ML20035E887

Summarizes 930406 Meeting W/Util Re MOV Operability Assessments.List of Attendees & Slides Used for Presentation Encl

ML20035E887
Person / Time
Site:	LaSalle
Issue date:	04/14/1993
From:	Martin T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	Delgeorge L COMMONWEALTH EDISON CO.
References
NUDOCS 9304200024
Download: ML20035E887 (14)

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/g CLEN ELLYN, ILUNOt$ 60137 April 14, 1993 Docket No. 50-373

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Docket No. 50-374 Commonwealth Edison Company m

ATTN: Mr. L. O. DelGeorge Vice President Nuclear Oversight and Regulatory Services Executive Towers West III 1400 Opus Place, Suite 300 Downers Grove, IL 60515

SUMMARY

OF MEETING HELD ON APRIL 6, 1993, WITH COMMONWEALTH EDISON COMPANY REPRESENTATIVES TO DISCUSS MOTOR-OPERATED VALVE OPERABILITY E

CRITERIA On April 6, 1993, NRC staff from Region III and EMEB/NRR met with representatives from Commonwealth Edison Company (CECO) to discuss motor-operated valve (MOV) operability assessments. The staff raised the operability assessment issue during a MOV inspection at Ceco's LaSalle County Station (373/374-92023) and was concerned that CECO was using what appeared to be nonconservative factors for determining required and available thrust for opening or closing MOVs. Specifically, the staff was concerned about values chosen by CECO for the following parameters: motor torque, application factor, actuator efficiency, stem friction coefficient, valve factor, and load sensitive behavior.

For example, using stall torque from generic motor curves for available motor torque, rather than limiting motor capability to a more realistic value; setting the application factor to 1, which doesn't take into account known operator frictional losses; and sot accounting for load sensitive behavior, even though it is a known phenomenon. While none of the LaSalle County valves reviewed by the staff were evaluated as inoperable, the operability methodology used at LaSalle is common to all Ceco facilities, thereby raising a generic concern with CECO.

NRC outlined the issues dealing with each parameter. The outline included the staff's understanding of CECO's position, a description of NRC concerns with that position, and discussed currently acceptable methods of dealing with the issue.

The slides attached to this letter provide details for each parameter discussed. While the discussion focused on the factors selected by CECO, the NRC stressed that NRC operability determination reviews are based on the relative combination of parameter values and assumptions.

Because the reviews are based on a cumulative effect, the staff believes it is neither necessary 9304200024 930414 PDR ADOCK 05000373 P

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Commonwealth Edison Company 2

April 14, 1993 nor would it be productive to define specific values for each parameter.

In this vein, the staff emphasized that consideration would be given to reasonable assumptions provided appropriate technical justifications were

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pr ovided.

The staff also emphasized that Ceco was ultimately responsible for timely MOV operability determinations.

l Commonwealth Edison Company indicated they would provide feedback to the staff after they had an opportunity to assess the information presented during the meeting.

i If you have any questions, please contact Mr. G. Wright of my staff at (708) 790-5695.

j Sincerely, D-T. O. Martin, Acting Director i

Division of Reactor Safety Attachments:

1.

MOV Meeting Attendees 2.

NRC Slide Presentation f

cc w/ attachments:

W. Murphy, Site Vice President i

G. Spedl, Station Manager J. Lockwood, Regulatory Assurance Supervisor D. Farrar, Nuclear Regulatory l

Services Manager OC/LFDCB Resident Inspectors-LaSalle, Dresden, Quad Cities Richard Hubbard J. W. McCaffrey, Chief Public Utilities Division T. Scarbrough, NRR T. Gody, Jr., NRR B. Stransky, LPM, NRR Robert N-n, Office of Public Counse:

ate of Illinois Center State Lie n

Officer Chairman, Illinois Commerce Commission b

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ATTACHMENT 1 MEETING ATTENDEES MOV OPERABILITY MEETING AT REGION 11].

APRIL 6. 1993 Nuclear Reaulatory Commission Title T. Martin Acting Director, Division of Reactor Safety (DRS)

C. Gainty Inspector, Materials and Processes Section, DRS M. Huber Inspector, Materials and Processes Section, DRS J. Jacobson Chief, Materials and Processes Section, DRS G. Replogle Inspector, Materials and Processes Section, DRS J. Smith Inspector, Materials and Processes Section, DRS G. Wright Chief, Engineering Branch, DRS Commonwealth Edison Company Title D. Farrar Nuclear Regulatory Services Manager B. Adams Regulatory Assurance Supervisor K. Brennan Mechanical and Structural Superintendent M. Depuydt Nuclear Licensing Administrator J. Gieseker Engineering and Construction Manager Y. Lassere MOV Program Manager J. Lockwood Regulatory Assurance Supervisor 3

L. Melander LaSalle Technical Staff H. Mulderink BWR MOV Coordinator S. Raborn MOV Engineer S. Reece-Koenig Regulatory Performance M. Reed Technical Services Superintendent D. Taylor Regulatory Assurance Supervisor Contractors Title J. Davies MOV Engineer (Bechtel)

D. Graham MOV Engineer (Bechtel)

J. Kelly MOV Project Manager (ABB Impell)

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AGENDA i

I n': roc.uc':ory Remar..cs e.

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- 7. Mar':in Issue ?resen~:a': ion & Jiscussion X:2C

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I Y O '.: O R '? O 2 Q E E NRC Understanding CECO Position:

O rpm torque / generic curve i

NRC Position.

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!) Limitorque won't endorse

2) Maximum Lirnitorque-110%

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3) 5 motor manufacturers i

4) Curves not guaranteed Discussion:

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A:?:?:L::CA"::ON FAC"O2 NRC Understanding CECO Position:

1) Use AP of 1

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2) Factor is all margin NRC Position:

!) Limitorque--0.9 z ' racior accounts for,1ricr.onal t

losses (exclude worm gear sei

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i NRC Understanding CECO Position:

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2) S.F.C. (.15 used i

i NRC Postion:

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) S.F C. of.15 for operabi ity call

2) Anythina (.l.5 reauires sioecific

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NRC Understanding CECO Position:

1) Eff. at stall used

2) Claims Inertial effects available 1

NRC Position:

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i) Lirnitorque and EPRI

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efficiency not aciual efficiency

2) Eff. is speed deoendent

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effects should not be credited I

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1 O'.?:EE:2 COXS:J:E:2K ::0XS NRC Understanding CECO Position:

1) Assumes low valve factors for untested valves (.3)

2) Load Sensitive Behavior not considered NRC Position:

1) Measured Valve Factors (avg. 6 highest 9)

2) CECO test shows substant:al Lcad Sensitive Behavior a) CECO 9% avg for low do's (as high as 2.3%)

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Discussion:

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Non-conservatisms Used by CECO:

1) Motor Torque Values

2) Application Factor

3) Stern Factor

4) Inertial Effects

5) Valve Factors l

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6) Load Sensitive Behavior l

i Factors used do not provide i

adequate assurance that valves will function.

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