ML13317B275
| ML13317B275 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 01/18/1991 |
| From: | Kokajko L Office of Nuclear Reactor Regulation |
| To: | Cotton G, Ray H San Diego Gas & Electric Co, Southern California Edison Co |
| References | |
| GL-89-010 NUDOCS 9101240423 | |
| Download: ML13317B275 (21) | |
Text
January 18, 199 Docket Nds. 50-206, 50-361 and 50-362 Mr. Harold B. Ray Mr. Gary D. Cotton Senior Vice President Senior Vice President Southern California Edison Co.
Engineering and Operations Irvine Operations Center San Diego Gas & Electric Co.
23 Parker Street 101 Ash Street Irvine, California 92718 San Diego, California 92112 Gentlemen:
SUBJECT:
GENERIC LETTER 89-10 PROGRAM AUDIT AT SAN ONOFRE NUCLEAR GENERATING STATION On December 10-13, 1990, the NRC staff conducted an audit of the program being developed at the San Onofre Nuclear Generating Station in response to Generic Letter 89-10, "Safety-Related Motor Operated Valve Testing and Surveillance."
The audit report, jointly prepared by the audit team members, is enclosed for your review.
The staff finds that you have begun the development of a program to verify the capability of motor operated valves to perform their function under design basis conditions. The audit team reviewed your plans and procedures to the extent possible during the development of the program. The staff has determined that planning for certain aspects of the program has progressed well, but a significant amount of work has to be completed in other areas. Additionally, although significant event-related motor operated valve problems may not have occurred at San Onfore, the staff would like to emphasize that you should not be lulled into complacency in the development and implementation of your program.
The staff assumes that you will continue to maintain your progressive efforts, will fulfill your commitments, and will incorporate, as appropriate, the recommendations of the audit team. With these assumptions, the staff concludes that you will be able to establish and implement an effective program in response to the aforementioned generic letter.
Sincerely, Original Signed By:
Lawrence E. Kokajko, Project Manager Project Directorate V PDR14043K9000020B Division of Reactor Projects III/IV/V P
PDR Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/enclosure:
See next page DISTRIBUTION Docket File NRC & Local PDRs PD5 Reading BBoger MVirgilio DFoster LKokajko GKalman OGC EJordan ACRS (10)
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/91 OFFICIAL RECORD COPY Documet Name:
SO GL 8 10 Ili
Messrs. Ray and Cotton San Onofre Nuclear Generating Southern California Edison Company Station, Units No. 1, 2, and 3 cc David R. Pigott, Esq.
Mr. Charles B. Brinkman Orrick, Herrington & Sutcliffe Combustion Engineering, Inc.
600 Montgomery Street 12300 Twinbrook Parkway, Suite 330 San Francisco, California 94111 Rockville, Maryland 20852 Mr. Robert G. Lacy Alan R. Watts, Esq.
Manager, Nuclear Department Rourke & Woodruff San Diego Gas & Electric Company 701 S. Parker St. No. 7000 P. 0. Box 1831 Orange, California 92668-4702 San Diego, California 92112 Mr. Sherwin Harris Resident Inspector, San Onofre NPS Resource Project Manager c/o U.S. Nuclear Regulatory Commission Public Utilities Department P. 0. Box 4329 City of Riverside San Clemente, California 92672 3900 Main Street Riverside, California 92522 Mayor City of San Clemente Mr. Phil Johnson 100 Avenida Presidio U.S. Nuclear Regulatory Commission San Clemente, California 92672 Region V 1450 Maria Lane, Suite 210 Chairman, Board of Supervisors Walnut Creek, California 94596 County of San Diego 1600 Pacific Highway, Room 335 Mr. Richard J. Kosiba, Project Manager San Diego, California 92101 Bechtel Power Corporation 12440 E. Imperial Highway Regional Administrator, Region V Norwalk, California 90650 U.S. Nuclear Regulatory Commission 1450 Maria Lane, Suite 210 James A. Beoletto, Esq.
Walnut Creek, California 94596 Southern California Edison Company Irvine Operations Center Mr. John Hickman 23 Parker Street Senior Health Physicist Irvine, California 92718 Environmental Radioactive Mgmt. Unit Environmental Management Branch State Department of Health Services 714 P Street, Room 616 Sacramento, California 95814 Mr. Don J. Womeldorf Chief, Environmental Management Branch California Department of Health Services 714 P Street, Room 616 Sacramento, California 95814 (14)
- ENCLOSURE NRC STAFF AUDIT OF THE PROGRAM BEING DEVELOPED AT SAN ONOFRE IN RESPONSE TO GENERIC LETTER 89-10 AUDIT DATES: DECEMBER 10-13, 1990 NRC AUDIT PARTICIPANTS:
T. G. Scarbrough, NRR*#
J. F. Smith, Region III*#
M. P. Huber, Region III*#
T. F. Stetka, Region IV*#
C. Myers, Region V*#
D. Corporandy, Region V*#
J. C. Watkins, Idaho National Engineering Laboratory (INEL)*#
M. R. Holbrook, INEL*#
J. A. Norberg, NRR#
LICENSEE PERSONNEL:
D. Brevig, Supervisor, Onsite Nuclear Licensing#
J. L. Cronk, Supervisor, Plant Maintenance#
P. Croy, Station Technical*
J. M. Curran, Manager of Design Basis Documentation*#
D. R. Heinicke, MOV Project Manager*#
D. A. Herbst, Site Quality Assurance Manager#
M. A. Herschthal, STEC Assistant Manager*#
J. Jamerson, Onsite Nuclear Licensing Lead Engineer*#
C. E. Kramer, Project Engineer Design Bases Documentation*#
J. Leavitt, Nuclear Training Division (NTD)
E. Lim, NEDO Electrical*
J. Lyle, Supervising Engineer - Station Technical*#
J. Mangum, Maintenance Training Administrator*#
D. Mauck, Electrical Foreman/MOVATS*#
S. W. McMahan, Assistant Maintenance Division Manager#
B. McPherson, SCE/INPO#
T. D. Mercurio, Senior Engineer - SCE Licensing*#
H. E. Morgan, Vice President - Site Manager#
D. Piontek, NTD B. Plappert, SCE Compliance*#
J. M. Price, Senior Project Administrator*#
T. Raidy, Licensing Engineer*#
J. Rainsberry, Supervising Engineer, Nuclear Licensing*#
M. B. Ramsey, Technical Services Quality Assurance Supervisor#
E. Ramos, Mechanical Engineer, Nuclear Engineering Design Organization*#
M. Rodin, Supervisor Reliability Engineering and Configuration Control*#
M. P. Short, Manager, Station Technical#
G. Stawniczy, Supervising Engineer, Mechanical Equipment Group, NEDO*#
W. Strom, SCE -
ISEG*
A. Threl, NEDO Electrical*
M. Vezzuto, Station Technical*
J. J. Wambold, Projects*
R. C. Zbavitel, Station Technical - Mechanical Engineer*#
1
OTHER INDUSTRY PERSONNEL:
P. H..Gilson, Project Manager, TU Electric*#
A. Marvray, Licensing Engineer, TU Electric*#
RESIDENT INSPECTOR C. Townsend*
- Present at entrance meeting.
