ML19343B218

Final Deficiency Report Re Feedwater Pipe Bend Below Design Min Wall Thickness,Originally Reported 800709.Pipe,supplied by Tx Pipe Bending,Appears to Be Isolated Case.Defective Pipe Spool Removed & Returned to Vendor

ML19343B218
Person / Time
Site:	Grand Gulf
Issue date:	12/11/1980
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-80-304, NUDOCS 8012160281
Download: ML19343B218 (2)

Text

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j MISSISSIPPI POWER & LIGHT COMPANY a Helping Build Mississippi h aa n menE P. O. 9 0 X 16 4 0. J A C K S O N , MISSISSIPPI 39205 TSEr$c*aNEd[ December 11, 1980 Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N.W.

Suite 3100 Atlanta, Georgia 30303 Attention: Mr. J. P. O'Reilly, Director

Dear Mr. O'Reilly:

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5 SUBJECI: Grand Gulf Nuclear Station 3 --- Units 1 and 2

'r Docket Nos. 50-416/417 File 0260/15525/15526

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- PRD-80/40, Final Report, Feedwater c Pipe Bend Below Design Minimum c Wall Thickness

AECM-80/304

Reference:

AECM-80/179, 8/4/80 On July 9, 1980, Mississippi Power & Light notified Mr. F. Can-trell of your office of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The defi-ciency concerns the minimum wall thickness of a feedwater pipe bend being below design requirements.

We have determined that this deficiency is reportable under l 10CFR50.55(e). This condition is not reportable under 10CFR21 because the system has not been offered for acceptance. Our final report on this matter is attached.

iours'trul

. P. McGaughy, Jr.

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EWC:mt Attachment l

cc: Mr. N. L. Stampley Mr. Victor Stello, Director.4 THIS COPY FOR.

Mr. R. B. McGehee Division of Inspection & Enforcement Mr. T. B. Conner U. S. Nuclear Regulatory Commission Washington, D.C. 20555 l

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Member Middle South Utilities System

Attachm2nt to AECM-80/304 Page 1 of 1 FINAL REPORT FOR PRD-80/40 B

I. Description of the Deficiency A pipe bend in the Feedwater System (B21), pipe spool piece QlB21G026-5-11, was identified as below minimum wall thickness for the schedule provided. Further ultrasonic test (U.T.) examin-ation of the entire bend area showed that some areas were also below the design minimum wall thickness for the system. This spool piece was located between the Reactor Pressure Vessel and the first (inside) isolation valve.

II. Analysis of Safety Implications Because of its location, this spool piece could possibly have become the source for a rupture in the primary coolant boundary which could not be isolated. Had the situation remained uncor-rected, it could have adversely affected the safe operations of the nuclear power plant at any time throughout the life of the plant. Therefore, the condition was determined to be reportable under 10CFR50.55(e)(1)(ii).

III. Corrective Actions Taken

1. The defective pipe spool piece was removed and returned to the vendor.

2. Our Architect / Engineer obtained information from the feedwater pipe supplier, Texas Pipe Bending, and performed an evaluation on both the feedwater pipe and the bending process used. The results of this investigation reveal that the cited condition is j an isolated occurrence, as no other pipe bend documentation was found which reflected an out-of-specification condition.

The Texas Pipe Bending procedure for pipe bending, " Hot Bending

Procedure HB-1, Rev. 3", was foun~d to be adequate for controlling l the bending process.

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3. Our Constructor performed an ultrasonic examination of the other 12-inch pipe bends supplied by Texas Pipe Bending for the Feed-water System. Measurements were taken every six inches along the pipe bend and they verified that the minimum wall require-ment of 0.552 inch had not been violated. Bence, the cited con-

! dition appears to be an isolated case since no similar defective condition is evident from the data received.

To preclude recurrence, the procurement supplier quality organiza-tion of our Architect / Engineer has alerted area representatives of l the problem. Other actions necessary to correct the discrepant con-l dition are in progress and are delineated in the Constructor's Man--

agement Corrective Action Report, MCAR-GGNS No. 91.

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