Session: 04-02: SMRs, Advanced Reactors and Fusion

Paper Number: 134519

134519 - Three-Dimensional Temperature Field Monitoring of Heat Pipe Reactor Core 

Abstract: 

The heat pipe is a typical passive heat transfer element. During operation, the liquid working medium in the evaporation section absorbs heat and evaporates into a gaseous state, which is driven by the density gradient generated by the temperature difference to move to the condensation section. Compared with the traditional way of heat transfer using fluid, heat pipe has the characteristics of high reliability, small heat transfer temperature difference and no need for driving force. It is widely used in nuclear engineering, aerospace, energy and chemical industries. The heat pipe reactor is a new type of nuclear reactor based on the principle of heat pipe heat transfer. It adopts the concept of solid core design, and transfers the fission heat through the matrix to the heat pipe by heat conduction. This type of reactor exhibits good inherent safety and single point failure resistance, and is an ideal candidate for space nuclear power systems and transportable nuclear power supply.

The core monitoring of nuclear reactor refers to the process of monitoring the reactor power output, neutron flux, coolant temperature and flow rate in the nuclear reactor core. Thereinto, the monitoring of thermal parameter is a key part. Different from the traditional reactor core, there are no fluid can be monitored in the heat pipe cooled reactor. The thermal monitored thermal parameter should be changed to the solid temperature. According to this characteristic, this paper studies the core temperature monitoring method of heat pipe reactor based on three-dimensional temperature field reconstruction method. The reconstruction method is based on the value of thermocouple arranged inside the matrix. In each assembly, there are 6 sets of thermocouples. They are used to monitor the temperature of matrix and to predict the temperature of cladding and fuel pins. The temperature field reconstruction method reconstructs the whole temperature field through a small number of discrete measuring points of thermocouple, and then expand the measurement data in large quantities. In this paper, the biharmonic spline interpolation method using Green's function is used to reconstruct the temperature field. Firstly, the value of thermocouple is generated by modelling the reactor core using COMSOL. Then, the biharmonic spline interpolation method is used to reconstruct the three-dimensional temperature distribution in the matrix of heat pipe reactor core.The reconstruction results are compared with the one from 3D calculation using COMSOL. Using this method, the heat pipe failure and cladding failure were predicted, the specific location of the failed heat pipe is determined by monitoring the relative temperature change of the thermocouples at different positions.

Keywords: Heat pipe reactor, Heat pipe failure, Core temperature monitoring, Temperature field reconstruction

Presenting Author: Shidi Wang Xi'an Jiaotong University

Presenting Author Biography: Shidi Wang is currently working toward the M.S. degree in Nuclear Energy Science and Engineering with the School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an, China.

Authors:

Shidi Wang Xi'an Jiaotong University
Youqi Zheng Xi'an Jiaotong University
Xiayu Wang Xi'an Jiaotong University
Lunhe Fan Xi'an Jiaotong University
Bowen Xiao Xi'an Jiaotong University