ML18113A852
| ML18113A852 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna  |
| Issue date: | 02/02/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Proffitt W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NUDOCS 7902230139 | |
| Download: ML18113A852 (5) | |
Text
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In Reply Refer RII:JPO 50-338, 50-339 50-404, 50-405
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50-281 To:
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UNITED STATES NUCLEAR REGULATORY COMMISSION REGION II 101 MARIETTA STREET, N.W.
ATLANTA, GEORGIA 30303 FEB 2 1979 Virginia Electric and Power Company Attn:
Mr. W. L. Proffitt Senior Vice President, Power Operations P. O. Box 26666 Richmond, Virginia Gentlemen:
23261 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 eo indicate, an IE Circular or Bulle~n will be issued to recommend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate RRC Regional Office.
Sincerely,
.d c<,?>t sP~;
Enclosures:
- 1.
IE Information Notice No. 79-01
- 2.
List of IE Information Notices Issued in 1979 ctor J
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Virginia Electric and Power Company cc w/encl:
P. G. Perry, Senior Resident Engineer P. 0. Box 38 Mineral, Virginia 23117 W.R. Cartwright, Station Manager North Anna Power Station Box 402 Mineral, Virginia 23117 W. L. Stewart, Station Manager Surry Power Station P. 0. Box 315 Surry, Virginia 23883 e
FEB 2 1979
e UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C.
20555 February 2, 1979 IE Information Notice No. 79-01 BERGEN-PATERSON HYDRAULIC SHOCK AND SWAY ARRESTORS (BSSA)
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 BSSA-3-6, BSSA-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 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 committed to functionally test all Bergen-Paterson snubbers subjected to transient conditions which ca~se 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 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 aubsequent functional testing of the affected Bergen-Paterson units revealed that one of aeven units failed the lockup test. This unit (Model No. BSSA-3-6) was disassembled and damage to the poppet valve and seat was observed.
The damage to the poppet valves ia presently being reviewed by both the licensee and Bergen-Pateraon.
At this time, the cause of damage has Dot been completely defined Dor has appropriate corrective action been determined.
Other licensee& have reported instances of poppet valve damage; however, the cause and extent of damage are not known at this time.
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e 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 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
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Information Notice No.
e Subject IE Information Notice No. 79-01 February 2, 1979 LISTING OF IE INFORMATION NOTICES ISSUED IN 1979 Date Issued Issued To
- 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.