ML20106B569

Interim Deficiency Rept 55-84-20 Re Application of Carboline Coating to Structural Steel within Primary Containment. Initially Reported on 840921.Primer Will Be Left on & Topcoat Removed.Next Rept Will Be Submitted in 60 Days

ML20106B569
Person / Time
Site:	Clinton
Issue date:	01/28/1985
From:	Hall D ILLINOIS POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
55-84-20, U-10243, NUDOCS 8502110677
Download: ML20106B569 (4)

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/LLINOIS POWER OOMPANY I10 jyy f392g3 j CLINTON POWER STATION. P.O. BOX 678 CLINTON, ILLINOIS 61727 January 28, 1985 l

l Docket No. 50-461 Mr.. James G. Keppler Regional Administrator Region III U. S. Nuclear Regulatory Commission Glen Ellyn, Illinois 60137

Subject:

Potential 10CFR50.55(e) Deficiency 55-84-20 Structural Steel Coatings

Dear Mr. Keppler:

On September 21, 1984, Illinois Power Company notified Mr.

F. Jablonski, NRC Region III (Ref: IP Memorandum Y-20842, dated September 21, 1984) of a potentially reportable deficiency concerning the application of an unknown coating to structural steel within the Primary Containment at the Clinton Power Station (CPS). This initial notification was followed by one (1) interim report (ref. IP letter U-10209, D. P. Hall to J.=G. Keppler dated October 24, 1984). Our investigation of this issue is progressing and this letter is submitted as an interim report in accordance with the requirements of 10CFR50.55(e). Attachment A provides the details of our investigation to date.

We trust that this interim report provides sufficient information to perform a general assessment of this potentially reportable deficiency and adequately describes our overall approach to resolve this issue.

Sincerely.yours, S

DO o Q PDR

. . Hall Vice President RLC/lr (NRC2)

Attachment cc: NRC Resident Office Director, Office of I&E, US NRC, Washington, DC 20555 Illinois Department of Nuclear Safety INPO Records Center g w +o

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~ ATTACHMENT A-Illinois Power Company Clinton Power Station Docket No. 50-461 Potential 10CFR50.55(e) Deficiency 55-84-20 Structural Steel Coating Interim Report Statement of Potentially Reportable Deficiency ~

A condition potentially adverse to quality was identified in the area of structural steel-coatings. Vendor coating

. documentation on file indicates that all structural steel inside '

containment was coated in accordance with Specification K-2947, utilizing Carbo Zinc-11. During the course of investigation into

.the deficiencies reported on Nonconformance Report (NCR) No.

20271, it was determined that some structural steel located inside~ Containment was coated with a primer other than Carbo Zinc-11. An investigation and evaluation of this issue is_being performed to' determine the extent of this problem, root cause, effect on installed hardware, and significance to the safety of operation of CPS. ~

Background

Bristol Steel has provided shop primed structural steel for use at CPS, both inside and outside_ of Containment. . The project specification for1 steel inside Containment,' requires a primer coat of Carbo Zinc ll (aniinorganictethylisilicate, zinc-rich e

coating), manufactured by Carboline Company, St. Louis, Missouri.

The vendor inspection records 11ndicate'that Carbo. Zinc-ll primer.

was used by Bristol Steel for structural' steel-inside Contain-ment. For structural steel outside of Containment, Mobil' '

13-F-20, a phenolic resin, zinc' dust, zine oxide primer was designated for use by Specification K-2947.

The. coating applicator, Midway Industrial Contractors,'was contracted to apply a finish coat to the shop primed structural steel at Clinton Power Station. The finishing coat was Carboline 191-HB, a polyamide epoxy also manufactured by Carboline -Company.-

The work began in:1981~ with Midway reporting instances of delamination of the' epoxy _ topcoat from the primer coat on' August i

'5, 1981. Carboline visited the job site in September and j October, 1981 to conduct testing and remove coating samples. 1 This removal included portionsHof the primed structural steel for '

subsequent Design Basis Accident (DBA) testing.

