Icone15-10105 Inert Matrix Fuel Assembly as an Option for the Laguna Verde NPP Fuel Reloads

Abstract

The availability of large amounts of reactor and weapons grade plutonium in the world shows the necessity of anticipating situations for the use and disposition of it. Because Light Water Reactors (LWRs) prevail on the stage of electric energy generation by nuclear power, it is important to take into account the potential of these reactors to reduce the plutonium inventory. Several studies performed in Pressurized Water Reactors (PWRs) show that reactor and weapons grade plutonium can effectively be burned in these reactors, in assemblies with fertile-free fuel, and maintaining reactivity control and other safety issues at least comparable to those related to the standard fuel normally used.The Instituto Nacional de Investigaciones Nucleares, currently carries out research on diverse alternatives to use Inert Matrix Fuel (IMF) as an option to fuel reloads for the two BWR/5 Units at the Laguna Verde Nuclear Power Plant. This work presents first the neutronic analysis of a fuel assembly conceptual design, which contains a combination of plutonium oxide (in an inert matrix) fuel rods, uranium oxide fuel rods, and uranium oxide with gadolinia fuel rods. Then, simulations for three different fuel assembly reload options were performed for Unit 1. Results of reactor operation from the different reload options are presented.The results obtained with reload fuel using inert matrix fuel assemblies observe a decrease in the length of operation cycle in the plant. However, the mass of uranium used is minor to require for make all fuel assemblies.