RCS Purpose / Design basis: RCS transfers thermal energy to the...? Design Pressure is...? MWth Rated Thermal Power (RTP) is...?

RCS Purpose / Design basis: Transfer thermal energy to the SGs. Second fission product barrier. Core cooling. _Design pressure (2500 psia)_ _3990 MWth (Rated Thermal Power – RTP)_

Primary Safety Valves: Lift at psia? ?... Acoustic VPI powered from ?...

Primary Safety Valves: Lift at _2475 psia_ Rapidly open to 70% [huddle chamber] Prevent exceeding the safety limit of _2750 psia_: Loss of external load Turbine trip _Loss of condenser vacuum (worse case event)_ MSIV closure LOOP Loss of MFW Acoustic _VPI_ _powered from NNN-D11_ 0% / 9% / 100% lights VPI required by TLCO 3.3.105 PAM 1 per safety valve

Pressurizer: Minimum pressure during operating transients is above the which setpoint?... 33-52.5%: Ensures ?... Volume prevents PZR heaters from being uncovered by outsurge following: Step load drop of #% from #% to #% power 5#/min ramp decrease from #% to #% power.

Pressurizer: Minimum pressure during operating transients is above the SIAS setpoint Maximum pressure is below the high pressure reactor trip during transients. _33-52.5%: Ensures heaters covered and steam space for spray (maintains pressure control)_ Volume prevents draining the PZR as a result of a reactor trip. Volume prevents PZR heaters from being uncovered by outsurge following: Step load drop of _10% from 25% to 15% power_ _5%/min ramp decrease from 100% to 15% power_.

LCO 3.4.9 Pressurizer Applicable: Modes ?... PZR level #-#%?... B1/B2 Back-up heaters operable?... ?...

LCO 3.4.9 Pressurizer _Applicable: Modes 1–3._ PZR level _27 - 56%_ (Does not apply \> 5%/min ramp or \> 10% step) [_Mode 3 in 6 hours_, M4 in 12 hours] _B1/B2 Back-up heaters operable_ (capacity ≥ 125 KW each) [_one inop – 72 hour LCO_, both inop – LCO 3.0.3] _High level - bubble maintained_ for pressure control (heaters/spray, prevent water in safeties) _Low level - ensures heaters are covered_. Maintain pressure control (subcooling margin) during natural circulation (LOOP) and SGTR. Capacity is sufficient to maintain the RCS near NOP when accounting for heat losses through the PZR insulation. A wide subcooling margin to saturation can be obtained in the loops.

[Not highlighted in Welch's Notes...] Steam Generators: Transfers #? MWT from RCS to the secondary?... ?...

[Not highlighted in Welch's Notes...] Steam Generators: Transfers 3990 MWT from RCS to the secondary. ~17.2 x 106 lbm/hr of 1039 psia saturated steam when provided with 448°F MFW.

Reactor Coolant Pumps (RCPs): RCPs operating & RCS temperature ranges?... Power Supplies: ?... control power?... Flywheel: Increases what? why?... Anti-reverse rotation device: ?...

Reactor Coolant Pumps (RCPs): Minimum flow rate ensures adequate heat removal capabilities in all modes of operation. Maximum flow rate limits the _uplift forces_ on the core. To prevent lift, RCPs are limited to _3 or less when temp is \< 500°F_. For _P-T concerns_, only _two RCPs are allowed \< 200°F_. _Do not run 1A/2B or 1B/2A only (prevents journal bearing damage_) Power Supplies: _NAN-S01 (1A/2A) and NAN-S02 (1B/2B)_ _NKN-D44 (Control Power)_ _Flywheel: Increases coast-down time during loss of power to maintain DHR._ _Anti-reverse rotation device: Withstands reverse torque in case of reversed power leads or during accident conditions_. Contains its own guide, thrust bearing and oil reservoir which are supplied with lube oil from an internal pump operating off of the thrust collar. Internal pump supplies oil only when the motor is operating at ≥ 1/2 speed. Bearings self-lubricated from the oil reservoir during slow speed conditions.

RCP Seals: gpm?... pressure drops across the 3 seals?... Can Seal bleedoff (controlled bypass flow) be isolated?... Loss of Seal Injection...?

RCP Seals: ~ 6.6 gpm Seal injection water 16 gpm journal bearing return Mixes in the jet pump 22.6 gpm (from jet pump) Cooled by HP seal cooler (NCW) Supplied to #1 seal high pressure cavity In the #1 seal high pressure cavity, flow splits (20 gpm down / 2.6 gpm up): 20 gpm flows down (aux impeller) through the journal bearing (cooling and lube) 4.0 gpm to RCS (minimizes ingress of contaminants into the seals) 16 gpm back to the jet pump 2.6 gpm flows up thru the seal Flows out the seal through a cooler as controlled bypass flow Then flows into #2 seal high pressure cavity. Flow paths through and around #2 seal are identical to #1 seal. ~ 2.6 gpm returns to VCT (from #3 seal flows to seal bleed off line) #3 seal – vapor seal Leakage past the vapor seal flows to RDT. ~ 10-12 gpm total seal bleedoff flow returns to the VCT Pressure drop across #1 seal is ~42% of system pressure. #2 seal is ~42%. #3 seal is ~16%. Each seal is designed to provide a 100% pressure drop in the event of a failure of the seal below it and is capable of operating at full system pressure. Controlled bypass flow (seal bleedoff) may be isolated for each pump. Seal Bleedoff Isolation Valves are interlocked with running RCPs. _Will NOT close if associated RCP is running_. HP cooler MOVs: Key locked HS. Normally de-energized. Used to isolate RCS to NC leak. _Loss of seal injection only, may result in reduced seal life due to introduction of contaminants_ from RCS water.

