ML19257C737

Loss of Adhesion Between Epoxy Decontaminable Surfacer Coats on Containment Interior Walls Detected.Cause Unknown. Investigation Underway.Further Rept Scheduled for 800130

ML19257C737
Person / Time
Site:	Midland
Issue date:	11/30/1979
From:	Bailey K BECHTEL GROUP, INC.
To:
Shared Package
ML19257C731	List: ML19257C730 ML19257C733 ML19257C737
References
MCAR-35, NUDOCS 8001300226
Download: ML19257C737 (3)

Text

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, Bechtel Power D-309-79orporation l.

SUBJECT:

MCAR'35 (issued 11/13/79) w . , :. . , _ . _ __ . . . . . _ m . a Containment Internal -

Structures oating INTERIM P.EPORT 1 ,

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DATE: November 30, 1979 / gi -

PROJECT: Consumers Power Compcny 1 .

t Midland Plant Units 1 & 2 f U

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Bechtel Job .7220 ,

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Introduction ru As requested in MCAk 35, this report cunmarizes project enginee ring 's evaluation and action regarding the failure of coatings on concrete, as applied by subcontractor J.L. Manta, in the containment building to ,

maintain adhesion between successive laye,rs of the coating system.

Descri tion of Deficiency Specification 7220-A-15(Q) requires an application of a three-coat epoxy decontaminable surfacer, designated as System 9 in Specification 7220-A-15(Q), on certain concrete walls. The three-coat system consists of one coat of Ameron 117 (surfacer) followed by two costs of t.meron 90 (tcpcoat). The specification, allows.a second coat of A=eron 117 as necessary to ensure the required coverage. It was noted in Consu=ers Power Company Nonconformance Report (NCR) M01-4-9-132 that there was a loss of adhesion between coats of this system on Unit 2 containment interior concrete walls- Preliminary examination of these walls by Bechtel revealed that the second coat of Aneror. 117 surfacer had de- +

laminated from the first coat of A::2eron 117 surfacer. --

Investication Investigation revealed that the deficiencies were noted mostly between elevations 595' and 650'. At this early stage nf examination, there was .

no apparent cause identified nor was it possible to mal.e an accurate estimate of the extent of the deficiencies.

t Therefore, to establish the adequacy of the System 9 coatings, an t-F evaluation program will be undertaken as described under Corrective Action. [

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Safety Imolications l 0 .) .) A33 Project engineering's investigation of the deficienc y shows an impli-cation of an adverse ef fecc on plant safety, and therefore is reportable under 10 CFR 50.55(e). The bases for this determination are as follow.

8001300

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1. This deficiency, were it to have remainca uncorrected, could have -

adversely af fected the saf ety of operations of the Midland plant at any time throughout the expected lifetime of the plant.

The loss of adhesion between the first and second layers of coating

• Systen 9 has the potential for causing paint material to be carried into the containment sump as a result of a reactor accident followed by initiation of the containnent spray systen. The containment sump is a safety-related structure, the function and design of which are described in FSAR Subsection 6.2.2.1.2.2. In accordance -

with NRC Regulatory Guide 1.82, the sucp is designed to allow 50% i clogging of the fine inner screen eithout degrading spray pump or decay heat pump npsh, and to limit hydraulic approach velocities to the inner screen to approximately 0.2 ft/see to facilitate settlins out of debris. However, it cannot he conclusively determined that the failure of the containment coatings described in MCAR 35 would result in less than 50% blockage of the inner sump screen. Therefore,

,adecuate npsh for the spray pumps and decay heat pumps could potentially have been adversely af fected, were this deficiency to have remained ~

uhecrrected.

2. This deficiency represents a significant deviation f rom performance specifications which will require either extensive evaluation, ex-tensive redesign, or extensive repair to establish the adequacy of the component to neet the crfteria and bases stated in the safety analysis report or construction pernit, or to otherwise establish the adequacy of the component to perform its intended safety function.

FSAR Subsection 6.1.2 states that the protective coatinge used inside containnent have been denonstrated en withstand th'e design basis accident conditions and to comply wit Regulatory Guide 1.54, ,

except in certain cases where non-LOCA qualified coatings are used on s=all components with a limited painted surface. At this time, the extent of the delamination indicates that it'nay not be restricted to a localized area or justified by a single isolated cause.

Corrective Action  !

Project engineering is implementing a program to acconplish the action reconnended by MCAR 35, as follows. .

1. Quantify, by mapping and testing coated areas to determine the extent i of the physical problem.

. 2. Review design specifications, subcontractor procedures, and quality records for acceptability of techniques, procedures, equipment, and nacerials used.

3. Perforn analysis of materials used for compliance with design and quality requirements. ,

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. MCAR 35 INTEP.IM REPORT 1 gechtel Power Corporation =

Page 3 4 Establish and implement an acceptance test procedure to demon-strate that adhesion requirements are met.

Results from th'e mapping, testing, docunent review, and material analysis will be evaluated by Bechtel. Evaluation will include the deterr'. nation

• of root cause(s), steps necessary to preclude recurrence, t.nd ccr rective action to put the coating system into conpliance with Regulatory Guide 1.54.

The next report is scheduled for January 30, 1980, and will provide a status E report on the testing program.

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