ML20063F353
| ML20063F353 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 10/05/1993 |
| From: | Hutchinson C ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-89-10, GNRO-93-00113, GNRO-93-113, NUDOCS 9402140256 | |
| Download: ML20063F353 (7) | |
Text
4
= ENTERGY l'"" "'"" * '
C. R. Hutchin son October 5.
1993 U.S. Nuclear Regulatory Commission Mail Station P1-37 Washington, D.C.
20555 Attention:
Document Control Desk
Subject:
Grand Gulf Nuclear Station Docket No. 50-416 License No. NPF-29 Grand Gulf Nuclear Station Response to Generic Letter 89-10, Supplement 5:
" Inaccuracy of Motor-Operated Valve Diagnostic Equipment" GNRO-93/00113 Gentlemen On July 7, 1993, the Grand Gulf Nuclear Station (GGNS) received Supplement 5 to Generic Letter (GL) 89-10.
Supplement 5 discusses the NRC staff's new info = nation collected on the reliability of data provided by MOV diagnostic equipment.
The staff requested that licensees reexamine their Motor-Operated Valve (MOV) programs and to identify measures taken or planned to account for uncertainties in properly setting valve operating thrust to ensure operability.
In April 1992, Grand Gulf initiated measures to evaluate GL 89-10 valves for overthrust conditions emanating from inaccuracies in MOV diagnostic equipment.
Actions taken since this date were based on routine internal responses to the generic communications later referenced in Supplement 5, i.e.,
NRC Information Notices, ITI-MOVATS " Potential Issue" notification, and Liberty Technologies 10 CFR Part 21 notification.
GGNS considers these actions adequate to ensure valve operability and to address diagnostic error deficiencies identified in GL 89-10, Supplement 5.
The extent of the actions taken are discussed in detail in the attached response to Supplement 5.
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PDR ADOCK 05000416 j
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october 5. 1993 GNRO-93/00113 Page 2 of 3 P
Should you have additional questions or concerns regarding the attached, please contact Ms. Jewel Summers at (601) 437-2149 for assistance.
Yours tru A
sh'//
CRH/JS/ams attachment:
GGNS Response to Generic Letter 89-10, Supplement 5:
" Inaccuracy of Motor-Operated Valve Diagnostic Equipment" cc:
Mr. R. H. Bernhard (w/a)
Mr. H. W. Keiser (w/a)
Mr. R. B. McGehee (w/a)
Mr. N. S. Reynolds (w/a)
Mr. H. L. Thomas (w/o)
Mr. Stewart D. Ebneter (w/a)
Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta St.,
N.W.,
Suite 2900 Atlanta, Georgia 30323 Mr.
P. W. O'Connor, Project Manager (w/2)
Office of Nuclear Reactor Regulation-U.S. Nuclear Regulatory Commission Mail Stop 13H3 Washington, D.C.
20555 i
G9309081 1
.l BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION i
LICENSE NO. NPF-29 DOCKET NO. 50-416 IN THE MATTER OF MISSISSIPPI POWER & LIGHT COMPANY
)
and SYSTEM ENERGY RESOURCES, INC.
and SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION and ENTERGY OPERATIONS, INC.
AFFIRMATION j
i I,
C. R. Hutchinson, being duly sworn, state that I am Vice President, Operations GGNS of Entergy Operations, Inc.; that i
on behalf of Entergy Operations, Inc., System Energy Resources, Inc., and South Mississippi Electric Power Association I am authorized by Entergy Operations, Inc. to sign and file with the Nuclear Regulatory Commission, this application for amendment of the Operating License of the Grand Gulf Nuclear Station; that I signed this application as Vice President, Operations GGNS of Entergy Operations, i
Inc.; and that the statements made and the matters set forth therein are true and correct to the be of knowledge, information and belief.
~C. R. Hutchinson STATE OF MISSISSIPPI COUNTY OF CLAIBORNE j
SUBSCRIBED AND SWORN TO before me, a Notary Public, in and for the County and State above named, this M
day'of
/2.fA 1993.