- Present at exit meeting.
BACKGROUND On June 28, 1989, the NRC staff issued Generic Letter 89-10, "Safety-Related Motor-Operated Valve Testing and Surveillance," which requested licensees and construction permit holders to establish a program to ensure that switch settings for safety-related motor-operated valves (MOVs) and certain other MOVs in safety-related systems are selected, set and maintained properly. The staff held public workshops to discuss the generic letter and to answer questions regarding its implementation. On June 13, 1990, the staff issued Supplement I to Generic Letter 89-10 to provide the results of those public workshops. In Supplement 2 to Generic Letter 89-10 (August 3, 1990), the staff states that inspections of programs developed in response to Generic Letter 89-10 would not begin until January 1, 1991, but that audits would be conducted to determine licensees' progress in developing those programs. In response to concerns raised by the results of NRC-sponsored MOV tests, the staff issued Supplement 3 to Generic Letter 89-10 on October 25 which requests that BWR licensees evaluate the capability of MOVs used for containment isolation in the steam supply lines to the High Pressure Coolant Injection and Reactor Core Isolation Cooling Systems, in the supply line to the Reactor Water Cleanup System, and in the lines to the isolation condenser, as applicable.
In Generic Letter 89-10, the NRC staff requested licensees to submit a response to the generic letter by December 28, 1989. In a letter dated January 11, 1990, the licensee of Units 1, 2, and 3 of the San Onofre nuclear station submitted an initial response to the generic letter. The staff provided comments on the licensee's response by letter on May 30, 1990. In June 1990, the branch chief of EMEB/NRR visited the San Onofre station to discuss, among other things, the status of the licensee's MOV program. At that time, the licensee appeared to be planning only minimal activity beyond its efforts in response to NRC Bulletin 85-03. In a letter dated August 29, 1990, the licensee indicated that it had revised its plans regarding the generic letter program in light of the supplements to the generic letter and the NRC staff's comments.
The NRC staff conducted audits of the programs being developed in response to Generic Letter 89-10 at two plant sites. The first of these audits took place on November 6 to 8, 1990, at Unit 3 of the Millstone nuclear facility. The staff conducted the second audit at San Onofre on December 10-13, 1990. The Mechanical Engineering Branch (EMEB) of NRR led the audits with the 2
participation of region inspectors. One of the principal objectives of the audits was to provide feedback to the licensees regarding their progress in developtng an acceptable generic letter program.
AUDIT PLAN The staff used the draft temporary instruction (TI) for Generic Letter 89-10 as a guide in conducting the audit of the program being developed at the San Onofre nuclear station. Part 1 of the draft TI involves a review of the generic letter program developed by the licensee and certain aspects of the overall program for providing assurance of the proper.performance of MOVs.
Part 2 of the draft TI involves verification of the implementation of the program by means of.sampling MOVs in safety-related systems. Because of the early stages of the licensee's generic letter program, the audit focused on Part 1 of the TI.
Each audit team member took the lead for the review of the licensee's efforts to satisfy an area of the generic letter. These areas were (1) establishment of the scope of the generic letter program, (2) the performance of design basis reviews for MOVs within the program, (3) the determination of correct MOV switch settings, (4) the demonstration of design-basis capability of MOVs within the program by testing or, where testing is not practicable, by alternative methods, (5) establishment of a method for the periodic verification of MOV capability, (6) establishment of a method for analyzing, justifying and trending MOV failures and corrective actions, and (7) establishment of a schedule for the completion of the recommended actions of the generic letter.
As part of the review of the licensee's program in response to the generic letter, it was necessary to review certain aspects of the licensee's overall program for providing assurance of proper MOV performance. Such aspects included oversight of the MOV program, control of MOV switch settings, inservice testing in accordance with the ASME Boiler & Pressure Vessel Code, maintenance plans and procedures, training of personnel involved in MOV activities, review of industry experience and vendor information, procurement of MOVs and associated equipment, use of MOV diagnostics, and open MOV maintenance items. As time permitted, the audit team reviewed these aspects of the MOV program at San Onofre.
The results of the audit are described below. Attached is a list of the licensee documents reviewed by the audit team.
GENERAL COMMENT
S At the entrance meeting with the San Onofre licensee, the NRC staff team described the objectives of the audit. The licensee then provided a presentation on its development of a program in response to the generic letter. The audit team considered the presentation to have been helpful in providing an overview of the licensee's planned generic letter program.
