ML20210T483

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Requests That Recipient Div Assume Responsibility for Evaluating Adequacy of Licensee Corrective Action Program Re Apparent vibration-induced Failures of Main Steam Line Attachments.Failures Began After Startup in 1985
ML20210T483
Person / Time
Site: Fermi, 05000000
Issue date: 01/07/1987
From: Greenman E
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To: Paperiello C
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20210T193 List:
References
FOIA-87-50 NUDOCS 8702180198
Download: ML20210T483 (2)


Text

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- i G V.*b JAN 7 191rf MEMORANDUM FOR:

Carl J. Paperiello, Director, Division of Reactor Safety FROM:

Edward G. Greenman, Deputy Director, Division of Reactor Projects

SUBJECT:

REQUEST FOR ASSISTANCE -- APPARENT VIBRATION INDUCED FAILURES OF MAIN STEAM LINE ATTACHMENTS AT FERMI 2 On January 2,1987, the licensee notified the resident inspector of three broken instrument lines attached to main steam piping between the turbine control valves and the main turbine itself. The licensee plugged, capped, and welded the broken lines. The unit was returned to operation and subsequently on January 5, another line/ valve cracked weld connection was identified. The turbine was again taken off-line and the weld was repaired. During this period the licensee also identified and repaired five missing or loose connectors on snubber brackets associated with the main steam lines downstream of the stop valves. The unit was returned to power and on January 6, another broken instrument line was identified, this time attached to a main turbine throttle valve.

These are the most recent in a series of vibration induced failures of main steam piping and components which have occurred since Fermi 2 started up in 1985. The most well-known of these problems was the vibration induced cracking of the main steam bypass lines. While this particular problem may be resolved there are still questions remaining concerning the entire subject of main steam piping vibration.

The licensee has begun a corrective action program involving frequent monitoring of the lines, engaging a consultant, and conducting engineering evaluations in an attempt to identify the root cause of these apparent main steam line vibrations. Among possibilities being considered are system design, installation, and interaction between portions of the system which were designed or installed by different organizations, r

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Per a discussion that was held between you, Nick Chrissotimos, and I n

January 7, it is requested that your Division assume responsibilit or evaluating the adequacy of the licensee's program in this area.

' Original Sfsned by E.9 tensee Edward G. Greenman, Deputy Director Division of Reactor Projects cc:

C. E. Norelius W. G. Guldemond G. C. Wright M. J. Farber W. G. Rogers N. V. Gilles I

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