ML20079N947

Fifth Interim Deficiency Rept Re Threaded Studs W/Insufficient Threaded Engagement Into Embedded Strip Plates.Evaluation of Eight Plates & Rework on Seven Plates Complete.Extension Until 830401 Requested for Final Rept

ML20079N947
Person / Time
Site:	Harris
Issue date:	02/24/1983
From:	Parsons R CAROLINA POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8303040474
Download: ML20079N947 (4)

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C9&L Carolina Power & Light Company P. O. Box 101, New Hill, N. C. 27562 ,

February 24, 1983 I co &,

Q lly Mr. James P. O'Reilly NRC44 :4 United States Nuclear Regulatory "ommission 5 %f Region II - p 101 Marietta Street, Northwest (Suite 3100) - ;gn l Atlanta, Georgia 30303 3

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CAROLINA POWER & LIGHT COMPANY **

EP SHEARON HARRIS NUCLEAR POWER PLANT .r T' 1986 900,000 KW - UNITS 1 & 2 O THREADED STUDS WITH INSUFFICIENT THREADED ENGAGEMENT ~

INTO EMBEDDED STRIP PLATES, ITEM 63

Dear Mr. O'Reilly:

Attached is the fif th interim report on the subject item which was deemed reportable on November 10, 1981. All the corrective action we have proposed is complete. Engineering evaluation of the eight previously remaining plates and required rework on seven of these plates is complete. We expect to have rework on the remaining plate completed by the end of March. For this reason, we request an extension until April 1, 1983 for submitting the final report.

Thank you for your consideration in this matter.

l Yours very truly, R. M. Parsons Project General Manager Shearon Harris Nuclear Power Plant RMP/sh Attachment I cc: Mr. G. Maxwell (NRC-SHNPP)

Mr. V. Stello (NRC) gyptCtALCN\

8303040474 830224  !*

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CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT-

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UNITS NO. 1 AND 2 4

INTERIM REPORT February 24, 1983 ITEM 63 THREADED STUDS WITH INSUFFICIENT THREADED ENGAGEMENT INTO EMBEDDED STRIP PLATES Reportable Under 10CFR50.55(e) l I

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SUBJECT:

Shearon Harris Nuclear Power Plant / Units No. 1 and 2 10CFR50.55(c), reportable deficiency. Thread ce; age-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 weld (d-on Nelson headed studs.

SUPPLIED BY: Not a suppiter-related deficiency. The studs and strip plates were assembled in the field.

NATURE OF DEFICIENCY: The defic!.ency involves Seismic Category I embedded strip pieces with screwed-in studs that have insufficient thread engagement. These screwed-in studs are used in lieu of welded-on Nelson headed studs. The deficient plates / studs were found 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 notified 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 i 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 of the problem plus the extensive evaluation and/or rework required.

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CORRECTIVE ACTION: Appropriata' 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 attachments have been. identified and all l have been evaluated by the engineer using test data I provided to them on shear resistance. All eight '

plates previously requiring ccrrective action have been reworked except for one for which corrective action is in progress. To eliminate attachments to these plates once the plant becomes operational, operations 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 soon as the remaining plate with attachments has been corrected. We expect to have this work completed and a final report submitted by April 1, 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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