05000245/LER-1997-026-01, :on 970414,unqualified Coatings in Torus, Discovered.Cause Under Investigation.Future Torus Coating Work Will Not Be Performed Until Qualified Process for Controlling Applications Is Developed

:on 970414,unqualified Coatings in Torus, Discovered.Cause Under Investigation.Future Torus Coating Work Will Not Be Performed Until Qualified Process for Controlling Applications Is Developed

ML20141G164
Person / Time
Site:	Millstone
Issue date:	05/14/1997
From:	Robert Walpole NORTHEAST NUCLEAR ENERGY CO.
To:
Shared Package
ML20141G150	List: 05000245/LER-1997-026, Forwards LER 97-026-00 Per 10CFR50.73(a)(2)(ii).Also Includes Commitments Made in Ltr 05000245/LER-1997-026-01, :on 970414,unqualified Coatings in Torus, Discovered.Cause Under Investigation.Future Torus Coating Work Will Not Be Performed Until Qualified Process for Controlling Applications Is Developed
References
LER-97-026-01, LER-97-26-1, NUDOCS 9705220184
Download: ML20141G164 (3)

LER-1997-026, on 970414,unqualified Coatings in Torus, Discovered.Cause Under Investigation.Future Torus Coating Work Will Not Be Performed Until Qualified Process for Controlling Applications Is Developed

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(viii) 10 CFR 50.73(a)(2)(v), Loss of Safety Function
2451997026R01 - NRC Website

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NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OM8 NO. 3150-0104 1

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FACIUTY NAME (1)

DOCKET NUMBER m PAGE(31 Millstone Nuclear Power Station Unit 1 05000245 1 of 3 4

TITLE 44)

Unqualified Coatings in the Torus EVENT DATE (5)

LER NUMBER (6)

REPORT DATE (7)

OTHER FACILITIES INVOLVED (B)

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MONTH DAY YEAR YEAR SEQUENTIAL REVISION MONTH DAY YEAR FACIUTY NAME DOCKET NUMBER NUMBER

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04 14 97 97 026 00 05 14 97 I

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OPERATINO THIS REPORT is SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR i: (Check one or more) (11)

MODE (9)

N 20.2201(b) 20.2203(aH2Hv) 50.73(aH2)(i) 50.73(a)(2)(viii)

POWER i

LEVEL (101 000 20.2203(a)(1) 20.2203(aH3Hi>

X so.73(a)(2Hii) 50.73(aH2)(x) 20.2203(aH2Hi>

20.2203(a)(3fini 50.73(aH2Hiii) 73.71 20.2203(a)(2Hii) 20.2203(aH4) 50.73laH2Hiv)

OTHER

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20.2203(aH2)hii) 50.36(cH1) 50.73(a)(2)(v) specify m Abstract below or m NRC Form 366A 20.2203(aH2Hiv) 50.36(c)(2)

So.73(a)(2)(vu) l LICENSEE CONTACT FOR THis LER (12)

NAME TELEPHONE NUMBER linclude A,ea Codel 5

Robert W. Walpole, MP1 Nuclear Licensing Manager (860)440-2191 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE l SYSTEM COMPONENT MANUF ACTURER REPORTABLE

CAUSE

SYSTEM COMPONENT MANUFACTURER RE PORT ABLE TO NPROS TO NPRDS SUPPLEMENTAL REPORT EXPECTED (14)

EXPECTED MONTH DAY YEAR f

SUBMISslON YES NO 03 31 98 Of yes. complete EXPECTED SUBMISSION DATE).

4 ABSTRACT (Limit to 1400 spaces, i.e.. approximately 15 single spaced typewritten lines) (16)

On April 14, 1997, with the plant shut down and the reactor in the COLD SHUTDOWN condition, it was discovered based on a historical review that a significant amount of coating work inside the Millstone Unit 1 Torus may be unqualified. A number of different coating materials and systems have been used inside the Torus. The locations and extent of various coating systems is not clear. The potential safety consequence of this condition is that these coatings may not remain in place and intact after a loss of coolant accident (LOCA) and could compromise Engineered Core Cooling Systems (ECCS) recirculation flows.

This unanalyzed condition was reported on April 16,1997, pursuant to 10CFR50.72(b)(2)(i).

