ML19269C705

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Forwards IE Info Notice 79-01,Bergen-Paterson Hydraulic Shock & Sway Arrestors (Hssa)
ML19269C705
Person / Time
Site: Midland
Issue date: 02/02/1979
From: James Keppler
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To: Howell S
CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
Shared Package
ML19269C706 List:
References
NUDOCS 7902120106
Download: ML19269C705 (1)


Text

1-UNITED STATES t

p NUCLEAR REGULATORY COMMISSION fI\\;Ci j

REGION 111 799 ROOSEVELT Ro AD

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g GLEN E LLYN, ILLINolS 60137

~77 Docket No. 50-329 Docket No. 50-330

- ;a, Consumers Power Company ATTN:

Mr. Stephen H. Howell Vice President 1945 West Parnall Road Jackson, MI 49201 Gentlemen:

This Information Notice is provided as an early notification of a possibly significant matter. It is expected that recipients vill review the information for possible applicability to their facilities. No specific actica or response is requested at this time. If further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recommend or request specific licensee actions. If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.

Sincerely, WS Y

(# James G. Ke er Director

Enclosures:

1.

IE Information Notice No. 79-01 2.

List of IE Information Notices Issued in 1979

.c w/encls:

Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR JSIC TIC Ronald Callen, Michigan Public Service Commission Dr. Wayne E. North Myron M. Cherry, Chicago 790212 O/06

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U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT REGION III February 2,1979 IE Information Notice No. 79-01 BERGES-PATERSON KYDRAULIC SHOCK AND SWAY ARRESTORS (HSSA)

On December 4, 1978, Rancho Seco Nuclear Generating Station reported the failure of seven Bergen-Paterson HSSA (Snubber) units to lockup in the compression direction and the failure of one additional unit to lockup in the extension direction. These failures were identified during surveillance testing and the affected models included HSSA-3-6, ESSA-10-6 and HSSA-20-6. When the units were disassembled, the licensee observed damage to the poppet valve and seat on the compression side of the valve blocks of the seven units that failed in the compression It was also observed that five of the seven units had the direction.

The licensee poppet spring entrapped between the poppet and the seat.

actributed the seven failures in the compression direction to abusive handling during compression of the units for installation following The cause of the single testing at the previous refueling outage.

failure in the extension direction has not been determined. In addition to exercising greater care in reinstallation, the licensee co=mitted to functionally test all Bergen-Paterson snubbers subjected to transient conditions which cause either physical damage to or significant movement of piping. This testing will include verification of piston movement, The Bergen-Paterson Technical Maintenance Manual lockup and bleed.

recommends that additional inspections should be made on units which may,have participated in an unusual shock occurrence involving known damage to piping or equipment.

On January 3, 1979, the licensee reported that the decay heat removal system had been subjected to a transient condition in the form of a

" water hammer." This transient, caused pipe movement great enough to The subsequent functional damage two rigid pipe support wall attachments.

one of seven testing of the affected Bergen-Paterson units revealed that units failed the lockup test. This unit (Model No. HSSA-3-6) was disassembled and damage to the poppet valve and seat was observed.

The damage to the poppet valves is presently being reviewed by both the licensee and Bergen-Paterson. At this time, the cause of damage has not been completely defined nor has appropriate corrective action been determined. Other licensees have reported instances of poppet valve damage; however, the cause and extent of damage are not known at this time.

DdP6

.7002120059

February 2, 1979 IE Information Notice No. 79-01 This information is provided as an early notification of a possibly It is expected that recipients will review the significant matter.

information for possible applicability to their facilities. No specifft action or response is requested at this time.

If further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to reconmend or If you have questions regarding request specific licensee actions.

this matter, please contact the Director of the appropriate NRC Regional Officc.

Page 2 of 2

IE Information Notice No. 79-01 February 2, 1979 LISTING OF IE INFORMATION NOTICES ISSUED IN 1979 Information Subject Date Issued To Notice No.

Issued An Information Notice is a new method of communicating items of potential interest to licensees. This item, Information Notice No. 79-01, is the first of this new form of communication.

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