Abstract
In the present work, relationship between probability of piping failure and loss of function in the system, and risk by piping failure are evaluated for the system of plural pipes in nuclear power plants. Appling these risk-informed, the calculation model and the code to minimize amount of total piping weight (piping cost) is developed by performing suitable thickness distribution of every piping under the condition of equivalent or lower than the present risk. Validity and applicability of the code are investigated.
