ML20207G025
| ML20207G025 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 03/03/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20207G017 | List: |
| References | |
| GL-96-05, GL-96-5, NUDOCS 9903110394 | |
| Download: ML20207G025 (10) | |
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NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 30086 00lH k
i SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTORREGULATION '
t REGARDING LICENSEE RESPONSE TO GENERIC LETTER 96-05. "PERIQQLQ VERIFICATION OF DESIGN-BASIS CAPABILITY OF SAFETY-RELATED TQ -
MOTOR-OPERATED VALVES" ;
i DUANE ARNOLD ENERGY CENTER
- DOCKET NO. 50-331 !
1.0 INTRODUCTIQN !
Many fluid systems at nuclear power plants depend on the successful operation of I motor-operated valves (MOVs) in performing their safety functions. Several years ago, MOV operating experience and testing, and research programs sponsored by the nuclear industry and the U. S. Nudear Regulatory Commission (NRC), revealed weaknesses in a wide range of ,
activities (including design, qualification, testing, and maintenance) associated with the :
performance of MOVs in nuclear power plants. For example, some engineering analyses used :
in sizing end setting MOVs did not adequately predict the thrust and torque required to operate ;
valves under their design-basis conditions. In addition, inservice tests of valve stroke time under j zero differential-pressure and flow conditions did not ensure that MOVs could perform their ,
safety functions under design-basis conditions.
i Upon identification of the weaknesses in MOV performance, significant industry and regulatory I activities were initiated to verify the design-basis capability of safety-related MOVs in nuclear l power plants ' After completion of these activitiec, nuclear power plant licensees began establishing long-term programs to maintain the design-basis capability of their safety-related MOVs. This SE addresses the program developed by lES Utilities, Inc. (licensee) to verify periodically the design-basis capability of safety-related MOVs at the Duane Arnold Energy Center.
2.0 BF,GULATORY REQUIRE;MENTS The NRC regulations require that MOVs important to safety be treated in a manner that provides assurance of their intended performance. Criterion 1 to Appendix A," General Design Criteria for Nuclear Power Plants," to Part 50 of Title 10 of the Code of Federal Regulations (10 CFR Part 50) states, in part, that structures, systems, and components important to safety shall be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. The quality assurance program to be applied to safety-related components is described in Appendix B, " Quality Assurance Criteria for Enclosure 9903110394 990303 PDR ADOCK 05000331 9 F PDR -
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. Nuclear Power Plants and Fuel Reprocessing Plants," to 10 CFR Part 50. In Section 50.55a of 10 CFR Part 50, the NRC requires lica nsees to establish inservice testing (IST) programs in accordance with Section XI of the American Society cf Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. ;
1 In response to concems regarding MOV performance, the NRC staff issued Generic . Letter
. (GL) 89-10 (June 28,1989), " Safety-Related Motor-Operated Valve Testing and Surveillance," l which requested that nuclear power plant licensees and construction permit holders ensure the capability of MOVs in safety-related systems to perfonn the:r intended functions by reviewing l MOV design bases, verifying MOV switch settings initially and periodically, testing MOVs under i design-besis conditions where practicable, improving evaluations of MOV failures and l necessary corrective action,. and trending MOV problems. The staff requested that licensees l complete the GL 89-10 program within approximately three refueling outages or 5 years from I the issuance of the generic letter. Permit holders were requested to complets the GL 89-10 l program before plant startup or in acccrdance with the above schedule, whichever was later. ;
The NRC staff issued seven supplements to GL 89-10 that provided additional guidance and information on MOV program scope, design-basis reviews, switch settings, testing, periodic i verification, trending, and schedule extensions. GL 89-10 and its supplements provided only limited guidance regarding MOV periocic verification and the measures appropriate to assure preservation of design-basis capability. Consequently, the staff determined that additient?!
