ML20058B923
| ML20058B923 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 06/15/1982 |
| From: | Chiangi N CAROLINA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, CQAD-82-1232, NUDOCS 8207260198 | |
| Download: ML20058B923 (4) | |
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/V FILE: SH N-2/18 CQAD 82-1232 ITEM 63 Mr. James P. O'Reilly United States Nuclear Regulatory Commission Region II 101 Marietta Street, Northwes t Atlanta, Georgia 30303 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NOS. 50-400, 50-401 THREADED STUDS WITH INSUFFICIENT THREAD ENGAGEMENT INTO EMBEDDED STRIP PLATES
Dear Mr. O'Reilly:
1 Attached is a third interim report on the subject item which was deemed as reportable on November 10, 1981. All corrective action listed in the last interim report has been completed.
In addition, an agreement between the Nuclear Power Plant Construction Department and the Nuclear Operations Department has been reached whereby a permanent sticker will be applied to the embeds in question to preclude attachment to the plates during the life of the plant without first obtainng engineering approval.
As a result of having to perform additional tests, we currently project that the final report will be submitted by September 17, 1982.
Thank you for your consideration in this matter.
i NJC/gea (206)
Yours very truly,'
Attachment
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cc: Mr. G. Maxwell W/A c
Mr. V. Stello (2) W/A l
i N. J Chian i - Manage l
Enginc-(ing & Constru ton Quality Assurance / Quality Control l
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l 8207260198 820615 PDR ADOCK 05000400 S
PDR OFFICIALcyg 411 Fayetteville Street e P. O. Box 1551 + Ra eigh. N C. 27602 E 17 cx==aa=zwxm=z=w=alwa=a
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CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT UNITS NO. 1 AND 2 REPORTABLE ITEM - THREADED STUDS WITH INSUFFICIENT THREAD ENGAGEMENT INTO EMBEDDED STRIP PLATES l
I
. INTERIM REPORT July 14, 1982 Reportable Under 10CFR50.55(e)
s
SUBJECT:
Shearon Harris Nuclear Power Plant / Units No. 1 and 2 10CFR50.55(e), reportable deficiency.
Thread engagement e
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.
l NATURE OF DEFICIENCY:
The deficiency involves Seismic Category I embedded strip plates with screwed-in studa that have insufficient thread engagement.
These screwed-in studs are used in i
lieu of welded-on Nelson headed studs.
The deficient plates / studs were found after concrete placements and acceptance of the placements.
DATE PROBLEM k'AS CO:: FIRMED 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 potentially reportable.
November 10, 1981, Mr. N. J. Chiangi no'tified 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 inspec-tion 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 l
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.
Sufficient investigation has not been conducted to actually evaluate the loading on the identified plates.
REASON DEFICIENCY IS REPORTABLE:
Reportable due to the magnitude of the problem plus the extensive evaluation and/or rework required.
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.
All the plates in question are threaded completely through the plates and, therefore, are readily identifiable.
This action will prevent a plate from being overlooked during the construction period.
Plates already having attachments have been identified and submitted to the Engineer for evaluation (PW-AS-1498, 1510R1, and 1620).
To date no resolution has been received as a result of field testing for shear resistance of the plates with various engagement lengths.
To eliminate attachments to these plates once the plant becomes operational, operating personnel have agreed to implement inspection of the plates in their procedures prior to making any attachments.
In addition, prior to turnover of the plant, the plates with insufficient thread engagement will be identified by using either a sticker or paint.
FINAL REPORT:
A final report will be issued once the plates having attachments are evaluated and reworked, if required.
It is currently projected that the submittal date will be September 17, 1982.
,