ML20101T121

Final Deficiency Rept (53564-K159) Re Concrete Coatings Inside Containment.Initially Reported on 841213.Destructive Adhesion Tests Performed on Locations Selected by Sampling Plan to Verify Acceptability of Coatings

ML20101T121
Person / Time
Site:	Wolf Creek
Issue date:	01/25/1985
From:	Koester G KANSAS GAS & ELECTRIC CO.
To:	Denise R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
(53564-K159), KMLNRC-85-027, KMLNRC-85-27, NUDOCS 8502050831
Download: ML20101T121 (4)

Text

KANSAS GAS AND ELECTRIC COMPANY THIE ELECimC COWMW GLENN L NOESTER

w. m m em January 25, 1985 Mr. R.P. Denise, Director l 0N$ h Wolf Creek Task Force l U.S. Nuclear Regulatory Comission I ggg 9ll Region IV 611 Ryan Plaza Drive, Suite 1000 Arlim ton, Texas

. p 76011 IHINRC 85-027 Re: Docket No. SIN 50-482 Subj: Final 10CFR50.55(e) Report - Concrete Coatings Inside Containment (53564-K159)

Dear Mr. Denise:

This letter provides the final report subnitted pursuant to 10CFR50.55(e) concerning concrete coatirgs inside the Containnent at Wolf Creek Generating Station (WCGS) . This matter was initially reported by Mr. O.L. Maynard of Kansas Gas and Electric Company (E&E) to Mr. Lawrence Martin of the Nuclear Regulatory Comission, Region IV on Decenber 13, 1984. Extensions fran the original report due date were received via telecon with Mr. Iawrence Martin.

In December 1984, Bechtel Power Corporation an3 m&E Nuclear Plant Engineerirg personnel received a copy of a Nonconfonnance Report (NCR 1SN 21203C) which addressed several areas inside containnent at the elevation 2000'-0" floor for which docunentation of coatirgs inspections could not be located. Wis Nonconformance Report e s written, at the direction of E&E, as a result of an investigation into an allegation comunicated to E&E's Quality First Organization.

We allegation was made by an exiting Quality Control Coatings Inspector.

He stated that he had inspected coatings work recently performed inside Containnent, but had not coupleted same of the correspon31ng inspection i reports, as subsequently docunented in NBC 1SN 21203C, to docunent his j inspection of those coatings. We inspector alleged that, since he was  ;

leaving NCGS, the inspection reports for this work may be, or may have been,  !

prepared by someone other than himself. We resulting investigation, f performed by m&E's Quality First Organization, concluded that this 1 allegation was unfounded. Concrete coatings inspection reports for the .

areas involved in the allegation had not been forged; however, not all  !

coatings inspection reports were available for these areas.

In accordance with the SNUPPS FSAR, Sections 6.1.1.1.2 and 6.1.2, concrete coating systems used inside the WCGS Containnent building are designed to ,

meet the criteria of ANSI N101.2 (1972), including a demonstration that the I coating system withstands the Design Basis Accident (DBA) conditions. %e l concrete coating systems specified for NCGS have been qualified by Carboline to the generic irradiation and DBA test parameters recomnended by ANSI B502050831 850125 gDRADOCK05000g gy 201 N. Market - WicNta, Kansas - Mad Address: RO. Box 206 i Nchita, Kansas 67201 - Telephone: Area Code (316) 2t 1-6451 l

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$y 10cutC 85-027.

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. N191.2 (1972). 1hese generic test. recommendations envelope the WCGS radiation and DBA conditions.. To ensure that the field application of. the  ;

described coating systen is similar to- the application used for the qualified coating system, . the coatirg system is to be applied in accordance ,

with ' Regulatory -Qaide 1.54 as described in the SNUPPS FSAR, Table 6.1-2.

The coating applicator is to have an' established program to ensure that all

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coatings work is accomplished' in accordance with the manufacturer's

. reconnended procedures. i The coating areas addressed by the Nonconformance Report represented approximately 3999 square feet of floor coatings at elevation 2099'-8", for

!- which some inspection reports were missing.. Although there is evidence that the. coatings in these areas had been inspected and found acceptable by the inspector, : inspection docunentation was not available to clearly establish

! that the coatings were applied in accordance with approve $ procedures.

j To provide an inclication of the acceptability of these coatings, destructive

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adhesion _ tests were performed on coating locations selected by a

statistically' selected randan sampling plan._ An evaluation of these i preliminary test results concluded that the coatings described in NCR ISN I

