ML20137J685

Responds to 850813 Request for Review of Util Position Paper Re Visual Insp of Painted Support Welds.Reinsp Through Paint Acceptable to Determine Presence,Location & Size,Not Quality,Of Structural Steel Weldments

ML20137J685
Person / Time
Site:	Comanche Peak
Issue date:	08/29/1985
From:	Johnston W Office of Nuclear Reactor Regulation
To:	Noonan V NRC - COMANCHE PEAK PROJECT (TECHNICAL REVIEW TEAM)
Shared Package
ML20137J690	List: ML20137J685 ML20138C498 ML20138C503
References
NUDOCS 8509040052
Download: ML20137J685 (3)

Text

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, o, AUG 2 9 1985

% . . . . . /e MEMORANDUM FOR: Vincent S. Noonan, Director

. ComanchePeakProject 1

Division of' Licensing ,

i FROM: William V. Johnston, Assistant Director

Materials, Chemical & Environmental Technology Division of Engineering i

SUBJECT:

VISUAL INSPECTION OF PAINTED' SUPPORT WELDS  !

This is in response to your memorandum, dated August 13, 1985, for [

! J. P. Knight, Acting Director, Division of Engineering, requesting that the Materials Engineering Branch review an applicant's position paper I and formulate a coordinated staff position. By memorandum dated

August 16, 1985, we proposed to you that we provide our reply by

! September 6, 1985.

The American Welding Society's 01.1 Code (Section 3.10.1 of 0 1.1-75)  :

requires that the initial acceptance inspection of welds be performed prior

to the ap Reinspection of welds, with or without  ;

i coatings, plication of a coating.is.not addressed in 01.1 or any other weld inspect  ;

Recently, the. Nuclear Construction Issues Group (NCIG) prepared the document, l m " Visual Weld Acceptance Criteria for Structural Welding at Nuclear Power Plants" (VWAC), NCIG-01, Rev. 2 of 05/07/85, providing guidance on the sub- L i sequent ins ... with the concurrence of the Engineer." (emphasis pection of welds after. coating "ituations where stripping of the added). There are s coating or other inspection techniques, such as magnetic particle examinations, ,#

may be required. By experience, there are too many situations and options

peculiar to individual sites, vendors, coating systems, or types of defects, such that an overall staff position on the~ acceptability of inspection ]

i of coated welds cannot and should not be. established. As we briefly stated  ;

in our August 16, 1985 memorandum, the staff has dealt with this issue strictly  ;

! on a case-by-case basis. However, some guidelines can be provided that may be  !

i of benefit for the Comanche Peak Project: i Reinspection thru paint may be acceptable to determine presence, f j location, length, and size of welds in structural steel-weldsents. The  ;

apparent size of-fillet welds (leg length).is actually reduced when  !

measured by gages with the presence of a coating, and accordingly, ,

i represents a conservative measurement.

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i To determine weld attributes related to quality, such as lack of fusion, i cracks, porosity, or slag inclusions, the practical demonstration of  !

examinations for. these type defects through even relatively thin coatings ~  !

(maximum of 5 mils) has not been achieved. We have records of two  !

instances where a qualification program was attempted; i.e., unmarked ,  !

weld specimens with many inspectors, and various controls. These quali-

fication programs were not successfully completed. The applicants

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t decided themselves that the tests were inconclusive, and this approach was not used. i N x .

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- Vincent S. Noonan The Stone & Webster Position Paper makes comparisons between the Comanche Peak Project and Wolf Creek Generating Station about the similarities of paint systems and their situations. At the Wolf Creek site,.there were two samples of uncoated weld inspections performed to back up a 100% reinspection of accessible welds. The first sample consisted of more than 40 percent of the accessible welds that were not coated. The second sample was made of a random selection, by the NRC team, of 59 welds that were coated. The second sample was inspected by the NRC visually and by magnetic particle technique as coated. Then the welds in the sample were stripped of coating and reinspected by visual and magnetic particle examination. Results of these two sample inspections were used as the basis for assuring the quality of coated welds and inaccessible welds in the population. In short, weld attributes representing quality have not been proven to be reliably and consistently inspected when the welds are coated. Qualification tests attempted at Clinton and Zimmer sites were not successful even with coatings 5 mils or less in thickness. Accordingly, we do not believe that the resolution at Wolf Creek is appropriate for accepting Stone & Webster's position on this issue for this or any particular site.

Notwithstanding the above discussion, we suggest the following approach for the Comanche Peak project:

The applicant be requested to propose a qualification program for inspection thru coating by their inspectors consistent with guidelines provided above, for certain weld attributes that are of structural signifi-ficance. The staff envisions that such a qualification program would be very much like the applicant of Wolf Creek did at that particular site; and a random sample inspection be conducted to the NCIG acceptance criteria NRC inspectors, by third of at party, least qualified 64 welds withinspectors, andstripped their coatings witnessedandby/or welds which have never been coated that are representative of coated welds to be inspected.

Results of this reinspection should be reviewed and assessed jointly by the Materials Engineering Branch, Comanche Project, and Region IV staff.

N n % u, V 'A2 t,. m C .

William V. Johnston,' Assistant Director . -

Materials, Chemical & Environmental ,

Technology '

Division of Engineering <

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