ML20197G540
| ML20197G540 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/19/1997 |
| From: | Salas P TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-89-10, NUDOCS 9712310049 | |
| Download: ML20197G540 (10) | |
Text
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Tennessee Vaney Authority, Post O'fce Box 2000, SoddcDaisy, Temessee 37379-2000 December 19, 1997 U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.C.
20555 Gentlemen:
In the Matter of
-)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 SEQUOYAH NUCLEAR PLANT (SQN) - STATUS LETTER REGARDING COMMITMENT CLOSURE FOR NRC GENERIC LETTER (GL) 89-10
Reference:
TVA letter to NRC dated July 8, 1997, "Sequoyah Nuclear Plant (SON) - Con,mitments Regarding
'3eneric Letter IGL) 89-10 Program Closure" The purpose of this letter is to provide a status of TVA's 1
GL 89-10 commitments as provided in the referenced letter.
By the referenced letter, TVA committed to nine long-term actions associated with SON's GL 89-10 program.
TVA, as part of SON's commitments to GL 89-10, agreed to provide a status latter by the end the calendar year 1997.
The status information is enclosed.
Note that with the exception of the scheduled actions described below, SON has completed the nine long-term commitment items for SQN's GL 89-10 program.
SCHEDULED ACTIONS TVA plans to perform modifications to four valves in SON's containment spray system during the Cycle 9 refueling outage for both units, f
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6 U.S..hoclear Rcgulatory Commission Pago;2 December 19,.1997 i
i TVA's commitment - for-performing maintenance improvements j
to SON's power-operated relief valve block valves was completed for Unit 2 during the Unit 2. Cycle-_8 refueling outage.
This commitment.is-to be completed for Unit 1 i
during.the Unit 1 Cycle 9 refueling outage.
The Unit 1 action is contained in SON's commitment tracking system as-NCO 970056005.
-Enclosure _1 provides_the status for SON's-GL 89-10 commitments and a description of the actions-taken to complete each commitment. -provides a new TVA commitment for-the scheduled action item-1 described above.
Please direct questions concerning this issue to me at (423) 843-7170 or J.
D. Smith at (423) 843-6672.
Sincerg,, j
- /
r Pedro Salas i
Licensing and Industry Affairs Manager Subscribejtoand'sworntobefore-me this /9 day of December /997 4
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Notary Public'
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-My Commission Expires
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U.S. Nuclear Regulatory Commission
. Page 3 December 19, 1997 Enclosures cc (Enclosures):
Mr. R. W.
Hernan, Project Manager Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 NRC Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy-Daisy, Tennessee 37379-3624 Regional Administrator U.S. Nuclear Regulatory Commission Region II Atlanta Federal Center, 61 Forsyth St.,
SW, Suite 23T85 Atlanta, Georgia 30303-3415
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RU.S. Nuclear ~ Regulatory Commission
-Page 3 December 19, 1997 I
i PS:JDS:DVG:PMB Enclosures t
cc (Enclosures):
Mr..R. W..Hernan, Project' Manager Nuclear Regulatory Commission One White Flint,' North l
11555 Rockvillo Pike Rockville, Maryland 20852-2739 NRC Resident Inspector
'Sequoyah Nuclear-Plant
-2600 Igou Ferry Road i
soddy-Daisy, Tennessee 37379-362f i
i Regional Administrator U.S. Nuclear Regulatory Commission Region-II l'
Atlanta Federal Center, 61 Forsyth St.,
SW, Suite ~23T85 I.tlanta, Georgia 30303-3415 J. A. Bailey, LP 6A-C M. Bajestani, OPS 4A-SQN C.
J.- Burzynski, BR 4J-C
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E.-S.
J.
Fecht, OPS 4A-SQN K. N. Harris, LP 6A-C J. T. Herron, POB 28-SQN NSR8 support, BR 4J-C J. A.
Scalice, LP 6A-C RIMS, WT 3B-K (Re:
S64 970714 802) 1:GL'89-10 Commitment Status 9
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ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY SEQUOYAN NUCLEAR PLANT (SQN)
UNITS 1 AND 2 STATUS LETTER REGARDING CODMITMENT CLOSURE FOR NRC
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GENERIC LETTER (GL) 89-10 j
"1.
TVA Comunitment:
TVA will revise gate valve calculations to incorporate a 0.6 valve factor unless differential pressure test data is
.iailable to indicate a valve factor other that 0.6.
This commitment will be completed by November 7, 1997.
Note:
For any gate valve groups.that have less than acceptable differential pressure (dp) test data to support a 0.6 valve factor, TVA plans to evaluace industry dp test data to justify existing valve factors."
Status:
t This commitment is complete.
TVA revised 138 gate valve calculations to either:
increase valve factors to 0.6 or e
incorporate additional justification supported by industry differential pressure test data.
"2.
TVA Conunitment:
TVA will participate in a but,terfly valve test program with Duke Power Company or obtain appropriate test data from other sources (i.e.,
Kalsi Engineering or Duke Engineerjng Services) to validate Pratt design information.
The validation-will be completed by December 31, 1997.
Note:
TVA has reevaluated the data associated with SON's GL 89-10 butterfly valves.
This reevaluation determined that the.available margin for these valves is greater than 30 percent."
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"gi status:-
TVk-considers _thiscommitmentcompleteforSQN'sGL89-10
. program._ Duke is continuing to provide test data as.part of Duke's differential pressure test program for Henry Pratt Butterfly valves.. Preliminary differential. pressure test _ data from two eight-inch Henry Pratt butterfly valves-shows that an increase of-nine percent in the torque-value would be required.
The lowest available margin for SQN's Henry Pratt butterfly 1
4 valves is 31 percent margin.
