Mitigation of end flux peaking in CANDU fuel bundles using neutron absorbers

End flux peaking (EFP) is a phenomenon where a build-up of neutrons occur at the end regions between two adjoining fuel bundles. EFP affects the axial flux profile of the reactor core, because peaks of high neutron flux occur in these regions. This can lead to an increase in the fission rate and therefore greater heat generation and higher temperatures in the fuel adjacent to the end regions. It is known that addition of neutron absorbers into fuel bundles will mitigate EFP, yet their implementation in Canada Deuterium Uranium (CANDU) type reactors using natural uranium fuel has not been pursued. To simulate the addition of a small amount of neutron absorbers strategically at the bundle ends, Monte Carlo N-Particle code (MCNP) 6 Beta 3.0 was used. Models of a single fuel bundle with two type of absorbers (Gd₂O₃/Eu₂O₃ mixture) placed in three locations were constructed. These locations include; placing the neutron absorbers within a thin disk at the bundle ends, in the CANLUB coating, and finally within the end pellets. This paper will present some preliminary results collected thus far. (author)