ML20205B207

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Rev 2 to Emergency Operating Procedure EOP 35 ES-0.2, Natural Circulation Cooldown
ML20205B207
Person / Time
Site: Millstone, Haddam Neck, 05000000
Issue date: 06/15/1988
From:
CONNECTICUT YANKEE ATOMIC POWER CO.
To:
Shared Package
ML20204H467 List: ... further results
References
EOP-35-ES-.2, EOP-35-ES-0.2, NUDOCS 8810260204
Download: ML20205B207 (11)
v • d • e


Text

_ _ _ _ _ _

e Stephen E.

ace 3-31-87 87-12 g

Forr.; Approved by Stattun Superintendent Ef fective One 50RC Mtg. No.

STATION PROCEDURE COVER SHEET l

'l C-A.

IDENTIFICATION Number: E0P 35 ES-0.2 Rev.

2

Title:

NATURAL CIRCULATION C00LDOWN Prepared By: H. K. COVIN B.

REVIEW I have reviewed the above procedure and have found it to be satisfactory.

TITLE SlGNATURE DATE e

,d.

- <, /h, ocy DEPARTMENT HEAD C.

SPECIFIC UNREVIEWED SAFETY QUESTION EVALUATION REQUIRED:

Modifies intent of procedure and changes operation of systems as described in design documents.

YES [ ]

NO [-T (If yes, perform written USQ determination and Safety Evaluation, and contact Manager, Safety Analysis Branch to determine need for Integrated Safety Evaluation.)

(

)

C/

ENVIRONMENTAL REVIEW REQUIRED (Adverse environmental impact)

YES [ ]

NO [(

D.

SPECIFIC SAFETY EVALUATION REQUIRED Affects response of safety systems, performance of systems which may have been credited in the safety analysis or non-credited systems which may indirectly affect safety system response.

YES [ ]

NO W (If yes, perform written Safety Evaluation and contact Manager, Safety Analysis Branch to determine need for Integrated Safety Evaluation.)

E.

INTEGRATED SAFETY EVALUATION REQUIRED YES [ ]

NO ((

PROCEDURE REQUIRES h /50RC REVIEW F.

(in addition to review, ite with a YES response j

must be documented in the f0 /50RC meeting minutes.)

YE S [ vf NO [ ]

G.

'50RC APPROVAL SORC Meeting Number 3-R7-Mi H.

APPROVAL AND IMPLEMENTATI^N The attach edure i reby approved, and effective on the date below:

~y Station / Service / Unit Superintendent Etfective Date SF 301 Rev. 9 9'

8810260204 891007 PDR ADOCK 05000213 P

PDR

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'l l-E0P 35 ES-0.2 Page 1 I

Rev. 2 a

NATURAL CIRCULATION C00LOOWN k

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Page No.

Eff Rev.

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k NATURAL CIRCULATIdN C00LDOWN E0P 35 ES-0.2 Page 2 Rev. 2

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A.

PURPOSE This procedure provides actions to perform a natural circulation RCS' cooldown and depressurization to cold shutdown, with no accident in progress, under requirements that will preclude any upper head void formation.

B.

ENTRY CONDITIONS This procedure was written for Modes 1, 2 and 3, near no load conditions.

Using this procedure when not in these modes requires a step by step evaluation to determine if the required action is still applicable to current plant conditions.

This procedure is from 1)

E0P 35 ES-0.1, REACTOR TRIP RESPONSE, Step 13, when it has been determined that a natural circulation cooldown is required.

2)

E0P 35 ECA-0.1, LOSS OF ALL AC POWER RECOVERY WITHOUT SI REQUIRED, Step 21, when it has been determined that a natural circulation cooldown is required.

O 3)

E0P 35 ES-1,1, SI TERMINATION, Step 34, when it has been determined that a natural circulation cooldown is required.

ONc4 2 3 44

NATURAL CIRCULATION C00LDOWh' E0P 35 ES-0.2 Page 3 Rev. 2

,y J

STEP ACTION / EXPECTED RESPONSE RESPONSE NOT COTAINED CAUTION If SI actuation occurs during this procedure, E0P 35 E-0, REACTOR TRIP OR SAFETY INJECTION, should be performed.

NOTE

1. Foldout page should be open.
2. RCPs should be run in order of priority (2, 1, then 3 or 4) to provide normal PZR spray.
3. If conditions can be established for starting an RCP during this procedure, Step 1 should be repeated.
4. If the computer is not available to measure core exit TCs, manually measure TCs.
5. If auxiliary spray is required during procedure performance, maintain spray flow and throttle charging flow as necessary.

