[en] A formal system of N-reactor equipment maintenance standards is described which is designed to provide the following: (A) the organized framework for continuing improvement of surveillance procedures; (B) quantitative information regarding critical system performance for risk and environmental evaluations; (C) a visible record for use in auditing performance and in improving system designs; and (D) procedures that will greatly increase the flexibility of operators, craftsmen, managers, and engineers in the operation and maintenance of complex power generation plants and other industrial plants