Particle Swarm Optimisation (PSO) is a metaheuristic technique based on the social aspects of intelligence. Some PSO models have been developed for combinatorial optimisation, although none of them presented satisfactory results to optimise the combinatorial problem of the Nuclear Reactor Reload Problem (NRRP). The Particle Swarm Optimisation with Random Keys (PSORK) model is a variant of the PSO applied to combinatorial problems such as the NRRP. In this paper, we present the results of the in-core fuel optimisation of the Angra 1 Nuclear Power Plant (NPP) located at the southeast of Brazil and a survey on the confinement of particles in the PSORK for the NRRP. A confinement analysis is interesting in a continuous function optimisation since it may influence the search, resulting in biases that favour particular regions of the search space. Nevertheless, there are no similar studies for confinements applied to a combinatorial optimisation. We have submitted the PSORK to a confinement analysis when applied to the Travelling Salesman Problem (TSP) Rykel48 (ry48p), a benchmark for a combinatorial optimisation, in order to study the consequences of the confined PSORK in this type of combinatorial problem. Finally, the Confinement for the Combinatorial Optimisation (CCO) of the NRRP is proposed and the results are presented.