ML20091M382
| ML20091M382 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 06/01/1984 |
| From: | Parsons R CAROLINA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| CON-NRC-229 112, NUDOCS 8406110272 | |
| Download: ML20091M382 (4) | |
Text
, _
o CP&L Q
P. O. Box 101, New Hill, N. C. 27562 June 1,1984 Mr. James P. O'Reilly NRC-229 United States Nuclear Regulatory Commission I
Region II 101 Marietta Street, Northwest (Suite 2900)
Atlanta, Gecrgia 30303 CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT 1986 - 900,000 K W - UNIT 1 DEFICIENCIES IN BOLTED STRUCTURAL CONNECTIONS, frEM 112
Dear Mr. O'Reilly:
Attached is our third interim report on the subject item which was deemed reportable per the provisions of10CFR50.55(e) on April 26, 1993. CP&L is pursuing this matter, and it is currently projected that corrective action and submission of the final report will be accomplished by January 1,1985.
i Thank you for your consideration in this matter.
Yours very truly, W
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) i 20 s
Oyy1CIALCbP
$1A1i.
CAROLINA POWER & IJOHT COMPANY SHEARON HARRE NUCLEAR POWER PLANT UNirNO.I a
THIRD INTERIM REPORT DEFICIENCIES IN BOLTED STRUCTURAL CONNECTIONS ITEM III J
June 1,1984 i
REPORTABLE UNDER IGCFR59.55(e)
G
SUBJECT:
Shearon liarris Nuclear Power Plant / Unit No. I10CFR50.55(c),
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 seismically 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 previomly inspected and accepted.
DATE PROBLEM OCCURRED:
December 13,1982.
DATE PROBLEM N
On December 29, 1982, Mr. N. J. Chiangt notified the NRC (Mr. A. liardin) that this item was potentially reportable. On April 26,1983, Mr. Chiangt notified Mr. liardin the item was reportable per the provisions of10CFILSO.55(e).
SCOPE OF PROBLEM:
A reinspection of the Turbine Building, including all those connectiom where there exists a probability init holes would have been burned (e.g., to case fit-up), or where, per enginc;cring 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 ellp 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 M
Reportable due to the extemive evaluation and/or rework requirM.
s.
g s-CORRECTIVE AcrION:
Inspection and craft personnel have received additional training in inspection and ercetion of structural steel, both in formal classes and on-the job training.
Permanent Walvers
-(PW's) were written, mquiring engineering evaluation, for the defielent connection. Each connection has been accepted "as-IsP If not significantly defielent, or has been or will be repaired to make it acceptable, based en the engineerlig evaluation. To date, all connections with torch cut holes have been evaluated, and all with torch cuts alone have been mpaired or accepted as-is, and the undersized bolts have been replaced. Some of the connections with torch cut bolt holes also had gaps between mating surfaces for whleh rework is required before reinspection and final acceptance.
FINAL REPORT:
A final report will be issued when the rework is complete. We now er.pect to issue a final report by January 1,1985.
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