The primary cooling piping of HANARO is classified as safety class 3, seismic class 1 and quality class Q. This piping as safety related feature has been designed, manufactured and tested in accordance with ASME SEC. Ⅲ, DIV 1, Class 3. In October of 2000, the first step of the in-service inspection for this piping was carried out in accordance with ASME SEC. XI. This describes the results of the Inspection including the preparation of inservice inspection plan and inspection method. It is verified through the results that the safety related piping is maintained the mechanical and structural Integrities.