[...not highlighted...] RCP seal limits apply: Seal injection required when: ? NCW required \> ? temp?... Bleed-off valve required to be open \> ? (for seals to be self-venting...)

[...not highlighted...] RCP seal limits apply: Seal injection required when: \> 195°F RCS temp \> 215 psia RCS pressure \> 102 ft RCS level NCW required \> 195°F RCS temp Bleed-off valve required to be open \> 30 minutes with RCS pressure \> 215 psia for the seals to be self-venting.

Lift Oil Pump (NHN): Manual Start - ?... Auto Starts - ?... Auto Stops - ?... EOP/OP: ?... RCP shutdown, without a lift pump available, can be done if necessary. but it may... Lift Oil Pump may trip on overload if ALL are met: ?...

Lift Oil Pump (NHN): Manual Start - will run until RCP started (have to _hold in start if pump is already running_) _Auto Starts_ - when you secure a RCP (must be manually stopped) _Auto Stops_ - After 2 min once the RCP is running Lift pump oil is _critical for RCP startup_ EOP/OP: run lift pump for 7 minutes prior to RCP start RCP _shutdown, without a lift pump available_, can be done if necessary. _May shorten the life_ of rotating components but not cause catastrophic failure. Lift Oil Pump may trip on overload if ALL are met: Unit is in an outage RCP is the last RCP to be started RCS is ≥ 2250 psia Lift Oil Pump is operated for \> 9 minutes

RCP Start Permissives: B... O... N... E... RCP Trips: ?... ?... ?... ?... RCP Vibration Cabinet is located...(Alarm on B0#?) RCP trip required if \> _#_ mils

_RCP Start Permissives (BONE):_ B: RCP Seal _B_leedoff Valve open O: Sufficient _O_il Lift Flow N: _NC water_ flow is sufficient E: No Motor Faults( electrical ) _RCP Trips:_ Undervoltage Coastdown (Breaker remains closed until 80% voltage or 20 seconds, whichever is first) Over-current Speed \ 10 mils_

Refueling Water Level Indicating System (RWLIS): Used in MODEs ?... NR LIs... WR LIs... Power supplies?... Alarms?... ?...

Refueling Water Level Indicating System (RWLIS): Used in MODEs 5 and 6. HP Taps – Thot HPSI line, SDC return (A – loop 2, B – loop 1) Dry reference legs – connect to PZR spray lines Prevent filling reference legs from SDC flow NR LIs (2) 0" = Bottom of the hot leg (ID) 99' 7" elev. 40" = 2" below top of hot leg (ID) 102'11" elev. WR LIs (2) Bottom of hot leg (ID) 99' 7" elev to Top of refueling pool 140' elev. Level readings can be _automatically compensated for SDC flow_ using flow signals from FTs SIA-306 and SIB-307 in the SDC lines. Inaccurate if SDC flow \> 5000 gpm _Power Supplies_ NNN-D11 (A) / NNN-D12 (B) PNA-D25/PNB-D26 powers the flow compensation Alarms: Refueling Water Level Low Refueling Water Level Low - Low Level recorder 2 local sight glasses 1 set of tygon tube connectors. (A side only) Sight glass / tygon: connects to PT-105 condensing pot. (PZR Level - Wet reference leg) (Refueling Water Level - Dry reference leg)

REP (Hot EALs Modes 1-4) RCS leakage ≥ minutes? ≥ #? gpm unidentified / pressure boundary ≥ #? gpm identified / outside CTMT Loss of RCS barrier (ALERT) ?... Potential Loss of RCS barrier (ALERT) ?...

REP (Hot EALs Modes 1-4) RCS _leakage ≥ 15 minutes (NOUE)_ _≥ 10 gpm_ unidentified / pressure boundary _≥ 25 gpm_ identified / outside CTMT Loss of RCS barrier (ALERT) Unisolable RCS leak / SGTR requiring SIAS Potential Loss of RCS barrier (ALERT) Unisolable RCS leak / SG tube leak that requires letdown isolation and the standby charging pump to be started

Identified Leakage: ?... Unidentified Leakage: All leakage that is NOT...? Pressure Boundary Leakage: ?...

