【国外标准】 Standard Guide for Establishing Procedures to Monitor the Performance of Safety-Related Coating Service Level III Lining Systems in an Operating Nuclear Power Plant

4.1 Establishment of an in-service linings monitoring program permits planning and prioritization of lining maintenance work as needed to maintain lining integrity and performance in nuclear Coating Service Level III systems. Refer to ASTM MNL-8, Manual on Maintenance Coatings for Nuclear Power Plants,7 and Guide D7230, which provides guidance for selecting lining materials for new construction or maintenance of safety-related lining systems.4.2 A linings monitoring program enables early identification and detection of potential problems in lining systems. Some Coating Service Level III lining systems may be known in advance to be suspect, deficient, or degraded. Monitoring lining performance will assist in developing follow-up procedures to resolve any significant deficiency relative to lining work.4.3 Degraded linings may generate debris under normal operation and testing or during upset conditions that could adversely affect the performance of safety-related systems. In most cases, the consequence of the debris generation is flow blockage, essential heat transfer reduction, or both; ultimately leading to degradation of equipment or system performance. A linings monitoring program may be required to fulfill licensing commitments for Coating Service Level III lining work.1.1 This guide covers procedures for establishing a program to monitor the performance of Coating Service Level III lining (and coating) systems in operating nuclear power plants. Monitoring is an ongoing process of evaluating the condition of the in-service lining systems.1.2 Coating Service Level III lining systems subject to this guide are generally those applied to metal substrates comprising raw water, condensate-quality water, or fuel oil wetted (that is, full or intermittent immersion) surfaces in systems that may include:1.2.1 Service water piping upstream of safety-related components,1.2.2 Service water pump internals (draft tube, volutes, and diffusers),1.2.3 Service water heat exchangers including the channels, pass partitions, tubesheets, end bells, and covers1.2.4 Service water strainers,1.2.5 Reactor water storage tanks (RWSTs),1.2.6 Refuel cavity water storage tanks,1.2.7 Reactor makeup water system,1.2.8 Component cooling water system,1.2.9 Lube oil tanks for safety-related equipment, and1.2.10 Emergency diesel fuel oil system.1.3 It is the intent of this guide to provide a recommended basis for establishing a linings monitoring program, not to mandate a singular basis for all programs. Variations or simplifications of the program described in this guide may be appropriate for any given operating nuclear power plant depending on its licensing commitments. Similar guidelines may be applicable for certain Coating Service Level II applications such as fluid immersion systems.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.