ML20204G397

Forwards Engineering Evaluation Rept on Operational Data Re motor-operated Valve Failure Due to Hydraulic Lockup from Excessive Grease in Motor Operator Spring Pack.Issuance of IE Info Notice to Alert Licensees Recommended

ML20204G397
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	03/19/1987
From:	Ellen Brown NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD)
To:	Rubin S NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD)
Shared Package
ML20204G235	List: ML20204G231 ML20204G295 ML20204G397 ML20204G465
References
AEOD-E702, NUDOCS 8703260389
Download: ML20204G397 (3)

Text

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March 19, 1987 MEMORANDUM FOR: Stuart D. Rubin, Chief AE0D/E702 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data FROM: Earl J. Brown Engineering Section Reactor Operations Analysis Branch Office for Analysis and Evaluation of-Operational Data

SUBJECT:

M0V FAILURE DUE TO HYDRAULIC LOCKUP FROM EXCESSIVE GREASE IN SPRING PACK An engineering evaluation report on operational data involving motor operated valve (M0V) failure due to hydraulic lockup from excessive grease in the.

spring pack area of the motor operator is enclosed. The available event data is applicable to Limitorque SMB motor operators. The evidence demonstrates that hydraulic lockup has occurred and is a potential common mode failure mechanism for SMB motor operators. Although the parameters and conditions that cause hydraulic lockup are not fully defined or understocd, the phenomenon appears related to use of EXXON NEBULA EP-0 grease. This grease is a recommended environmentally qualified lubricant that is less viscous than the only other qualified grease.

The report illustrates that different designs of SMB motor operators are adversely affected, that different corrective actions may be needed to prevent hydraulic lockup, and that industry comunication procedures have resulted in inaccurate _or misleading guidance to licensees concerning this issue.

Therefore, it is recomended that IE issue an information notice to alert licensees.about the phenomenon and provide a description of the hydraulic lockup events. The report should also be distributed to NRR for information and consideration in the effort on Generic Issue II.D.6.1. In addition, the report recomends .imediate industry effort to (1) identify conditions, sequences, or procedures that ;esult in hydraulic lockup; (2) develop solutions for all types of motor operators currently in use (modification kits, design changes, etc.); and (3) disseminate the corrective actions to are users. It is suggested that this effort be coordinated through NUMARC as part of the overall program for industry action on MOVs.

8703260389 870399 PDR S ADOCK 05000271 ppg

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_2-The report should also be forwarded to INP0 separately, rather than the AEOD batch distribution, because it identifies.possible inaccurate information provided by the industry communications procedures.

Earl J. Brown Engineering Section Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data

Enclosure:

As stated-DISTRIBUTION:

See attached sheet

, OFC :ROAB :ROAB:SCL . :ROAB:BC/  :  :  :  :

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NAME':EBrown:nc :MChiramal :SRubin // :  :  :  :

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_____:____________:____________:_7__/87 DATE :2/27/87

2/7 /87  ://v  :  :  :  :

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ROAB C Tle, NRR AE0D S/F. UPatapovs, IE

'AE00 C/F EMerschoff, IE EBrown RLasky, IE MChiramal JStone, IE

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.Plam PBaranowsky VRooney, NRR WRaymond, RI Vermont Yankee TElsasser, RI REMartin, NRR GKelly, RI-Limerick RGraham, RI Limerick RGallo, RI JJohnson, RI .

TWamback, NRR ESwanson, RI Palisades BBurgess, RIII PWohld, RIII SEick, RIII RKiessel, IE

'RBaer, IE ADromerick, IE ORothberg, NRR FCherny, NRR RBosnak, NRR JVora, RES WFarmer. RES GWeidenhamer, RES JRichardson, RES LMarsh, NRR BLiaw, NRR

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