ML17310B084
| ML17310B084 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 03/07/1994 |
| From: | Polich T Office of Nuclear Reactor Regulation |
| To: | Conway W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| References | |
| GL-89-10, TAC-M87980, TAC-M87981, TAC-M87982, NUDOCS 9403100060 | |
| Download: ML17310B084 (10) | |
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UNITED STATES Nt ICLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 March 7, 1994 Docket Nos.
50-528, 50-529 and 50-530 Hr. William F.
Conway Executive Vice President, Nuclear Arizona Public Service Company Post Office Box 53999
- Phoenix, Arizona 85072-3999
Dear Hr. Conway:
SUBJECT:
GENERIC LETTER 89-10, SUPPLEMENT 5, "INACCURACY OF MOTOR-OPERATED VALVE DIAGNOSTIC EQUIPMENT" (TAC NOS.
- H87980, M87981, AND M87982)
On June 28, 1993, the NRC staff issued Supplement 5, "Inaccuracy of Hotor-Operated Valve Diagnostic Equipment," to Generic Letter (GL) 89-10, "Safety-Related Motor-Operated Valve Testing and Surveillance," requesting nuclear power plant licensees and construction permit holders (1) to re-examine their HOV programs and to identify measures taken to account for uncertainties in properly setting valve operating thrust to ensure operability, and (2) to evaluate the schedule necessary to consider the new information on MOV diagnostic equipment inaccuracy and to take appropriate action in response to that information.
Within 90 days of receipt of Supplement 5 to GL 89-10, licensees were required (1) to notify the NRC staff of the diagnostic equipment used to confirm the proper size, or to establish settings, for safety-related
- HOVs, and (2) to report whether they had taken actions or planned to take actions (including schedule) to address the new information on the accuracy of HOV diagnostic equipment.
The staff has reviewed the responses, and has found that, for the most part, licensees and permit holders have been actively addressing the uncertainties regarding the accuracy of HOV diagnostic equipment.
The increased inaccuracy of HOV diagnostic equipment can raise questions regarding (1) the adequacy of torque switch settings to provide sufficient thrust while not exceeding thrust or torque structural limits and (2) the capability of actuator motors at current settings.
In their responses, licensees and permit holders indicated that many HOVs had the potential for underthrusting or overthrusting as a
result of the higher than expected inaccuracy of HOV diagnostic equipment.
Consequently, some licensees reported that HOVs have been retested,
- adjusted, or modified to resolve the concerns regarding the accuracy of HOV diagnostic equipment.
Your response to Supplement 5 dated September 28, 1993, stated that the MOV diagnostic equipment used at Palo Verde Nuclear Generating Station (PVNGS) was manufactured by ITI MOVATS, Liberty Technologies, and Teledyne Engineering.
090003 9403100060 940307'PDR ADOCK. 05000528' PDR
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Hr. William F.
Conway You evaluated 139 MOVs using the ITI MOVATS thrust measuring device (TMD) methodology.
Of these
- 139, 25 were Rotork actuators, 75 were Limitorque type SHB actuators, and the remaining 39 were Limitorque type SHC-04 actuators.
Since the Rotork actuators have two spring packs, they were reevaluated using guidance from that vendor.
All Rotork actuators were found to meet the operability requirements.
The Limitorque type SHB actuators were evaluated using ITI HOVATS Engineering Report (ER) 5.2, "Limitorque Actuator Open vs.
Close TH Data Analysis Procedure,"
and found to meet the operability requirements.
Limitorque type SHC-04 actuators had not originally considered in ITI MOVATS ER 5.2.
A test program was performed at
- PVNGS, and the results were provided to ITI MOVATS for inclusion of an accuracy calculation in ER 5.2.
ITI MOVATS provided you a letter containing coefficients for evaluating the SMC-04 test data, which you found meet the operability requirements, Although you determined that the Rotork,
- SMB, and SMC actuators were operable despite the additional inaccuracy in the diagnostic equipment, you decided that some of the actuators will be reset using direct stem measurement data since this method provides greater accuracy and results in a greater available margin of thrust.
Your response stated that the ITI HOVATS TMD methodology is now used only when direct stem measurement is not possible.
The data from HOV tests you performed with VOTES equipment was reevaluated using adjusted setpoint bands developed from vendor guidance.
