ML20116H485

Final Potential Deficiency Rept 55-84-20 Re Application of Unknown Coating to Structural Steel within Primary Containment.Initially Reported on 840921.Item Not Reportable Per 10CFR50.55(e)

ML20116H485
Person / Time
Site:	Clinton
Issue date:	04/01/1985
From:	Hall D ILLINOIS POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
55-84-20, U-10261, NUDOCS 8505020233
Download: ML20116H485 (4)

Text

_ _ _ _ _ _ _

3md ILLIN0/S POWER COMPANY 1A.'20

[g3 U 10261 CLINTON POWER STATION. P.O. BOX 678. CLINTON. ILLINOIS 617.'7 April 1, 1985 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 two (2) interim reports (ref. IP letter U-10209, D. P. Hall to J. G. Keppler dated October 24, 1984 and IP letter U-10243, D. P. Hall to J.

G. Keppler dated January 28, 1985). Illinois Power's investigation of this issue is complete. Our investigation into this matter has determined that this issue does not represent a reportable deficiency under the provisions of 10CFR50.55(e).

This letter is submitted as a final report in accordance with the requirements of 10CFR50.55(e). Attachment A provides the details of our investigation.

We trust that this final 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, 8505020233 DR 850401 g ADOCK 05000461 PDR D. P. 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 APR , 41985 INPO Records Center I

- - - _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ [___ M_2 2___

w w ATTACHMENT A Illinois Power Company Clinton Power Station Docket'No. 50-461 Potential 10CFR50.55(e). Deficiency 55-84-20 Structural Steel Coating Final 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 Sargent & Lundy (S&L)

Specification K-2947, utilizing Carbo.Zine-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 was performed to determine the extent of this problem, root cause, effect on installed hardware, and significance to the safety of operations of CPS.

Background

Bristol Steel (a structural steel supplier) has provided shop primed structural steel for use at CPS, both inside and outside of Containment. The project specification for steel inside Containment, requires a primer coat of Carbo Zinc-Il (an inorganic ethyl silicate, zinc-rich coating), manufactured by Carboline Company, St. Louis, Missouri. Bristol Steel's inspection records indicate that they used Carbo Zine-11 primer

~

for coating the structural steel to be used inside Containment.

Midway Industrial Contractors, a coating applicator, was contracted to apaly a finish coat to the shop primed structural steel at CPS. Tae 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 5, 1981.

Carboline visited the job site in September and October,1981 to conduct testing and remove coating samples. This removal included portions of 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 4 action was to replace the epoxy topcoat with the sealer in Page 1 of 3

e :e' I

ATTACHMENT A l (continued)

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

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

The minutes-of;these meetings indicate that Carboline subjected l -the test samples of the gnorganic zinc primer coating, applied by Bristol Steel,-to 1 X 10 rads and a DBA 340* F curve. These tests were performed with satisfactory results. The test results also indicated that the sealer when applied over the existing primer coat lassed the irradiation /DBA requirements. However, several mont2s 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 ganels was also powdery and flaking from the primer coating. Further examination, by Carboline, indicated 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 the primer applied to the structural steel was not Carbo Zinc 11.

Investigation Results/ Corrective Action Illinois Power prepared and has implemented an investigation to' determine the extent of this problem at CPS.

I Several documentation reviews have been performed of structural steel purchase order C-14583 and Baldwin Associates' (BA) receipt inspection reports (RIRs) No. S-10984, S-10414, S-8233, S-8569, S-1125, S-10250, and S-10180. No discrepancies were identified as a result of these reviews.

KTA-Tator, Inc, (KTA) was contracted to provide testing services for investigation of this matter.

Our 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 arimer were compared with samples of Carbo Zinc-11 (CZ-11), Mobil Zinc-7, and Dimetcote-6. Although the features of the unknown primer and the CZ-11 were similar, there was a distinct difference at a particular spectrographic band. The saectrographic comparison of other known primers differed consideraily from the unknown primer. Our investigation has concluded that the unknown primer is an inorganic zinc compound, but it is not CZ-11. Neither Carboline, nor KTA-Tator could identify the brand of the unknown primer.

( Page 2 of 3 i

L ._

n i w a

. o ,

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 would be acceptable for use in the containment environment and would be able to perform as well as CZ-ll. NCR No. 20271 was dispositioned "USE-AS-IS".

The clear sealer (D3904-111) over the sup3ression pool area was wiped down with a cloth. The purpose of the wipe down was to remove dusting of the clear topcoat. The prime coat was left "as-is" (Ref. NCR No. 20771).

The flaking topcoat (191-HB) at elevation 755 between Azimuth 90' and 180' was removed except for the inaccessable areas which would have involved disturbing steel frames. These areas were left as-is. Any loss of prime coat was restored to proper specification by applying CZ-ll on top of the unknown primer. The flaking top coat was removed because of the undesirability of having flakes of paint, periodically falling to the areas below (Ref. NCR No. 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 apalied an inorganic zine primer, which does not completely meet tie product specifications for CZ-ll, to the structural steel supplied to CPS.

Safety Implication / Significance Illinois Power's investigation of this issue is complete.

Extensive testing has proven that the unknown primer met or exceeded the requirements for use in containment. Sargent &

Lundy has reviewed and evaluated the NCRs associated with this issue and have stated that the identified deficiencies do not represent a condition adverse to the safety of operations of CPS.

On this basis the issue is considered to be not reportable under the provisions of 10CFR50.55(e)

Page 3 of 3