Establishes the applicable code requirements and boundaries for the design and installation of instrument-sensing lines interconnecting nuclear safety-related power plant processes with both nuclear safety-related and non-nuclear safety-related instrumentation. Covers design, protection, and installation of nuclear safety-related instrument sensing lines for light water-cooled nuclear power plants and covers the pressure boundary requirements for sensing lines up to and including 1-inch (25.4-mm) outside diameter or three-quater-inch nominal pipe.