XI.S8 (NUREG-1801 R2)
XI.S8 PROTECTIVE COATING MONITORING AND MAINTENANCE PROGRAM
Program Description
Proper maintenance of protective coatings inside containment (defined as Service Level I in U.S. Nuclear Regulatory Commission [US NRC] Regulatory Guide (RG) 1.54, Rev. 1, or latest version) is essential to ensure operability of post-accident safety systems that rely on water recycled through the containment sump/drain system. Degradation of coatings can lead to clogging of Emergency Core Cooling Systems (ECCS) suction strainers, which reduces flow through the system and could cause unacceptable head loss for the pumps.
Maintenance of Service Level I coatings applied to carbon steel and concrete surfaces inside containment (e.g., steel liner, steel containment shell, structural steel, supports, penetrations, and concrete walls and floors) also serve to prevent or minimize loss of material due to corrosion of carbon steel components and aids in decontamination. Regulatory Position C4 in US NRC RG 1.54, Rev. 2, describes an acceptable technical basis for a Service Level I coatings monitoring and maintenance program that can be credited for managing the effects of corrosion for carbon steel elements inside containment. American Society for Testing of Materials (ASTM) D 5163-08 and endorsed years of the standard in US NRC RG 1.54 are acceptable and considered consistent with NUREG-1801. In addition, Electric Power Research Institute (EPRI) Report 1019157, Guidelines for Inspection and Maintenance of Safety-related Protective Coatings, provides additional information on the ASTM standard guidelines.
A comparable program for monitoring and maintaining protective coatings inside containment, developed in accordance with US NRC RG 1.54, Rev. 2, is acceptable as an aging management program for license renewal.
Service Level I coatings credited for preventing corrosion of steel containments and steel liners for concrete containments are subject to requirements specified by the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code, Section XI, Subsection IWE ( AMP XI.S1). However, this program (AMP XI.S8) reviews Service Level I coatings to ensure that the protective coating monitoring and maintenance program are adequate for license renewal.
Evaluation and Technical Basis
- 1. Scope of Program: The minimum scope of the program is Service Level I coatings applied to steel and concrete surfaces inside containment (e.g., steel liner, steel containment shell, structural steel, supports, penetrations, and concrete walls and floors), defined in US NRC RG 1.54, Rev. 2, as follows: "Service Level I coatings are used in areas inside the reactor containment where the coating failure could adversely affect the operation of post-accident fluid systems and thereby impair safe shutdown." The scope of the program also should include any Service Level I coatings that are credited by the licensee for preventing loss of material due to corrosion in accordance with AMP XI.S1.
- 2. Preventive Action: The program is a condition monitoring program and does not recommend any preventive actions. However, for plants that credit coatings to minimize loss of material, this program is a preventive action.
- 3. Parameters Monitored or Inspected: Regulatory Position C4 in US NRC RG 1.54, Rev 1, states that "ASTM D 5163-96 provides guidelines that are acceptable to the US NRC staff for establishing an in-service coatings monitoring program for Service Level I coating systems in operating nuclear power plants..." ASTM D 5163-96 has been superseded by ASTM D 5163-08. ASTM D 5163-08 identifies the parameters monitored or inspected to be "any visible defects, such as blistering, cracking, flaking, peeling, rusting, and physical damage."
- 4. Detection of Aging Effects: ASTM D 5163-08, paragraph 6, defines the inspection frequency to be each refueling outage or during other major maintenance outages, as needed. ASTM D 5163-08, paragraph 9, discusses the qualifications for inspection personnel, the inspection coordinator, and the inspection results evaluator. ASTM D 5163-08, subparagraph 10.1, discusses development of the inspection plan and the inspection methods to be used. It states that a general visual inspection shall be conducted on all readily accessible coated surfaces during a walk-through. After a walkthrough, or during the general visual inspection, thorough visual inspections shall be carried out on previously designated areas and on areas noted as deficient during the walk-through. A thorough visual inspection shall also be carried out on all coatings near sumps or screens associated with the Emergency Core Cooling System (ECCS). This subparagraph also addresses field documentation of inspection results. ASTM D 5163-08, subparagraph 10.5, identifies instruments and equipment needed for inspection.
- 5. Monitoring and Trending: ASTM D 5163-08 identifies monitoring and trending activities in subparagraph 7.2, which specifies a pre-inspection review of the previous two monitoring reports, and in subparagraph 11.1.2, which specifies that the inspection report should prioritize repair areas as either needing repair during the same outage or as postponed to future outages, but under surveillance in the interim period.
