NRC Generic Letter 78-04, GAO Blanket Clearance For Letter Dated 12/09/77

text

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.All PWR Facility LicenseesFebruary 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