The Placement of Lateral Region in 1D MTR Fuel Lattice Cell Models

Abstract

Small experimental test reactors came to the forefront of the nuclear industry in the early development period of the 1950's and 1960's. Detailed analysis of plate-type fuel was done at the time with the constraints of the existing computer power and available codes. Since then the focus, in Canada and the United States, has shifted towards pin-type fuel currently used in newer research facilities and power reactors. However, recent operational and licensing issues at the McMaster Nuclear Reactor (MNR) have led to a renewed interest in characterization of these plate-type fuels. The current industry standard lattice code, WIMS-AECL is restricted to infinite-slab geometry for plate-fuel. Detailed models using this code and a similar lattice code, DRAWN, are presented and compared to the more simplistic models developed in the late 1970's and 1980's as part of the IAEA research reactor core conversion studies. Specifically, the extending of the lattice cell geometry and the inclusion of peripheral structural material is considered A brief methodology for plate-fuel lattice cell analysis is also presented and discrepancies between the two lattice codes are discussed. This work is currently in progress.