ML20196B277

Forwards 120-day Response to GL 98-04, Potential for Degradation of ECCS & CSS After LOCA Because of Const & Protective Coating Deficiencies & Foreign Matl in Containment,

ML20196B277
Person / Time
Site:	Pilgrim
Issue date:	11/23/1998
From:	Ted Sullivan BOSTON EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BECO-2.98.141, GL-98-04, GL-98-4, NUDOCS 9812010033
Download: ML20196B277 (5)

Text

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Boston Edison A BEC ENERGY COMPANY T.A. Sullivan Vice President Nuclear and Station Director November 23. 1998 BECo Ltr. 2.98.141 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Docket No. 50-293 License No. DPR-35 l

Pilarim 120-Day Response to GL 98-04 Concernino Containment Coatinas, j Construction, and Forelan Meterial issues l

References:

(1) NRC Generic Letter 98-04: Potential for Degradation of the Emergency Core Cooling System and the Containment Spray System After a Loss-of-Coolant Accident Because of Construction and Protective Coating Deficiencies and Foreign Material in Containment.

(2) EPRI TR-109937: Guidelines on the Elements of a Nuclear Safety-Related Coatings Program, dated April 1998.

By letter dated July 14,1998, the Nuclear Regulatory Commission issued Generic Letter 98-  !

04 (GL98-04) addressing issues having generic implications concerning the impact of .j potential coating debris on the operation of safety-related systems, structures, and components (SSC) during a postulated design basis loss-of-coolant accident (LOCA).

Protective coatings are necessary inside containment to control radioactive contamination and to protect surfaces from erosion and corrosion. Detachment of the coatings from the substrate is postulated to make the emergency core cooling systems (ECCS) unable to NN satisfy the requirement of 10 CFR 50.46(b)(5) to provide long-term cooling and core spray functions following a LOCA.

GL 98-04 requested information under 10 CFR 50.54(f) by letter dated July 14,1998, to allow NRC evaluation of licensee's programs for ensuring Service Level 1 protective coatings inside containment do not detach from their substrate during a design basis LOCA and interfere with the operation of the ECCS.

Pilgrim reviewed its procedures and practices assosciated with protective coatings and GL98-04 concerns and determined GL98-04 information request (2) (ii) is appropriate to Pilgrim in that Pilgrim is a plant without the licensing-basis requirements discussed in 9812010033 981123 PDR ADOCK 05000293 P PDR L Pilgrirn Nuclear Power Station, Rocky Hill Road, Plymouth, Massachusetts 02360

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information request (2)(i). Therefore, this letter's attachment provides the information requested in (1) and (2)(ii).

If you have any questions, please contact Peter M. Kahler, Regulatory Affairs Department, at (508) 838-7939.

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. A. Sullivan Commonwealth of Massachusetts)

Country of Plymouth )

Then personally appeared before me, T. A. Sullivan, who being duly sworn, did state that he is Vice President Nuclear, Station Director of Boston Edison Company and that he is duly authorized to execute and file the submittal contained herein in the name and on behalf of Boston Edison Company and that the statements are true to the best of his knowledge and belief.

My commission expires:

ANvu g2g,1ggg

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/ DATE ~~ NOTARY PU LIC Attachment : Generic Letter 98-04 Requested Information ,

cc: Mr. Alan B. Wang, Project Manager U.S. Nuclear Regulatory Commission Project Directorate 1-3 Region i Office Of Nuclear Reactor Regulation 475 Allendale Road Mail Stop: OWFN 14B20 King of Prussia, PA 19406 1 White Flint North 11555 Rockville Pike Senior Resident inspector Rockville, MD 20852 Pilgrim Nuclear Power Station 1

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Attachm nt to Pilorim R~ponm to Grn ric Lctt r 98-04 Information Reauest No.1 A' summary description of the plant-specific program or programs implemented to ensure Service Level 1 protective coatings used inside the containment are procured, applied and maintained in compliance with applicable regulatory requirements and the plant-specific licensing basis for the facility. Include a discussion of how the plant-specific program meets the applicable criteria of 10 CFR Part 50, Appendix B, as well as information regarding any applicable standards, plant-specific procedures, or other guidance used for: (a) controlling the procurement of coatings and paints used at the facility, (b) the qualification testing of protective coatings, and (c) surface preparation, application, surveillance, and maintenance activities for protective coatings.

Maintenance activities involve reworking degraded coatings, removing degraded coatings to sound coatings, correctly preparing the surfaces, applying new coatings, and verifying the quality of the coatings.

Response to Reauest No.1 Boston Edison has implemented controls for the procurement, application, and maintenance of Service Level 1 protective coatings used inside the containment in a manner that is consistent with the licensing basis and regulatory requirements applicable to Pilgrim Nuclear Power Station. The requirements of 10 CFR 50, Appendix B, are implemented through specification of appropriate technical and quality requirements for the Service Level 1 coatings program which includes ongoing maintenance activities implemented by qualified vendors selected in accordance with Pilgrim's approved Quality Assurance Program.

For Pilgrim Nuclear Power Station, Service Level 1 coatings are subject to the requirements of USNRC Regulatory Guide 1.54, Revision 0; ANSI N101.4-72 (excepting Section 6.2.4); and ANSI N5.12-74, Section 10, and plant specific design specifications.