_Identified Leakage:_ Leakage (pump seals or valve packing (except RCP seal injection or leak off), that is captured and conducted to collection systems or a sump or collecting tank; Leakage to CTMT atmosphere from sources that are identified and known either not to interfere with the operation of leakage detection systems or not to be pressure boundary leakage; or Primary to Secondary leakage Includes PIV leakage (LCO 3.4.15) _Unidentified Leakage:_ All leakage that is NOT identified _Pressure Boundary Leakage:_ Leak through a non-isolable fault in RCS component body, pipe wall, or vessel wall

E-Plan (Modes 1-4 EALs) I-131 \> μCi/gm: Loss of Fuel Clad Barrier (ALERT) RCS activity LCO limits exceeded (UE): ?... _Letdown RU-155D alarm (UE)_ – ?...

E-Plan (Modes 1-4 EALs) I-131 _\> 300 μCi/gm: Loss of Fuel Clad Barrier_ (ALERT) RCS activity LCO limits exceeded (UE): LCO 3.4.17.C is entered (not restored in 48 hours OR \>60 μCi/gm) _Letdown RU-155D alarm (UE)_ – indicates RCS activity LCO is exceeded

.AR RC-RCS (Welch's Highlighted Notes) Flashcards by Alex Reyes

RCS Purpose / Design basis:

RCS transfers thermal energy to the…?
Design Pressure is…?
# MWth Rated Thermal Power (RTP) is…?

RCS Purpose / Design basis:

Transfer thermal energy to the SGs. Second fission product barrier. Core cooling.
Design pressure (2500 psia)
3990 MWth (Rated Thermal Power – RTP)

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Primary Safety Valves:

Lift at # psia?
?…
Acoustic VPI powered from ?…

Primary Safety Valves:

Lift at 2475 psia
Rapidly open to 70% [huddle chamber]
Prevent exceeding the safety limit of 2750 psia:
- Loss of external load
- Turbine trip
- Loss of condenser vacuum (worse case event)
- MSIV closure
- LOOP
- Loss of MFW
Acoustic VPI powered from NNN-D11
- 0% / 9% / 100% lights
- VPI required by TLCO 3.3.105 PAM

1 per safety valve

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Pressurizer:

Minimum pressure during operating transients is above the which setpoint?…
33-52.5%: Ensures ?…
Volume prevents PZR heaters from being uncovered by outsurge following:
- Step load drop of #% from #% to #% power
- 5#/min ramp decrease from #% to #% power.

Pressurizer:

Minimum pressure during operating transients is above the SIAS setpoint
Maximum pressure is below the high pressure reactor trip during transients.
33-52.5%: Ensures heaters covered and steam space for spray (maintains pressure control)
Volume prevents draining the PZR as a result of a reactor trip.
Volume prevents PZR heaters from being uncovered by outsurge following:
- Step load drop of 10% from 25% to 15% power
- 5%/min ramp decrease from 100% to 15% power.

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LCO 3.4.9 Pressurizer

Applicable: Modes ?…
PZR level #-#%?…
B1/B2 Back-up heaters operable?…
?…

LCO 3.4.9 Pressurizer

Applicable: Modes 1–3.
PZR level 27 - 56% (Does not apply > 5%/min ramp or > 10% step) [Mode 3 in 6 hours, M4 in 12 hours]
B1/B2 Back-up heaters operable (capacity ≥ 125 KW each) [one inop – 72 hour LCO, both inop – LCO 3.0.3]
- High level - bubble maintained for pressure control (heaters/spray, prevent water in safeties)
- Low level - ensures heaters are covered.
- Maintain pressure control (subcooling margin) during natural circulation (LOOP) and SGTR.
- Capacity is sufficient to maintain the RCS near NOP when accounting for heat losses through the PZR insulation. A wide subcooling margin to saturation can be obtained in the loops.

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[Not highlighted in Welch’s Notes…]

Steam Generators:

Transfers #? MWT from RCS to the secondary?…
?…

[Not highlighted in Welch’s Notes…]

Steam Generators:

Transfers 3990 MWT from RCS to the secondary.
~17.2 x 10⁶ lbm/hr of 1039 psia saturated steam when provided with 448°F MFW.

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Reactor Coolant Pumps (RCPs):

RCPs operating & RCS temperature ranges?…
Power Supplies:
- ?…
- control power?…
Flywheel: Increases what? why?…
Anti-reverse rotation device: ?…

Reactor Coolant Pumps (RCPs):

Minimum flow rate ensures adequate heat removal capabilities in all modes of operation.
Maximum flow rate limits the uplift forces on the core.
- To prevent lift, RCPs are limited to 3 or less when temp is < 500°F.
For P-T concerns, only two RCPs are allowed < 200°F.
Do not run 1A/2B or 1B/2A only (prevents journal bearing damage)
Power Supplies:
- NAN-S01 (1A/2A) and NAN-S02 (1B/2B)
- NKN-D44 (Control Power)
Flywheel: Increases coast-down time during loss of power to maintain DHR.
Anti-reverse rotation device: Withstands reverse torque in case of reversed power leads or during accident conditions.
- Contains its own guide, thrust bearing and oil reservoir which are supplied with lube oil from an internal pump operating off of the thrust collar.
- Internal pump supplies oil only when the motor is operating at ≥ 1/2 speed.
- Bearings self-lubricated from the oil reservoir during slow speed conditions.

