ML19283B604
| ML19283B604 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 02/02/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Nichols T SOUTH CAROLINA ELECTRIC & GAS CO. |
| References | |
| NUDOCS 7903010097 | |
| Download: ML19283B604 (4) | |
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NUCLEAR REGUL ^ ~ ORY COMMISSION R E WON il 8
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FEB E 1979 In Reply Refer To:
RII:JPO 50-395 South Carolina Electric and Gas Company Attn:
Mr. T. C. Nichols, Jr., Vice President and Group Executive Power Production and System Operations P. O. Box 764 Columbia, South Carolina 29218 Gentlemen:
This Information Notice is provided as an early notification of a It is expected that recipients vill possibly significant mitter.
review the information for possible applicability to their facilities.
If further No specific action or response is requested at thia time.
NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recocnend or request specific licensee actions.
If you have questions the Director of the appropriate regarding this matter, please contact NRC Regional Office.
Sincerely,
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- ames7, Reilly Director
Enclosures:
1.
IE Information Notice No. 79-01 2.
List of IE Information Notices Issued in 1979 7903010097
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMDIT WASHINGTON, D. C.
20555 February 2, 1979 IE Information Notice No. 79-01 BERGEN-PATERSON 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 cocpression 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 BSSA-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 direction. It was also observed that five of the seven units had the poppet spring entrapped between the poppet and 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 coc=itted 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, lockup and bleed. The Bergen-Paterson Technical Maintenance Manual recocmends 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 beat removal system had been subjected to a transient condition in the form of a
" water ha=mer."
This transient, caused pipe movement great enough to damage two rigid pipe support wall attachments. The subsequent functional testing of the affected Bergen-Paterson units revealed that one of seven units failed the lockup test. Tnis unit (nodel No. ESSA-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.
IE Information Notice No. 79-01 February 2,1979 This information is provided as an early notification of a possibly significant matter.
It is expected that recipients will 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 vill be issued to recam=end 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 Subj ect 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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