21293C could not, on the basis of adhesion testing alone, be considered acceptable. The poor adhesion encountered on the coating areas was thought _

to be attributed to localized contamination. At this time, RGEE began

removing coatings associated with NCR ISN 21293C. Subsequent laboratory-l analysis of core samples indicated that the poor adhesion test results were i the result of residual solvents in the coating system rather than localized l contamination. Based on this' new information, coating removal. work

! associated with NCR ISN 21293C was suspended. A total of approximately 3999 1 l square feet of coatings were removed from the elevation 2999'-9" floors. '

i-i Subsequent to the initial adhesion testing and the preliminary laboratory i results indicating the presence of residual solvents, another Nonconformance Report- (NCR ISN 21544C) was initiated.to assess the qualification of all concrete coatings inside Containnent. Additional destructive adhesion tests '

were performed -on a statistically selected random sample of all concrete

' coatings inside Containnent, excluding the areas already tested under -NCR  ;

-+ ISN 21293C. Results from these adhesion tests were similar in~that the '

l renaining concrete coatings could not be considered acceptable on the basis ,

- of adhesion-testing alone.

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Information fran the statistical adhesion' tests', localized adhesion tests, concrete coating ' inspection reports' (CrIR's) , subjective field

-investigations, and . laboratory analyses was correlated to establish the

" worst case" coating locations fran which core ' samples could be removed, irradiated- and' DBA1 tested. Sets of' samples were then renoved from these locations. Core samples from each' set were subjected ~ to . a - DBA testing sequence at Oak-Ridge National Laboratory, while.another sample from each l

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MMDIRC 85-927 Page 3' set was indeperdently chemically and physically analyzed. Some of the

. aforementioned . core samples - were pre-irradiated, others were DBA tested without irradiation. We results of the DBA test sequences indicate that the ' " worst case" coating samples meet the intent on ANSI N191.2 (1972) paragraph 1.4.2.2, in that the coatings will perform- satisfactorily under the WOGS design basis accident conditions, for both spray and innersion environnents.

We results of the laboratory testing, adhesion tests and data from the WCGS CCIR's indicated two causes for the poor adhesion streg th exhibited by same of the concrete coating insiCa containment. One indicated cause of poor adhesion was residual solvents trapped within the coatig system. We cause of the solvent entrapment can be linked- to the use of solvents -during surface preparation in combination with a specific set of ambient-temperature and time conditions, as identified on (rIR's, which adversely impact the ability of the solvents to evaporate out of the coating system. >

me other cause involved minute fracturing of the concrete surface.resulting from normal residual internal stresses arxVor mechanical impacting of the

- surface. - %ese minute fractures in the concrete surface do not adversely affect the strength of the concrete, nor do they directly affect the .

qualification of the coating . system as confirmed by the DBA testing ,

sequences.

In conclusion, although localized areas of concrete coatings may exhibit poor adhesion, this poor adhesion does not affect adversely the ability of the coating system to withstand DBA conditions, in accordance with comnitments described in the SNUPPS FSAR, Sections 6.1.1.1.2 and 6.1.2.

We coatings removed from the elevation 2000'-0" floor inside Containment will be replaced after fuel load while in MoSe Five. Scheduled duration of Mode Five is ' thirty-three days, 'while all post fuel load recoating activities are scheduled to be completed - within twenty-four days after entering Mode Five.- MGEE does not ant '-8.pate any significant' schedular or technical impact to result from th( recoating activities being coMucted concurrently with scheduled start-up te_ ting activities during Mode Five.

A comprehensive and detailed work plan i as been written to ' direct aM control activities related to concrete recoating on the. elevation 2990'-0" floor inside Containnent. In order to minimize any future residual solvent i entrapnent within the coating systems, both coating work and quality procedures have been revised to strictly control-the use of solvents during 3

surface L preparation. We_ work plan also includes information regarding:

t scope, schedules, prerequisites, specifications, manufacturer's data, tools and equipment, security, ventilation, fire protection procedures, safety procedures, and cleantiness procedures. his work plan is available-at WCGS for your review.

0 0 -* D MMINRC 85-927

-Page 4 In addition, the complete technical report regarding this matter will be available at WCGS for your review. If you have any questions concerning this matter, please contact me or Mr. Otto Maynard of my staff.

Yours very truly, V Glenn L. Koester Vice President - Nuclear-cc: P0'Connor (2)

HBundy WGuldemond I