Eleven of these MOVs had data that fell'utside the adjusted setpoint bands.
Further evaluation determined those 11 HOVs were within the design limits of their respective setpoint calculations and therefore, acceptable.
Your response also stated that Teledyne Engineering had issued two technical reports on the accuracy of stem-mounted strain gages and that the vendor's evaluation will be completed in February 1994.
During a future inspection, the NRC staff will discuss the licensee's resolution of the HOV diagnostic equipment accuracy issue.
Particularly, the staff will discuss the licensee's operability evaluations of HOVs that were retested or that fall outside the licensee's acceptance band.
This completes all efforts on TAC NOS. H87980,
- H87981, and H87982.
If you have any questions regarding this issue, please call me at (301) 504-1038.
Sincerely, Timothy J.
olich, Acting Project Manager Project Directorate V
Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation cc:
See next page
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Nr. William F.
Conway Arizona Public Service Company Palo Verde CC:
Nr. Steve Olea Arizona Corporation Commission 1200 M. Washington Street Phoenix, Arizona 85007 James A. Beoletto, Esq.
Southern California Edison Company P. 0.
Box 800
- Rosemead, California 91770 Senior Resident Inspector Palo Verde Nuclear Generating Station 5951 S. Wintersburg Road
- Tonopah, Arizona 85354-7537 Regional Administrator, Region V
U. S. Nuclear Regulatory Commission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 Mr. Charles B. Brinkman, Hanager Mashington Nuclear Operations ABB Combustion Engineering Nuclear Power 12300 Twinbrook Parkway, Suite 330 Rockville, Maryland 20852 Hr. Aubrey V. Godwin, Director Arizona Radiation Regulatory Agency 4814 South 40 Street
- Phoenix, Arizona 85040 Chairman Naricopa County Board of Supervisors 111 South Third Avenue
- Phoenix, Arizona 85003 Jack R.
- Newman, Esq.
Newman E Holtzinger, P.C.
1615 L Street, N.W., Suite 1000 Washington, D.C.
20036 Mr. Curtis Hoskins Executive Vice President and Chief Operating Officer Palo Verde Services 2025 N. 3rd Street, Suite 220
- Phoenix, Arizona 85004 Roy P.
Lessey, Jr.,
Esq.
Bradley M. Jones, Esq.
Akin, Gump, Strauss, Hauer and Feld El Paso Electric Company 1333 New Hampshire Ave., Suite 400 Washington, D.C.
20036 Nr. Ronald J. Stevens, Director Nuclear Regulatory Affairs Arizona Public Service Company P. 0.
Box 52034
- Phoenix, Arizona 85072-2034
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arch 7, 1994 Hr. William F.
Conway You evaluated 139 HOVs using the ITI HOVATS thrust measuring device (THD) methodology.
Of these
- 139, 25 were Rotork actuators, 75 were Limitorque type SHB actuators, and the remaining 39 were Limitorque type SMC-04 actuators.
Since the Rotork actuators have two spring packs, they were reevaluated using guidance from that vendor.
All Rotork actuators were found to meet the operability requirements.
The Limitorque type SHB actuators were evaluated using ITI HOVATS Engineering Report (ER) 5.2, "Limitorque Actuator Open vs.
Close TH Data Analysis Procedure,"
and found to meet the operability requirements.
Limitorque type SHC-04 actuators had not originally considered in ITI HOVATS ER 5.2.
A test program was performed at
- PVNGS, and the results were provided to ITI HOVATS for inclusion of an accuracy calculation in ER 5.2.
ITI HOVATS provided you a letter containing coefficients for evaluating the SHC-04 test data, which you found meet the operability requirements.
Although you determined that the Rotork,
- SHB, and SHC actuators were operable despite the additional inaccuracy in the diagnostic equipment, you decided that some of the actuators will be reset using direct stem measurement data since this method provides greater accuracy and results in a greater available margin of thrust.
Your response stated that the ITI HOVATS THD methodology is now used only when direct stem measurement is not possible.
The data from HOV tests you performed with VOTES equipment was reevaluated using adjusted setpoint bands developed from vendor guidance.
Eleven of these HOVs had data that fell outside the adjusted setpoint bands.