3
At the exit meeting, the audit team noted that the licensee had made significant progress in developing an MOV program since EMEB's visit in June 1990. The audit team was encouraged by this progress and recommended that the licensee maintain its efforts. Although significant, event-related MOV problems may not have occurred at San Onofre, the audit team emphasized that the licensee should not be lulled into complacency or minimum compliance in the development of its program. For example, the licensee should consider, and be alert for, the potential MOV deficiencies listed in Generic Letter 89 10, including those that have not occurred specifically at San Onofre. The audit team recommended that the licensee take a leadership role in resolving the MOV issue, including exceeding the recommendations of Generic Letter 89 10 where appropriate.
The audit team considered the increased involvement by the licensee's engineering organization in establishing appropriate MOV sizing and switch setpoints under Generic Letter 89-10 to be an improvement over itsBulletin 85-03 program. Further, the licensee noted that nuclear power facilities in the western region of the country had formed a group to assist one another in resolving the MOV issue at each facility. The audit team commended the licensee for this cooperative effort.
GENERIC LETTER 89-10 AREAS (1)
Scope of the Generic Letter Program The NRC staff position is that the scope of Generic Letter 89-10 includes all
.safety-related MOVs and other MOVs that are position-changeable in safety related piping systems. Through Supplement 1 to the generic letter, the staff defined "position-changeable" as any MOV in a safety-related piping system that is not blocked from inadvertent operation from the control room.
The licensee has committed to develop its MOV program in accordance with the scope recommended in Generic Letter 89-10 and its supplements. The licensee indicated that 34 Unit 1 MOVs and 144 MOVs each at Units 2 and 3 in safety related systems were to be included in the Generic Letter 89-10 program. In addition, the licensee stated that a number of non-safety related MOVs would be included in part of the generic letter program at each unit. The audit team verified the inclusion of appropriate MOVs in the program by sampling MOVs in several systems. The particular systems reviewed included the Closed Cooling Water System in Unit 1, the Safety Injection Systems in Units 2 and 3, and the Auxiliary Feedwater (AFW) System in Unit 3.
(2)
Design-Basis Reviews In recommended action a of Generic Letter 89-10, the staff requests the review and documentation of the design basis for the operation of each MOV within the generic letter program to determine the maximum differential pressure and flow expected for both normal operations and abnormal conditions.
The licensee stated that it intends to follow the recommendations of Generic Letter 89-10 in this area including the consideration of valve mispositioning.
However, the licensee had not made significant progress in this area. Because 4
of the minimal work that had been completed, the audit team considered this area to be of particular concern.
The licensee's procedure for design calculations was brief. For example, although the licensee stated that emergency operating procedures will be considered in the design-basis review, the licensee's procedure did not specifically reflect this commitment. Further, the procedure was not focused on Generic Letter 89-10, but rather, related for the most part to design basis reconstitution.
The audit team stated that the design-basis review under Generic Letter 89-10 should be a stand alone effort for each MOV within the generic letter program.
Further, the design-basis reviews should provide useful quantitative determinations of design-basis conditions, such as maximum differential pressure and flow, for input into the switch setting calculations and design basis testing. The design-basis reviews should allow accurate assessment of the margins associated with the capability of each MOV in the Generic Letter 89-10 program. The design-basis reviews should not yield bounding values that are excessively conservative, but rather should establish a quantitative basis for switch setting calculations, design-basis testing, and assessing deficiencies which may affect MOV capability. The audit team also recommended that the licensee provide formal controls for obtaining design-basis infermation from Limitorque and other valve equipment vendors.
(3)
MOV Switch Settings In recommended action b of Generic Letter 89-10, the staff requests licensees to review, and to revise as necessary, the methods for selecting and setting all MOV switches.
The licensee is planning to follow a more conservative approach for Generic Letter 89-10 than had been used in response to Bulletin 85-03. The licensee obtained calculations of thrust requirements for Bulletin 85-03, but did not base the torque switch settings on those calculations. Rather, the licensee's methodology for itsBulletin 85-03 program was testing-based with each torque switch setting selected to obtain a minimum thrust equal to 2.5 times the running thrust or unseating thrust. Under-Generic Letter 89-10, the licensee will establish switch settings using more-formalized conservative calculations that will be verified by testing. As a starting point, the licensee stated that it plans to use its calculational methodology performed for Bulletin 85 03, but with a more conservative valve factor. However, the licensee has not developed administrative procedures or other documentation to implement recommended action b of the generic letter. The licensee stated that it was planning to finalize the methodology to-be used for the calculations by early 1991.
The licensee plans to include verification of actuator capabilities at reduced voltage conditions. In order to evaluate that margin exists to operate the MOV at reduced voltage conditions, the licensee should account for voltage drops from the motor-control center (MCC) to the actuator. The licensee is in the process of performing expected-voltage calculations for Unit 1, but no calculations currently exist. Although such calculations exist for Units 2 5
and 3, the licensee has yet to review those calculations. When performing calculations to obtain the thrust/torque requirements, the minimum voltages available at the MOVs need to be known to ensure that the thrust/torque is achievable at the minimum voltages. Therefore, the licensee should aggressively pursue completion of the undervoltage calculations. A recent NRC Electrical Distribution Safety Function Inspection conducted at San Onofre also identified the lack of undervoltage calculations. This item will be evaluated further during future inspections to address Generic Letter 89-10.
With respect to thermal overload protection for MOVs, the licensee indicated that most MOVs have their thermal overload protection bypassed at all times.