(SEAL) 21 m / Notary PuYlic My commission expires: Ab M.2k/9%' G9309081
m - d Attachm:nt-to GNRO-93/00113 Page 1 of 4 RESPONSE TO GENERIC LETTER 89-10, SUPPLEMENT NO. 5 INACCURACY OF MOTOR-OPERATED VALVE DIAGNOSTIC EQUIPMENT REQUESTED ACTIONS: On the basis of the new information on MOV diagnostic equipment inaccuracy..., licensees are requested to: 5 Action No. 1: Reexamine their MOV programs and to identify measures taken or planned to account for uncertainties in properly setting valve operating thrust to ensure operability. Licensees should not limit their evaluation to only the specific examples of increased inaccuracy of MOV diagnostic equipment provided in the Discussion section of this GL supplement, but should consider any information reasonably available to them. GGNS Response GGNS uses two distinctly different types of' diagnostic equipment for testing MOVs for compliance with Generic Letter 89-10' requirements for establishment of valve thrust settings. The diagnostic techniques used at GGNS are the ITI-MOVATS 3000 Series and the VOTES 100 System. Guidelines have been developed for proper installation and use'of test equipment to obtain the required thrust settings for all safety-related MOVs. The ITI-MOVATS equipment is only used-for those MOVs with substantial margin between the minimum required operating thrust and the maximum allowable thrust. The MOVATS 3000 system is also used to test butterfly MOV's. Below is a list of current measures that have been implemented to compensate for uncertainties in thrust readings produced by MOV diagnostic equipment for safety related MOVs at GGNS. j A. ITI MOVATS. Inc.. 3000 Series Test System The final results of validation testing of MOV diagnostic equipment conducted for the Motor Operated Valve Users Group (MUG) indicated that MOV diagnostic equipment that relies on j indirect stem thrust measurement techniques of monitoring i spring pack displacement to estimate stem thrust may not i meet the accuracy claims of the vendors. On February 28, 1992, ITI-MOVATS issued notification of a " Potential Issue"(pursuant to 10 CFR Part 21) regarding the use of spring pack displacement to estimate closing stem thrust. The nature of the issue concerned the accuracy of the.ITI-MOVATS thrust measuring device (TMD) methodology when used for valves'whose safety function is in the closed direction (or whose safety function is required in both the opened and closed directions). The NRC subsequently issued an G9309081 l
y Attachment to GNRO-93/00113 Page 2 of 4 4 Information Notice (92-23) to provide the results of validation testing of MOV diagnostic equipment conducted for the MOV Users Group (MUG) of nuclear power plant licensees. In response to these documents the following actions were taken: 1. An engineering evaluation was performed for all MOVs previously tested utilizing the ITI-MOVATS 1FD test methodology. The reevaluation of test results included not only closed torque switch settings but also included open torque switch settings. For valves that have a "close" direction safety function the evaluation consisted of a review of existing baseline test results using the ITI-MOVATS methodology (as outlined in ITI-MOVATS engineering report 5.2 "Limitorque Actuator Open va. Close TMD Analysis procedure") to determine if any thrust requirements were outside of their design limits. The evaluation concluded that previous baseline test results were acceptable, except for two MOVs which remained in question. These two valves were later retested and found acceptable. The open torque switch settings were reevaluated using the results of the MUG validation testing. The results of this evaluation showed that there were no outstanding operability concerns. 2. The MOV Torque Switch Setpoint Methodology procedure has been revised to account for the equipment inaccuracies noted in the MUG final report. All MOVa that have as left closed thrust set by the MOVATS DMT (f ormerly TMD) and load cell methodology and any new MOVs tested using the MOVATS 3000 system with the DMT and Load Cell combination will be reviewed against the ITI-MOVATS acceptance criteria developed in response to the Part 21 notification. B. Liberty Technolooies. VOTES 100 System On October 2, 1992, Liberty-Technologies, manufacturer of the Valve Operation Tests and Evaluation System (VOTES), issued a Part 21 Notification pursuant to 10 CFR 21. This notification concerned inaccuracies in valve thrust readings obtained using the VOTES' system. The following actions were taken: 1. An engineering evaluation was performed of valves tested using the VOTES system. It was determined that 32 MOVs had been tested using VOTES during the previous refueling outage (RF05). The evaluation G9309081
g. ~ Attnchment to GNRO-93/00113 Page 3 of 4 revealed that the corrected as-left thrust for 19 of the 32 valves in question exceeded the maximum allowable stem thrust values for MOVs at GGNS. A Material Nonconformance Report (MNCR) was' issued to_ document this condition. All affected MOVs have been determined to be operable, however corrective actions (increasing the torque value for actuator to valve yolk bolts) are planned for the next refueling outage (RF06) to address the concerns documented in the MNCR. All required corrective actions will be tracked by the MNCR. 2. The GGNS procedure that provides the methodology for establishing field set points for MOV actuator torque switch settings has been revised to account for the additional inaccuracies noted in the Part 21 notification. Any MOVs that were tested using the VOTES system between issuance of the notification and the revision to the procedures accounted for the inaccuracies as documented in the individual work package for the valve being tested. 3. Liberty Technologies has subsequently issued a revision to the VOTES software (version 2.31) which adjusts the field measurement values to address the Part 21 issues. GGNS currently-uses the new version of the VOTES software. Action No. 2 Licensees are requested to evaluate the schedule necessary (a) to consider the new information on MOV diagnostic equipment inaccuracy and (b) to respond to that infonnation. GGNS Response: The Operating Experience group at GGNS reviews and evaluates all operating experience documentation and detemmines if a problem is applicable to GGNS. If applicable, the documents are distributed to the appropriate GGNS departments for evaluation. The group reviews documents such as NRC Information Notices, Nuclear Network Operating Experience Reports and INPO Significant Operating Experience Reports. The GGNS Industry Operating Experience Review Program was _ instrumental in the dissemination, review, and resolution of the diagnostic equipment issue contained in GL 89-10, Supplement 5. l G9309081
r Attachm:nt to GNRO-93/00113 Page 4 of 4 This program ensured that the generic documents identified in Supplement 5 were addressed in a timely manner. Because of this, the concerns relating to MOV diagnostic equipment have already been addressed. It is GGNS' position that the actions previously taken in response to NRC Information Notice 92-23, test results from the MUG Validation Committee's Final Report, and the 10 CFR Part 21 issues are adequate to address GL 89-10, Supplement-5. No further actions have been planned to supplement previous actions taken concerning inaccuracy of MOV Diagnostic equipment. G9309081 t .}}