An above waterline survey of the Torus will be performed to establish the present condition of the coating systems as applied based on sampling and testing to enable their precise or generic identification. The need for a hydrodynamic transport analysis will be evaluated to potentially determine the affect of delamination of coatings within the Torus on ECCS recirculation flows. The results of the survey will be used to determine the need for additional surveys and to evaluate the various coating materials and systems within the Torus, The results of the survey and the potential hydrodynamic analysis will be evaluated and, if required, sections of the Torus will be recoated.

9705220184 970514 PDR ADOCK 050.0245 S

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- U.s. NUCLEAR REGULATORY Commission l

(499 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION t

FACILITY NAME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE (3) l YEAR SEQuiiNTIAL REvlSION i

Millstone Nuclear Power Station Unit 1 05000245 NUMBER NUMBER 2 of 3 97 026 00 TEXT fit more space is required, use additional copies of NRC Form 366A) (17) 1.

Descriotion of Event On April 14,1997, with the plant shut down and the reactor in the COLD SHUTDOWN, it was discovered based on a historical review that a significant amount of coating work inside the Millstone Unit 1 Torus may be unqualified. Because of the lack of documentation to identify the coating systems used in the Torus; the quality j

of application; and the present condition of the coatings, it is believed that these coatings may be unqualified.

These coatings must remain in olace and intact during a LOCA in order not to compromise ECCS recirculation flows.

i The current status of coatings inside the Torus has been reviewed by the licensee and industry coatings consultants. This review included coating specifications, the Updated Final Safety Analysis Report, Standard Evaluation Plan Topic VI,

'.C correspondence, and reports on work accomplished in the Torus from 1968 1

through 1994. Interviews have been conducted with personnelinvolved in various stages of coating work inside the Torus from construction to present. Based on the documentation reviews, and the interviews, it is clear that I

a number of different coating materials and systems have beu used inside the Torus. The locations and extent of various coating systems is, at present, not clear.

Some coatings have been removed and replaced, other coatings have been partially removed and over-coated,

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and other coatings have just been over-coated. Some unknown percentage of the various coating systems that were applied during and since construction and various combinations of those systems are still in place inside the Torus. Based on the lack of documentation, the uncertain identification of coating systems, the quality of i

toplication and the present condition of the coatings, there is currently no basis for their adequacy to remain intact and adherent during a LOCA.

11. Cause of Event

i The cause of this condit:on is still under investigation. The cause of the condition will be provided in a supplement to this report.

Ill. Analysis of Event The coating systems and the surface preparation for these coatings systems inside the Torus it, indeterminate based on the review of existing documentation. The critical relationship of coating work inside containment to ECCS is that it is e%ential that the coating remain in place and intact after a LOCA in order not to compromise i

ECCS recirculation flows. Since the qualification status cannot be determined based on existing information and i

the number and types of systems cannot be clearly identified, there is no basis to show that coatings will remain adhered during a LOCA.

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! '.U.s. NUCLEAR REGULATORY CoMMisSloN 14 9*1 UCENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE (3)

YEAR SEQUENTIAL REVISION Millstone Nuclear Power Station Unit 1 05000245 NUMBER NUMBER 3 of 3 97 026-00 TEXT Uf more space is required, use additional copies of NRC form 366A) (110

IV. Corrective Action

No future Torus coating work will be performed until a qualified process for controlling application is developed.

i The present condition of the coating systems inside the Torus will provide the basis for any decision on the qualification status of Torus coatings and how to treat areas coated with those systems.

1. An above waterline survey of the Torus will be performed to establish the present condition of the coating systems as applied based on sampling and testing to enable their precise or generic identification. The survey will determine the identity, thickness, and condition of coatings within the Torus. The results of the survey will be used to determine the need for additional surveys and how much of tha existing coatings can l

be qualified to adhere to the Torus during a postulated LOCA event prior to startup for operating cycle 16 1

2. A hydrodynamic transport analysis will be performed, if required by the results of the Torus coating survey, to evaluate the affect o, dunmiation of coatings witnin the Torus on ECCS recirculation flows prior to startup for operating cycle 16.

3. The results of the survey and the potential hydrodynamic transport analysis will be evaluated and, if required, sections of the Torus will be recoated prior to startup for operating cycle 16.

4. The cause of this condition and any additional corrective actions will be included in a supplement to this report prior to startup for operating cycle 16.

V.

Additional Information

None

Similar Events

None Manuf acturer Data Not applicable.