guidance on the periodic verification of MOV design-basis capability should be prepared. i I
On September 18,1996, the M~lC staff issued GL 96-05, Periodic Verification of Design-Besis '
Capability of Safaty-Related Motor-Operated Valves," requesting that each licensee estaolish a program, or ensure the effectiveness of its current program, to verify on a periodic basis that i safety-related MOVs continue to be capable of performing their safety functions within the ;
current licensing bases of the facility. In GL 96-05, the NRC staff summarized severalindustry and regulatory activities and programs related to maintaining long-term capability of safety-related MOVs. For example, GL' 96-05 discussed r: > mandatory ASME Code Case i OMN-1, "Altemative Rules for Preservice and inservice Testing of Certain Electric Motor Operated Valve Assemblies in LWR Power Plants, OM Code 1995 Edition; Subsection ISTC,"
which allows the replacement of ASME Code requirements for MOV quarterly stroke-tima I testing with exercising of safety-related MOVs at least once per operating cycle and perio$c l MOV diagnostic testing on a frequency to be determined on the t, asis of margin and degradation l rate, in GL 96-05, the NRC staff stated that the method in OMN-1 meets the intent of the !
generic letter with certain limitations.- The NRC staff alto noted in GL 98-05 that licensees !
remain bound by the requirements in their code of record regarding MOV stroke-time testing, as supplemented by relief requests approved by the NRC staff.
In GL 96-05, licensees were requested to submit the following information to the NRC:
- a. within 60 days of the date of GL 96-05, a written response indicsting whet'er or !
not the licensee would implement the requested actions; and I
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- b. within 180 days of the date of GL 96-05, or upon notification to the NRC of !
completion of GL 8910 (whichever was later), a written summary description of the licensee's MOV period:c verification program.
The NRC staffis preparing safety evaluatior,s on the response of each licensee to GL 96-05. f The NRC staff intends to rely to a signiticant extent on an industry initiative to identify valve noe related degradation which could adversely affect the design-basis capability of L MAy-relatad MOVs (described in Section 3.0) where a licensee commits to implernent that i industry pregram. The NRC staff will conduct inspections to verify the implementation of l
GL 96-05 programs at nuclear power plants as necessary.
3.0 JOlMT OWNERS GROUP PROGRAM ON MOV PERIODIC.yfBjflCATION in response to GL 96-05, the Boiling Water Reactor Owners Group (BWROG), Westinghouse Owners Group (WOG), and Combustion Engineering Owners Group (CEOG) jointly developed an MOV periodic verification program to obtain benefits from the sharing of information between '
licensees. The Joint Owners Group (JOG) Program on MOV Periodic Varification is described
- by the BWROG .in its Licensing Topical Report NEDC-32719, *BWR Owners' Grcup Program on Motor-Operated Valve (MOV) Periodic Verification," and described by the WOG and the CEOG in their separately submitted Topical Report MPR-1807, " Joint BWR, Westhghouse and i Combustion Engineering Owners' Group Program on Motor-Operated Valve (MOV) Periodic Verification." The stated objectives of the JOG Program on MOV Periodic Verification are (1) to provide an approach for licensess to use immediately in their GL 96-05 programs, (2) to develop a basis for addressing the potential age-related increase in required thrust or torque under dynamic conditions, and (3) to use the developed bas s to confirm, or if necessary to modify, the applied approach. The specific elements of the JOG program are (1) providing an " interim" MOV periodic verification program for applicable licensees to use in response to GL 96 05, (2) conducting a dynamic testing prcgram over the next 5 years to identify potential age refated ;
increases in required thrust or torque to operate gate, globe, and butterfly valves under dynamic cond:tions, and (3) evaluating the information from the dynamic testing program to confirm of modify the interim program assumptions.
The JOG interim MOV periodic verification program incluc'es (1) continuation of MOV stroke-time testing required by the ASME Code IST program, and (2) performance of MOV static i
diagnostic testing on a frequency based on functional capability (age-related degradation margin over and above margin for GL 89-10 evaluated parameters) and safety significance. In implementing the interim MOV static diagnostic test program, licensees will rank MOVs within the scope of the JOG program according to their safety signifie:ance. The JOG program specifies that licensees need to justify their approach for risk ranking MOVs. In Topical Report iIEDC-32264, " Application of Probabilistic Safety Assessment to Generic Letter 89-10 Implementation," the BWROG descrJbed a methodology to rank MOVs in GL 8S-10 programs with respect to their relative importance to core-damage frequency and other consideretions to be added by an expert panel. In a SE dated f ebruary 27,1996, the NRC staff accepted the BWROG methodology for risk ranking MOVs in boiling water reactor nuclear plants with certain conditions and limitations. In the NRC SE (dated October 30,1997) on the JOG Program on MOV Periodic Verification, the NRC staff indicated its view that the BWROG methodology for MOV risk ranking is appropriate for use in response to GL 96-05. With respect to
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Westinghouse-designed pressurized water reactor nuclear plants, the WOG prepared I i Engineering Report V-EC-1658, " Risk Ranking Approach for Motor-Operated Valves in i Response to Generic Letter 96-05." On April 14,1998, the NRC staffissued an SE accepting !
with certain conditions and limitations the WOG approach for ranking MOVs based on their risk
i their MOV risk-ranking approach individually.