Further evaluation determined those 11 HOVs were within the design limits of their respective setpoint calculations and therefore, acceptable.
Your response also stated that Teledyne'ngineering had issued two technical reports on the accuracy of stem-mounted 'strain gages and'that the vendor's evaluation will be completed in February 1994.
During a future inspection, the NRC staff will discuss the licensee's resolution of the MOV diagnostic equipment accuracy issue., Particularly, the staff will discuss the licensee's operability evaluations of HOVs that, were retested or that fall outside the licensee's acceptance, band.
This completes all efforts on TAC'OS. H87980,
- H87981, and H87982.
I'f you have any questions regarding this issue, plkease callme at, (301) 504-1038.
Sincerely, Oroginal signed, by:
Jk Timothy J. Polich, Acting Project Manager Project Directorate V
Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation cc:
See next page DISTRIBUTION:
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AHansen NRC Local PDRs PDV R/F TPolich TScarbrough EAdensam DFoster-Curseen LTran Tguay ACRS (10)
JRoe OGC OFC:
NAME:
DATE:
LA:PDV DFoster-Curseen 3/3 /94 PDV PH LTran ~
3/ S/94 PH PDV TPolich 3I 3/94 PD PDV 3/ 7/94 OFFICIAL RECORD COPY DOCUMENT NAME: PVHGL8910. 123
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rch 7, 1994 Hr. William F.
Conway You evaluated 139 HOVs using the ITI HOVATS thrust measuring device (THD) methodology.
Of these
- 139, 25 were Rotork actuators, 75 were Limitorque type SHB actuators, and the remaining 39 were Limitorque type SHC-04 actuators.
Since the Rotork actuators have two spring packs, they were reevaluated using guidance from that vendor.
All Rotork actuators were found to meet the operability requirements.
The Limitorque type SHB actuators were evaluated using ITI MOVATS Engineering Report (ER) 5.2, "Limitorque Actuator Open vs.
Close TH Data Analysis Procedure,"
and found to meet the operability requirements.
Limitorque type SHC-04 actuators had not originally considered in ITI HOVATS ER 5.2.
A test program was performed at
- PVNGS, and the results were provided to ITI HOVATS for inclusion of an accuracy calculation in ER 5.2.
ITI MOVATS provided you a letter containing coefficients for evaluating the SHC-04 test data, which you found meet the operability requirements.
Although you determined that the Rotork,
- SHB, and SHC actuators were operable despite the additional inaccuracy in the diagnostic equipment, you decided that some of the actuators will be reset using direct stem measurement data since this method provides greater accuracy and results in a greater available margin of thrust.
Your response stated that the ITI HOVATS THD methodology is now used only when direct stem measurement is not possible.
The data from MOV tests you performed with VOTES equipment was reevaluated using adjusted setpoint bands developed from vendor guidance.
Eleven of these HOVs had data that fell outside the adjusted setpoint bands.
Further evaluation determined those 11 HOVs were within the design limits of their respective setpoint calculations and therefore, acceptable.
Your response also stated that Teledyne Engineering had issued two technical reports on the accuracy of stem-mounted strain gages and that the vendor's evaluation will be completed in February 1994.
During a future inspection, the NRC staff will discuss the licensee's resolution of the HOV diagnostic equipment accuracy issue.
Particularly, the staff will discuss the licensee's operability evaluations of MOVs that were retested or that fall outside the licensee's acceptance band.
This completes all efforts on TAC NOS.
- H87980, M87981, and H87982.
If you have any questions regarding this issue, please call me at (301) 504-1038.
Sincerely, Oroginal signed by:
Timothy J. Polich, Acting Project Manager Project Directorate V
Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation cc:
See next page DISTRIBUTION:
Docket File PDV R/F TPolich AHansen TScarbrough EAdensam NRC Local PDRs DFoster-Curseen LTran Tguay ACRS (10)
JRoe OGC OFC:
LA:PDV PDV PH PH PDV.-~
PD PDV NAME:
DFoster-Curseen DATE:
3 /3 /94 OFFICIAL RECORD COPY LTran
~/ ~/94 Tqua
~
TPolich
>/ ~/94 3/ 7/94 DOCUMENT NAME: PVHGL8910. 123
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