- 6. Acceptance Criteria: ASTM D 5163-08, subparagraphs 10.2.1 through 10.2.6, 10.3, and 10.4, contains one acceptable method for the characterization, documentation, and testing of defective or deficient coating surfaces. Additional ASTM and other recognized test methods are available for use in characterizing the severity of observed defects and deficiencies. The evaluation covers blistering, cracking, flaking, peeling, delamination, and rusting. ASTM D 5163-08, paragraph 11, addresses evaluation. It specifies that the inspection report is to be evaluated by the responsible evaluation personnel, who prepare a summary of findings and recommendations for future surveillance or repair, and prioritization of repairs.
- 7. Corrective Actions: A recommended corrective action plan is required for major defective areas so that these areas can be repaired during the same outage, if appropriate. As discussed in the Appendix for GALL, the staff finds the requirements of 10 CFR 50, Appendix B, acceptable to address the corrective actions.
- 8. Confirmation Process: As discussed in the Appendix for GALL, the staff finds the requirements of 10 CFR 50, Appendix B, acceptable to address the confirmation process.
- 9. Administrative Controls: As discussed in the Appendix for GALL, the staff finds the requirements of 10 CFR 50, Appendix B, acceptable to address the administrative controls.
- 10. Operating Experience: US NRC Information Notice 88-82, US NRC Bulletin 96-03, US NRC Generic Letter (GL) 04-02, and US NRC Generic Letter 98-04 describe industry experience pertaining to coatings degradation inside containment and the consequential clogging of sump strainers. US NRC RG 1.54, Rev. 1, was issued in July 2000. Monitoring and maintenance of Service Level I coatings conducted in accordance with Regulatory Position C4 is expected to be an effective program for managing degradation of Service Level I coatings and, consequently, an effective means to manage loss of material due to corrosion of carbon steel structural elements inside containment.
References
10 CFR Part 50, Appendix B, Quality Assurance Criteria for Nuclear Power Plants, Office of the Federal Register, National Archives and Records Administration, 2009.
ASTM D 5163-05, Guide for Establishing Procedures to Monitor the Performance of Coating Service Level I Coating Systems in an Operating Nuclear Power Plant, American Society for Testing and Materials, 2005.
ASTM D 5163-08, Standard Guide for Establishing a Program for Condition Assessment of Coating Service Level I Coating Systems in Nuclear Power Plants, American Society for Testing and Materials, 2008.
ASTM D 5163-96, Standard Guide for Establishing Procedures to Monitor the Performance of Safety Related Coatings in an Operating Nuclear Power Plant, American Society for Testing and Materials, 1996.
EPRI Report 1003102(Archived), Guideline on Nuclear Safety-Related Coatings, Revision 1, (Formerly TR-109937), Electric Power Research Institute, November 2001.
EPRI Report 1019157, Guideline on Nuclear Safety-Related Coatings, Revision 2, (Formerly TR-109937and 1003102), Electric Power Research Institute, December 2009.
US NRC Bulletin 96-03, Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling-Water Reactors, U.S. Nuclear Regulatory Commission, May 6, 1996.
US 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, U.S. Nuclear Regulatory Commission, July 14, 1998.
US NRC Generic Letter 04-02, Potential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized-Water Reactors, U.S. Nuclear Regulatory Commission, September 13, 2004.
US NRC Information Notice 88-82, Torus Shells with Corrosion and Degraded Coatings in BWR Containments, U.S. Nuclear Regulatory Commission, November 14, 1988.
US NRC Information Notice 97-13, Deficient Conditions Associated With Protective Coatings at Nuclear Power Plants, U.S. Nuclear Regulatory Commission, March 24, 1997.
US NRC Regulatory Guide 1.54, Rev. 0, Quality Assurance Requirements for Protective Coatings Applied to Water-Cooled Nuclear Power Plants, U.S. Nuclear Regulatory Commission, June 1973.
US NRC Regulatory Guide 1.54, Rev. 1, Service Level I, II, and III Protective Coatings Applied to Nuclear Power Plants, U.S. Nuclear Regulatory Commission, July 2000.
US NRC Regulatory Guide 1.54, Rev. 2, Service Level I, II, and III Protective Coatings Applied to Nuclear Power Plants, U.S. Nuclear Regulatory Commission, October 2010.