A model of heat transfer dynamics of coupled multiphase‐flow and neutron‐radiation: Application to a nuclear fluidized bed reactor

Abstract

Purpose

To present dynamical analysis of axisymmetric and three‐dimensional (3D) simulations of a nuclear fluidized bed reactor. Also to determine the root cause of reactor power fluctuations.

Design/methodology/approach

We have used a coupled neutron radiation (in full phase space) and high resolution multiphase gas‐solid Eulerian‐Eulerian model.

Findings

The reactor can take over 5 min after start up to establish a quasi‐steady‐state and the mechanism for the long term oscillations of power have been established as a heat loss/generation mechanism. There is a clear need to parameterize the temperature of the reactor and, therefore, its power output for a given fissile mass or reactivity. The fission‐power fluctuates by an order of magnitude with a frequency of 0.5‐2 Hz. However, the thermal power output from gases is fairly steady.

Research limitation/implications

The applications demonstrate that a simple surrogate of a complex model of a nuclear fluidised bed can have a predictive ability and has similar statistics to the more complex model.

Practical implications

This work can be used to analyze chaotic systems and also how the power is sensitive to fluctuations in key regions of the reactor.

Originality/value

The work presents the first 3D model of a nuclear fluidised bed reactor and demonstrates the value of numerical methods for modelling new and existing nuclear reactors.

Citation

Pain, C.C., Gomes, J.L.M.A., Eaton, de Oliveira, C.R.E. and Goddard, A.J.H. (2005), "A model of heat transfer dynamics of coupled multiphase‐flow and neutron‐radiation: Application to a nuclear fluidized bed reactor", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 15 No. 8, pp. 765-807. https://doi.org/10.1108/09615530510625084