A Model for Calculating the Accident Washout Factor for a Coastal Nuclear Power Plant Site

A set of deterministic and probabilistic models for estimating the accident washout factor are developed and established based on accident dispersion factor models given by current guidelines. The deterministic washout factor for different time intervals after accident release, the probabilistic washout factor, and the dose corresponding to various pathways are estimated based on the measured meteorological data on the site of a coastal nuclear power plant to be built in the southeastern part of China. The results show that for doses obtained from 0 to 8 h after a design-basis accident release, the external exposure dose from washout deposition given by the deterministic model is ~55% of that from dry deposition and 22% of individual effective dose (except wet deposition dose); the ratios of external exposure dose from washout to that from dry deposition and to effective dose (except wet deposition dose) given by the probabilistic model are ~5.73 and 2.29, respectively.