ML20237J007

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Rev 1 to Emergency Instruction ES-3.2, Post-Steam Generator Tube Rupture Cooldown Using Backfill
ML20237J007
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-3.2, NUDOCS 8708170458
Download: ML20237J007 (8)
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Text

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s.

TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT _

EMERGENCY INSTRUCTION -

l ES-3.2 POST-SGTR COOLDOWN USING BACKFILL -.

4..

Revision 1 .

PREPARED BY: StricklanO

, RESPONSIBLE SECTION: Operatip [

REVISED BY: G. kl d SUBMITTED BY: 48/N >

'hn l# Re'sjion's le S'6 tion Supervisor

.PORC REVIEW DATE: ~AU 21Gb5  ;

APPROVED BY:  % W( c$th Pldht ' Manager DATE APPROVED: .AUG 21 E85 Reason for revision (include all Instruction Change Form Nos.):

Revised to delete reference to SI-48, and to clarify note.

I 4

- C.

The lart page of this instruction is number: 6 8700170450 870811 DR ADOCK O y7

SEQUOYAH NUCLEAR PLANT PLANT INSTRUCTION REVISION LOG -

EMERGENCY INSTRUCTION ES-3.2 ,,

~

REVISION Date Pages REASON FOR REVISION (INCLUDE COMMIT-LEVEL _ Approved Affected MENTS AND ALL ICF FORM NUMBERS)

^

O_ 10/04/84 ALL gjg g g jgg 3,6 Revised to delete reference to SI-48, 1 and to clarify note.

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et -

1 0274L/mbs

SQNP

. ES-3. 2 Unit 1 or 2 Page 1 of G Rev. O F

I

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POST- SGTR COOLDOWN USING B ACKFILL A. PURPOSE This guideline provides actions to cooldown and depressurize the plant to cold shutdown ' conditions following a steam generator tube rupture, This recovery method depressurizes the ruptured S/G by draining it through the ruptured S/G tube into the RCS.

B. SYMPTOMS None ,

C. TRANSITION FROM OTHER INSTRUCTIONS ES-3.1, SI Termination Following SGTR

.c

SQNP ES-3.2 Unit 1 or 2

. Page 2 of 6 Rev. O F

POST- SGTR COOLDOWN USING B ACKFILL STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED 1 Establish Pzr Press Control

a. Pzr bubble established
b. Pzr liquid- at saturation temp
1) Control pzr heaters as necessary
c. Maintain RCS press at ruptured S/G press

.c 2 Check If Cold Leg Accumulators Should Be Isolated

a. WHEN RCS press < 1000 psig AND STABLE,

, , T11EN :

1) Restore power to isolation valves
2) Close cold leg accumulator 2) IF, isolation valve can isolation valves NOT be closed, TIIEN vent any unisolated accumulator 3 Check Shutdown Margin During Cooldown
a. Periodically sample RCS boron concentration
b. During cooldown, borate RCS due to dilution from ruptured S/G I

SQNP ES-3. 2 Unit 1 or 2

. Page 3 of 6 Rev. 1 lfk POST- SGTR COOLDOWN USING BACKFILL

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STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED 4 Initiate RCS Cooldown To 200 F

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$. a. Start SI-127

b. Cooldown a's quickly as possible but do not exceed -

T-cold cooldown of 100 F in any 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />

c. Dump steam to condenser c. IF condenser NOT from intact S/Gs available,

... THEN use intact S/G PORVs

d. Maintain intact S/G d. IF any S/G 1evel levels s 33% Increases in an uncontroHed manner, THEN go to
  • E-3,

..e J

e. Refer to GOI-3C as required
f. Refer to ES-0.2 as required ,

5 Adjust Pzr Level l

a. Establish pzr level between j 20% and 30% [50% and 60%  !

FOR ADVERSE CNTMT]

1) Adjust charging and letdown as necessary
2) Control pzr heaters as .

necessary -

SQNP

. ES-3.2 Unit 1 or 2 Page 4 of 6 Rev. O POST- SGTR COOLDOWN USING B ACKFILL STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED Note: When refilling ruptured S/G, if the S/G press increases to 1015 psig or decreases in an uncontrolled manner, then stop AFW flow to the ruptured S/G. Adjust RCS press to the ruptured S/G press.

O Established Ruptured S/G Level > 25%

a. Control ruptured S/G a. IF ruptured S/G level between 25% and 50% "

level > 50%,

T11EN stop AFW to ruptured S/G 7 Start Backfilling Ruptured

( S/G Into RCS

.e l k a Slowly depressurize RCS a. IF letdown is in service, below ruptured S/G press THEN use aux spray using normal pzr sprays IF letdown NOT in service, THEN use one pzr PORV and note following:

1) Upper head may void
2) PRT may rupture
b. Verify backflow  ;
1) Pzr level increasing
2) Ruptured S/G level decreasing l

l

I SQNP ES-3.2 Unit 1 or 2 Page 5 of 6 Rev. O F\

I POST- SGTR COOLDOWN USING B ACKFILL

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STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED 8 Check If RCS Depressurization Should Continue

a. Pzr level < 80% a. IF_ pzr level > 80%,

' TIIEN:

1) Equalize RCS press and ruptured S/G press
2) Restore pzr level

< 80% before -

continuing RCS depressurization

b. Ruptured S/G b. I_F ruptured S/G level > 25%

~

level < 25%,

g THEN;

1) Equalize RCS press and ruptured S/G  !

press

2) Restore ruptured S/G 1evel > 25%

before continuing RCS depressurization

c. RCS subcooling > 40 F c. IF RCS subcooling not )

met, l THEN ' reestablish RCS )

subcooling before  !

continuing depressurization l 1

l l

I 1

.___________o

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a

, SQNP

, ES-3.2 Unit 1 or 2 Page 6 of 6 Rev. 1 llk-

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POST- SGTR COOLDOWN USING BACKFILL STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED i 9 Check IF RHR Can Be Placed Tn Service

a. Check the following:
1) RCS temp 5 350 F
2) RCS press 3 380 psig
b. Place RHR in service per SOI-74.1 A
c. Use RHR and intact S/G .-

for cooldown 10 Check If RCPs Must Be Stopped

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{ a. WHEN conditions for running

.A. # ~ RCPs can NOT be maintained, THEN stop RCPs 11 Continue RCS Cooldown To 200 F 12 Continue Backfilling Ruptured S/G Into RCS 13 Evaluate Long Term Plant Status

a. Maintain cold shutdown
b. Consult with plant staff p Note: In order to isolate the ruptured S/G from RCS, the ruptured C hG S/G and pzr level must be below the break elevation. Because -

F the S/G tube sheet (elev.

  • 703') is below the pzr level lower -

4 tap (elev. s 711'5") and S/G wide range level lower tap 4 (elev. N 704'8"), the pzr level and S/G wide range level may

  • be required to be downscale when ruptured S/G is drained.

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