purpose of the SITs

Ensure sufficient volume of borated water in injected into the for for initial heat removal after a LOCA

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Where is the LTOP located in the SDC system

Between the CNTMT isolation vlvs for SDC

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How is the SDC cooldown rate controlled

Throttling the SDC HX bypass MOV

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How is the SDCHX warmed up

SI-690/691 system warmup bypass vlvs

- balance flow to maintain 19*F/MINUTE H/U rate

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What is the concern with SI-690/691 warmup bypass vlvs

The vlvs are down stream of the SDC flow indicator.
If they are open indicated flow does not match flow
through core
Could result in insufficient core cooling

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How is flow to SDC purification controlled

CVCS back pressure control vlvs

- Throttling LPSI injections vlvs

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How is flow controlled during full flow recirc of the RWT

Study These Flashcards

Throttling the SDHX outlet vlv

What control/safety system starts the SI pumps during SIAS, CSAS, RAS

- PPS-ESFAS sends a signal to BOP-EASFAS | - BOP-ESFAS DIRECTLY starts SI pumps

What is the setpoint for the LTOP

467 psia

What flow limits are there for LPSI pump

- 1 Hour mini flow - 100 gpm - Unlimited mini flow - 2400 gpm - Rumble region - 2500-3500 gpm

What flow limits are there for CS pump

- 1 Hour mini flow - 150 gpm - Unlimited mini flow - 2100 gpm - Rumble region - 1800-2800 gpm

What flow limits are there for HPSI pump

- 1 Hour mini flow - 85 gpm - Unlimited mini flow - 225 gpm - Shut off head - 1880 psia

What is the capacity and pressure of a SIT

- 14,000 gallons | - ≈600 psig of N2

What auto actions are there for the SIT outlet vlvs

- Auto OPEN - SIAS - Auto OPEN - >410 psia - CLOSE permissive - <405 psia

What unique feature is there for SDHX outlet isolation vlv

- Valve seats were removed | - Concerns about vlv sticking with high D/P

What is the preset value for Hot leg injection flow

600 gpm

What must be in service prior to operating SIC-653 and SID-654

Their respective batteries must be in service to help power their inverters

What interlock is there for SDC isolation valves

- Cannot be opened unless <385 psia to protect SDC lines

What concern is there for SI pump operation when a CSAS w/out a SIAS occurs

- No override capability - Stopping the pump will Anti-pump - Control power must be cycled or signal cleared - If a SIAS occurs, pump can be overridden

What limitation is there for ALL foxboro flow indicators

- Go off scale around 10% ie HPSI flow first indicates at 75 gpm - Limited by square root extractors

What indications can be used to detect RCS Check valve leakage

- Hot leg injection chk vlv leakage press | - SIT line Pressures

What automatic actions occur in SI on receipt of a SIAS

- All SI pumps START - Cold leg injection vlvs OPEN - SIT outlet vlvs OPEN (signal) - Misc. drn hdr to RWT CLOSE - SI to RC loop drains CLOSE - Hot leg chck vlv leakage drain CLOSE

What automatic actions occur in SI on receipt of a CSAS

- All SI pumps START | - CS Spray isolations OPEN

What automatic actions occur in SI on receipt of a RAS

- LPSI pumps STOP - SI pump mini-flow CLOSE - Combined mini-flow CLOSE - Containment Sump isolations OPEN

What automatic actions occur in SI on receipt of a LOP/ LS

- All SI pumps STOP

What causes a SIAS

- 1837 psia in RCS | - 3 psig in CNTMT

What Causes a CSAS

- 8.5 psig in CNTMT

What is the purpose of the Tri-Sodium Phosphate baskets in CNTMT

- Raises pH of water during LOCA - Maintains iodine in solution - Minimizes stress corrosion cracking - Reduce Hydrogen from corrosion

What is the concern with the alarm: SDC TRAIN A/B FLOW LO

- Inputs for running pumps are from the breaker - BRKR trip removes input and wont alarm - SESS alarm will already be locked in - Only indication is silent SESS alarm

What is the concern with the alarm: SI CHK VLV LEAK PRESS HI

- Indicates HI HPSI line press - May indicate RCS chk vlv leakage - If press > 1525 psig LPSI INOP

What causes a Blue SEAS alarm for INST AIR ISOL VLV UV-2

'A' CSAS with the vlv not fully closed

What is required for LTOPS to be OPERABLE

Mode 4 when Tc < 21*F Mode 5 Mode 6 with Head on 2 SDC suction line reliefs aligned OR ≥16 in2 vent

What is required for SITs to be OPERABLE in higher modes

Mode 1, 2 Mode 3, 4 with press ≥1837 psia 4 SITs shall be operable 2 or more SIT inop: 1 HOUR Restore to at least 3 SITs

What is required for SITs to be OPERABLE in lower modes

Mode 3,4 with press < 1837 psia 4 SITs shall be operable w/ 40-82% level OR 3 SITs shall be operable w/ 61-82% level 2 or more SIT inop: IMMEDIATELY Enter LCO 3.0.3

What is required for ECCS to be OPERABLE while shutdown

Mode 3 with RCS <1837 psia and < 485*F Mode 4 1 HPSI train shall be OPERABLE Req'd HPSI inop: 1 HOUR Restore to operable

What is required for the RWT to be OPERABLE

Mode 1-4 RWT shall be OPERABLE: ≥60*F and ≤120*F above min volume Boron ≥4000 ≤4400 ppm RWT level req't not met: 1 HOUR Restore level

What is required to make Tri-Sodium Phosphate baskets OPERABLE

Mode 1-3 Baskets shall have ≥524 ft3 of active TSP

What is required for RCS loops to be OPERABLE in mode 4

Mode 4 2 loops of RCS or SDC shall be operable and 1 loop or train shall be in service No more than 2 RCP's ≤200*F No more than 3 RCP's ≤500*F 1 loop and 2 trains inop: IMMEDIATELY begin actions to restore second loop or train no RCS loops or SDC operable: IMMEDIATELY - Suspend actions that reduce Boron - start actions to restore

What is required for SDC to be OPERABLE in mode 5 with loops filled

Mode 5 with loops filled - 1 SDC train shall be operable and in operation - & an additional SDC train shall be operable OR SG levels ≥25% Conditions not met: IMMEDIATELY restore, no dilutions

What is required for CS to be OPERABLE

Mode 1-3 Mode 4 RCS ≥385 psia 2 trains operable Minimum header level 113' 2 Trains inop: IMMEDIATELY Enter LCO 3.0.3

What is required for SDC to be OPERABLE with high RFP water level (137'4")

Mode 6 with RFP ≥23' above flange level 1 SDC loop shall be operable and in operation requirements not met: IMMEDIATELY - Stop dilutions - Stop fuel moves - Begin actions to restore SDC

What is required for SDC to be OPERABLE with low RFP water level (<137'4")

Mode 6 with RFP <23' above flange level 2 SDC trains operable with 1 in service 1 SDC loop inop: IMMEDIATELY -Begin to restore SDC loop OR - Raise RFP level >23' above flange

Safety Injection Flashcards

(59 cards)