Evaluation of existing nuclear safety-related concrete structures may be required as a result of identified degradation or abnormal performance@ in support of physical modifications@ or for periodical validation of structural integrity. Comprehensive evaluation of all safety-related plant structures at periodic intervals is also desirable to monitor operational effects and possible degradation due to environmental conditions. Economics and scheduling concerns@ however@ can prohibit this level of evaluation. This chapter describes the procedural steps that can be used to effectively monitor and maintain the safety-related concrete structures via prioritized evaluation.3An evaluation procedure document should be developed by the plant owner (Section 3.4). This document should be comprehensive and include provisions for addressing the variety of potential uses such as those cited in Chapter 1. The two procedural methods of evaluation that can be performed are ??selective?? and ??periodic?? evaluations (Sections 3.2 and 3.3@ respectively). These two methods use similar evaluation tools@ such as visual inspections@ but are quite different in terms of scope. The primary components of an evaluation procedure and guidelines for preparing the evaluation procedure document are further discussed in Section 3.4.