Simulation Research On Passive Safety Injection System Of Nuclear Power Plant

Passive safety systems make corresponding safety functions less dependenting on operator and external energy supply, they are used to provide significant and measurable improvements in plant safety, reliability and economics. Passive safety systems have been widely utilized in the design of new generation nuclear power plants at home and abroad.In this thesis, two modeling tools, thermal-hydraulic engineering analysis tools for real-time - THEATRe and two-phase flow modeling tool - JTOPMERET, which were developed by GSE company in United States, are used as research tools on passive safety. The two tools are used for simulation calculating and run on the real-time simulation platform -SimExec. At the same time, their modeling principle and usage are described in detail.AP1000 is the advanced passive 1000MWe PWR, its reactor coolant system and the passive core makeup tanks are modeled and the LOCAs are simulated. Some important parameters, such as the mass flow rate of core makeup tank discharge line, the water level of vessel and the fuel clad surface temperature, are calculated and analyzed. According to the calculation results, the core makeup tank can operate in passive form and is avail to cool core. The qualitative analysis on simulation results is accomplished in the paper. Finally the conclusion is that during a small LOCA, the core makeup tank can provide makeup water to the reactor coolant system in passive form and insure emergency cooling core and prevent core damage.