- The objectives of the JOG dynamic test program are to determine degradation trends in i dynamic thrust and torque, and to use dynamic test results to adjust the test frequency and j method specified in the interim program if warranted. The JOG dynamic test program includes
(1) identification of conditions and features which could potentially lead to MOV degradation, i l (2) definition and assignment of valves for dynamic testing, (3) testing valves three times over a j 5-year interval with at least a 1-year interval between valve-specific tests according to a l
! standard test specification, (4) evaluation of results of each test, and (5) evaluation of collective i test results.
! In the last phase of its program, the JOG will evaluate the test results to validate the .
l assumptions in the interim program to establish a long-term MOV periodic verification program {
j to be implemented by licensees. A feedback mechanism will be established to ensure timely i sharing of MOV test results among licensees and to prompt individual licensees to adjust their !
own MOV periodic verification program, as appropriate. :
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- Following consideration of NRC staff comments, the BWROG submitted Licensing Topical
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j Repo.rt NEDC-32719 (Revision 2) describing the JOG program on July 30,1997._ Similarly, the J
l program on August 6 and 12,1997, respectively. On October 30,1997, the NRC staff issued an 4 SE to the BWROG, CEOG snd WOG accepting the JOG program with certain conditions and i limitations as an acceptable industry-wide response to GL 96-05 for valve age-related I
degradat.;on.
l l 4.0 DUANE ARNOLD GL 96-05 PROGRAM i
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On November 15,1996, IES Utilities, Inc., submitted a 60-day response to GL 96-05 notifying c the NRC that it would ensure the effectiveness of current program at Duane Amold to verify, on a periodic basis, that safety-related MOVs continue to be capable of performing their safety functions wthin its current licensing basis. On March 17,1997, the licensee submitted a 180-day response to GL 96-05 providing a summary description of the MOV periodic verification program planned to be implemented at Duane Amold. In a submittal dated May 13,1998, the licensee updated its commitment to GL 96-05. On November 20,1998, the licensee provided a response to a request for additional information regarding GL 96-05 forwarded by the NRC staff on September 23,1998. )
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'n its letter dated May 13,1998, the licensee stated that it plans to continue participating in the JOG Program on MOV Periodic Verification as a member of the BWROG and plans to implement the program described in Topica! Report NEDC-32719 (Revision 2). In its submittal dated March 17,1997, the licensee described the three phases of the JOG program for implementation at Duane Amold. _ With respect to its interim MOV static diagnostic testing i
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program, the licenses indicated that the criteria for ranking MOVs according to their risk significance at Duane Amold were based on BWROG Topical Report NEDC-32264. The !
licensee stated that its then-ongoing MOV periodic verification program would be superseded by i the GL 96-05 Periodic Verification Program during Refueling Outage RFO-15 in the spring of 1998.
5.0 NRC STAFF EVALUATION The NRC staff has reviewed the information provided in the licensee's submittals describing the i program to verify periodically the design-basis capability of safety-related MOVs at !
Duane Amold in response to GL 96-05. The staff also reviewed NRC Inspection Report (IR) 50-331/95011 which provided the results of an inspection to evaluate the completion of the 1 licensee's program to verify the design-basis capability of safety-related MOVs in response to i GL 89-10. The NRC staff closed the review of the GL 8910 program at Duane Amold in IR 95011. The NRC staffs evaluation of the licensee's response to GL 96-05 is described below.
. 5.1 MOV Program Scope ,
In GL 96-05. the NRC staff indicated that all safety-related MOVs covered by the GL 89-10 i
program should be considered in the development of the MOV periodic verification program. !