Due to the_ difficulty with topcoat adhesion, Carboline recommended,the use:of D3904-111 clear sealer, an inorganic silicate with_only 6% solids by volume. The intent-of this action was'to replace the epoxy topcoat with the sealer in-PageilLof 3

,, e. .

.. ; , c l: ATTACHMENT A ,

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= (continued) '

order to-provide a more readily decontaminable surface while eliminating the problem with topcoat' adhesion.

. jIn December, 1982, meetings were held with Carboline i concerning the problem of topcoat adhesion to the primer coat.

The minutes of these meetings indicate that. Carboline subjected-i~

.~thetestsamplesofthejnorganiczineprimercoating,appliedby Bristol Steel, to 1 X 10 rads and a DBA 340' F curve. These Lests.were performed with satisfactory 1results. The test results  ;

also indicated.that the sealer when applied over the existing

. primer coat passed the irradiation /DBA requirements.- However, I several months after the sealer was applied, the- job site reported to Carboline that.it' appeared that the sealer was cracking and  ;/-

, flaking from the surface of the structural steel in very fine particle sizes. In July, 1984 Carboline ~ stated that the sealer

on their laboratory' test panels was also powdery and-flaking from the primer coating. Further examination,'by Carboline, indicated

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that-the cracking extended through the. sealer and the sealer had curled from the primer, indicating that the sealer had not penetrated into the primer. Carboline also indicated that the physical characteristics of the primer along with microscopic

! examination (revealed the presence of blue-fibers) suggests that i the primer applied to the structural steel was not Carbo Zine 11.

i o Investigation Results/ Corrective Action i

j Illinois Power prepared and is implementing an investigation plan to determine the extent of this problem at CPS.

Several documentation. reviews have been performed of structural steel purchase order'C-14583 and Baldwin Associates' i

(BA) receipt inspection reports (RIRs) No. S-10984, S-10414, t- S-8233, S-8569, S-1125, S-10250, Land S-10180. No significant

discrepancies were identified'as a result of these reviews.

j- KTA-Tator, Inc; (KTA) was' contracted to provide testing

services for investigation of this matter, i

i Since our last report, the investigation has concentrated ~on

identifying the unknown primer. Identification efforts consisted

, of comparing the test data obtained.by infrared spectroscopic

, analysis of various samples. Samples of the unknown primer were l compared with samples of Carbo Zinc-11~(CZ-11), Mobil Zine-7, and i Dimetcote-6. Although the features of the unknown primer and the p CZ-11 were similar, there was a distinct ~ difference at a j particular spectrographic band.. The spectrographic comparison of

( other known primers differed considerably from the unknown primer. Our-investigation has concluded that the unknown primer-is an inorganic zine compound, but'it is not CZ-ll.- Neither

' Carboline, nor KTA-Tator could identify the brand of the unknown primer.

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ATTACHMENT A (continued)

Because positive identification of the unknown primer could not be made, a detailed chemical analysis was ordered along with DBA, radiation and decontamination tests. KTA-Tator, Coors/ Structure Probe, and Pittsburgh Testing Laboratories provided assistance with the chemical analysis. It was requested that the chemical analysis determine if the unknown primer contained any elements which would be hazardous to the safety or integrity of the Containment. No such elements were identified.

Oak Ridge Laboratory performed the DBA, decontamination, and radiation tests. The test results indicate that the unknown primer met specification requirements.

Based on the test results of the unknown primer, it has been determined that the unknown primer could be left as-is. The peeling top coat will be removed and any future touch-up will be made utilizing CZ-ll over the unknown primer (ref. NCR 20771).

Root Cause The findings of this investigation were reviewed to determine the root cause. Based on this review it was determined that Bristol Steel applied an inorganic zine primer, which does not completely meet the product specifications for CZ-11, to the structural steel supplied to Clinton Power Station.

Safety Implication / Significance Illinois Power's Investigation of this issue is continuing, the Safety implications and significance will be assessed following review and evaluation of the final test'reaorts. It is anticipated that approximately sixty (60) days will-le necessary to complete our investigation, determine reportability, and file a final report on the matter.

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