In this paper, a statistical method is suggested for the best-estimate analysis of transients that are important in designing and operating the nuclear power plants. This method is the various experimental designs including the Latin Hypercube Sampling, the analytical methods using the Response Surface Method and the Monte Carlo Simulation. Best-estimate output variables with sufficient reliability can be generated with this method.
Previously, deterministic analysis methods were widely used and excessive loss of operational margin resulted by assuming conservative values for the input variables. However, in the statistical analysis method, the uncertainties of input variables are dealt with statistically and thus increased operational margin can be secured. At the same time, effective sensitivity calculation of major safety parameters can be carried out.
In this paper, a statistical analysis method is applied for the Main Steam Line Break accident which is a design basis accident. In order to investigate the feasibility of removing the Boron Injection Tank, which is causing problems due to the usage of high concentration boric acid, the emergency core cooling system is assumed not. to have the Boron Injection Tank. The results show that the minimum DNBR is maintained above the limiting value of 1.3
This study has shown that the statistical method, i.e. "Experimental Designs - Response Surface Method - Monte Carlo Simulation", is an effective method for the safety analysis of nuclear power plants, and in its application, has verified the possibility of the removal of Boron Injection Tank.
