ML18039A743
| ML18039A743 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 03/30/1999 |
| From: | Abney T TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-96-05, GL-96-5, TAC-M97021, TAC-M97022, NUDOCS 9904150040 | |
| Download: ML18039A743 (16) | |
Text
CATEGORY 1 REGULATORY INFORMATION DISTRIBUTI SYSTEM (RIDS)
ACCESSION NBR:9904150040 DOC.DATE: 99/03/30 NOTARIZED: NO FACIL:50-260.Browns Ferry Nuclear Power Station, Unit 2, Tennessee
.-'50'=296'rowns Ferry Nuclear Power Station, Unit 3, Tennessee AUTH.NAME AUTHOR AFFILIATION ABNEY,T.E.
Tennessee Valley Authority RECIP. NAME RECIPIENT AFFILIATION Records Management Branch (Document Control Desk)
DOCKET 05000260 05000296
SUBJECT:
Responds to NRC 990112 RAI re BFN program,per GL 96-05, "Periodic Verification of Design-Basis Capability of. Safety-Related MOVs."
DISTRIBUTION CODE: A073D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: GL-96-05 Periodic Verif. of Design Basis CaPability of Saf ty-Related NOTES:
RECIPIENT ID CODE/NAME PD2-3-PD COPIES LTTR ENCL 1
1 RECIPIENT ID CODE/NAME DEAGAZIO,A COPIES LTTR ENCL 1
1 INTERNAL: ACRS LE C
0 NRR/HANSEN, A RES/DST EXTERNAL: NOAC 1
1 1
1 1
1 1
1 1
1 AEOD/SOD/RAB NRR/DE/EMEB RES/DET/EIB/B RES/DST/PRAB NRC PDR 1
1 1
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1 RCIÃkmB NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD)
ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED:
LTTR 12 ENCL 12
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Tennessee Valley Authority, Post Office Box 2000. Decatur, Afabama 35609 March 30, 1999 U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.C.
20555 Gentlemen:
In the Hatter of Tennessee Valley Authority Docket Nos.
50-260 50-296 BROWNS FERRY NUCLEAR PLANT (BFN)
UNITS 2 AND 3 GENERIC LETTER (GL) 96-05, PERIODIC VERIFICATION OF DESIGN-BASIS CAPABILITY OF SAFETY-RELATED MOTOR-OPERATED VALVESI REQUEST FOR ADDITIONAL INFORMATION (TAC NOS.
M97021 AND M97022)
This letter provides TVA's reply to a request from the NRC Staff, dated January 12, 1999, for additional information regarding the BFN GL 96-05 program.
TVA is a member of both the Westinghouse Owners Group and the Boiling Water Reactor Owners Group (BWROG) which have established a joint committee to develop a generic program for GL 96-05.
TVA is participating in the Joint Owners Group (JOG) Motor-Operated Valve (MOV) Periodic Verification (PV)
Program and has committed to implement the JOG Program at BFN by letter dated April 28, 1998.
Based on its review of the BFN GL 96-05 program, the results of on-site GL 96-05 NRC inspections, and emergent industry issues, the Staff is requesting that TVA describe its intentions regarding certain aspects of the BFN program.
9904150040 990330 PDR ADOCK 05000260 PDR J U~
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<U.S. Nuclear Regulatory Commission Page 2
March 30, 1999 The enclosure to this letter contains the specific NRC Staff requests and the corresponding TVA responses.
If you have any questions regarding this response, please contact me at (256) 729-2636.
Si cerely, Ab Manager of Lice and Industr A'ffair Enclosure cc:
See page 3
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~U.S..Nuclear Regulatory Commission
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Page 3
March 30, 1999 Enclosure cc (Enclosure):
Mr. Paul E. Fredrickson, Branch Chief U.S. Nuclear Regulatory Commission Region II 61 Forsyth Street, S.W.
Suite 23T85 Atlanta, Georgia 30303 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road
- Athens, Alabama 35611 Mr. Albert W.
De Agazio, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852
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ENCLOSURE TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNITS 2 AND 3 GENERIC LETTER 96 05 g PERIODIC 'VERIFICATION'F DES IGN BASIS CAPABILITY OF SAFETY-RELATED MOTOR-OPERATED VALVES NRC REQUEST FOR ADDITIONAL INFORMATION Back round On September 18,
- 1996, NRC issued Generic Letter (GL) 96-05, "Periodic Verification of Design-Basis Capability of Safety-Related Motor-Operated Valves," to request that licensees establish a program to verify on a periodic basis that safety-related motor-operated valves (MOVs) continue to be capable of performing their safety functions within the current licensing basis.
TVA is a member of both the Westinghouse Owners Group and the Boiling Water Reactor (BWR) Owners Group which have established a joint committee to develop a generic program for GL 96-05.
TVA is participating in the Joint Owners Group (JOG) Motor-Operated Valve (MOV) Periodic Verification (PV)
Program and has committed to implement the JOG Program at BFN by letter dated April 28, 1998.
As a result of the Staff's review of BFN's GL 96-05 response, subsequent NRC on-site GL 96-05 inspections, and emergent industry issues, the Staff requested by letter dated January 12, 1999, that TVA provide additional information.
The specific NRC questions and the corresponding TVA responses are provided below.
NRC Question No.
1 In NRC Inspection Report No. 50-259,
- 260,
& 296/98-05, the NRC staff closed its review of the motor operated valve (MOV) program implemented at Browns Ferry Nuclear Plant (Browns Ferry) in response to Generic Letter (GL) 89-10, "Safety-Related Motor Operated Valve Testing and Surveillance,"
based on the results of the inspection and the licensee's actions to resolve outstanding MOV issues as described in a letter dated July 16, 1998.
