Unsteady two-dimensional multiphysical simulation of a pressure tube model expanded to contact with the outer concentric tube

For the blind calculation of the International Collaborative Standard Problem (ICSP) experiment on heavy water reactor moderator subcooling requirements, the COMSOL Multiphysics code is used to simulate plastic deformation of a pressure tube (PT) as a result of the interaction of stress and temperature. It is shown that the thermal stress model of COMSOL is compatible to simulate the multiple heat transfers (including the radiation heat transfer and heat conduction) and stress strain in the simplified two-dimensional problem. The benchmark test result for radiation heat transfer is in good agreement with the analytical solution for the concentric configuration of PT and calandria tube (CT). Since the original strain model of COMSOL only considers an elastic deformation with thermal expansion coefficient, the PT/CT contact cannot be predicted in the ICSP. Therefore, the plastic deformation model by the Shewfelt and Godin, widely used in the fuel channel analysis of CANadian Deuterium Uranium (CANDU) reactor, is implemented to the strain equation of COMSOL. The heat-up of PT, the strain rate, and the contact time of the PT/CT are calculated with the boundary conditions (BCs) given for blind calculation of the ICSP experiment.

The result shows a sudden expansion of the inner concentric PT within a few milliseconds. This unsteady simulation should be helpful for the conceptual design of experiment as well as for the understanding of multiphysics inside the fuel channels of the CANDU reactor.     

非能动安注箱的设计与分析

介绍了非能动安注箱的设计与实验,并用CATHENA程序分析其特性:注入流量的峰值,高注入流量的持续时间,最低注入流量等。计算结果表明非能动安注箱设计满足主要的性能要求,CATHENA程序计算结果与实验数据基本一致,可用于概念设计与事故分析。     

Integration of CATHENA Thermal-Hydraulic Model with CANDU 6 Analytical Simulator Controller

This paper introduces a powerful design and analysis tool named SIMCAT, that is developed to support applications to license a CANDU nuclear reactor, refurbish projects, and support the existing CANDU stations. It consists of the CATHENA （Canadian Algorithm for Thermo-Hydraulic Network Analysis）, the control logics from C6SIM （CANDU 6 Analytical Simulator）, and a communication protocol, PVM （parallel virtual machine）. This is the first time that CATHENA has been successfully coupled directly with a program written in another language. The independence of CATHENA and the C6SIM controllers allows the development of both CATHENA and C6SIM controller to proceed independently.     

TACR非能动慢化剂余热排出系统消除不稳定性研究

为了解决非能动慢化剂余热排出系统的不稳定性,本文对原系统结构设计进行了更改,并采用cATHENA程序模拟了在失流事故工况下改进后的系统排热能力.对模拟计算的结果分析表明,改进后的非能动慢化剂余热排出系统能够保证反应堆安全,并且消除了系统中的不稳定性.     

钍基先进坎杜堆非能动慢化剂系统概念设计

以钍基先进重水堆（简称TACR）慢化剂系统作为研究对象,提出了一种满足非能动安全要求的概念设计。在此设计中,首次将慢化剂冷却系统和余热排出系统合二为一,并用热工水力分析程序CATHENA Mod3．5c／Revl分析了反应堆在正常工作时的稳态运行情况,为验证设计的可行性奠定了基础。     

Benchmark Calculations of a Radiation Heat Transfer for a CANDU Fuel Channel Analysis using the CFD Code

To justify the use of a commercial Computational Fluid Dynamics (CFD) code for a CANDU fuel channel analysis, especially for the radiation heat transfer dominant conditions, the CFX-10 code is tested against three benchmark problems which were used for the validation of a radiation heat transfer in the CANDU analysis code, a CATHENA. These three benchmark problems are representative of the CANDU fuel channel configurations from a simple geometry to a whole fuel channel geometry. For the solutions of the benchmark problems, the temperature or the net radiation heat flux boundary conditions are prescribed for each radiating surface to determine the radiation heat transfer rate or the surface temperature, respectively by using the network method.

The Discrete Transfer Model (DTM) is used for the CFX-10 radiation model and its calculation results are compared with the solutions of the benchmark problems. The CFX-10 results for the three benchmark problems are in close agreement with these solutions, so it is concluded that the CFX-10 with a DTM radiation model can be applied to the CANDU fuel channel analysis where a surface radiation heat transfer is a dominant mode of the heat transfer.     

全厂断电事故时TACR-1000非能动慢化剂余热排出系统排热能力研究

为了评估非能动慢化剂余热排出系统的有效性,本文采用CATHENA程序模拟了正常工况及冷却水流失事故工况下非能动慢化剂余热排出系统的排热能力.通过对慢化剂冷却系统的模拟计算得到稳态运行结果,将该结果作为瞬态分析的初始条件计算了非能动慢化剂余热排出系统的排热能力,对计算结果进行了分析.分析结果表明,非能动慢化剂余热排出系统能够保证反应堆安全.