ML19283B606
| ML19283B606 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 02/02/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Stampley N MISSISSIPPI POWER & LIGHT CO. |
| References | |
| NUDOCS 7903010107 | |
| Download: ML19283B606 (4) | |
Text
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TER9 UNITED STATES f 8800g NUCLEAR REGULATORY COMMISSION
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e,'o REGloN 11 101 MARIETTA STREET, NJf.
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ATLANT A. GEORGI A 30303 FEB 2 1979
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In Reply Refer To:
RII:JPO 50-416, 50-417 Mississippi Power and Light Company Attn:
Mr. Norris L. Stampley Vice President of Production P. O. Box 1640 Jackson, Mississippi 39205 Gentlemen:
This Information Notice is provided as an early notification of a It is expected that recipients will possibly significant matter.
review the information f or possible applicability to their f acilities.
If further No specific action or response is requested at this time.
NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recoc:=end or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely.
/}/L-l mf m
a=es77 Reilly Directer
Enclosures:
1.
IE Information Notice No. 79-01 2.
List of IE Information Noticea Issued in 1979 cc w/ encl:
W. L. Nail, Plant Superintendent P. O. Box 756 Port Gibson, Mississippi 39150 79030101o'7
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C.
20555 February 2, 1979 IE Information Notice re. 79-01 BERGEN-PATERS 0E HYDRAULIC 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, HSSA-10-6 and HSSA-20-6. When the units were disasse= bled, the licensee observed dr. cage to the poppet valve and acat on the co=pression side of the valve blocks of the seven units that failed in the compression direction. It was also observed that five of the seven units had the poppet spring entrapped between the poppet anl the seat. The licensee attributed the seven failures in the compression direction to abusive handling during compression of the units for installation following testing at the previous refueling outage. The cause of the single failure in the extension direction has not been determined. In addition to exercising greater care in reinstallation, the licensee committed to functionally test all Bergen-Paterson snubbers subjected to transient conditions which ca6se either physical damage to or significant movement of piping. This testing vill include verification of piston movement, lockup and bleed. The Bergen-Paterson Technical Maintenance Manual recommends that additional inspections should be made on units which may have participated in an unusual shock occurrence involving known damsge to piping or equipment.
On January 3,1979, the licensee reported that the decay heat removal syste= had been subjected to a transient condition in the form of a
" water hammer." This transient, caused pipe movement great enough to damage two rigid pipe support vall attachments. The subsequent functional testing of the affected Bergen-Paterson units revealed that one of seven units failed the lockup test. This unit (Model No. HSSA-3-6) was disasse= bled and da= age 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 cocpletely 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.
IE Information Notice No. 79-01 February 2, 1979 This information 10 provided as an early notification of a possibly significant matter.
It is expected that recipients wdll review the information for possible applicability to their facilities. No specific action 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.
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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 cocnnuaicating 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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