Since its first criticality in 1962, Thailand Research Reactor has been used regularly for conventional neutron activation analysis (NAA). Three years ago, a new method of NAA called k₀-NAA was developed for neutron flux characterization in the irradiation tubes and applications of large sample NAA. The k₀-NAA technique has become increasingly used in many laboratories world-wide due to its favorable features. These involve mainly the possibility to determine a large number of elements without the need of irradiation and measurements of their standard reference materials, which significantly increases the efficacy of NAA. A discussion is held on mutual influences and differences between (relative) comparator-type and (standardless) k₀-NAA.