Motor-Operated ValveRegulatory Activities

Mi h l F FMichael F. Farnan

Component Performance & Testing Branch

Division of Component Integrity

Office of Nuclear Reactor Regulation

U.S. Nuclear Regulatory Commission

MOV Users’ Group

January 2010 1

NRC Regulations

• 10 CFR 50.49 – Environmental Qualification

• 10 CFR 50.55a – Inservice Testing

• 10 CFR Part 50, Appendix A – General Design Criteria

• 10 CFR Part 50, Appendix B – Quality Assurance

• 10 CFR Part 100 – Seismic Qualification

• 10 CFR 50.69 – Risk-Informed Treatment

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Generic Letters (GL)

• GL 89-10 requested licensees to verify design basis capability of safety-related motor-operated valves (MOVs)

• GL 95-07 requested licensees to address potential pressure locking and thermal binding of power-operatedpressure locking and thermal binding of power-operated gate valves

• GL 96-05 requested licensees to develop programs to periodically verify MOV design basis capability

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Reg Guide 1.192 Operation and Maintenance Code Case Acceptability, ASME OM Code

• Regulatory guide lists OM Code Cases that are acceptable to the NRC for implementation in the Inservice Test (IST) of light-water-cooled nuclear power plantsplants

• Revision 1 to RG 1.192 (NRC approval of ASME OM Code Cases, 2002-2006 Addenda) – first quarter 2010 public comment, final end of 2010

• ASME OMN-1 acceptable as alternative to MOV quarterly stroke-time testing using periodic diagnostic testing and exercising (with conditions)

• ASME OMN-11 provides acceptable risk-informed guidance for use of OMN-1 with conditions

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Joint Owners Group (JOG) Program on MOV Periodic Verification (PV)

• Risk-informed program to share test information on valve performance for GL 96-05

Interim phase specified static diagnostic testing at• Interim phase specified static diagnostic testing at frequency based on risk and margin

• 5-year dynamic testing of sample MOVs for each plant

• Safety Evaluation (SE) (10/97) issued on initial JOG Topical Report (7/97)

• Long term guidelines based on dynamic test results provided in JOG Topical Report (2/04)

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NRC Safety Evaluation on JOG Program

• JOG program is an acceptable industry wide GL 96-05 response for valve age related degradation when implemented with SE (10-30-97 and 9-25-06)implemented with SE (10 30 97 and 9 25 06)

• Operating experience might reveal need for adjustments

• Engineering judgment applied consistent with GL 96-05

• For MOVs or application outside JOG Scope (Class D), or deviations from JOG schedule or recommendations, notify NRC staff per GL 96-05 commitments

• Licensees responsible for MOV output verification

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Current MOV Issues/Activities

• GL 96-05 implementation• Class D valves• Degraded Stem Lubricantg• Motor magnesium rotor degradation• Spare Motors• SMB-000 Torque Switch• NUREG-1482 Revision 2• New Reactors

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GL 96-05 Implementation

• NRC staff reviewed GL 96-05 descriptions submitted by licensees and performed sample inspections

• SE dated September 25, 2006 describes NRC staff review and acceptance of JOG Program

• Licensees continue to implement GL 96-05 programs

• Licensees have six year window to implement final recommendations with start date of SE issuance

• NRC staff plans to revise MOV Inspection Manual adding attributes of JOG program

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NRC Expectations for Class D Valve Notifications

• Valve Identification Number - (tag number)• System• Valve Type (gate, globe, butterfly, etc.)

V l I l (Fl ibl W d D bl Di k )• Valve Internals (Flexible Wedge, Double Disk, etc.)• Valve Size• Valve Manufacturer• Classification Analysis - (explain why this valve is

considered to be a Class D valve)• Proposed Periodic Verification Program - (describe

program that will periodically verify the design basis capability)

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NRC Expectations for Class D Valve Notifications (cont’d)

• Licensee submittal via supplemental response to GL 96-05

• NRC will evaluate each submittal• NRC will provide GL 96-05 supplemental letter to

licensees detailing the results of the Class D submittal

• Plants with no Class D valves do not have to submit a response

• For future Class D valve installations, NRC staff would expect update to GL 96-05 response

• Generic Class D PV approach can be submitted to address future needs

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Degraded Stem Lubricant

• 2009 – There were 5 instances of MOV failures due to stem lubricant degradation

• Stem lubricant degradation can affect the efficiency of actuator torque conversion thus reducing marginq g g

• Licensees are responsible for addressing MOV actuator output and potential degradation

• NRC staff preparing information notice to alert licensees on the importance of assessing lubricant performance as it relates to preventive maintenance (PM) intervals, maintenance practices, environmental conditions, safety margins and surveillance testing

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Magnesium Motor Rotor Degradation• NRC issued IN 86-02, 2006-26 and 2008-20 to alert

licensees of MOV failures by magnesium motor rotor degradation

• Failures due to oxidation and corrosion from exposure to high humidity and temperaturesto high humidity and temperatures

• Failure mechanisms include galvanic corrosion, general corrosion, and thermally induced stress

• Number of recent failures illustrate need for adequate MOV PM

• BWROG Valve Technical Resolution Group developed guideline “Inspection of Motor Operated Valve Limitorque AC Motors with Magnesium Rotors”

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Spare Motors

• July 31, 2009 - Crystal River Unit 3 identified a potential reportable condition of a spare motor

• Motor was being inspected to address magnesium rotor concerns

• Visual indications were observed in the outboard end of the motor

• Cracked weld with dislodged metal

• Report submitted to NRC pursuant to 10 CFR 21.21

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SMB-000 Torque Switch

• Operating experience and inspection reports examined over the last 15 years

• Several events involving SMB 000 Torque• Several events involving SMB-000 Torque Switch

• Majority of instances noted dirty and/or hi resistance on contacts

• Many failures occurred shortly after maintenance activity

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NUREG-1482 Revision 2

• NUREG-1482 “Guidelines for Inservice Testing at Nuclear Power Plants” is currently being updatedupdated

• The last update (Revision 1) was completed in 2004

• Projected completion in 2010

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New Reactors

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New Reactor Applications

• Combined License applications received: – 4 U.S. Evolutionary Power Reactor (U.S. EPR) – 7 Advanced Passive 1000 (AP1000)– 1 U.S. Advanced Pressurized-Water Reactor (US-APWR)

4 Economic Simplified Boiling Water Reactor (ESBWR)– 4 Economic Simplified Boiling-Water Reactor (ESBWR)– 1 Advanced Boiling-Water Reactor (ABWR)

• Design Certification applications under review:– AP1000 amendment– ESBWR– U.S. EPR– US-APWR

• Four Early Site Permits Issued

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