1 Try To Restart An RCP a.

Establish conditions a.

Place PZR Pressure f~)

for starting an RCP Master Controller in Ns

1) OP-3301D, RCP OPERATION HANUAL and control heaters as required to.

maintain desired pressure, then go to Step 2.

b.

Start one RCP b.

Place PZR Pressure Master Controller in MANUAL and control heaters as required to maintain desired pressute, then go te Step 2.

c.

Go to OP-3208, PLANT C00LD0%N m

bSC441 344

NATURAL CIRCULATION C00LDOWN E0P 35 ES-0.2 Page 4 Rev. 2 k

)

s._-

STEP ACTH3PL EXPECTED RESPONSE RESPONSE NOT OSTAINED 2

Borate RCS To Cold Shutdown Boron Concentration by one of the following a.

Normal Reactor Makeup system b.

Borate by transferring Charging Pump suction to the RWST.

c.

Boration using BAT gravity drain lines and charging pump discharge throttling valves for boration rate.

Charging pump flow path to cold leg injection flow path may be used.

3 Verify Cold Shutdown RCS Boron Ret. urn to Step 2.

Concentration By Sampling s

}

the RCS 4

Check VCT Makeup Control System a.

Makeup set for cold a.

Adjust controls as shutdown boron necessary, concentration b.

Makeup set for automatic b.

IF normal makeup is not control available THEN use the RWST for inventory makeup 5

Verify 2 CRDM Fans -

Start 2 CRDM fans.

IF KUNNING 2 CRDM fans cannot be started, THEN establish Rx vessel head excess letdown to maintain head cooling in accordance with OP 3304A, CilARGING AND LETDOVN oPK441 3-44

NATURAL CIRCULATION C00LDOWN E0P 35 ES-0.2 Page 5 Rev. 2 A

STEP ACTION /EXPECTkD RESPONSE RESPONSE NOT OBTAINED CAUTION 1)

Shift AFW pump suction to the CST if DVST level decreases to < 80,000 gal 2)

Steps 1-5 should be completed prior to proceeding to Step 6.

6 Initiate RCS Cooldown To Cold Shutdown a.

Maintain cooldown rate in RCS cold legs

< $0*F/HR b.

Dump steam to condenser b.

Dump steam to atmosphere c.

Maintain SG narrow c.

Control feed flow as range level - AT necessary.

approximately 50%

d.

Maintain RCS temperature

,)

and pressure to the right of the applicable curve on x-Tech Spec Figure 3.4-3 RCS C00LDOWN LIMIT.\\TIONS 7

Check RCS Hot Leg Return to Step 6.

Temperatures < 550*F NOTE To reduce thermal shock on the RCS if there is no urgency to innediately depressurize the RCS, PZR heaters may be de-energized to allow the RCS to depressurize slowly by heat losses to ambient.

8 Depressurize RCS To approximately 1950 psia a.

Check letdown - IN SERVICE a.

Try to establish letdown.

IF letdown can NOT be established, THEN use one PZH 10RV.

Go to Step 9.

b.

lise auxiliary spray b)

\\--

QPVE8-t 3-$4

NATURAL CIRCULATION C00LDOWN E0P 35 ES-0.2 Page 6 Rev. 2 A

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Q,1 STEP ACTICH4/EXPE CTED MESPONSE RESPONSE NOT ORT AINED CAUTION SI actuation circuits will automatically unblock if PZR pressure increases to > 2000 psia.

9 Block SI Actuation train A and B a.

Main Steam Line SI -

BLOCK A/B b.

PZR SI BLOCK A/B 10 Maintain Following RCS Conditions a.

RCS pressure - AT approximately 1950 psia b.

PZR level - AT approximately 25%

c.

Cocidown rate in RCS cold legs < 50*F/HR d.

Maintain RCS temperature and pressure to the right of the applicable curve on Tech Spec Figure 3.4-3 RCS COOLDOW LIMITATIONS 11 Monitor RCS Cooldown a.

Core exit TCs - DECREASING b.

RCS hot leg temperatures -

DECREASING c.

RCS subcooling based on core exit TCs - INCREASING w

05%N4 1 3-84

NATURAL CIRCULATION C00LDokN E0P 35 ES-0.2 Page 7

=

Rev. 2 A

STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED NOTE If at any time it is determined that a natural circulation cooldown and depressurization must he performed at a rate that may form a steam void in the vessel, refer to E0P 35 ES-0.3, NATURAL CIRCULATION C00LD0kN WITH STEAM VOID IN VESSEL (with RVLMS) or E0P 35 ES-0.4, NATURAL CIRCULATION C00LD0kN WITH STEA't VOID IN VESSEL (without RVLMS).