- The NRC staff noted that the program should consider safety-related MOVs that are assumed to be capable of returning to their safety position when placed in a position that prevents their
, safety system (or train) from performing its safety function; and the system (or train) is not i declared inoperable when the MOVs are in their nonsafety position. In its letter dated March 17, 1 1997, the licensee stated that the safety-related MOVs within the scope of the Duane Amold l GL 89-10 MOV program at that time would be included within the scope of its GL 96-05 Periodic i Verification Program. ]
Ouring the implementation of GL 89-10, the licensee proposed to delete from its GL 89-10 program 17 MOVs that have safety-related functions but are normally in their safety position. In an SE dated June 25,1996, the NRC staff concluded that those 17 MOVs must be capable of returning to their safety position (if they are out of their safety position for surveillance or testing) or the provisions of the appropriate Technical Specifications for the systems (or trains) out of service must be followed. The NRC staff noted that the licensee needed to addreas any applicable containment isolation or pipe break isolation requirements for those MOVs. The NRC staff concluded that the commitments made by the licensee as discussed in IR 95011 and subsequent licensee letters provided adequate confidence that the licensee had demonstrated and would maintain capability of the 17 MOVs to retum to their safety position under accident conditions. The NRC staff stated that the licensee would be expected to take appropriato cetion according to its Technical Specifications if plant or industry information revealed that these MOVs were not capable of returning to their safety position. Finally in the SE dated June 25, 1996, the NRC staff stated that the licensee would be expected to evaluate periodically the capability of those MOVs to retum to their safety position as part of its long-term MOV program.
in its letter dated March 17,1997, in response to GL 96-05, the licensee reported that the periodic verification criteria for the 17 MOVs in question would be as follows: (1) torque switch
. 6 settings would be maintained not less than previously tested values, (2) industry operating experience and data feedback would be evaluated to determine if any adjustments to control switch settings are required, and (3) if torque switch setting adjustments are required, adjustments would be performed during the next appropriate scheduled maintenance activity, but periodic verification dynamic or static diagnostic testing would not be performed on these MOVs. In a letter dated September 23,1998, the NRC staff stated that, although recognizing the low risk significance of those MOVs, it was not apparent that the licensee's stated periodic verification criteria would provide confidence that the MOVs would remain capable of retuming to their safety position without (1) plans for performing required switch setting adjustments promptly, (2) any specified MOV operation under dynamic conditions, or (3) any future diagnostic testing. The NRC staff requested that the licensee describe the bases for its confidence that (1) those MOVs would continue to be capable of retuming to their safety i position, (2) any degradation in MOV performance would be identified prior to causing the MOVs I to be incapable of retuming to their safety position, and (3) any action necessary to ensure MOV capability would be taken in a timely manner.
In its Scope,Also Encl|letter dated November 20,1998]], the licensee stated that, on August 1,1998, Duane Amold had converted to the improved Standard Technical Specifications. As a result, the licensee stated that the Duane Amold philosophy was modified to require systems to be considered inoperable when the performance of a Surveillance Test Procedure (STP) results in a condition that would not allow the system to automatically respond to an initiation signal. The licensee stated that the STPs for the 17 MOVs in question had been revised to state that: "While Primary Containment isolation System valves are out of their standby read l ness position for stroke timing, they are considered inoperable and while ECCS [ Emergency Core Cooling System]
valves are out of their standby readiness position for stroke timing, the ECCS system is considered inoperable." With these provisions, the licensee considers that a special MOV
_ program is no longer needed for those 17 MOVs. The NRC staff finds the licensee's resolution of the MOV scope issue at Duane Amold to be acceptable.
The NRC staff considers the licensee to have made adequate commitments regarding the scope ofits MOV program under GL 96-05.
5.2 MOV Assumptions and Methodo;ogies ,
The NRC staff expects licensees to maintain the assumptions and methodologies used in the i development of its MOV programs for the life of the plant (a concept commonly described as a l "living program"). For example, the design basis of safety-related MOVs will need to be .
maintained up to date, including consideration of any pisnt modifications or power uprate l conditions.
In IR 95011, the NRC staff reviewed the licensee's justification for the assumptions and i methodologies used in the MOV program in response to GL 89-10 at Duane Arnold. With certain long-term aspects discussed in the following section, the staff determined that the ;
licensee had adequately justified the assumptions and methodologies used in its MOV program.- l in its Scope,Also Encl|letter dated November 20,1998]], the licensee discussed ongoing activities, such as review !
of motor actuator output, to update its MOV program assumptions and methodologies. The j NRC staff considers the licensee to have adequate processes in place to maintain the I
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j assumptions and methodologies used in its MOV program, including the design basis of its safety-related MOVs.
