ML19269C701
| ML19269C701 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 02/02/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Gerstner W ILLINOIS POWER CO. |
| Shared Package | |
| ML19269C702 | List: |
| References | |
| NUDOCS 7902120100 | |
| Download: ML19269C701 (1) | |
Text
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Docket No. 50-461 Docket No. 50-462 f[ 3 '
J-Illincis Power Company ATTN:
Mr. W. C. Gerstner Executive Vice President 500 South 27th Street Decatur, IL 62525 Gentlemen:
This Information Notice 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 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, Q h'A VJamesG.Ke"pher Director
Enclosures:
1.
IE Information Notice No. 79-01 2.
List of IE Information Notices Issued in 1979 cc w/encls:
Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local POR SIC IIC Mr. Dean Hansell, Office of Assistant Attorney General 790212 din
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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 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 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 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 The licensee poppet spring entrapped between the poppet and the seat.
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 co==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-Patersen Technical Maintenance Manual 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 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. 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 et this time.
Dd P6 7902120059
a.
f 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.
No specific information for possible applicability to their facilities.
If further NRC evaluations action or response is requested at this time.
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.
Page 2 of 2
b, f
IE Information Notice No. 79-01 February 2 1979 LISTING OF IE INFORMATION NOTICES ISSUED IN 1979 Information Subject Date Issued To Issued Notice No.
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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