Procurement of Service Level 1 coatings used for new applications or repair / replacement activities are procured from a manufacturer (s) with a quality assurance program meeting the applicable requirements of 10 CFR 50, Appendix B.

The applicable technical and quality requirements that the manufacturer (s) is required to meet are specified by Boston Edison in procurement documents. Acceptance activities are conducted in accordance with procedures that are consistent with ANSI N45.2 requirements (e.g., receipt inspection, source surveillance). This specification of required technical and quality requirements combined with appropriate acceptance activities provides assurance the coatings received meet the requirements of the procurement documents and applicable design specifications. Pilgrim's work control process and manufacturer oversight ensures vendors apply, repair, and inspect Service Level 1 coatings in accordance with the appropriate specification.

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Tha qualification testing of Ssrvice Level 1 coatings used for new applications or repair / replacement activities inside containment meets the applicable requirements contained in the standards and regulatory commitments referenced above. These coatings, including any substitute coatings, have been evaluated to meet the applicable standards and regulatory standards previcusly referenced.

Surface preparation, application, surveillance and maintenance of Service Level 1 coatings used for new applications or repair / replacement activities inside containment >

meet the applicable portions of the standards and regulatory commitments referenced above which are addressed in plant specific design specifications and implemented by l approved, qualified suppliers.

1 Our response applies to Service Level 1 coatings used in primary containment that are l

procured, applied and maintained by Boston Edison or its contractors. This response '

does not address coatings applied by manufacturers on supplied equipment.

Pilgrim engaged a consultant to assist it in developing a program for conducting periodic condition assessments of Service Level 1 coatings inside containment as part of the ASME Section XI, subsection IWE inspection of containment. Guidance contained in 10 CFR 50.56, ASME Section XI, subsection IWE, and the EPRI coatings guideline will be used in development of this assessment program. This program development is currently in progress.

Information Reauest No.(2)(ii) l I

For plants without the above licensing-basis requirements, information shall be provided l to drmonstrate compliance with the requirements of 10CFR50.46b(5), "Long-term i Coc5ng" and the functional capability of the safety-related CSS as set forth in your \

licensing basis. If a licensee can demonstrate this compliance without quantifying the i amount of unqualified coatings, this is acceptable. l 5

Response to Reauest No.(2)(ii)  !

In response to NRC Bulletin 96-03, large passive replacement ECCS suction strainers l were installed at Pilgrim. The following discussion addresses the anticipated licensing I basis pending resolution of NRC Bulletin 96-03. The LOCA debris generation and I strainer head loss analysis is in process and will be submitted as a final report to complete NRC Bulletin 96-03 requirements.

The design input to the ECCS strainer calculations for the amount of unqualified coatings, qualified coatings in steam / water jet zone of influence, and degraded qualified coatings in the containment as estimated from previous observations is documented in the new ECCS strainer hydraulic calculations. To satisfy the loading assumptions of the strainer design, the amount of these coating materials is managed, in addition to managing the quantity of fibrous, particulate, and other miscellaneous debris to ensure the analyzed functional capability of the ECCS is not compromised.

The newly-installed ECCS pump suction strainers have been designed to perform satisfactorily in the presence of 100% of the containment coatings that are installed in the LOCA pipe break steam / water jet zone of influence. This amount of coating debris Page 2 of 3

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is daterminad in accordance with the methodology documented in the BWR Owners' Group Utility Resolution Guidance (URG) document (NEDO-32686), Section 3.2.2.2.2.1.1. The conservative methodology used to establish the amount of coating debris has been accepted by the NRC, as documented in the NRC's Safety Evaluation Report (SER) on the URG dated August 20,1998.

l An additional amount of coating debris is added to the debris from the zone of influence.

This amount accounts for potential debris that may result from coatings which are unqualified and/or degraded. Results of BWR Owners' Group LOCA testing of coupons representing unqualified coating systems provide compelling evidence that failure of typical unqualified coating systems which pass a visual inspection is highly unlikely in the first 30 minutes of the LOCA. Only for the first 2 to 15 minutes of the LOCA event, depending upon the pipe break size, are suppression pool turbulence levels sufficient to maintain coating debris in suspension in the pool where it would be available for accumulation on the ECOS strainers. Since the coating debris will quickly settle to the bottom of the suppression pool after the turbulence subsides, none of the coating debris '

(if eventually released sometime after the first 30 minutes of the LOCA) would be available to accumulate on the strainers. In sizing the replacement ECCS strainers for <

Pilgrim, no credit was taken for the delayed release of coating debris; therefore, these  !

designs are conservative with respect to the limit on this coating debris source. Boston Edison is participating in the BWR Owners' Group Containment Coatings Committee and activities in progress are expected to result in an increase in the quantity of containment coating debris that can be accommodated on the strainers without challenging their functional capability. In addition to the estimated 85 lbs of paint chips from the jet zone of influence, 85 lb. of paint chips from long-term degradation were added to the strainer debris loading (170 lbs. total). Finally, a long-term parametric i study was performed to evaluate the effects of doubling the quantity of paint chips to 340 lbs.; the results of the parametric study indicates a negligible effect on strainer head loss.

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