VVER机组事故分析耦合程序开发及应用OA

Neutronics/thermal-hydraulic coupled code was developed to model the accidents for VVER units especially in which strong neutronics/thermal coupling effect and obvious change of local power distribution exist.Through dynamic link library technology and building coupling interface model,three-dimensional neutronic kinetics code and thermal-hydraulic code were coupled.Transient simulation on the inadvertent dilution of boric acid accident of VVER-1000 units was carried out based on the coupled code.The sequence of event and parameters in the primary and second circuits were analyzed.Finally,compliance of critical safety-relevant parameters with acceptance criteria was evaluated.Results indicate that simulated values obtained by the coupled code agree well with measured data of the power plant.Variation trends of neutronic and thermal-hydraulic parameters present overall consistence with those of FSAR,and the deviation of the extreme values is small.The computing performance and reliability of the coupled code were proved.Safety acceptance criteria related to maximum fuel temperature,minimum DNBR and other values are satisfied.Neutronics/thermal-hydraulic coupled code could be used as an effective tool for accurate accident modeling of VVER units.