AC estimation code and risk evaluation based on the code

FAC risk has been defined as the mathematical product of the possibility of wall thinning occurrence and its hazard scale. The possibility of wall thinning occurrence was designated as the time margin for pipe rupture determined by applying a one-dimensional FAC code, which could predict wall thinning rate with an accuracy within a factor of 2, while the hazard scale was defined as the volume of effluent steam and water from the ruptured mouth, which was enthalpy of water originally flowing in the pipe multiplied by the square of the pipe inner diameter. High FAC risk zones along entire cooling systems could be evaluated only in a tenth or a hundredth of computer time for 3D FAC code to determine the priority for inspection order importance. (author)