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RCP Seals:

gpm?…
pressure drops across the 3 seals?…
Can Seal bleedoff (controlled bypass flow) be isolated?…
Loss of Seal Injection…?
*

RCP Seals:

~ 6.6 gpm Seal injection water
16 gpm journal bearing return
Mixes in the jet pump
22.6 gpm (from jet pump)
- Cooled by HP seal cooler (NCW)
- Supplied to #1 seal high pressure cavity
In the #1 seal high pressure cavity, flow splits (20 gpm down / 2.6 gpm up):
- 20 gpm flows down (aux impeller) through the journal bearing (cooling and lube)
  - 4.0 gpm to RCS (minimizes ingress of contaminants into the seals)
  - 16 gpm back to the jet pump
- 2.6 gpm flows up thru the seal
  - Flows out the seal through a cooler as controlled bypass flow
  - Then flows into #2 seal high pressure cavity.
Flow paths through and around #2 seal are identical to #1 seal.
~ 2.6 gpm returns to VCT (from #3 seal flows to seal bleed off line)
- # 3 seal – vapor seal
- Leakage past the vapor seal flows to RDT.
- ~ 10-12 gpm total seal bleedoff flow returns to the VCT
Pressure drop across #1 seal is ~42% of system pressure. #2 seal is ~42%. #3 seal is ~16%.
- Each seal is designed to provide a 100% pressure drop in the event of a failure of the seal below it and is capable of operating at full system pressure.
Controlled bypass flow (seal bleedoff) may be isolated for each pump.
- Seal Bleedoff Isolation Valves are interlocked with running RCPs.
- Will NOT close if associated RCP is running.
HP cooler MOVs: Key locked HS. Normally de-energized. Used to isolate RCS to NC leak.
Loss of seal injection only, may result in reduced seal life due to introduction of contaminants from RCS water.

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[…not highlighted…]

RCP seal limits apply:

Seal injection required when:
- ?
NCW required > ? temp?…
Bleed-off valve required to be open > ? (for seals to be self-venting…)

[…not highlighted…]

RCP seal limits apply:

Seal injection required when:
- > 195°F RCS temp
- > 215 psia RCS pressure
- > 102 ft RCS level
NCW required > 195°F RCS temp
Bleed-off valve required to be open > 30 minutes with RCS pressure > 215 psia for the seals to be self-venting.

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[…not highlighted…]

First RCP start limits to prevent lifting LTOP reliefs:

?…

[…not highlighted…]

First RCP start limits to prevent lifting LTOP reliefs:

Stable PZR pressure
≤ 33% L_PZR - SG secondary side temp < 20°F above Tcold.
> 33% L_PZR or solid - do not start if SG temp is higher than Tcold.

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Lift Oil Pump (NHN):

Manual Start - ?…
Auto Starts - ?…
Auto Stops - ?…
EOP/OP: ?…
RCP shutdown, without a lift pump available, can be done if necessary. but it may…

Lift Oil Pump may trip on overload if ALL are met:

?…

Lift Oil Pump (NHN):

Manual Start - will run until RCP started (have to hold in start if pump is already running)
Auto Starts - when you secure a RCP (must be manually stopped)
Auto Stops - After 2 min once the RCP is running
Lift pump oil is critical for RCP startup
EOP/OP: run lift pump for 7 minutes prior to RCP start
RCP shutdown, without a lift pump available, can be done if necessary. May shorten the life of rotating components but not cause catastrophic failure.

Lift Oil Pump may trip on overload if ALL are met:

Unit is in an outage
RCP is the last RCP to be started
RCS is ≥ 2250 psia
Lift Oil Pump is operated for > 9 minutes

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RCP Start Permissives:

B…
O…
N…
E…

RCP Trips:

?…
?…
?…
?…

RCP Vibration

Cabinet is located…(Alarm on B0#?)

RCP trip required if > # mils

RCP Start Permissives (BONE):

B: RCP Seal Bleedoff Valve open
O: Sufficient Oil Lift Flow
N: NC water flow is sufficient
E: No Motor Faults(electrical)

RCP Trips:

Undervoltage
Coastdown (Breaker remains closed until 80% voltage or 20 seconds, whichever is first)
Over-current
Speed < 600 RPM after 14 seconds of running

RCP Vibration

Cabinet outside MCR (alarm on B07).