The licensee stated that a consideration in following this approach was its perception that the NRC staff preferred that licensees bypass MOV thermal overload protection. The audit team referred the licensee to Regulatory Guide 1.106 for the staff position on MOV thermal overload protection. The regulatory guide indicates that setting overload devices conservatively or bypassing those devices are each accepted by the staff. The audit team recommended that the licensee follow the approach most appropriate and justifiable for San Onofre.
(4)
Design-Basis Differential Pressure and Flow Testing In recommended action c of the generic letter, the staff requests licensees to test MOVs within the generic letter program in situ under their design-basis differential pressure and flow conditions. If testing in situ under those conditions is not practicable, the staff allows alternate methods to be used to demonstrate the capability of the MOV. The staff suggests a two-stage approach for a situation where design-basis testing in situ is not practicable and, at this time, an alternate method of demonstrating MOV capability cannot be justified. With the two-stage approach, a licensee would evaluate the capability of the MOV using the best data available and then would work to obtain applicable test data within the schedule of the generic letter.
Consistent with recommendations of Generic Letter 89-10, the licensee stated that MOVs within the scope of the generic letter program would be tested under design-basis differential pressure and flow conditions where practicable. At the time of the audit, the licensee estimated that design-basis tests would be performed on a minimum of 50% of the MOVs within the scope of the generic letter program at San Onofre.
Where design-basis testing was not practicable, the licensee stated that it would attempt to test the MOVs under conditions as close as possible to design-basis conditions with extrapolation of the results to design-basis conditions. As discussed in Supplement I to Generic Letter 89-10, the audit team indicated that, as with other alternatives to design-basis testing, the licensee would need to justify any extrapolation of MOV test data. Where such extrapolation could not be justified, the licensee stated that the two-stage approach would be followed. Overall, it appeared that the licensee was actively pursing design-basis testing for all MOVs in its generic letter program.
6
(5)
Periodic Verification of MOV Capability In recommended action d of the generic letter, the staff requests that licenseet prepare or revise procedures to ensure that adequate MOV switch settings are determined and maintained throughout the life of the plant. In paragraph j of the generic letter, the staff recommends that the surveillance interval be based on the safety importance of the MOV as well as its maintenance and performance history, but that the interval not exceed 5 years or 3 refueling outages. Further, the capability of the MOV will need to be verified if the MOV is replaced, modified, or overhauled to an extent that the existing test results are not representative of the MOV.
At the time of the audit, the licensee had not developed a specific periodic verification procedure for Generic Letter 89-10. Rather, the licensee plans to accomplish periodic verification as part of a preventive maintenance program. The licensee currently intends to perform static testing (i.e.,
under zero differential pressure conditions) to fulfill its commitments to Generic Letter 89-10 for the periodic verification of MOV capability. The audit team discussed with the licensee the inadequacies of static testing in predicting MOV performance under design-basis differential pressure and flow conditions. Because of the lack of an accepted relationship between MOV performance under static conditions and design-basis conditions, the audit team recommended that the licensee reconsider its plans for the use of static testing in attempting to verify MOV capability on a periodic basis.
The preventive maintenance program presently provides an interval of every third refueling outage or six years. The licensee stated that it is considering shortening this interval to five years. This interval is not firm and can be adjusted as necessary. For example, the interval can be shortened based on (1) repetitive component failures trended through the Nonconformance Report (NCR) process, or (2) an analysis of failures that are identified through the corrective maintenance program. These changes in the preventive maintenance interval are initiated by Repetitive Maintenance Change Forms which are usually completed by the electrical or mechanical planners, but may be completed by anyone in the plant..
Post-maintenance testing for safety-related MOVs is controlled by Maintenance Procedures SO1-XV-1 and S023-XV-1. These procedures also require only static condition diagnostic testing with no provisions for flow testing. The audit team discussed with the licensee the weaknesses of static testing in demonstrating post-maintenance capability of MOVs.
The licensee indicated that all safety-related MOVs should be included in Procedures S01-XV-1 and S023-XV-1. If an MOV is not included, however, the licensee uses Procedure S0123-I-1.25 to provide testing direction. This procedure requires only limited testing and does not specify any diagnostic evaluation of MOVs. The audit team stated that this procedure was inadequate for post-maintenance testing of safety-related MOVs.
With respect to valve packing adjustments, this work is performed by maintenance personnel in accordance with Procedure S0123-I-6.16. Post maintenance testing following these adjustments are covered in the XV-1 7
procedures which require only a leak rate test, full stroking of the valve, and a position indication check. Even though packing adjustments may affect valve thrust requirements, these procedures do not require any type of valve diagnostic test. The licensee provides some additional testing following valve packing adjustments in Operations Procedure 50123-0-23.1. This procedure requires the measurement of MOV motor current values following the packing adjustments. This requirement was not in the XV-1 procedures; however, the licensee stated that these procedures were to be modified to require that such current measurements be made. The audit team indicated to the licensee that its use of current testing to verify that adequate thrust margin exists following valve packing adjustments had not been justified.
Licensee procedures do not require diagnostic testing following valve stem lubrication. Because stem lubrication can affect the conversion of torque to thrust within the MOV, the audit team recommended that the licensee review the post-maintenance testing provisions following this work.
(6)
MOV Failures, Corrective Actions, and Trending In recommended action h of the generic letter, the staff requests that licensees analyze or justify each MOV failure and corrective action. The documentation should include the results and history of each as-found deteriorated condition, malfunction, test, inspection, analysis, repair, or alteration. All documentation should be retained and reported in accordance with plant requirements. It is also suggested that the material be periodically examined (every 2 years or after each refueling outage after program implementation) as part of the monitoring and feedback effort to establish trends of MOV operability. These trends could provide the basis for a licensee revision of the testing frequency established to verify periodically adequate MOV capability. The generic letter indicates that a well-structured and component-oriented system is necessary to track, capture, and share equipment history data.
