RNS(1) - Normal Residual Heat Removal

Simplified Diagram

RNS

Containment Isolation

This is not a “T” signal, this is an RNS Onerous isolation

V061 CVS Purification Return Line is the only “T” valve

RNS

Pressure Boundary Isolations

RNS

Containment Inventory MU

RNS

Normal SDC Operations

Turbine Bypass valves will cooldown to <350F and <400psig*

RNS cools down to <125F within 96hrs

Once <130F RNS can be aligned to purification

*During Purification flow CVS makeup is NOT available to RCS

*E-Network Limitations: 400F and 417psig

RNS

Cooldown Limitations

LTOP

When on RNS the RCS is normally <350F

Below 350F, the cooldown limit is 50F/hr

RNS-V020/V021 Lift at 470/500psig respectively and discharge to Containment Sump

*V020: 1”(50gpm) V021: 3”(850gpm)

RNS Purification

Temperature Limitation?

Flow?

RNS-V029 isolates if CVS-T002 >135.5F

<40gpm

3.4.14 Low Temperature Overpressure Protection (LTOP)

LCO

At least one of the following methods must be Operable WITH Accumulators isolated

1. BOTH LTOP valves Operable and CVS-091 Closed

   1. RCS Vented >/= 4.15 in²

3.4.14 Low Temperature Overpressure Protection (LTOP)

Applicability

MODE 4 Any Cold Leg </=275F

MODE 5

MODE 6 with Head on

3.4.14 Low Temperature Overpressure Protection (LTOP)

<1hr Action(s)

Accumulator connected when Acc. Pressure > RCS CL:

Isolate Acc. 1hr

CVS-V091 Not Closed:

Close 1hr (Not needed when vented)

RNS to Spent Fuel Pool

Local Manual Alignment

CAN align both trains to SFP if needed

RNS to CLP

Limited to ONE train due to NPSH limitation

Flowpath: From CLP through RNS to SFP

Therefore; CLP and SFP MUST be crosstied (gate open) during performance

RNS

IRWST Cooling

Can use BOTH trains if desired

RNS
CLP Injection to RCS

RNS

IRWST Forced Injection to RCS

RNS

IRWST Gravity Injection to RCS

RNS

Post Containment Flooding

RNS

Suction Line Isolation

0 sec: 1A & 1B Close

+60sec: 2A & 2B Close

Delay due to IDS loading limitation

RNS

Automatic Isolation

RNS

Containment Evacuation Alarm

RNS

Hot Leg Suction Isolations

RNS

IRWST Suction CIV MOV

(RNS-V023)

RNS

CVS Suction CIV AOV

(RNS-V061)

RNS

Suction Header CIV MOV

(RNS-V022)

RNS

SFP & CLP Alignment Paths

T 3.7.1 RNS - RCS Makeup

LCO

Applicability

ONE train shall be Functional

MODES 1, 2, and 3

T 3.7.1 RNS - RCS Makeup

TRS

Head on recirc?

Valves stroke open?

330 feet of head

RNS-V011, V022, V023, V055

T 3.7.1 RNS - RCS Makeup

Bases

Makeup (To be Functional): From CLP and IRWST into RCS

“Pressure boundary maintenance cannot be performed when RNS is in SDC, therefore PB maintenance should be done in MODES 1, 2, and 3”

T 3.7.2 RNS - RCS Open

LCO

Applicability

TWO trains shall be Functional AND ONE pump in operation

MODE 5: Open

MODE 6: UppIntern in place

MODE 6: <23’ above flange

T 3.7.2 RNS - RCS Open

TRS

One Pump flow requirement?

Two Pumps flow requirement?

One: >1,580gpm

Two: >2,000gpm

T 3.7.2 RNS - RCS Open

Bases

Standby train requirements?

Neither train Functional limitations?

Planned maintenance?

If standby: Must be available to be placed in service from MCR

Plant should NOT enter RCS-Open if NO train Funcitonal

MODE 1, 2, 3, or 6 >23’ flange

SFP Suction Isolation RNS-V052

Manual Valve, NOT affected by RNS Isolation or any other signal(s)