RCP trip required if > 10 mils

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Refueling Water Level Indicating System (RWLIS):

Used in MODEs ?…
NR LIs…
WR LIs…
Power supplies?…
Alarms?…
?…

Refueling Water Level Indicating System (RWLIS):

Used in MODEs 5 and 6.
HP Taps – Thot HPSI line, SDC return (A – loop 2, B – loop 1)
Dry reference legs – connect to PZR spray lines
- Prevent filling reference legs from SDC flow
NR LIs (2)
0” = Bottom of the hot leg (ID) 99’ 7” elev.
40” = 2” below top of hot leg (ID) 102’11” elev.
WR LIs (2)
Bottom of hot leg (ID) 99’ 7” elev to
Top of refueling pool 140’ elev.
Level readings can be automatically compensated for SDC flow using flow signals from FTs SIA-306 and SIB-307 in the SDC lines.
Inaccurate if SDC flow > 5000 gpm
Power Supplies
- NNN-D11 (A) / NNN-D12 (B)
- PNA-D25/PNB-D26 powers the flow compensation
Alarms:
- Refueling Water Level Low
- Refueling Water Level Low - Low
Level recorder
2 local sight glasses
1 set of tygon tube connectors. (A side only)

Sight glass / tygon: connects to PT-105 condensing pot.

(PZR Level - Wet reference leg)*
(Refueling Water Level - Dry reference leg)*

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2.1.1 Reactor Core SLs

DNBR ≥ ?

2.1.2 RCS safety limit - pressure ≤ ? psia

Safety Limit Violation: Notify NRC within how many hour(s)? NRC permission for startup?…

2.1.1 Reactor Core SLs

DNBR ≥ 1.34.
Peak fuel centerline temp < 5080°F (↓ by 58°F per 10,000 MWD/MTU for burnup and adjusting for burnable poisons). (4901°F Framatome fuel)
Applicable in Modes 1 & 2
Restore and be in MODE 3 within 1 hour.

2.1.2 RCS safety limit - pressure ≤ 2750 psia

Applicable Modes 1 – 5
- Modes 1-2: restore / MODE 3 within 1 hour.
- Modes 3-5: restore within 5 minutes.
Protects integrity of the RCS against overpressurization

Safety Limit Violation: Notify NRC within 1 hour AND NRC permission required to start-up.

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REP (Hot EALs Modes 1-4)

RCS leakage ≥ # minutes?

≥ #? gpm unidentified / pressure boundary
≥ #? gpm identified / outside CTMT

Loss of RCS barrier (ALERT)

?…

Potential Loss of RCS barrier (ALERT)

?…

REP (Hot EALs Modes 1-4)

RCS leakage ≥ 15 minutes (NOUE)

≥ 10 gpm unidentified / pressure boundary
≥ 25 gpm identified / outside CTMT

Loss of RCS barrier (ALERT)

Unisolable RCS leak / SGTR requiring SIAS

Potential Loss of RCS barrier (ALERT)

Unisolable RCS leak / SG tube leak that requires letdown isolation and the standby charging pump to be started

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Identified Leakage:

?…

Unidentified Leakage:

All leakage that is NOT…?

Pressure Boundary Leakage:

?…

Identified Leakage:

Leakage (pump seals or valve packing (except RCP seal injection or leak off), that is captured and conducted to collection systems or a sump or collecting tank;
Leakage to CTMT atmosphere from sources that are identified and known either not to interfere with the operation of leakage detection systems or not to be pressure boundary leakage; or
Primary to Secondary leakage
Includes PIV leakage (LCO 3.4.15)

Unidentified Leakage:

All leakage that is NOT identified

Pressure Boundary Leakage:

Leak through a non-isolable fault in RCS component body, pipe wall, or vessel wall

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E-Plan (Modes 1-4 EALs)

I-131 > # μCi/gm: Loss of Fuel Clad Barrier (ALERT)
RCS activity LCO limits exceeded (UE):
- ?…
Letdown RU-155D alarm (UE) – ?…

E-Plan (Modes 1-4 EALs)

I-131 > 300 μCi/gm: Loss of Fuel Clad Barrier (ALERT)
RCS activity LCO limits exceeded (UE):
- LCO 3.4.17.C is entered (not restored in 48 hours OR >60 μCi/gm)
Letdown RU-155D alarm (UE) – indicates RCS activity LCO is exceeded

Head / PZR Vents:

SOVs flow to ?…
?…
High pressure alarm at (psia)?…

Head / PZR Vents:

SOVs flow to RDT or CTMT.
Flow orifices limits flow.
Must prevent backpressure hammer on valves RC-HV-103/109.
- Internals to HV-109 will be damaged if the valve is exposed to a sudden increase in downstream pressure without the upstream side being in contact with RCS pressure.
High pressure alarm at 2,000 psia

LCO 3.4.1 RCS DNB

?…

LCO 3.4.1 RCS DNB

PZR pressure 2130 - 2295 psia
- Mode 1 and 2
- Does NOT apply during > 5% /min ramp OR > 10% step.
Tcold within an area of acceptable operation (0% < 570°F, 100% < 564°F)
- Mode 1 and 2 with K_eff ≥ 1.0
RCS total flow rate ≥ 155.8 E6 lbm/hr.
- Mode 1 only
Restore within 2 hours
Initial conditions for DNB limited transients analyzed in the safety analyses

LCO 3.4.2 Minimum Temperature for Criticality:

Tcold ≥ ?…
?…

LCO 3.4.2 Minimum Temperature for Criticality:

Tcold ≥ 545°F in Mode 1 or 2 with K_eff ≥ 1.0
Be in Mode 3 within 30 minutes, if not met.
If RCS is < 550°F, ensure > 545°F every 30 minutes. Verify within 30 minutes of going critical.
Bases: Ensures instrument accuracy (within normal temp ranges), accident analysis assumptions, and vessel above min nil ductility ref temp.
Prevent criticality below the minimum NOT (550°F)
Provides a reasonable distance to the limit of 545°F. Allows time to trend and take actions prior to exceeding the limit.