The audit team reviewed the licensee's practice for responding to MOV failures. One particular example of past licensee practice that would be unacceptable under a Generic Letter 89-10 program involved Field Change Notice (FCN) 3911 of AFW valves 2HV4712 and 4713. In that FCN, the licensee indicated that the thrust available to operate the valves was significantly less than estimated by the licensee's calculations. The licensee, however, justified the acceptability of the MOVs based on test results. The FCN did not call for an evaluation of the cause of this inconsistency between calculations and test results, but merely recommended replacement of the spring pack in both MOVs. The licensee acknowledged that such a resolution of an MOV problem would not be appropriate in the wake of Generic Letter 89-10.
The audit team recommends that the licensee review its procedures for analyzing and responding to MOV failures.
The audit team interviewed Site Support Services Division (SSSD) personnel responsible for the trending program and reviewed relevant plant procedures.
The primary MOV data collected for trending involves safety-related MOV failures identified in NCRs and corrective maintenance orders. This information is used by SSSD as input into the San Onofre Maintenance 8
Management System (SOMMS) and the industry-wide Nuclear Plant Reliability Data System (NPRDS). The data collected by SSSD identifies the failed MOV and the mode of failure. Currently, SSSD uses the SOMMS data to identify global trends for valve failures specific to San Onofre and uses the NPRDS data to compare San Onofre global failure rates to industry-wide failure rates. Every quarter, SSSD provides a component failure analysis report (CFAR) for components (including, if appropriate, MOVs) whose failure rates are found to be inconsistent with industry trends.
Licensee documentation indicated ten MOV failures over the last 18 months which was reported to be less than the industry average. Although this global trending is useful, the data available in SOMMS could be of significant benefit in trending MOV failures and specific failure modes. The current San Onofre system places heavy reliance on cognizant system engineers for recognizing these trends. The audit team indicated that this reliance on cognizant system engineers results in the potential failure to recognize MOV failure and mode trends spanning more than one system.
The audit team noted that MOV training for maintenance and testing technicians contains minimal instruction on failure analysis. The audit team recommended that maintenance and testing technicians receive additional training in recognizing failures, potential failure conditions, and accelerated component degradations. Because the technicians are most closely involved with.MOV performance, failure analysis training could enhance the trending data base by increasing the likelihood of identifying potential failures and accelerated component degradation which might be overlooked in the current program.
The audit team noted that maintenance and testing personnel attend "lessons learned" meetings to discuss problems encountered during MOV maintenance and testing, as well as precautions and recommended solutions to alleviate similar problems in the future. Where significant,'"lessons learned" have been incorporated into revised maintenance and testing procedures. Given the dynamic nature of the effort to improve maintenance and testing in order to ensure MOV capability, the audit team encourages the licensee to continue these "lessons learned" meetings on a regular basis.
(7)
Schedule In Generic Letter 89-10, the staff requested that licensees complete all design-basis reviews, analyses, verifications, tests, and inspections that were initiated in order to satisfy the generic letter recommended actions by June 28, 1994, or 3 refueling outages after December 28, 1989, whichever is later.
The licensee has committed to meet the schedule recommended in Generic Letter 89-10. Discussions by the audit team with cognizant scheduling personnel revealed that the licensee has considered the available time, equipment, personnel, and other limitations, in committing to this schedule. The licensee indicated that the schedule can be met based on conservatively assuming that only one MOV diagnostic system will be available. (The licensee currently possesses two such systems with the procurement of two more systems in process.) The licensee plans to test 20 or 30 MOVs per outage to avoid a 9
large number of valves requiring testing in the fifth year of the generic letter program. Under these assumptions, the testing could be completed on schedule although it might be the critical path item. The audit team requested the licensee to notify the NRC if it becomes evident that the schedule might not be met.
The audit team reviewed the specific schedule for each portion of the licensee's generic letter program. Because of the overlapping completion dates, the licensee's current plan does not ensure the completion of the calculations of MOV thrust requirements before the commencement of testing MOVs and setting MOV torque switches. This arrangement could result in the need to retest MOVs or reset their switches. The licensee was aware of this possibility and indicated that it was caused by the availability of personnel performing the calculations. The licensee stated that it would review the scheduling arrangements in an effort to improve the coordination of the MOV activities.
WALKDOWN The audit team performed a walkdown inspection of a safety-related MOV (3HV6366) in Train A of the Component Cooling Water System in Unit 3. No specific problems were found by the team during the walkdown. The audit team, however, did provide suggestions to the licensee based on the walkdown.
Specifically, the audit team noted that the licensee should consider (1) removing or replacing any torque switch calibration stickers that are damaged or are invalid as result of new torque switch calculations; (2) rocking the torque switch after deenergizing the MOV in an open position because it provides a simple method of identifying significant spring pack relaxation; and (3) removal or control of any ink markings on torque switches.
OTHER MOV AREAS ADDRESSED (1)
Overall Administration of MOV Activities The licensee's program in response to Generic Letter 89-10 draws support from several different groups within its organization. The licensee.indicated that, upon completion, its Generic Letter 89-10 program will be incorporated into the day-to-day plant activities. However, the licensee does not have a documented administrative procedure for the overall control and coordination of MOV activities. For the three-unit facility, the licensee stated that only one engineer was assigned full time to MOV issues. In addition, an engineer was responsible for the coordination of MOV activities in addition to other duties. Although the audit team did not identify any current problems with the licensee's approach, the audit team recommended that the licensee review the adequacy of its control and coordination of MOV activities, including the need to prepare specific documentation for assignment of responsibility.
With respect to particular plant systems, the licensee has assigned system responsibilities to designated engineers. These cognizant engineers are familiar with their systems and all maintenance work or testing involving 10
their systems. The licensee also assigns system responsibilities to individual system design engineers. These design engineers are involved in any analyses, test proposals, modifications and other items of a design nature for their systems. The audit team noted the benefits of such an approach and considers its use to be a strength of the licensee's overall program.
