ML19269C671
| ML19269C671 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Byron, Braidwood, Quad Cities, Zion, LaSalle  |
| Issue date: | 02/02/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Brian Lee COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 7902120054 | |
| Download: ML19269C671 (4) | |
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GLEN E LLY N, ILLINOIS 60137 s y FEB 0 21979 Docket Nos. 50-10, 50-237, 50-249, 50-254, 50-265, 50-295, 50-304, 50-373, 50-374,40-454, 50-455, 50-456, 50-457 Commonwealth Edison Compcny ATTN:
Mr. Byron Lee, Jr.
Vice President P. O. Box 767 Chicago, IL 60690 Gentlemen:
This Information Notice is provided as an early notification It is expected that recipients of a possibly significant matter.
will review the information for possible applicability to their facilities. No specific action or response is requested at this If further NRC evaluations so indicate, an IE Circular time.
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, b gg.k%
(/ James G. KeppIer Director
Enclosures:
1.
IE Information Notice No. 79-01 2.
List of IE Information Notices Issued in 1979 cc w/encls:
Mr. R. Cosaro, Project Mr. B. B. Stephenson, Station Superintendent Superintendent Mr. N. Kalivianakis, Central Files Station Superintendent Director, NRR/DPM Mr. N. Wandke, Station Director, NRR/ DOR PDR Superintendent Local PDR Mr. L. J. Burke, Site NSIC Project Superintendent Mr. R. J. Legner, Quality TIC Assurance Supervisor Anthony Roisman, Esq., Attorney Mr. Ct.nner Sorensen, Site Mr. Dean Hansell, Office of Aasistant Attorney General Project Superintendent 7902]2oo$y Ce
l 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 It was also observed that five of the seven units had the direction.
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 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==itted to functionally test all Bergen-Paterson snubbers subjected to transtent 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 additional inspections should be made on units which recommends that may.have participated in an unusual shock occurrence involving known datage to,' piping or equipment.
On January 3, 1979, the licensee reported that the decay heat removal condition in the form of a system had been subjected to a transient
" water hammer." This transient, caused pipe movement great enough to The subsequent functional damage two rigid pipe support wall attachments.
testing of the affected Bergen-Paterson units revealed that one of seven This unit (Model No. HSSA-3-6) was units failed the lockup test.
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 caur. of damage has not been completely defined nor has appropriate corrective action been Other licensees have reported instances of poppet velve determined.
damage; however, the cause and extent of damage are not known at this time.
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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-If you have questions regarding request specific licensee actions.
this matter, please contact the Direct'or of the appropriate NRC Regional Office.
Page 2 of 2
IE Information Notice No. 79-01 February 2, 1979 LISTING OF IE INFORMATION NOTICES ISSUED IN 1979 Intormation Subject Date Issued To Issued Notica No.
An Information Notice is a new method of communicating items of potential interest to licensees. This item, Information Notice No. 79-01, ic the first of this new form of communication.
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