LCO 3.4.3 RCS Pressure and Temperature (P/T) Limits

CDR ≤ #?°F/HR (RCS > 100°F); ≤ #?°F/HR (RCS ≤ 101°F)
HUR ≤ #?°F/HR
Applicable at all times, except when head is…
Modes 1-4 – restore within ?…
Other modes – restore…?
Engineering evaluation required when?…

LCO 3.4.3 RCS Pressure and Temperature (P/T) Limits

CDR ≤ 100°F/HR (RCS > 100°F); ≤ 30°F/HR (RCS ≤ 101°F)
HUR ≤ 75°F/HR
Applicable at all times, except when head is fully detensioned.
Modes 1-4 – restore within 30 minutes
Other modes – restore immediately
Engineering evaluation required if exceeded (LCO NOTE ensures this is performed even if the LCO is exited)
SR: Monitor every 30 minutes during H/U and C/D operations and RCS in-service leak and hydrostatic testing.
Prevent undetected flaws from propagating and causing nonductile failure of the RCPB (unanalyzed condition).

T3.4.102 Pressurizer Heatup and Cooldown Limits:

≤ #?°F/HR at all times
Restore within # minutes?…

T3.4.102 Pressurizer Heatup and Cooldown Limits:

≤ 200°F/HR at all times
Restore within 30 minutes and perform engineering evaluation.
Record spray water ∆T for each cycle of main spray when < 4 RCPs are operating and each cycle of auxiliary spray valves.

[…Not highlighted in Welch’s Notes…]

LCO 3.4.4 Two RCS loops shall be OPERABLE and in operation. (Modes 1 and 2):

Actions: ?…
Ensures…

[…Not highlighted in Welch’s Notes…]

LCO 3.4.4 Two RCS loops shall be OPERABLE and in operation. (Modes 1 and 2):

Actions: Be in Mode 3 within 6 hours.
Ensures adequate heat removal and maintains DNBR.

LCO 3.4.5 Two RCS loops shall be OPERABLE and one RCS loop shall be in operation. (Mode 3):

All RCPs may be de-energized for ≤ #?…
?…

LCO 3.4.5 Two RCS loops shall be OPERABLE and one RCS loop shall be in operation. (Mode 3):

All RCPs may be de-energized for ≤ 1 hour per 8 hour period, provided no dilutions and ≥ 10°F SCM.
- Indicated must be ≥ 37°F (instrument inaccuracies). If < 350 psia, use NR PZR PT.
One required RCS loop inoperable. Restore in 72 hours
Two loops inoperable OR no RCP running. Immediately stop dilutions and initiate actions to restore.
DHR and boron mixing
Single RCS loop with one RCP is sufficient to remove core decay heat.
RCP loop operability requires one RCP and the WR SGWL ≥ 25%

LCO 3.4.6 RCS Loops - MODE 4

#? loops or trains of RCS loops (one RCP / ≥ 25% WR level) and/or SDC trains shall be operable and at least one in operation.
All RCPs / SDC may be de-energized for ≤ # hours?…
?…

LCO 3.4.6 RCS Loops - MODE 4

Two loops or trains of RCS loops (one RCP / ≥ 25% WR level) and/or SDC trains shall be operable and at least one in operation.
All RCPs / SDC may be de-energized for ≤ 1 hour per 8 hour period, provided no dilutions and ≥ 10°F SCM.
- Indicated must be ≥ 72°F (instrument inaccuracies). If < 350 psia, use NR PZR PT.
No RCP can be started if any Tcold ≤ 221°F (LTOP enable temp) unless SG temp is <100°F above Tcold.
- Prevents a large RCS pressure surge.
≤ 2 RCPs running if Tcold ≤ 200°F. ≤ 3 RCPs running if Tcold > 200°F but ≤ 500°F.
- Maintains analysis assumptions of the flow induced pressure correction factors due to RCP operation.
Actions:
- One required RCS loop and two SDC trains inoperable. Immediately restore one.
- One required SDC train inoperable and two required RCS loops inoperable. Mode 5 in 24 hours.
- No RCS loop or SDC train operable or operating. Immediately stop dilutions and restore.
DHR and boron mixing
Any 1 train or loop is sufficient for DHR. Second loop provides redundancy.
Operable SDC train: LPSI pump, SDC HX, and flow path for heat removal. > 4000 gpm

**LCO 3.4.7 RCS Loops - MODE 5, Loops _Filled:_** * **#?** SDC train shall be operable and in operation **(\> 3780 gpm)**, and either: * ?... * ?...

