AECM-83-033, Interim Deficiency Rept Re Nelson Stud Failures on Embedded Plates.Initially Reported on 821221.Lab Testing of Plates in Progress.Deficiency Reported Per 10CFR21 for Unit 1 & 10CFR50.55(e) for Unit 2.Final Rept Expected by 830315

Interim Deficiency Rept Re Nelson Stud Failures on Embedded Plates.Initially Reported on 821221.Lab Testing of Plates in Progress.Deficiency Reported Per 10CFR21 for Unit 1 & 10CFR50.55(e) for Unit 2.Final Rept Expected by 830315

ML20083M910
Person / Time
Site:	Grand Gulf
Issue date:	01/20/1983
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-83 10CFR-050.55E, 10CFR-50.55E, AECM-83-033, AECM-83-33, NUDOCS 8302010495
Download: ML20083M910 (4)

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MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi EnMhldidd5 P. O. B OX 164 O. J A C K S ON. MIS SISSIP PI 3 92 05 w

JAMES P. McGAUGHY, JR.

AS$iSTANT VICE PRESIDENT January 20, 1983 Of fice of Inspection & Enforcement U. S. Nuclear Regulatory Commission  :

Region II ~~-

101 Marietta Street, N.W.

• Suite 3100 N Atlanta, Georgia 30303 Attention: Mr. J. P. O'Reilly, Regional Administrator .

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket No. 50-416/417 License No. NPF-13 File 0260/15525/15526 PRD-82/38, Interim Report, Nelson Stud Failure AECM-83/033 On December 21, 1982, Mississippi Power & Light Company notified Mr. R.

Butcher, of your of fice, of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency concerns Nelson Stud failures on embed plates.

MP&L has evaluated this deficiency and determined that it is reportable under the provisions of 10CFR21 for Unit I and potentially reportable under the provisione of 10CFR50.55(e) for Unit 2. However, an Interim Report is being submitted due to the fact that the cause, extent and total corrective action cannot be formulated until lab testing of the embed plates is completed and a determination of the mode of failure is made.

Upon initial notification to your of fice, Mr. R. Butcher confirmed that the time requirements for the 10CFR50.55(e) written report for Unit 2 would j apply to the Part 21 report for Unit 1.

Details are provided in our attached Interim Report. MP&L expects to submit a Final Report by March 15, 1983.

URjYs W "4

,'l J. P. McGaughy, Jr.

ACP:dr ATTACHMENT cc: See page 2 '

8302010495 830120 PDR ADOCK 05000416 g g' g ff S PDR Aember Middle South Utilities System /

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Mr. J. P. O'Reilly AECM-83/033 NRC Page 2 cc: Mr. N. L. St ampley 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 t

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, At tcchment to AECM-83/033 Pcgs 1 of 2 1

INTERIM REPORT FOR PRD-82/38

1. Name and address of the individual ... informing the commission:

J. P. McGaugby, Jr.

Assistant Vice-President, Nuclear Production P.O. Box 1640 '

l Jackson, Mississippi 39205 1

I 2 Identification of the facility ... which ... contains a deficiency: l Grand Golf Nuclear Station (GGNS) Unit 1 Port Gibson, Mississippi 39150

3. Identification of the firm .. . supplying the basic component which ...

contains a deficiency:

The design was supplied to Grand Gulf by Bristol Steel and Iron Works i through Bechtel Power Corporation.

4 Nature of the deficiency ... and the safety hazard which ... could be l

created by such a deficiency . . .:

A. Description of the Deficiency ,

I l This PRD concerns the failure of two 6" x 6" x 3/4" thick plates embedded into a concrete wall using 4 - 3/8" diameter Nelson i studs. The failure occurred at the interface of the studs and the plate. The plates each had a 40 in. piece of tubular steel  !

attached in a cantilever configuration as part of a design modification. ,

I B. Analysis of Safety Implications i

The two embeded plates which failed were used to anchor the SRM/IRM neutron monitoring module supports. The SRM/IRM neutron monitoring system is operated by of f-site power and; therefore, not required for safe shutdown of the plant.

Piping which is part of the reactor coolant pressure boundary system is located below the motor module supports. The collapse of these supports could jeopardize the pressure boundary piping and possibly result in a LOCA condition.

Addicianally, the potential exists, that safety related conduit could be damaged by the collapse of the supports. It has not been determined at this time which conduits are safety related.

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• *^ Attcchment to AECM-83/033 Pcgs 2 of 2 MP&L - Engineering has postulated the potential failure to all (29) 6" x 6" x 3/4" embedded plates located in the RPV pedestal wall and considers this condition a defect in a basic component which could create a substantial safety hazard. It has not been determined at this time that a similar deficiency exists in Unit 2.

5. The date on which the information of such deficiency ... was obtained.

Mississippi Power and Light received information of the deficiency on December 17, 1982. We reported the deficiency to Mr. R. Butcher, of your of fice as a Potentially Reportable Deficiency on December 21, 19R2. An evaluation for Part 21 has been completed and the MP&L

" Responsible Of ficer," Mr. J. P. McGaughy, Jr., will be notified when he returns to his office.

6. In the case of the basic component ... the number and location of all such components.

The embedded pistes which failed were design type 86 as shown on drawing C-1070B. Thirty plates of this type were provided by the fabricator, of which only 29 wer6 installed. All 29'were embedded in the Reactor Pressure Vessel pedestal wall - outside face.

7. The corrective action which has been taken . . . the name of the individual ... responsible for the action; and the length of tine that has been . . . taken to complete the action.

A. Corrective Actions Taken The cause, extent, and the total corrective action cannot be formulated until lab testing of the plates is completed and a determination of the mode of failure is made.

B. Responsible Individual C. K. McCoy T. M. Cloninger Plant Manager Unit 2 Project Manager Mississippi Power & Light Co. Mississippi Power & Light Co.

Responsible for Unit 1 Responsible for Unit 2 C. Length of Time to Conolete Actions At this time, we expect to submit a Final Report by March 15, 1983.

8 Any advice related to the deficiency ... that has been, is being, or will be given to purchasers or licensees:

Since the cause of this deficiency has not been determined, this item will be addressed in MP&L's Final Report.