W 5.3 GL 89-10 Long-Term items
- When closing the NRC review of the GL 89-10 program at Duane Amold, the NRC r,taff
. discussed in IR 95011 several aspects of the licensee's MOV program to be addressed over the long term. In its submittal dated November 20,1998, the licensee reported on the status of i those long-term GL 89-10 aspects. For example, the licensee had reviewed the NRC SE dated j March 15,1996, and its supplement dated February 20,1997, on the Electric Power Research j institute (EPRI) MOV Performance Prediction Methodology (PPM). The licensee repo'ted that the valve disc guides of MOVs MO-2700, " Reactor Water Clean Up inboard Isolation Valve,"
) and MO-2701, " Reactor Water Clean Up Outboard Isolation Valve," had been modified during RFO-15 to obtain predictable EPRI MOV PPM results. The licensee was continuing to monitor i test results for any evidence of load sensitive behavior and stem lubrication degradation. As
! noted in IR 95011, the NRC staff is addressing the licensee's actions in response to GL 95-07,
! " Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves," in a l separate manner.
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! In IR 95011, the NRC staff discussed the licensee's computer-based program for tracking and trending MOV parformance parameters, failures, and corrective maintenance actions at l Duane Amold. 'In its Scope,Also Encl|letter dated November 20,1998]], the licensee listed additional qualitative l and quantitative trending methods including periodic lubrication and inspection, overhaul and j diagnostic testir:g. In IR 95011, the NRC staff noted that the licensee would prepare tracking l and trending reports once per fuel cycle.
i l In IR 95011, the NRC staff concluded that the licensee had demonstrated the design-basis ;
i capability of its safety-related MOVs at Duane Amold. With the licensee's ongoing MOV l- activities and trending program, no outstanding issues regarding the licensee's GL 89-10 l program remain at Duane Amold.
f 6.4 JOG Program on MOV Periodic Verification l
1 in its letter dated May 13,1998, the licensee updated its commitment to implement the JOG Program on MOV Periodic Verification as described in Topical Report NEDC-32719
- - industry-wide response to GL 96-05 with certain conditions and limitations. The licensee's i commitment to implement the JOG program includes (1) the JOG interim static diagnostic test
[ program, (2) the JOG 5-year dynamic test program, and (3) the JOG long-term periodic test program. The NRC staff considers the commitments by the licensee to implement the JOG l program at Duane Amold to be an acceptable response to GL 96-05 for valve age-related i degradation. The licensee is responsible for reviewing and implementing the limitations and j conditions discussed in the NRC SE dated October 30,1997, in applying the JOG program at
. Duane Amold. This includes the coordination and feedback of test information obtained ftom l
- the JOG dynamic testing program. Where the licensee proposes to implement an approach at
- Duane Amold different from the JOG program, the licensee will be expected to notify the NRC and to provide justification for the proposed attemative approach.
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. 8 in its submittal dated March 17,1997, the licensee presented its interim MOV static diagnostic test program with a test frequency based on the safety significance and functional capability of each GL 96-05 MOV. The MOV static diagnostic test frequency matrix at Duane Amold is consistent with the JOG recommendations. Guidance for the calculation of MOV margin is provided in the JOG Topical Report NEDC-32719 and the NRC SE dated October 30.1997.
The licensee reported that its MOV risk-ranking criteria were based on BWROG Topical Report NEDC-32264. The licensee will be expected to satisfy the NRC SE dated February 27,1996, which accepted BWROG Topical Report NEDC-32264 with certain conditons and limitations, in its implementation of the BWROG MOV risk-ranking methodology.
In its submittal dated March 17,1997, the licensee stated that its static diagnostic testing may include a mix of testing to obtain performance data directly at the MOV and from the Motor Control Center (MCC). In applying test data obtained from the MCC in its GL 96-05 program, the licensee will be expected to address the following issues as applicable to its use of MCC test data: (1) the correlation between new MCC test data and existing direct MOV data measurements; (2) the relationship between changes in MCC test data and MOV thrust and torque performance; (3) system accuracies and sensitivities to MOV degradation for both output and operating performance requirements; and (4) validation of MOV operability using MCC testing.