12 Initiate RCS Depressurization a.

Check CRDM fans -

a.

Perform one of the Tk'O RUNNING following

1) Maintain RCS and head subcooling based on core exit TCs > 130*F.

Go to Step 12c.

-OR-

2) If desired establish excess letdown from the vessel head vent

\\s -

per OP-3304A, CHARGING AND LETDOWN b.

Maintain RCS subcooling based en core cxit TCs

> 80*F c.

Check letdown - IN SERVICE c.

Use one PZR PORV. Go to Step 13.

d.

Use auxiliary spray J

OPM64 1 3 48 i

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a NATURAL CIRCULATION COOLDOWN E0P 35 ES-0.2 Page 8 Rev. 2 q

V STEP j ACTl0P0 EXPECTED RESPONSE RESPONSE NOT OOTAINED 13 Continue RCS Cooldown And Depressurization a.

Maintain cooldown rate in RCS cold legs

< $0'F/}{R b.

Maintain subcooling b.

Stop depressurization and requirements of Step 12 reestablish subcooling.

c.

Maintain RCS temperature and pressure to the right of the applicable curve on Tech Spec Figure 1.4-3 FCS C00LDOWN LIMITA~tIONS 14 Check for Steam Void in Repressurize RCS within limits Reactar Vessel of the area to the right of a.

PZR Level -

applicable curve on Tech Spec NO UNEXPECTED LARGE Figure 3.4-3 RCS COOLDOWN VARIATIONS LIMITATIONS to collapse

[

100%.

~~~

potential voids in system and b.

RVLMS head AND plenum -

continue cooldown.

IF RCS

~

\\s-depressurization must continue.

THEN go to E0P 35 ES-0.3 NATURAL CIRCULATION C00LD0kN WITil STEAM VOID IN VESSEL (with RVLMS) or E0P 35 ES-0.4 (without RVLMS )

15 Check If SI Accumulators Should Be Isolated a.

Check PZR pressure a.

DO NOT Isolate SI 1000 psia Accumulators. Continue

(

with Step 16.

WilLN requirements met, TJHEN do Step 15b.

i, b.

CLOSE the S1 b.

IF any accanulators Accumulator Isolation cannot be isolated valves and Ol'EN TitES vent off pressure Accumulator Isolation from unisolated accumu-motor supply breakers lators (32-JR-R5F, 32-2W-R3J, 32-2R-F4M, 32-2W-F4M)

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NATURAL CIRCULATION C00LDOWN E0P 35 ES-0.2

.Page 9 Rev. 2 (Om-)

RESPONSE NOT CBTAINED STEP ACTIONiEXPECTED RESPONSE 16 Maintain Letdown Flow a.

Open letdown orifice isolation valves as necessary b.

Adjust low pressure letdown control valve setpoint as necessary 17 Maintain Required RCP Seal In.jection Flow between 8 to 13 gpm 18 Check If RER System Can Be

(

Placed In Service a.

RCS temperature a.

Return to Step 13.

< 350 F b.

RCS pressure b.

Return to Step 12.

< 390 psia s

c.

Place RHR System in service as follows

1) OP-3310A, RESIDUAL HEAT REMOVAL SYSTEM
2) OP-3208, PLANT COOLDOWN d.

Disable all but one charging pump and at least one Si pwnp prior to cooling down to

< 350*r e.

Arm cold overpressure protection 19 Continue RCS Cooldown To Cold Shutdown O

NAIUKAL ClKCULAfl0N COULDubN E0P 35 ES-0.2 Pr. ge 10 i

Rev. 2

/T

)

<J STEP ACTitM0 tXPECTED RESPONSE RESPONSE NOT CSTAINED CAUTl0N Depressurizing the RCS before the entire RCS is < 200*F may result in void formation in the RCS.

20 Continue Cooldown Of inactive Portton Of RCS Cool upper he'ad region 4.

IF the head cannot be 4.

using CRDM fans cooled by CRDM fans TilEN use vessel head vent excess letdown b.

Cool SG U-tubes by dumping steam from ALL SGs 21 Determine If RCS Depressurization Is Permitted a.

Entire RCS AND RVLits a.

DO NOT DEPRESS'JRIZE RCS,.

licad TCs < 206'T Return to Step 19.

l O

L b.

Go to OP-3208. PLANT 1

C00LD0kN i

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