**LCO 3.4.7 RCS Loops - MODE 5, Loops _Filled:_** * **One** SDC train shall be operable and in operation **(\> 3780 gpm)**, and either: * One additional SDC train shall be OPERABLE * SGWL **≥ 25% (WR)** * Same Note as LCO 3.4.6 (M4). Indicated must be ≥ 20°F for SCM (instrument inaccuracies). * One SDC train may be **inoperable for ≤ 2 hours for STs** provided that the other SDC train is operable and operating. * SDC **may be secured for planned heatup to M4** when at least one RCS loop is in operation. * Actions: * _One SDC train inoperable and any SGWL \< 25%. **Immediately** restore one._ * _Required SDC train inoperable or not operating. **Immediately stop dilutions and restore**_. * Loops filled requires the RCS to be intact, nozzle dams removed, and gases removed (U-tubes available). **LPSI pump or CSP (_≤ 200°F, ≤ 250 psia_) can be used.**

**LCO 3.4.8 RCS Loops - MODE 5, Loops _Not Filled:_** * **#?** SDC trains shall be OPERABLE and one SDC train shall be in operation (**\> 3780 gpm**). * ?...

**LCO 3.4.8 RCS Loops - MODE 5, Loops _Not Filled:_** * **Two** SDC trains shall be OPERABLE and one SDC train shall be in operation (**\> 3780 gpm**). * SDC may be stopped for **≤ 1 hour per 8 hou**r period (no dilutions, ≥ 10°F SCM (20°F indicated), and no RCS draining) * 2 hour surveillance test allowance. * _If not met, **immediately** restore. No dilutions if none running or both inoperable_. * CSP or LPSI pump can be used. * **CSPs not used in mid-loop** (\< 103’ 1”) due to potential air entrainment / gas binding.

**T3.4.101 RCS Chemistry (At all times):** * Dissolved O₂ ...? * Chloride? * Fluoride? * ?...

**T3.4.101 RCS Chemistry (At all times):** * Dissolved _O₂_ 0.10 ppm / 1.00 ppm (Steady state / Transient) * _Limit is NOT applicable with Tcold ≤ 250°F_. * Chloride 0.15 ppm / 1.50 ppm * Fluoride 0.10 ppm / 1.00 ppm * Maintains RCS integrity by limiting corrosion.

**LCO 3.4.10 PZR Safety Valves:** * **Four PZR safety valves operable** **with lift settings (range) psia?...** * **Modes ?...** * **One inoperable**: restore within **# minutes?...** * **?...**

**LCO 3.4.10 PZR Safety Valves:** * **_Four PZR safety valves operable_** **with lift settings _2450.25 - 2549.25 psia_.** * **_Modes 1-3_** * **_One inoperable_**: restore within **_15 minutes_ OR RICT** (cannot voluntarily enter) * If **_not restored or \> 1 inoperable: Mode 3 in 6 hours_** * Required lift pressure is **_2475 psia (+3%, -1%)_**. Post testing, they are required to be **± 1%.** * Ensures RCS pressure will be **limited to 110% of design pressure**. * Accident analysis **assume that all 4 safeties are operable**. (No single failure)

**LCO 3.4.11 One pressurizer safety valve operable in Mode 4 ≥ 221°F:** * **Immediately** be in **M# with one SDC suction line relief** valve in service and operable. * Then be **\< #°F within # hours** to place LTOP in-service?... * SDC suction line relief valve is operable when...? * ?...

**LCO 3.4.11 One pressurizer safety valve operable in _Mode 4 ≥ 221°F_:** * _**Immediately** be in **M4 with one SDC suction line relief** valve in service and operable._ * Then be **_\< 221°F within 8 hours_** to place LTOP in-service. * SDC suction line relief valve is operable when its isolation valves are open and lift setpoint is set at **≤ 467 psig**. * **One is adequate** to relieve any overpressure condition which could occur during shutdown above LTOP temperatures.

**TLCO 3.4.100 Both auxiliary spray valves functional in Modes 1-4:** * One non-functional: restore #? hours * Both non-functional: restore #? hours * Required to depressurize the RCS for SDC when normal spray is... * ?...

**TLCO 3.4.100 _Both auxiliary spray valves_ functional in _Modes 1-4_:** * One non-functional: restore 72 hours * Both non-functional: restore 6 hours * Required to depressurize the RCS for SDC when normal spray is not available (during natural circ and later stages of a normal RCS cooldown). * Distributes boron to the PZR when normal spray is not available. * TSR requires CH-524 and CH-532 to be locked open (ensures charging flow path from RWT to aux spray)

**LCO 3.4.13 LTOP System shall be OPERABLE:** * **?**... * ?...

**LCO 3.4.13 LTOP System shall be OPERABLE:** * **Two** SDC suction line relief valves with lift settings _**≤ 467 psig** **OR RCS vent of ≥ 16 in²**._ * Applicable: Mode 4 (any **_Tcold ≤ 221°F_** - LTOP enable), Mode 5, Mode 6 when vessel head is on. * LCO 3.0.4.b is not applicable when entering MODE 4. * Two relief valves required for redundancy. * **_Most limiting transients_****:** * Start of an idle **RCP with SG temp 100°F above RCS cold leg** temperatures * **Inadvertent SIAS** with two HPSI pumps injecting when solid, three charging pumps injecting, and letdown isolated. RCS vent: All PZR safety valves removed or removing PZR manway.

