ML20237H739

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Rev 1 to Emergency Instruction ES-0.3, Natural Circulation Cooldown
ML20237H739
Person / Time
Site: Sequoyah  Tennessee Valley Authority icon.png
Issue date: 08/21/1985
From: Patterson B, Strickland G
TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20237H133 List: ... further results
References
ES-.3, ES-0.3, NUDOCS 8708170333
Download: ML20237H739 (11)
v • d • e


Text

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'k, TENNESSEE VALLEY AUTHORITY SEQUOYAF NUCLEAR PLANT

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L EMERGENCY INSTRUCTION

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ES-0.3 NATURAL CIRCULATION COOLDOWN

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s Revision 1 PREPARED BY:

G. Stric"kland RESPONSIBLE SECTION:/ Operatiodh REVISED BY:

G. 5 nd SUBMITTED BY:

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Res'p6n blej ection Supervisor PORC REVIEW DATE:

APPROVED BY:

3:owk a l T T,r s %

l P l a n't M a n a g e r 21 E DATE APPROVED:

Reason for revision (include all Instruction Change Form.Nos.):

Revised to add transitions from other instructions and to delete reference to SI-48.

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The last page of this instruction is number:

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lC 8708170333 87[PDRh7 PDR ADOCK O P

4 SEQUOYAH NUCLEAR PLANT.

PLANT INSTRUCTION REVISION LOG EMERGENCY INSTRUCTION ES-0.3 REVISION Date Pages REASON FOR REVISION (INCLUDE COMMIT-LEVEL Approved Affected MENTS AND ALL ICF FORM NUMBERS) 0 10/04/84 ALL Revised to add trar.sitions f rom other 1

A JG 21 E instructions and delete reference to I,4 SI-48.

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ES-0.3 Unit 1 or 2 Page 1 of 9 Rev. 1

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NATURAL CIRCULATION COOLDOWN A.

PURPOSE This guideline provides actions to perform a natural circulation RCS cooldown and depressurization to cold shutdown.

B.

SYMPTOMS None C.

TRANSITION FROM OTHER INSTRUCTIONS 1.

ES-0.1, Reactor Trip Response i

2.

ES-0.2, SI Tehaination

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3.

ECA-0.1, Recovery From Loss Of All AC Power Without SI Required l

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SQNP ES-0.3 Unit 1 or 2 Page 2 of 9 Rev. 0 NATURAL CIRCULATION COOLDOWN STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED CAUTION:

If SI actuation occurs, then E-0, Reactor Trip Or Safety Injection, should be used.

t Note:

If at any time nn RCP. can be restarted, then go to appropriate rdrTnal cdoldown instruction 1

Try To Restart An RCP E an RCP can NOT be started, a.

Loop 2 preferred THEN verify natural circulation b.

Refer to SOI-68.2 RCS subcooling c.

Start an RCP and go to appropriate plant S/G press stable or instruction decreasing T-hot stable or decreasing Core exit T/C stable or decreasing

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T-cold at saturation temp for S/G press E natural circulation NOT verified, THEN increase dumping steam l

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SQNP ES-0.3 Unit 1 or 2 Page 3 of 9 Rev. O F-NATURAL CIRCULATION COOL DOWN STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED i

2 Borate RCS To Cold Shutdown Boron Concentration a.

Determine boron concentration per TI b.

Increase the RCS boric acid addition by 15% to compensate for the inability to borate the pzr 3

Verify Cold Shutdown Concentration By Sampling a

RCS hot leg b.

Letdown line l(

.<e q 4

Check VCT Makeup System a.

Makeup set for cold shutdown boron concentration 5

Start All CRDM And Lower Compartment Fans a.

AUgn CRDM dampers to the shroud and in manual (Not P-Auto) b.

IF_ 3 or 4 CRDM fans are b.

IF less than 3 CRDM running,

are running, THEN RCS subcooling THEN RCS subcooling must must be maintained > 50 F be maintained > 100 F c.

Maintain entmt within Tech Spec air temp limit

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SQNP l

ES-0.3 Unit 1 or 2 Page 4 of 9 Rev. 1 NATUR.AL CIRCULATION COOLDOWN STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED 6

Check CST Level a.

CST level > 3 ft a.

IF CST level < 3 ft, TIIEN verify ERCW l

aligned to AFW t

b.

CST level > 17 f t b.

IF CST level < 17 ft, THEN attempt to refill e

CST while co itinuing with this instruction

.I 7

Initiate RCS Cooldown To C613 Shutdown

)f-a.

Start SI-127 j,/

b.

