Questionnaire on Steam Generator Operating History (Generic Letter 78-04)

                                                              GL 78-04
                                UNITED STATES 
                         NUCLEAR REGULATORY COMMISSION
                             WASHINGTON D.C. 20555

                                        February 10, 1978

To All PWR Facility Licensees

Gentlemen:

By letter dated December 9, 1977, copy enclosed, we requested you and all
other PWR facility licensees to complete and submit a questionnaire on steam
generator operating history that was enclosed.  The letter stated that the
request for information was approved by GAO under a blanket clearance. 
Questions have been raised about the appropriateness of this request for
information in light of the Federal Reports Act and about the referenced GAO
blanket clearance.  These questions have been discussed with representatives
of GAO and it was determined that this clarifying letter should be sent to
each recipient of our original letter.  GAO has agreed that this request
properly fits under the GAO blanket clearance for reports concerning possible
generic problems and the applicable GAO clearance number should have been
R0072 rather than R0071.

The request for additional information was prompted by the continuing
degradation of tubes in all three vendors' steam generators.  Such degradation
is an important safety concern of the NRC because such tubes form part of the
primary coolant pressure boundary.  Several forms of degradation that have
been observed in steam generators in recent months have included the wastage
of tubes at Palisades and other facilities, stress corrosion at Ginna and
other facilities, vibration cracking and "dinging" of tubes at the Oconee
(B&W) facilities, antivibration bar fretting at San Onofre, and "denting" of
tubes and associated support plate "hourglassing" and cracking at Surry,
Turkey Point and about 15 other CE and W facilities.  These events have
resulted in many shutdowns of nuclear power stations and the safety
significance of certain of these events have prompted the NRC to issue safety
Orders.  It is this need for important safety information that has dictated
this request for additional information.





8004010573
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All PWR Facility Licensees          - 2 -                 February 10, 1978

Our previous letter acknowledge that selected portions of the information
being requested may already by available to the NRC, but not in a convenient
format which is readily accessible.  We therefore requested that you assist us
by returning a single completed copy of the enclosed questionnaire.  We would
like to clarify that an acceptable response to any item in the questionnaire
would be to provide specific reference to any information previously submitted
to the NRC, by an original response, or any combination thereof, whichever and
for whatever reasons you elect to use.

Our previous letter further requested that you submit any changes or additions
to your initial submittal to reflect the future operating experience with your
steam generators.  This would enable us to maintain the information current,
which, as we stated, we will periodically publish and send copies to all
participants.  As we indicated, this would enable the NRC, you and others to
draw from the operating experience of the entire nuclear industry on an
ongoing basis when making safety and other decisions concerning steam
generators in PWR plants.  We are planning to prepare a submission to GAO for
clearance of a request for reporting information regarding changes or
additions to your initial submittal under this request.

We hope that the need for this clarification caused you no inconvenience. 
Because of the problems discussed above, we are extending the date for
submitting the requested information to March 1, 1978.

                                      Sincerely,


                                      Karl R. Goller, Assistant Director
                                        for Operating Reactors
                                      Division of Operating Reactors

Enclosures:  

1.  Letter dtd. 12/9/77 to PWR Licensees
2.  Questionnaire