ML20073C670
| ML20073C670 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 03/30/1983 |
| From: | Mcgaughy J MISSISSIPPI POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, AECM-83-2-0002, AECM-83-2-2, NUDOCS 8304130257 | |
| Download: ML20073C670 (4) | |
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MISSISSIPPI POWER & LIGHT COMPANY Helping Build A1ississippi P. O. B O X 16 4 0. J A C K S O N, MIS SIS SIP PI 3 9 2O5
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March 30, 1983 9
..a JAMES P. McGAUGHY JR M
vics possioamt L'
i Of fice of Inspection & Enforcement 7
0 U. S. Nuclear Regulatory Commission
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Region II f
101 Martetta Street, N.W.
J Suite 2000 Atlanta, Georgia 30303 Attention:
Mr, J. P. O'Reilly, Regional Administrator
Dear Mr. O'Reilly:
SUBJECT:
Grand Gulf Nuclear Station Unit 2 Docket No. 50-417 License No. NPF-13 File 0260/15525/15526 PRD-83/04, Final Report, S. s i Failure Embed Plates AECM-83/2-0002 On February 23, 1983, Mississippi Power & Light Company notified Mr. R.
Butcher, of your office, of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency concerns the failure of stud welded anchors on embed plates.
Based on the results of the investigation, MP&L has determined that this deficiency is reportable under the provisions of 10CFR50.55(e) for Unit 2.
This deficiency is not applicable to Unit 1.
All details are provided in our attached Final Report.
This PRD was originally scheduled to be submitted on March 25, 1983. On March 23, 1983, Ms. L. Watson, of your of fice, granted an extension for the submission of this report to March 30, 1983.
Yours truly r
/J. P.
,%Gaughy, Jr.
ACP:dr ATTACHMENT cc:
See page 2 8304130257 830330 QWiCOLCOPY,-
PDR ADDCK 05000417
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S PDR Member Middle South Utilities System
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Mr. J. P. O'Reilly AECM-83/2-0002 NRC Page 2 cc:
Mr. J. B. Richard Mr. R. B. McGehee Mr. T. B. Conner-Mr. Richard C. DeYoung, Director Of fice of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. G. B. Taylor South Miss. Electric Power Association P. O. Box 1589 Hattiesburg, MS 39401 I
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e Attachment to AECM-83/2-0002 Page 1 of 2 l
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i FINAL REPORT FOR PRD-83/04 1.
Description of Deficiency-The deficiency concerns the failure of stud welded anchors on embed plates.
During installation of Type 5B embed plates for concrete pours #20183WIB and
- 21183WXA, Areas 20 and 21, elevation 166' of the Auxiliary Building, several of the stude broke off the embed plates.
The studs were being bent to avoid rebar interferences.
The deficiency only af fects the Auxiliary Building Superstructure, System T-22.
It does not apply to the NSSS vendor.
The cause of the deficiency was a malfunctioning plunger in one (1) stud gun.
10CFR21 is not applicable since the embed plates had not been of fered for acceptance by Bechtel to MP&L.
II.
Analysis of Safety Implications No interfacing systems exist in the case of this deficiency. The embed plates would have been installed on both the inner and outer walls of the blowout shaft to support Division I safety-related conduit and electrical junction boxes. The failure of these embed plates could have prevented D,ivision I safety-related equipment from performing their safety functions.
Had the condition remained uncorrected a simultaneous Division I failure with a single active' failure to Division 11 equipment could have adversely I
affected safety of the power plant.
l Therefore, MP&L has determined that this deficiency is reportable under the provisions of 10CFR50.55(e).
l III. Corrective Actions Taken The stud welds were made per the requirements of AWS Dl.1 at the Vicksburg Fabrication Shop. These welds were visually inspected-and found to be acceptable during fabrication. These welds failed prior to embedment.
t Through investigation, the problem was isolated to one (1) stud gun and -
fifty-nine (59) Type 5B embed plates..There were a total of ten (10). fail-ures from fabrication request FR-C-2365B-2696. Nine (9) of the embeds were the ones that failed and were documented on nonconformance report CR 8452 for pour number 20183WIB. The tenth plate, documented on CR 8452, was for pour number 21183WXA, The other forty-nine (49) Type SB embeds were located and all of the studs were bent to approximately 15 degrees and were acceptable.
The cause was determined to be a malfunctioning stud gun plunger which did l
not force the stud suf ficiently: deep enough into the plate base material to produce an adequate bond.-
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Attachment to AECM-83/2-0002 Page 2 of 2
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CR 8452 was issued noting the condition.
The ten (10) failed plates were sprayed with red paint and scrapped. They were replaced with new Type 5B l
plates which were tested and accepted, as dispositioned on CR 8452.
A Change Request to our Constructor's Work Plan / Procedure (WP/P)-35 was h
incorporated to provide for a maintenance program for all stud guns in use.
The change request will address the method, control and frequency of the l
maintenance to be performed on the stud guns.
In addition to the require-i ments of AWS DI.1, the change request provides for a randomly selected stud to be bent to fifteen (15) to thirty (30) degrees for members having less than twenty (20) studs per member. -This will be continued until such. time that a confidence level in the. effectiveness of the stud gun maintenance program has been established.
This change request to WP/P-35 was issued on March 30, 1983..
l Our Constructor has revised Quality Control Instruction (QCI)-0706T to i
require monitoring of the additional stud bending requirement and the main-tenance program of WP/P-35. This revision to the QCI was issued on March 30, 1983.
i On March 24, 1983, our Constructor initiated a recall of all stud guns.
Beginning March 25, 1983, all stud guns in use will be issued from and returned to the rod issue areas daily. Only those stud guns which have been through the maintenance program will be issued for use.
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