Maintain T-cold cooldown

)y rate < 50 F/hr c.

Dump steam to condenser c.

IF condenser NOT I

Eailable, t

d.

Maintain S/G narrow THEN use S/G PORV range level s 33%

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Refer to GOI-3 as required

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8 Check T-hot < 540 F Do not proceed untu T-hot < 540 F 9

Depressurize RCS To 1920 psig a.

IF letdown is in service, a.

IF letdown or aux TIIEN use aux spray s" pray NOT available, -

THEN itse one pzr PORV l

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SQNP ES-0.3 Unit 1 or 2 Page 5 of 9 Rev. O NATURAL CIRCULATION COOLDOWN

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STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED CAUTION:

SI actuation circuits will autoraatically unblock if RCS press increases above 1970 psig or if RCS temp increases above 540 F l

t 10 Block SI Actuation a.

Block low pzr press SI signal, P-11 b.

Block high steam flow SI signal, P 12 l

j 11 Depresaurize RCS To 1800 - 1900 psi-t 12 Isolate UHI m

a.

Close the 4 UHI isolation valves b.

Gag isolation valves c.

Tag out UHI 13 Maintain Following RCS Condition.

a.

RCS press s 1800 - 1900 psig b.

Pzr level

  • 25%

c.

T-cold cooldown rate

< Su 'F/hr d.

RCS within normal cooldown

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curve SQNP ES-0. 3 Unit 1 or 2 Page 6 of 9 Rev. O NATUR AL CIRCULATION COOLDOWN l

STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED 14 Monitor RCS Cooldown a.

Core exit T/C -

DECREASING

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t b.

T-hot - DECREASING c.

RCS subcooling - INCREASING CAUTION: During RCS depressurizatio:, periodically check the pzr level response for signs of RCS void formation 15 Initiate RCS Depressurization f

a, IF 3 or 4 CRDM fans are a.

IF less than 3 CRDM

  1. {(

running fans are running, THEN maintain 50 F THEN RCS subcooling subcooling must be maintained

> 100 F i

b.

IF letdown is in service, b.

IF letdown or aux THEN use aux spray spray NOT available, THEN use one pzr PORV j

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SQNP ES-0.3 Unit 1 or 2

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Page 7 of 9 Rev. O NATURAL CIRCULATION COOLDOWN STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED 16 Continue RCS Cooldown And Depressurization a.

Maintain T-cold cooldown rate < 50 F/hr b.

Maintain subcooling b.

IF subcooling requirement requirement NOT met, TIIEN stop depressurization and reestablish subcooling c.

Maintain RCS within normal cooldown curve

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17 Check Pzr Level a$ No unexpected changes a,, I_F pzr level response in level

abnormal, THEN repressurize RCS within limits of P-T curve to collapse potential RCS voids.

Continue RCS cooldown 18 Maintain Letdown Flow a.

Open letdown orifice l

valves as necessary

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b.

Adjust letdown press control valve as necessary

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SQNP ES-0.3 Unit I or 2

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.Page 8 of 9 i

Rev. O F

NATURAL CIRCULATION COOLDOWN

' STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED 19 Maintain ItCP Seal Injection Flow I

a.

Adjust FCV-62-89 'as necessary

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b.

Maintain seal injection flow

Restore power to isolation valves b.

Close and tag out isolation valves

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21 At 350 F, Lock Out ECCS Systems Not Required a.

Place non-operating CCP in PULL TO LOCK b.

Place SI Pumps in PULL TO LOCK c.

Close and tag out BIT inlet and outlet valves 1

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SQNP ES-0.3 Unit 1 or 2 Page 9 of 9 Rev. O I

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NATURAL CIRCULATION COOLDOWN STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED 22 Check If RIIR Can Be Placed In Service a.

Check the following:

1) RCS temp 1350 F
2) RCS press 5 380 psig l

b.

Place RHR in service per SOI-74.1 A c.

Use RHR and S/G for cooldown 23 Continue RCS Cooldown To 200 F b

.e CAUTION:

Depressurizing the RCS before the entire RCS temp is less than 212 F may result in void formation in the RCS.

24 Continue Cooldown Of Inactive Portion Of RCS a.

Maintain CRDM and lower compartment fans running b.

Cool S/G U-tubes by dumping steam from all S/Gs 25 Determine If RCS Depressurization Do not depressurire RCS Is Permitted a.

All S/Gs depressurized b.

T-hot $ 200 F c.

Avg core exit T/C 5 212 F d.

Go to appropriate plant instruction

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