ML20053C020
| ML20053C020 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 05/13/1982 |
| 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-82-850, NUDOCS 8206010423 | |
| Download: ML20053C020 (4) | |
Text
......
'<1;
?
Carolina Power & Light Company k 'G,
]}l44fy
' ' *.~~,
May 13, 1982 4,
- Da File:
SH N-2/18 CQAD 82-850 Item 63 Mr. James P. O'Reilly United States Nuclear Regulatory Commission Region II 101 Macietta Street, N3rthwer Atlanta, Georgia 30 M3 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NOS. 50-400 AND 50-401 THREADED STUDS WITH INSUFFICIENT THREAD ENGAGEMENT INTO EMBEDDED STRIP PLATES
Dear Mr. O'Reilly:
Attached is a second interim report on the subject item which was deemed as reportable on November 10, 1981. Due to the magnitude of the problem, CP&L and Ebasco are continuing to evaluate this matter; and it is currently projected that the final report will be submitted by July 16, 1982.
Thank you for your consideration in this matter.
Yours very truly, RDB/mt s
Attachment Q
g cc:
Mr. G. Maxwell W/A N. J. Chian i - Managy Mr. V. Stello (2) W/A Engi ering Construction Quality Ashrance/ Quality Control 9
OFFICIAL COpr
~~
f 411 Fayetteville Street e P. O. Box 1551
- Raleign, N. C. 27602
$( aQ7 gu.mmmmxam>w=v sz;mam rwxxxcii
-a
O s
CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT UNITS NO. 1 AND 2 INTERIM REPORT May 10, 1982 Reportable Under 10CFR50.55(e) w_-
_1_
SU3 JECT:
Shearon Harris Nuclear Power Plant / Units No.1 and 2 10CFR50.55(e), reportable deficiency.
Thread engagement of threaded studs into embedded strip plates.
ITEM:
Improperly installed threaded studs on e= bedded 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 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 p'lacements.
DATE PROBLEM WAS CONFIRMED TO EXIST:
October 13, 1981 DATE PROBLEM REPORTED:
October 13, 1981, Mr. N. J. Chinngi notified the NRC, Region II (Mr. R. Butcher), that the item was potentially 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, approximate.ly ferty-five percent (45%) of the inspection has been completed in the containment, fuel handling, reactor auxiliary, reactor auxiliary-common, j
diesel generator, diesel fuel oil storage tank, and tank 1 and 2 buildings.
The intake and screening structures have been completely checked.
A large l
number of plates that have threaded studs with improper thread engagement have been found.
- Also, hanger? have been found welded to plates that have threaded studs with improper thread engagement.
The investigation has been hampered by the advanced stages of construction in many areas (pipe hangers, pipes, cable tray hangers, cable trays, conduits, lights and HVAC ducts) and shoring in place.
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 t.hreaded completely through the plates and, therefore, are readily identifiable.
This action will prevent a plate from being overlodked during the construction period.
Plates already having attach-ments have been identified and submitted to the Engineer for evaluation (PW-AS-1391).
To date no resolution has been received.
To eliminate attach-ments to these plates once the plant becomes operational, operating personnel have agreed to implement inspection in their procedures.
FINAL REPORT:
A final te. port will be issued once the plates having attachments ; e evaluated and reworked, if required.
It is currently projected that the submittal date will be July 16, 1982.
i e
-w k