(2)
MOV Setpoint Control The licensee currently controls MOV output based either on torque switch setting, thrust from diagnostic equipment, or a combination of both. The audit team recommended that the licensee ensure that confusion does not occur from the use of different control parameters. Further, the audit team noted that, even if thrust is the control parameter, changes in switch settings should be trended to identify degradation in MOV performance.
The licensee reported that it had been necessary to remove torque switch limiter plates from certain MOVs to obtain the necessary thrust margin. The licensee indicated that a generic evaluation under 10 CFR Part 50.59 had been performed regarding the removal of the torque switch limiter plates. The audit team stated that a specific calculation should be performed to justify the removal of a limiter plate from each MOV. Further, the audit team noted that the licensee is responsible for control of the maximum torque switch settings where the limiter plate has been removed.
(3)
Inservice Testing A brief review of the ASME Boiler & Pressure Vessel Code Inservice Testing Program (IST) established by the licensee disclosed that the program conformed to the requirements of Section XI of the ASME Code and the recommendations of Generic Letter 89-04. The licensee indicated that the program had been reviewed by the NRC and that a safety evaluation report had been issued with several relief requests denied. In most areas, the program language is taken from Section XI or Generic Letter 89-04.
The calculation of the required action ranges for the licensee's stroke time testing is said to be based on the stroke tests normally observed for each valve in good operating condition. The minimum required action range might be as low as the mean plus two standard deviations. The IST Coordinator reviews this value and adds an appropriate amount to make the value practical.
For many MOVs, the standard deviation is so small that the IST Coordinator must make a significant addition to have the action range exceed the alert range from Section XI.
The audit team reviewed the acceptance criteria for a number of MOVs and detected several ac-powered MOVs that had abnormally high required-action values. The licensee committed to review the required action ranges for all MOVs within the Generic Letter 89-10 program to ensure appropriate values.
Position 8 of Attachment 1 to Generic Letter 89-04 indicates that a pump or valve with test parameters in the required action range is to be declared inoperable as soon as the condition is recognized. The licensee's IST Program reiterates this information. It was also said to be included in the training program and to be recognized by plant personnel.
However, this provision is 11
not specified in the procedure for IST at Units 2 and 3 despite the fact that several other bases for declaring equipment inoperable are included. In order to preclude future errors because of this omission, the licensee committed to specify the need to declare pumps or valves inoperable in all IST procedures when those components are found to have test parameters in the required action range.
The audit team noted that there was no requirement to report unusual test results such as abnormally short stroke times on ac-powered MOVs. ASME Section XI, IWV-5417, states that any abnormality or erratic action must be reported. The licensee committed to add such provisions to plant procedures, as appropriate.
(4)
Maintenance The licensee has in place an 18-month preventive maintenance program for the evaluation of the electrical and mechanical performance of safety-related MOVs. No diagnostic testing is performed during the 18-month preventive maintenance work. Adequate lubrication of the MOV, however, is among the aspects to be evaluated. The audit team discussed the appropriate use of MOV lubricants with licensee personnel. The comments of the audit team on post-maintenance testing are provided above. The audit team had no other significant comments in this area.
(5)
Training The audit team discussed the MOV training program at San Onofre with licensee personnel, reviewed training documentation, and toured the training facility.
The licensee conducts training on MOV design and operation for electricians and machinists in three and two day sessions, respectively. In addition, electricians can complete a five day course in the use of the Motor-Operated Valve Analysis and Test System (MOVATS) diagnostic equipment together with an on-the-job training program.
Because of the brevity of the training sessions, the audit team recommended that the licensee continue to evaluate the adequacy of the MOV training program. As noted earlier, the audit team also recommended that additional training be provided on failure analysis. The. licensee indicated that training is not provided in the performance of current testing from the motor control center (MCC) because of the similarity with current testing conducted during MOVATS testing. The audit team was not convinced that the similarity of these testing methods was sufficient to obviate the need for specific training in MCC current testing. Further, the audit team noted that MCC current testing was not described in the licensee's program documents as part of its intended diagnostic test method. The audit team recommended that the licensee ensure that the technicians are properly trained in MCC current testing. The audit team also recommended that the licensee provide periodic refresher training in the use of MOVATS equipment and the analysis of the data obtained from that equipment. Finally, the licensee should ensure that personnel using diagnostic equipment understand the inherent sensitivities and limitations of that equipment.
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(6)
Industry Experience and Vendor Information The audit team reviewed the licensee's method for the review of industry experience and the control of vendor information. The flow and distribution of vendor technical information at San Onofre is designed to initiate with input into the San Onofre Corporate Documentation Management (CDM) system.
Once in CDM, a copy of the original document goes to Configuration Control which distributes copies to cognizant disciplines for review, impact assessment, and subsequent disposition. This information is recorded on the licensee's Form 184. The licensee stated that it periodically contacts vendors by mail to provide confirmation that all relevant technical documents have been received into the CDM system.
The audit team noted that, in the case of Limitorque Maintenance Updates, the vendor was sending the documentation directly to an individual engineer. The engineer took the initiative to forward the vendor material to CDM. However, there was evidence that some of the vendor material was not being distributed in a timely manner. For example, Limitorque Maintenance Update 90-1 discussed a problem with spring pack relaxation on actuator sizes SMB-000 through 3 and identified the SMB-0 "0017" spring pack as the most susceptible to spring pack relaxation. Although Limitorque Maintenance Update 90-1 was issued in May 1990, the audit team found no evidence of an effort by the licensee to identify relaxed spring packs mentioned in the update.
