ML20247G630
| ML20247G630 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 05/13/1998 |
| From: | Wanczyk R VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BVY-98-72, NUDOCS 9805200306 | |
| Download: ML20247G630 (3) | |
Text
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VERMONT YANKEE
.- mg NUCLEAR POWER CORPORATION 185 Old Ferry Road, Brattleboro, VT 05301 7002 (802) 257-5271 May 13,1998 BVY 98-72 U. S. Nuclear Regulacry Commission Attention: Document Cc,,, trol Desk Washington, DC 20555
Subject:
Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)
Torus Coatina Activities On March 24, ifE3, representative of Vermont Yankee Nuclear Power Corporation met with members of the Staff to discuss, among other items, installation of emergency core cooling system (ECCS) strainers in the Torus. In the Staff's March 31,1998 letter summarizing the meeting (NVY 98-43), there was a commitment to provide to the Staff information regarding procedures and processes to ensure that Torus coating (painting) removal and recoating, which is being performed as part of the ECCS strainer modification, is pe-formed in compliance with appropriate stendards.
Accordingly, Attachment 1 provides the requested information. In summary, the coating was evaluated to ensure that it would remain intact following a postulated LOCA. The coating was app!ied under an approved quality assurance program to ensure compliance with the guidance of ANSI N101.4. Additionally, the coating system is considered qualified for the intended application in accordance with 'she guidance of ANSI N101.2.
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if you have any questions on this transmittal, please contact Mr. Thomas B. Silko at (802) 258-j 4146.
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I Sincerely,
[g VERMONT YANKEE NUCLEAR POWER CORPORATION M
G rt C +v Robert J. Wa z
- 4' l
Director of Sai and Regulatory Affairs L
Attachment cc:
USNRC Region 1 Administrator j
USNRC Resident inspector-VYNPS USNRC Project Manager -VYNPS Vermont Department of Public Service 9805200306 990513 PDR ADOCK 05000271
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PDR i
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-4r VERMONT YANKEE NUCLEAR POWER CORPORATION U.S. NucleIr Regulatory Commission BVY 98-72 / Attachment / Page 1 Vermont Yankee Nuclear Power Station Torus Coating Activities During the current refueling outage, Vermont Yankee is replacing the Core Spray and Residual Heat Removal. system suction strainers located within the Torus, in addition to this modification, Torus coating has been performed. Due to the condition of the Torus protective coating, the existing coating from the waterline and below was removed and recoated w'th qualified paint. Coating repairs were also performed on the vent header and downcomers.
PREPARATIONS L
.The-intemal Torus surface.was prepared to conform to a near white blast surface per SSPC-SP-10, and had a 1-3 mil surface profile, from one foot above the water line at the outboard inner surface, down across the bottom, and up the inboard inner surface to one foot above the waterline, including all submerged surfaces of ring girders, downcomers, supports,
- piping and other carbon steel items. Local areas were power tool cleaned to bare metal per SSPC-SP-11. Stainless steel surfaces were protected from grit blast.
Cleanliness was maintained after abrasive blasting by performing a thorough cleanup by blowing down, brushing and vacuuming all surfaces within the torus, to assure cleanliness l-
~ satisfied SSPC-SP-10, as applicable prior to coating.
COATING SYSTEMS The coating systems within the Torus are considered Coating Service Level 1 materials.- ANSI N101.2 " Protective Coatings (Paints) for Light Water Nuclear Reactor Containment Facilities" states that the protective coatings used in this service should remain intact following a design basis accident (DBA) and not be removed in sufficient quantities to affect the operation of any engineered safety system. For general qualification under this standard, protective coatings
- should be tested at conditions that simulate the plant DBA environment with respect to temperature, pressure, chemical solutions and radiation levels.
i A comprehensive analysis of DBA test results supplied for the following coating systems was completed:
Carboline Carbo-Zinc 11, Torus immersion Zone Coating e
- Carboline Phenoline 368WG/ Carbo-Zinc 11, Belly Band Coating Carboline 890 Epoxy / Carbo-Zinc 11, Vent Header Repair Coating e
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This analysis revealed that each combination of coating materials and surface preparation has been the subject of successful prototypical testing to establish performance verification. The DBA. test employed conditions that met or exceeded exposures anticipated during LOCA-
- related, critical coating performance periods. ' Each of the three coating systems to be used in the Torus area.is considered qualified for the intended application in accordance with the guidance of ANSI N101.2.-
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- VERMONT YANKEE. NUCLEAR POWER CORPORATION
- ...,. U.S. Nuclear Regulatory Commision BW 98-72 / Attachment / Page 2 ~
ADDITIONAL INFORMATION
. In addition to the specifics discussed above, it ic noted that quality control procedures were
. created for items such as:
Production Personnel Qualifications l
Abrasive Blast Cleaning -
e l
Application of Primer
. Application of Top Coat / Carboline Phenoline 368WG e: Certification of Coating inspectors.
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. Coatings inspection Reports Application of Top Coat / Carboline 890 e
These procedures were. reviewed and approved per. Vermont Yankees quality assurance program.
SUMMARY
lt is anticipated that the coating will remain intact following a postulated DBA. The coating application has been made under an approved quality. assurance program to ensure
. compliance with the guidance of ANSI N101.4 " Quality Assurance for Protective Coatings Applied to Nuclear Facilities". The coating system is considered qualified for the intended application in accordance with the guidance of ANSI N101.2.
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