United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 79-01, Bergen-Paterson Hydraulic Shock and Sway Arrestor

IN79001 
                              UNITED STATES 
                      NUCLEAR REGULATORY COMMISSION 
                         WASHINGTON, D. C. 20555 
                                     
                             January 31, 1979 

MEMORANDUM FOR:     B. H. Grier, Director, Region I 
                    J. P. O'Reilly, Director, Region II 
                    J. G. Keppler, Director, Region III 
                    K. V. Seyfrit, Director, Region IV 
                    R. H. Engelken, Director, Region V 

FROM:               Norman C. Moseley, Director, Division of Reactor 
                      Operations Inspection, OIE 

SUBJECT:            Information Notice No. 79-01, BERGEN-PATERSON 
                    HYDRAULIC SHOCK AND SWAY ARRESTOR 

The subject document is transmitted for issuance on February 2, 1979.  The 
Information Notice should be issued to all power reactor facilities with an 
operating license or a construction permit. Also enclosed is a draft copy of
the transmittal letter. No inspection followup is necessary since no action 
by the licensee is requested. We anticipate forwarding additional 
information when the Rancho Seco evaluation program for corrective action is 
completed. 


                                        Norman C. Moseley 
                                        Director 
                                        Division of Reactor 
                                          Operations Inspection, IE 

Enclosures: 
1.   Information Notice No. 79-01 
2.   Draft Transmittal Letter 

CONTACT:  H. A. Wilber, IE 
          (492-8180) 
.

(Draft letter to all power reactor facilities with an operating license or a 
construction permit)  
                                           Information Notice No. 79-01 

Addressee: 

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. 


                                        Signature 
                                        (Regional Director) 

Enclosures: 
1.   Information Notice No. 79-01 
2.   List of IE Information Notices 
       Issued in 1979 
.

                             UNITED STATES 
                      NUCLEAR REGULATORY COMMISSION 
                   OFFICE OF INSPECTION AND ENFORCEMENT 
                         WASHINGTON, D. C. 20555 
                                     
                            February 2, 1979  

                                           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 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 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 
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 at this time. 

                               Page 1 of 2 
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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. 

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