The NRC staff considers the timely distribution of and action on vendor information to be highly important in light of its potential impact on MOV capability. Further, the NRC staff expects licensees to review vendor notifications to the same extent as NRC Information Notices. The audit team recommended that the licensee carefully review all vendor notifications. With respect to the issue of hydraulic lock of MOV spring packs, the audit team recommended that the licensee ensure that its response is consistent with Limitorque Maintenance Updates 88-2 and 90-1.
Finally, the audit team recommended that the licensee instruct Limitorque, as well as other valve equipment vendors, to send all technical correspondence directly to CDM.
(7)
Procurement The audit team reviewed the licensee's process for the procurement of MOVs and associated equipment. Utility procurement activities are covered generically in Chapter 3 of the Topical QA Manual.
All Limitorque parts are given RSO (Receiving Services) numbers which are controlled through the Material Management System (MMS). The MMS has quality controls imposed upon it to assure system accuracy. The audit team considered the upgrading of parts or part changes to have adequate controls for updating parts listings and for ensuring that these listings remain current.
The licensee uses an additional parts tracing system, the Spare Parts Information System (SPIS), which is a subset of the Plant Equipment Data Management System (PEDMS). This system, however, apparently does not have sufficient QC/QA auditing acceptable to the licensee and is used only as an informational tool.
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(8)
Use of Diagnostics The licensee uses MOVATS diagnostic equipment to determine MOV thrust output and to confirm switch settings, such as torque switch bypass. The licensee currently has two MOVATS 2150 systems and has plans to obtain two MOVATS 3000 systems in the future. The MOVATS 3000 system has the capability to record more parameters for a given valve stroke than the 2150 system. The licensee also indicated that diagnostic equipment may be used to evaluate motor operators on butterfly valves.
The licensee stated that the MOVATS equipment vendor has reported an accuracy of 10% for its diagnostic equipment. Further, the licensee indicated that it had been informed that the overall accuracy varied as a function of the measured thrust. The licensee did not provide the audit team with documented justification for the accuracy estimates. The licensee should obtain justification for the assumed accuracy of the MOVATS equipment and should ensure that the accuracies are correctly reflected in the thrust calculations.
The audit team informed the licensee that this item would be stressed in future inspections.
The MOVATS diagnostic equipment calibrates the torque switch in the open direction. This calibration is then used to set the torque switch in both the open and close directions. The licensee needs to ensure that the thrust values seen when the torque switch trips on the opening stroke are accurate and are consistent with the verified values for both the open and close stroke. Further, the audit team noted that the licensee should ensure that the "rate of loading" phenomenon is adequately considered in its use of MOV diagnostic equipment.
The audit team reminded the licensee of the importance of balancing the torque switch. For example, the balancing of the torque switch can affect the thrust output when the torque switch is at the limiter plate maximum value. Further, the trending of torque switch setting changes can be disrupted if an effort is made to balance the torque switch during the trending process.
(9)
Open Maintenance Items The audit team reviewed the San Onofre Motor Operated Valve Active Maintenance Orders list for Units 1, 2, and 3. This list contains standard maintenance orders for preventative maintenance and testing as well as corrective maintenance orders. A small number of safety-related MOV maintenance items (approximately ten for all three units) were identified as overdue. None of the overdue maintenance orders were corrective in nature. Most of the outstanding orders pertained to preventative maintenance on MOVs that were accessible only during an outage. The licensee was revising the schedule to indicate the next refueling outage as the required due date for those MOVs.
The remaining few MOVs were overdue by no more than a few months. In summary, it appeared that the licensee is adequately controlling overdue maintenance on safety-related MOVs.
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(10)Bulletin 85-03 The licensee indicated that 15 Unit 1 MOVs and 23 MOVs each in Units 2 and 3 had been within the scope of Bulletin 85-03 program. The licensee stated that 46 of those MOVs had been tested at or near design-basis conditions. The licensee also stated that a total of 292 MOVs at the three units had been evaluated as a result of its expansion of the scope of Bulletin 85-03.
The audit team reviewed the methodology used to calculate the MOV switch settings for the Bulletin 85-03 MOV program. The calculations for the licensee'sBulletin 85-03 program were subcontracted to Kalsi Engineering.
The licensee's documentation of the calculations was organized such that conclusions, recommendations, and calculational methodology were presented first with data sheets attached. The data sheets contained design parameter inputs and calculational results, but the actual calculational steps were not documented for each valve.
The audit team selected a sample of six valves for verification of the associated calculations using the INEL developed Isolation Valve Assessment (IVA) computer program. From its review of the calculations, the audit team determined that standard industry methods were used to size the actuators with a 0.4 valve disk factor. Of the six calculations reviewed, however, two of the.calculations used a Motor Application Factor that was non-conservative and resulted in a misrepresentation of the actuator capabilities. This application factor (1.0) was unsupported by the methodology and the vendor supplied table of acceptable values that was included in an appendix to the calculations.
The licensee indicated that the Bulletin 85-03 calculations will provide a starting point for the Generic Letter 89-10 program calculations. The audit team does not believe, however, that a simple transfer of calculations from the Bulletin 85-03 program to the Generic Letter 89-10 program will be acceptable. In particular, the audit team does not believe that the licensee'sBulletin 85-03 documentation would comply with its guidance for documentation of design calculations provided in NES&L Procedure 24-7-15, Preparation and Verification of Design Calculations. The audit team stated that each calculation should document the formulas used with all intermediate steps specified. Further, the licensee should justify any industry-accepted parameters that are used in its calculations.
(11) Editorial matters From its review of licensee procedures, the audit team provided several editorial suggestions to the licensee for its consideration. One example of those editorial suggestions involved the clarification of the discussion of the evaluation of the adequacy of limit and torque switches in Maintenance Procedure S0123-1-9.5.
