Development of contamination estimation method for PWR

Accurate estimation of radioactive inventory is essential for nuclear power plant, since it effects on nuclide screening for clearance, disposal cost, collective dose and public exposure estimation. This paper describes contamination estimation method. Authors have developed contamination estimation method for PWR primary circuit and other systems. The method is based on the assumption that only particulates in the coolant are responsible for contamination and S. K. Beal’s theory of particle deposition and erosion model. There are various contamination calculation conditions and some of them, such as failed fuel fraction, are difficult to determine with plant design data and thus measured data of radioactive waste generated from the existing plant is used for estimating fission products contamination. Contamination estimation results are in good agreement with the measured data. For the application of this method to the contamination density estimation for the PWR operational waste and for decommissioning, the improvement of estimation accuracy will be required by conducting further data accumulation regarding the plant operating data and accurate plant design parameters.