The JOG program is intended to address most gate, globe and butterfly valves used in safety-related applications in the nuclear power plants of participating licensees. The JOG iniicates that each licensee is responsible for addressing any MOVs outside the scope of applicability of the JOG program. In the NRC SE dated October 30,1997, the NRC staff specifies that licensees implementing the JOG program must determine any MOVs outside the scope of the JOG program (including sewice conditions) and justify a separate program for periodic verification of the design-basis capability of those MOVs. The NRC staff recognizes that the JOG has selected a broad range of MOVs and conditions for the dynamic testing program. Consequently, the NRC staff expects significant information to be obtained on the performance and potential degradation of safety-related MOVs during the interim static diagnostic test program and the JOG dynamic test program. As the test results are evaluated, the JOG might include or exclude additional MOVs with respect to the scope of its program.
Although the test information from the MOVs in the JOG dynamic test program might not be adequate to establish a long term periodic verification program for each MOV outside the scope of the JOG program, sufficient information should be obtained from the JOG dynamic test
. program to identify any immediate safety concem for potential valve age-related degradation ,
during the interim period of the JOG program. Therefore, the NRC staff considers it acceptable I for the licensee to apply its interim static diagnostic test program to GL %-05 MOVs that currently might be outside the scope of the JOG program with the feeduack of information from the JOG dynamic test program to those MOVs. Upon completion of the JOG dynamic test program and development of the JOG Iong-term MOV periodic verification criteria, the licensee will be expected to establish a long-term MOV periodic verification program for those MOVs outside the scope of the JOG program by applying information from the JOG program or additional dynamic tests, as necessary.
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5.5 Motor Actuator Output l The 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 SE dated October 30,1997, on the JOG program, the NRC staff specifes that licensees are responsible for addressing the thrust or torque delivered by the MOV motor actuator and its potential degradation. Although l the JOG does not plan to evaluate degradation of motor actuator output, significant information -
on the output of motor actuators will be obtained through the interim MOV static diagnostic test program and the JOG dynamic test program.
In its submittal dated November 20,1998, the licensee stated that actions to monitor MOV motor actuator output consisted of a preventive maintenance program that includes periodic lubrication and inspection, overhaul, and d; agnostic testing to evaluate MOV performance for indications of-degradation. The NRC staff notes that several parameters can be obtained during MOV static and dynamic testing to help identify motor actuator output degradation when opening and closing the valve including, as applicable, capability margin, thrust and torque at control switch trip, stem friction coefficient, load sensitive behavior, and motor current. Further, plant-specific and JOG test information can provide support for the licensee's plan for monitoring MOV motor
- actuator output and its potential degradation. In IR 95011, the NRC staff discussed the monitoring of various MOV parameters (such as load sensitive behavior and stem lubricant degradation) at Duane Amold, and reported that the licensee had established a trending program for MOV performance parameters, including normal and alarm ranges. The licensee indicated in a discussion with the NRC staff following submittal of its Scope,Also Encl|letter dated November 20, 1998]], that it was monitoring several MOV parameters (such as stem friction coefficient, motor current, and load sensitive behavior in the valve opening and closing directions under static and dynamic conditions) to provide assurance that degradation in MOV output can be identified. In its submittal dated November 20,1998, the licensee reported that it had not identifed degradation in MOV performance to date.
In its submitte! dated November 20,1998, the licensee stated that it had reviewed and evaluated Limitorque Technical Update 98-01 and its Supplement i for the prediction of ac-powered MOV output. The licensee reported that it had revised and implemented its degraded voltage thrust calculation methodology as specified in the Limitorque technical update and that no operability concerns were identifed. In Supplement 1 to Technical Update 98-01, Limitorque noted that a future technical update would be issued to address the application of de-powered motors in i MOVs. In the follow-up discussion with the NRC staff, the licensee indicated that it was aware of industry activities in this area and would evaluate their applicability and take required actions as needed.
The NRC staff considers the licensee to be establishing sufficient means to monitor MOV motor actuator output and its potential degradation.
6.0 CONCLUSION
On the basis of this SE, the NRC staff finds that the licensee has established an acceptable program to verify periodically the design-basis capability of the safety related MOVs at Duane Arnold. Therefore, the staff concludes that the licensee has adequately addressed the actions
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, 10 requested in GL 96-05. The NRC staff may conduct inspections to verify the implementation of the MOV periodic verification program is in accordance with the licensee's commitments; this NRC SE; the NRC SE dated October 30,1997, on the JOG Program on MOV Periodic Verification; and the NRC SE dated February 27,1996, on the BWROG methodology for ranking MOVs by their safety significance.
Principal Contributor: T. Scarbrough, NRR Date: March 3,1999 i
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