ML20083N219
| ML20083N219 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 01/21/1983 |
| From: | Parsons R CAROLINA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| CON-NRC-34 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8302010590 | |
| Download: ML20083N219 (4) | |
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'LE, Carolina Power & Light Company b " 2b AllP. g Box 101, New Hill, N. C.
27562 January 21, 1983 Mr. James P. O'Reilly NRC-34.
United States Nuclear Regulatory Commission Region II 101 Marietta Street, Northwest (Suite 3100)
Atlanta, Georgia 30303 dh^'SO-Y2O CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT SG-4@l 1985 900,000 KW - UNITS 1 & 2 THREADED STUDS WITH INSUFFICIENT THREADED ENGAGEMENT INTO EMBEDDED STRIP PLATES, ITEM 63
Dear Mr. O'Reilly:
Attached is the fourth interim report on the subject item which was deemed reportable on November 10, 1981. All the corrective action we have proposed is complete, and we are still awaiting engineering disposition of eight attachments. We expect to have these evaluations completed by mid February.
For this reason, we would request an extension until February 25, 1983 for submitting the final report.
Thank you for your consideration in this matter.
Yours very truly,
$$f W R. M. Parsons Project General Manager Shearon Harris Nuclear Power Plant RMP/sh Attachment cc:
Mr. G. Maxwell (NRC-SHNPP)
Mr. V. Stello (NRC) n' GFFIGIAT!COPI
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8302010590 830121 gDRADOCK05000 gg4
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~I CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT UNITS NO. 1 AND 2 INTERIM REPORT January 20, 1983 ITEM 63 THREADED SfUDS WITH INSUFFICIENT THREADED ENGAGEMr.NT INTO EMBEDDED STRIP PLATES l
Reportable Under 10CFR 50.55(e) f e
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SUBJECT:
Shearon Harris Nuclear Power Plant / Units No. 1 and 2 10CFR50.55(e), reportable deficiency.
Thread engage-ment of threaded studs into embedded strip plates.
ITEM:
Improperly installed threaded studs on embedded strip plates.
These tapped strip plates and threaded studs have been used in many cases in lieu of strip plates with welded-on Nelson headed studs.
SUPPLIED BY:
Not a supplier-related deficiency. The studs and strip plates were assembled in the field.
NATURE OF DEFICIENCY:
The deficiency involves Seismic Category I embedded strip plates with screwed-in studs that have insufficient thread engage =ent.
These screwed-in studs are used in lieu of welded-on Nelson headed studs.
The deficient plates / studs were fouad after concrete placements and acceptance of the placements.
DATE PROBLEM WAS CONFIRMED TO EXIST:
October 13, 1981 DATE PROBLEM REPORTED:
October 13, 1981, Mr. N. J. Chiangi not'.fied the NRC, Region II (Mr. R. Butcher), that the item was poten-tially reportable.
November 10, 1981, Mr, N. J. Chiangi notified the NRC, Region II (Mr. R. Butcher), that this item was reportable per the provision of 10CFR50.55(e).
SCOPE OF PROBLEM:
Approximately 1300 of the strip plates to be used with screwed-in studs have been ordered. To date, all inspection has been completed in the containment, fuel handling, reactor auxiliary, reactor auxiliary-common, diesel generator, diesel fuel oil storage tank, tank 1 and 2 buildings, intake and screening structures. A large number of plates that have threaded studs with improper thread engagement have been found.
- Also, hangers have been found welded to plates that have threaded studs with improper thread engagement.
SAFETY IMPLICATION:
Pipe, cable tray, and HVAC hangers, as well as other miscellaneous items, attach to these plates.
Plates with studs not having proper thread engagement will possibly be overstressed in normal operation or during a seismic event.
REASON DEFICIENCY IS REPORTABLE:
Reportable due to the magnitude cf the problem plus the extensive evaluation and/or rework required.
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't CORRECTIVE ACTION:
Appropriate site work procedures have been revised requiring notification of site engineering personnel prior to attaching any item to an embedded plate with screwed-in studs.
In addition, all plates having insufficient thread engagement have been marked with stickers
- identifying them. Plates having attach-ments have been identified and all but eight have been evaluated by the engineer using test data provided to them on shear resistance. Any plates requiring corrective action have been reworked. To eliminate attachments to these plates once the plant becomes operational, operational personnel have agreed to implement inspection of the plates in their procedures prior to making any attachments.
FINAL REPORT:
A Final Report will be issued as.?9on as the remaining eight attachments have been evaluated by Engineering. We expect to have this completed by February 25, 1983.
- Note on sticker reads:
CAUTION Anchor studs for this plate have reduced thread engagement.
Evaluate plate load limits prior to making any attachments.
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