In the inspection report, the NRC staff discussed certain aspects of the
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licensee's MOV program to be addressed over the long term.
For
- example, the inspectors noted that
- 1) the licensee intends to use data from other licensees to justify the load sensitive behavior assumptions applied to MOVs with roller screw stem nuts; and 2) the licensee was developing a quantitative analysis to show that dc MOVs would perform their design-basis function within specified stroke time requirements.
In addition, NRC Inspection Report No. 50-259,
- 260, 296/98-03 noted that the licensee had not completed revisions to the Unit 2 thrust calculations and setting drawings.
These revisions were scheduled for completion by August 31, 1998.
The licensee should provide a summary status of actions taken to address the specific long term aspects of the MOV program at Browns Ferry noted in the NRC inspection reports and its letter dated July 16, 1998.
TVA Res onse Subsequent to the above referenced Inspection Reports, NRC Region II inspectors conducted a followup inspection for GL 89-10/96-05.
The results of that inspection are described in NRC Inspection Report 50-259,
- 260, 296/98-08 dated January 2S, 1999.
In this inspection report, each of the above concerns were resolved with the exception of IFI 50-260, 296/98-03-04 "Analysis of dc MOV motor stroke times based on GL 89-10 test data."
Although TVA had performed a quantitative analysis of dc MOV motor stroke
- times, the issue was held open for further review pending the expected release of additional dc motor stroke time test data by the Idaho National Engineering Environmental Laboratory this year.
As of this date, the additional information has not been published.
Also, the BWROG Valve Technical Resolution Group (VTRG) is developing a standardized methodology for performing dc MOV motor stroke time analyses.
BFN will continue to monitor this issue and evaluate the information as it becomes available relevant to its impact on the BFN dc MOV motor stroke time analyses.
NRC Question No.
2 The licensee indicates that its MOV static diagnostic periodic verification program will include test methods at the valve and the motor control center.
Will diagnostic data be obtained for all GL 96-OS MOVs? If not, the licensee should describe its plans to monitor degradation in capability for those MOVs not diagnostically tested.
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BFN plans to obtain static diagnostic test data for all MOVs within the scope of the BFN GL 96-05 program.
NRC Question No.
3 The licensee should briefly describe its plans for the use of test data from the motor control center (MCC) including (1) correlation of new MCC test data to existing direct force measurements; (2) interpretation of changes in MCC test data to changes in MOV thrust and torque performance; (3) consideration of system accuracies and sensitivities to MOV degradation for both output and operating performance requirements; and (4) validation of MOV operability using MCC testing.
TVA Res onse At this time TVA intends to use the MCC diagnostic test method to monitor degradation for butterfly valves only.
Since BFN does not have any butterfly valves in its GL 96-05 program, this question is not applicable.
NRC Question No.
4 The Joint Owner's Group (JOG) program focuses on the potential age-related increase in the thrust or torque required to operate valves under their design-basis conditions.
In the NRC safety evaluation dated October 30,
- 1997, on the JOG program, the NRC staff specified that licensees are responsible for addressing the thrust or torque delivered by the MOV motor actuator and its potential degradation.
In a letter dated April 28,
- 1998, the.
licensee stated that potential actuator degradation would be identified through review and trending of actuator performance parameters.
- Further, NRC Inspection Report NO. 50-259,
- 260, 296/98-03 noted that the licensee was revising actuator output calculations for the close direction to include more conservative pullout efficiencies and an application factor of 0.9.
- However, Limitorque had not yet released its Technical Update 98-01 at the time of this inspection.
Therefore, the licensee should provide the cu'rrent status of actions at Browns Ferry for ensuring adequate ac and dc MOV motor actuator output capability, including consideration of recent guidance in Limitorque Technical Update 98-01 and its Supplement 1.
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To address the potential degradation of the thrust or torque delivered by the MOV motor actuator, BFN plans to monitor and
- trend, except where limited by test instrument accessibility, the following actuator performance parameters:
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Thrust/Torque At Control Switch Trip,
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Total Thrust/Torque
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Average Running Thrust/Torque
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Average Running Current
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Peak Inrush Current
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Spring Pack Displacement At Control Switch Trip
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Stem Factor At Control Switch Trip, And
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Rate Of Loading When DP Data Is Available.
In addition, BFN is an active member of the BWROG-VTRG and any new recommendations from Limitorque and/or the BWROG regarding dc MOVs are evaluated for incorporation into the BFN MOV program.
BFN has also reviewed and implemented the technical recommendations of Limitorque Technical Update (TU) 98-01 and its Supplement 1.
A review of BFN ac motors was performed in accordance with TU 98-01.
The list of MOVs requiring specific configuration review was submitted to Limitorque for their review in accordance with TU 98-01 recommendations.
The results of these reviews have been incorporated into the actuator sizing portion of the MOV design basis calculations.
With the exception of those MOVs equipped with 60 foot-pound, 1800 rpm, Frame 56 motors, all MOV calculations use pullout actuator efficiency and an application factor of 0.9.
For those MOVs equipped with 60 foot-pound Frame 56 motors, the affected calculations were revised to include an additional actuator output capability reduction of 0.9, based on Limitorque's review of these MOVs.
BFN has no MOVs in the GL 89-10/96-05 programs equipped with 25 foot-pound, 3600 rpm, Frame 56 motors or SMB-1 actuators with a worm gear ratio of 66:1.
Therefore, all, actions required to address TU 98-01 and Supplement 1 have been performed.
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