Study On Thermal-hydraulics Calculation Method For The Core Of ADS

Accelerator Driven System(ADS) is a high-efficient nuclear waste transmutation incinerator and an important plat for the neutronice research. The investigation and development of ADS in foreign country are earlier than in China. Working about ADS in our country is having in hand, but it’s a lack of the thermal-hydraulics investigation. The method of thermal-hydraulics calculation, which has particular character, is one of the key issues in ADS design and that is very necessary. So in this paper, the method coupling neutronics and thermal-hydraulics and that based on porous medium are studied for the ADS core.The structure and operating condition of conceptual ADS have been introduced. The ADS features dense fuels in assemblies, inner and outer cores with two different enrichment, independent windowless spallation target which can be simulation calculated as an insulation part, and coolant system with three parallel circulation loops.First of all, neutronics and thermal-hydraulics coupled calculation method has been developed. Single channel model and the calculation method based on the model are analyzed, and then a thermal-hydraulics code has been developed after the thermophysical properties of materials in the core are investigated. Coupling the code with MCNP, the neutronics and other thermal-hydraulics coupled method is built. After the method has been validated correct in all details, the power distribution and thermal-hydraulic parameters of ADS are obtained with the method. A comparison between the result and that of the calculation without using the method shows the differences, that are in the result of different nuclear database. Then some suggestions, such as smoothing the radial power distribution, are given for advancing the design of the core.Secondly, the method based on porous medium has been investigated. The formula of porosity, permeability, coefficient of resistance, and other parameters were developed. And then by simulating the coolant circulation of core and pool in the Xi’ an Pulsed Reactor(XAPR) and comparing the result with the operating experiment data, the method is valid. With the method, the ADS core can be simplified as a subsystem, thus the analyses of the coolant circulation is easily completed, which makes on foundation for the following thermal-hydraulics research.At last, the work is concluded and the further research is prospected. The proposed method for ADS thermal-hydraulics calculation provides a base for further investigation and design as a approach, so that the designed ADS’ structure will be more appropriate and its operating will be safer.