ML20083H801

Responds to NRC Re Violations Noted in IE Insp Repts 50-424/83-18 & 50-425/83-18.Corrective actions:C-E Discontinued Practice of Gritblasting Close Heads Following Liquid Penetrant Exam

ML20083H801
Person / Time
Site:	Vogtle
Issue date:	12/14/1983
From:	Foster D GEORGIA POWER CO.
To:	Robert Lewis NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20083H799	List: ML20083H801
References
GN-295, NUDOCS 8401090468
Download: ML20083H801 (2)

Text

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i Georgia Power compar.y 333 P edmom Avenue Atlanta, Geo6gra 30308 Te:ephone 404 523-7726 "7c' 7 q ,

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Posi Office Box 4545 Atlanta, Georg a 30302 J NC 20 Pi: 02 Georgia Power D. O. Foster the sovttem ehrtm system Vice President and General Manager Vogtie Project December 14, 1983 (Jnited States Nuclear Regulatory Commission File: X78G10 Office of Inspection and Enforcement Log: GN-295 Region II - Suite 3100 101 Marietta Street Atlanta, Georgia 30303

Reference:

50-424/83-18, 50-425/83-18 Attention: Mr. R. C. Lewis Gentlemen:

The Georgia Power Company wishes to submit the following information concerning the violation discussed in your inspection report 50-424/83-18 and 50-425/83-18:

Violation 50-424,425/83-18-01, " Failure to Control a Special Process in the Nondestructive Examination (NDE) of the Closure Head Cladding" -

Severity Level IV.

(1) Georgia Power Company acknowledges the discrepancies identified in this violation.

(2) The reasons for the violation are as follows:

a. The contract with the reactor vessel manufacturer, Combustion Engineering, called for liquid penetrant examination (PT) of the Unit 1 closure head cladding surface prior to gritblasting.

PT is normally done in the finished condition but is not recommended on gritblasted surfaces. Combustion Engineering maintains that the three unacceptable rounded indications found in the Unit 1 closure head by PT at the site were not present at the surface during the ASME Boiler and Pressure Vessel Code acceptance PT at the Combustion Engineering shop. These indications were found, upon excavation, to be slag inclusions which apparently opened due to the gritblasting operation after the liquid penetrant examination.

The gritblasting was considered post-examination cleaning by the Authorized Nuclear Inspector, Combustion Engineering, and Westinghouse Power Corporation, the NSSS supplier, in accordance with Paragraph NB-5113,Section III, of the ASME Code. The Unit 2 closure head was not gritblasted as Combustion Engineering discontinued this practice in 1978. No unacceptable indications were found in the Unit 2 closure head.

b. Georgia Power Company cannot determine how or exactly when surface defects which appear to be arc strikes were inflicted on the Unit 2 closure head. They apparently occurred at some time between the PT examination at the Combustion Engineering shop and the inspection at the jobsite.

9401090468 831230 PDR ADOCK 05000424 G PDR

y-USNRC December 14, 1983 Page 2 (3) The closure head manufacturer, Combustion Engineering, was contracted to perform the following corrective actions:

a. The Unit 1 closure head cladding was thoroughly cleaned and buffed to minimize minor surface imperfections. 100% of the surface was thenliquidpenetrant(PT) examined. Three unacceptable rounded indications, identified as slag inclusions, were removed by grinding.

Two of the indications were on a slag line in the same plane and extended to the base metal but did not violate the pressure boundary.

The cladding was then weld repaired using approved procedures, heat treated, liquid penetrant examined (repaired areas only), and stress relieved.

b. The Unit 2 closure head was not gritblasted as was the Unit 1 head.

Some discoloration of the surface, however, raised some questions on the acceptability of some areas of the cladding. Therefore, the Unit

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2 cladding surface was also thoroughly cleaned, buffed, and liquid penetrant examined over 100% of its area. No unacceptable indications were found. The apparent arc strikes and some slag pockets were effectively removed during the surface cleaning and buffing.

c. All of the cleaning, buffing, repairing, and PT operations performed on the Unit 1 and Unit 2 closure heads have been properly documented.

The documentation was reviewed and approved by the Authorized Nuclear Inspector. Any questions which arose regarding procedures and materials were closely scrutinized and resolved. All corrective actions per-formed by Combustion Engineering were witnessed by Georgia Power.

(4) Action to prevent further violations is not applicable in this case.

Combustion Engineering has discontinued the practice of gritblasting closure heads following PT, but they have not manufactured a reactor vessel since 1978.

(5) Full compliance with applicable regulatory and code requirements was achieved on December 5, 1983.

This response contains no proprietary information and may be placed in the NRC Public Document Room upon receipt.

Yours truly D.D. Fos [er REF/D0F/cc xc: U. S. Nuclear Regulatory Commission ,

Attn: Victor J. Stello, Jr., Director Office of Inspection and Enforcement Washington, D. C. 20555 xc: R. J. Kelly D. E. Dutton J. A. Bailey L. T. Gucwa R. E. Conway W. F. Sanders 0. Batum M. Malcom G. F. Head R. H. Pinson H. H. Gregory, III G. Bockhold J. T. Beckham B. M. Guthrie C. W. Hayes P. D. Rice D. N. MacLemore R. A. Thomas E. D. Groover J. L. Vota

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