Accordingly, a nine percent
- increase in' torque' requirements would be acceptable for-SQN's l
Pritt butterfly valvsa.-
!l Note: 1TVA plans to monitor the progress of the Duke differential-
_ pressure test program for Henry Pratt Butterfly valves and
~
4 incorporate the'results into SON's GL 89-10 program.
Monitoring Lthis effort is a part of SON's ongoing program for GL 96-05,
- " Periodic' Verification of Design Basis Capability of-Safety Related Motor-Operated Valves."
l "L.
TVA commitment:-
TVA will issue a design change notice (DCN).to update the valve switch-setting sheets after calculations are completed. The DCN for both units will be completed by l
Dteember 1, 1997."
Status:
This action is.omplete.. TVA completed the calculations and-issued DCN S13223A to update the valve switch setting sheets.
"4.
TVA Commitment:
=TVA will review differential pressure test data to determine
-if a factor of 1.0 (in the closing direction) is appropriate-for SON's Velan globe valves.
The review will be completed by September 30, 1997."
Status:
This action is complete.
TVALreviewed differential pressure test data and determined;that a higher valve factor of 1.1 would be more1 appropriate _for the Velan globe _ valves.. The new valve
- factor has been incorpora
- ed into SON's GL 89-10 calculations and switch setting _ sheets.
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4 "5.. TVA commaitment:
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TVA will perform. maintenance improvements (e.g.,
radius internal valve edges, check internal valve clearances, 4
ensure proper alignment, inspect valve seat, etc.) and-
. perform the_EPRI Performance Prediction Program-(PPP) for SON's PORV block valves. This commitment will be complete for Unit 2 before restart from the Unit 2 Cycle 8 refueling outage-(currently' scheduled for. November 4, 1997).
This
_ commitment will be complete.for Unit 11before restart from the Unit:1 Cycle 9-refueling outage-(currently scheduled for October 19, 1998)."
t status:
This action is complete for Unit 2.
TVA performed maintenance i
improvements (i.e.,
chamfered interna 1Lvalve edges,-refurbished 4
. valve internals, iilspected gate guides for damage) and performed the EPRI PPP for SON's Unit 2 PORV block valves.
The same I
maintenance' improvements-are scheduled for-the Unit i valves during the~ upcoming Unit 1 Cycle 9 refueling outage.
"6.
TVA consmitment:
L Provide a plan to verify orientation and perform PPM on 11,2-FCV-72-2,-39.
TVA will determine improvements (i.e.,
obtain additional test data or perform-the EPRI PPP) for valve factors and other margins associated with these valves.
This commitment will be completed by September 30, 1997."
status:
This action is complete.
TVA evaluated the orientation of the valve internals and determined that valve internals is not a i
i factor for these valves.
The EPRI program requires a factor to Lbe applied to a valve that is closing against a differential pressure if the internals are oriented in the nonpreferred direction.
SON's valves are not required to close against a differential pressure.- Accordingly, orientation of the valve
' internals does not affect valve factors for these valves..
The conservative EPRI: Performance Prediction' Methodology -(PPM) increased the required opening thrust for these valves. The Lrequi' red opening thrust increased from 13,090 pounds to
- 22,095 pounds. This new thrust requirement exceeds the actuator capability of 14,500 pounds. -Based on conservatism provided by I
the EPRI PPM,'this is not a valve operability issue for GL 89-10.
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However, long-term qualification of these valves will require a design change.
Accordingly, TVA has scheduled design changes (DCN T13771A for Unit 1 and DCN T13770A for Unit 2) to be completed during the Cycle 9 refueling outages for each unit.
The design change will increase the actuator capability.
In addition, the new thrust requirement value is incorporated into the associated valve calculations and switch setting data sheets.
"7.
TVA Coramitment:
TVA will add a 5 percent margin as a minimun requirement for valve degradation.
This commitment will be completed by November 7, 1997."
Status:
This action is complete.
TVA added a five percent margin to SON's GL 89-10 calculations for valve degradation.
"8.
TVA Commitment:
TVA will add a 10 percent margin for ROL (until further evaluation is available).
This commitment will be complete by November 7, 1997."
status:
Thit action is complete.
TVA added a minimum 10 percent margir. to SON's GL 89-10 calculations f or rate of loading (ROL).
Where differential pressure test data indicated a higher ROL factor wa-required, a higher ROL factor was used.
"9.
TVA Commitment:
Provide plan for 2-FCV-68-332/333 actuator structural capability.
TVA will revise SQN calculations to provide an increase in the torque rating.
This commitment will be complete by November 7, 1997."
status:
This action is complete.
TVA utilized the Kalsi Limitorque Actuator Fatigue Life Analysis Program to justify an appropriate torque rating.
Tnis analysis resulted in a 12 percent increase in the torque rating.
Based on this increase, the calculations and switch setting data sheets were revised accordingly.
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"10. TVA Commitment:
TVA will submit a progress letter to NRC to provide an up-to-date status of the commitments described above.
This letter will be submitted by December 31, 1997."
status:
This action is complete.
This letter fulfills the commitment for providing a status of SON's GL 89-10 comatitments.
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ENCLOSURE 2 TENNESSEE VALLEY AUTHORITY t
SEQUOYAH NUCLEAR PLANT (SQN)
UNITS 1 AND 2 STATUS LETTER REGARDING COMMITMENT CLOSURE FOR NRC GENERIC LETTER (GL) 89-10 TVA COMMITMENT TVA will perform modifice.tions to increase actuator capability for four valves in SQN's containment spray system (1,2-FCV-72-2 and FCV-72-39).
This action will be complete prior to startup from the Cycle 9 refueling outage for both units.
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