**LCO 3.4.14 RCS operational leakage (Modes 1 – 4):** * ?... * ?...

**LCO 3.4.14 RCS operational leakage (Modes 1 – 4):** * *(...0, 1, 10, 150...)* * _No pressure boundary_ leakage * _1 gpm_ unidentified leakage * _10 gpm_ identified leakage * _150 gpd_ primary to secondary leakage through any **one** SG * Unidentified / identified leakage exceeded, restore in **_4 hours_**. * Other leakage or not restored, be in **_M3 in 6 hours_**. * MSLB analyses **assumes 1 gpm total 1° to 2° leakage** at time of event. * 150 gpd ensures 10CFR100 limits maintained.

*[...Not highlighted in Welch's Notes...]* **LCO 3.4.15 Leakage from each RCS PIV shall be within limits:** * ?... * ?...

*[...Not highlighted in Welch's Notes...]* **LCO 3.4.15 Leakage from each RCS PIV shall be within limits:** * Modes 1-4 (except valves in the SDC flow path when in-service) * **≤ 0.5 gpm** per nominal inch of valve size (**5 gpm max**) at NOP (2250 ± 20 psia). * SDC System open permissive interlock prevents the valves from being opened with RCS **≥ 410 psia**. *(Setpoint is 385 psia)* * Prevent an **inter-system LOCA**. SDC is most limiting (designed for 485 psig). * If exceeded, isolate within 4 hours and restore PIV within 72 hours. Or go to Mode 5.

**LCO 3.4.17 RCS Specific Activity (Modes 1-4):** * ?... * ?...

**LCO 3.4.17 RCS Specific Activity (Modes 1-4):** * _DE I-131 **≤ 1.0 μCi/gm**_. * DE XE-133 **≤ 550 μCi/gm**. * Can operate with Iodine \> 1.0 μCi/gm, but _\< **60 μCi/gm,** for **\< 48 hours**_. * If _**\> 60 μCi/gm**, **Mode 3 in 6 hours**_, Mode 5 in 36 hours * Can operate with Xe exceeding the limit for 48 hours. * LCO 3.0.4.c is applicable if \< 60.0 μCi/gm * _I-131 sample required if **≥ 15% power change in a 1 hour** period._ * _Ensures **off-site (10CFR100) and MCR dose limits maintained during a SGTR**_. Limits also used for establishing standardization in radiation shielding and plant personnel radiation protection practices.

*[...not highlighted in Welch's Notes...]* **LCO 3.3.10 PAM (Modes 1-3):** * ?...

*[...not highlighted in Welch's Notes...]* **LCO 3.3.10 PAM (Modes 1-3):** * Two Thot per loop and two Tcold per loop (WR) * Two WR PZR Levels (110X/110Y) * Two WR RCS Pressures (190A/190B)

*[...not highlighted in Welch's Notes...]* **LCO 3.3.11 RSP Instruments (Modes 1-3):** * ?...

*[...not highlighted in Welch's Notes...]* **LCO 3.3.11 RSP Instruments (Modes 1-3):** * One PZR pressure (PI-102A or 102B) * One Thot and one Tcold per loop * Two WR PZR Levels (110X/110Y)

**TLCO 3.4.104 Four vessel head vent paths functional:** * ?...

**TLCO 3.4.104 Four vessel head vent paths functional:** * Modes 1 – 3, Mode 4 **_≥ 385 psia_** * Exhaust noncondensible gases / steam from the RCS that could inhibit **natural circulation**. At least one vent path ensures the capability exists to perform this function. Vent path is from the **head to RDT or CTMT**.

**LCO 3.4.12 Four PZR vent paths operable:** * ?...

**LCO 3.4.12 Four PZR vent paths operable:** * Modes 1 – 3, Mode 4 **_≥ 385 psia_** * Vent path is from the **PZR to RDT or CTMT**. * Required during **SGTR design basis** event which assumes LOP and Aux Spray unavailable. * 2 or 3 paths nonfunctional: restore in 72 hours * All paths nonfunctional: restore at least one in 6 hours OR RICT (cannot voluntarily enter) * **_Loss of any single valve will cause two flow paths to become inoperable_**.

*{... not in Welch's notes...}* **LCO 3.4.16 - Both RCS Leakage & Detection monitors shall be OPERABLE with:** * ?...

*{... not in Welch's notes...}* **LCO 3.4.16 - Both RCS Leakage & Detection monitors shall be OPERABLE with:** * _1 CTMT sump monitor, and_ * _1 CTMT Atmosphere Radioactivity monitor (gaseous & particulate)_