ML20079L418
| ML20079L418 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 01/20/1984 |
| From: | Parsons R CAROLINA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| CON-NRC-170 112, NC-170, NUDOCS 8401260103 | |
| Download: ML20079L418 (4) | |
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CD&L Carolina Power & Light Company 8g af.32 P. O. Box 101, New Hill, N. C. 27562 January 20,1984
. Mr. James P. O'Reilly NRC-170 United States Nuclear Regulatory Commission
' Region II 101 Marietta Street, Northwest (Suite 2900)
Atlanta, Georgia 30303 CAROLINA POWElt & LIGHT COMPANY SHEARON HARRE NUCLEAR POWER PLANT 1986 - 900,000 KW - UNIT 1 DEFICIENCIES IN BOLTED STRUCTURAL CONNECTIONS, ITEM 112
Dear Mr. O'Reilly:
Attached is our second interim report on the subject item which was deemed reportable per the provisions of 10CFR50.55(e) on April 26, 1983. CP&L is pursuing this matter, and it is currently projected that corrective action and submission of the final report will be accomplished by June 1,1984.
. Thank you for your consideration in this matter.
Yours very truly, 9fffmvvi--
R. M. Parsons Project General Manager Shearon Harris Nuclear Power Plant RMP/sh Attachment ec:
Messrs. G. Maxwell /R. Prevatte (NRC-SHNPP)
Mr. R. C. DeYoung (NRC)
C g COV D 8401260103 840120 05000 0 gDRADOCK
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r CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT UNIT NO.1 SECOND INTERIM REPORT DEFICIENCIES IN BOLTED STRUCTURAL CONNECTIONS ITEM 112 January 20,19S4 l
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REPORTABLE UNDER 10CFR50.55(e) t y
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SUBJECT:
Shearon Harris Nuclear Power Plant / Unit No. I10CFR50.55(e),
reportable deficiency. Deficiencies in Bolted Structural Steel Connections.
ITEM:
Bolted structural steel connections in the Unit No.1 Turbine Building with flame cut bolt holes and undersized bolts.
SUPPLIED BY:
Not a supplier-related deficiency. All structural connections were field assembled.
NATURE OF DEFICIENCY:
The Turbine Building is seisraically designed per Regulatory Guide 1.29.
These flame cut bolt holes were oversized, irregular in shape and exceeded minimum edge distances. The bolts in some of these holes were smaller in diameter than specified.
The connections were previously inspected and accepted.
DATE PROBLEM OCCURRED:
December 13,1982.
DATE PROBLEM REi'ORTED:
On December 29, 1982, Mr. N. J. Chiangi notified the NRC (Mr. A. Hardin) that this item was potentially reportable. On April 26,1983, Mr. Chiangi notified Mr. Hardin the item was reportable per the provisions of 10CFR50.55(e).
SCOPE OF PROBLEM:
A reinspection of the Turbine Building, including all those connections where there exists a probability bolt holes would have been burned (e.g.,
to ease fit-up), or where, per engineering evaluation, they would be safety significant, has been completed.
Approximately 878 connections were reinspected, with a total of 25 connections with burned, holes and I with undersized bolts.
SAFETY IMPLICATION:
The reduced edge distance caused by the oversized hole could result in a shear failure on the clip or plate. The undersized bolt would have a smaller allowable load, thus contributing less to the clamping force between the mating surfaces than that for which it was designed.
Either of these conditions could reduce the allowable load of the connection below the actual load imposed, resulting in a failure of the connection.
REASON DEFICIENCY IS REPORTABLE:
Reportable due to the extensive evaluation and/or rework required.
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CORRECTIVE ACTION:. Inspection and craft personnel have received additional training in inspection and erection of structural steel, both in formal classes and on-the-job training. Permanent Waivers (PW's) have been written, requiring engineering evaluation, for the deficient connection. Each connection will be accepted "6s-is" if not significantly deficient, or repaired to make it acceptable, based on the engineering evaluation. To date, all but three (3) of the connections with burned holes have been repaired and the undersized bolts have been replaced.
Evaluation of the remaining connections required to close this item is continuing.
FINAL REPORT:
A fimil report willbe issued when the evaluation and rework arwmplete. We now expect to issue a nnal report by June 1, 1984.
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