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)
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Text

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'k, TENNESSEE VALLEY AUTHORITY SEQUOYAF NUCLEAR PLANT -

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L EMERGENCY INSTRUCTION ES-0.3

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NATURAL CIRCULATION COOLDOWN s

Revision 1 PREPARED BY: G. Stric"kland RESPONSIBLE SECTION:/ Operatiodh REVISED BY: G. 5 nd l

SUBMITTED BY: .//b .

Res'p6n blej ection Supervisor PORC REVIEW DATE:

l APPROVED BY: 3:owk a l T T,r s %

P l a n't M a n a g e r DATE APPROVED: 21 E Reason for revision (include all Instruction Change Form.Nos.):

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

om . .. I The last page of this instruction is number: 9 r

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8708170333 PDR P

ADOCK O 87[PDRh7

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 I,4 instructions and delete reference to SI-48.

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SQNP v ES-0.3 Unit 1 or 2

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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
\- 3. ECA-0.1, Recovery From Loss Of All AC Power Without SI Required l

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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 ~

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

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  • 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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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 t aligned to AFW
b. CST level > 17 f t b. IF CST level < 17 ft, e

THEN attempt to refill

, CST while co itinuing with this instruction

.I 7 Initiate RCS Cooldown To "

C613 Shutdown

)f- a. Start SI-127 j,/)y b.

Maintain T-cold cooldown 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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e. Refer to GOI-3 as required

[ 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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. 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 m 12 Isolate UHI

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

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d. RCS within normal cooldown 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 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 THEN maintain 50 F fans are running, 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 i

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ES-0.3 Unit 1 or 2 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

( 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 )
b. Adjust letdown press control valve as necessary

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, , SQNP ES-0.3 Unit I or 2 {

.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
a. 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 1

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

){ NATURAL CIRCULATION COOLDOWN

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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 ,

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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

.e b 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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