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CONCLUSIONS The licensee has begun the development of a program to verify the capability of MOVs to perform their functions under design-basis conditions. The audit team reviewed the licensee's plans and procedures to the extent possible during this development of the program. The licensee is well along in its planning for certain aspects of the program, but has a significant amount of work to be completed in other areas. The audit team assumes that the licensee will continue to maintain its efforts, will fulfill its commitments, and will incorporate, as appropriate, the recommendations of the audit team. With these assumptions, the audit team concludes that the licensee will be able to establish and implement an effective program in response to Generic Letter 89
- 10.
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Attachment I LICENSEE DOCUMENTS REVIEWED BY THE AUDIT TEAM AT SAN ONOFRE Letter, dated April 21, 1986, from J. W. Pfeifer, CE Owners Group, to CE Owners Group member, regarding Bulletin 85-03 Design-Basis analysis.
Letter, dated May 19, 1986 from J. L. Rainsberry, San Onofre, to John B.
Martin, NRC, regarding Bulletin 85-03.
Letter, dated January 11, 1990, from R. M. Rosenblum, Southern California Edison Company, to.NRC regarding Generic Letter 89-10.
Letter, dated May 30, 1990, from L. E. Kokajko, NRC, to Mssrs. H. B. Ray, Southern California Edison, and G. D. Cotton, San Diego Gas & Electric, regarding Generic Letter 89-10.
Letter, dated August 29, 1990, from F. R. Nandy, Southern California Edison, to NRC, regarding Generic Letter 89-10.
Maintenance Procedure S01-XV-1, Post Maintenance Retest Program.
Maintenance Procedure S0123-0-23.1, Valve Operation.
Maintenance Procedure S0123-1-1.25, Maintenance Verification Testing.
Maintenance Procedure S0123-I-1.3, Maintenance Documentation, Rev. 2, TCN 2 2, 11/28/90.
Maintenance Procedure S0123-I-1.9, Repetitive Maintenance Implementation and Scheduling, Rev. 1, TCN 1-4, 6/12/90.
Maintenance Procedure S0123-I-6.7, Limitorque Model SMB-000, SMB-00 and SB-00 Disassembly, Inspection, Repair and Assembly Maintenance Procedure S0123-I-6.8, Actuators - Limitorque Models SMB-0 through SMB-4 and SB-0 through SB-4 Disassembly, Inspection, Repair and Assembly Maintenance Procedure S0123-1-6.16, Valves - Inspection, Lubrication, Packing Replacement and Gland Adjustment, Rev. 0, TCN 0-2, 4/27/90.
Maintenance Procedure S0123-I-8.28, Actuators - Limitorque Valve.Actuators Lubrication and Inspection, Rev. 0, TCN 0-13, 6/7/89.
Maintenance Procedure S0123-1-8.313, Actuators - Motor Operated Valve Analysis and Testing System (MOVATS), Rev. 0, TCN 0-10, 8/31/89.
Maintenance Procedure S0123-1-9.5, Actuator -
Limitorque MOV Inspection, Rev.
0, Temporary Change Notice TCN 0-7, 4/9/90.
1
Maintenance Procedure S0123-XV-5, Non-Conforming Material, Parts, or Components, Rev. 3, TCN 3-9, 11/30/90.
Maintenance Procedure S023-XV-1, Post Maintenance Retest Program, Rev. 2, 6/22/90.
Memorandum, dated May 29, 1985, for Technical Department Supervisors, providing engineering job profiles.
Memorandum, dated June 23, 1987, from J.W.,Patterson, to D. E. Shull, regarding response to issue of hydraulic lock of NOV spring packs.
Motor-Operated Valve Overview Presentation Handout for NRC Audit on December 10-13, 1990.
Motor-Operated Valve Program Response for Generic Letter 89-10, Draft, 12/10/90.
NES&L Procedure 24-7-15, Preparation and Verification of Design Calculations.
NES&L Procedure 24-10-16, Development, Review, Approval and Release of SCE Design Change Packages (DCPs) and Minor Modification Packages (MMPs), Rev. 6, Procedure Change Notice (PCN) 1, 3/2/90.
NES&L Procedure 24-10-21, Field Change Notice (FCN) and Field Interim Design Change Notice (FIDCN), Rev. 4, 7/2/90.
NES&L Procedure 25-1-7, Motor Operated Valve Review Methodology, Rev. 0, 11/26/90.
Nuclear Plant Reliability Data System Component Failure Analysis Report, NPRC01AC, 11/27/90.
Nuclear Plant Reliability Data System Query Report, NPRS01AA, 11/27/90.
Piping and Instrumentation Drawings: Unit 1 Closed Cooling Water System (DWG No. 5178310-9); Unit 2 Safety Injection System (DWG Nos. 40112A-16, 40112B 16, 40112C-8, 40112D-9, and 40113B-7); Unit 3 Auxiliary Feedwater System (DWG Nos. 40160AS03-13, and 40160B503-10); and Unit 3 Safety Injection System (DWG No. 40113AS03-7).
Topical QA Manual for San Onofre.
Torque and Thrust Requirements on Motor Operated Valves for SONGS Unit 2 in Accordance with the Requirements of NRC Bulletin 85-03, 6/13/86.
Training Checklist for MOVATS On-The-Job Training.
Training Laboratory Guide for MOVATS.
Training Manual MT-7060, Limitorque Actuators (Mechanical), Rev. 3.
2
Training Manual MT-7355, Motor Operated Valves (Electrician), Rev. 0.
Trainforg Manual MT 7607, Motor Operated Valve Analysis and Test System, Rev.
Training Overview Handout of Nuclear Training Division on Motor-Operated Valve Training, undated.
Trending Handout on Safety-Related MOVs, undated.
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