The Frequency Stability Analysis Of The Supercritical Water System

Because of the excellent characteristics of supercritical water, the supercritical water has been widely used in the fossil fuel power reactors, there are lots of supercritical and ultra-supercritical fossil fuel water reactors all over around world. Meanwhile the supercritical water-cooled reactor (SCWR) is the only water-cooled reactor technology selected by GIF as one of the Generation-IV reactor candidates. Currently, SCWR related basic studies are receiving considerable publicity in many countries. Because of drastic change in its thermo-physical properties near the pseudo-critical temperature, and the drastic change may result in accident, so the stability analysis of SCWR is one of the challenging research topics.Firstly, the mathematic principle and the frequency domain method which be used in the supercritical water system stability analysis program (SCWSSA) is explained in the paper. The supercritical water system stability analysis program can be divided into two parts, first part: system steady state calculation and other part: system perturbation equation calculation. The former part provides the system steady state variables for the next part. And then in the paper two parts of the program be tested and verified by comparison analysis results between others programs in same supercritical water natural loop system, respectively. The results show the supercritical water system stability analysis program can provide a right analysis results for the steady state and the stability boundary of the supercritical water system.Then, the SCWR model which be proposed by INELL US is analyzed, the important variable distributions of the system in the steady state, such as temperature and pressure, are given in the paper. Meanwhile, the system decay ratio which is used to indicate the system stability extent is given with the power vs. inlet enthalpy. The result shows SCWR model which be proposed by US has a very good stability. And then the fast spectrum zone and whole reactor of the SCWR-M which be proposed by SJTU is analyzed by the program. The results show that both of them have a good stability. And then the variables sensitivity analyses of them are carry out. The research work has made a solid basis for the future in-depth stability analysis of supercritical water system.This research work is supported by the National Basic Research Program of China (2007CB029806).