The modified spectral index r(α); the Westcott gLu(Tn) factor and absolute neutron temperature Tn were determined for the handling of non-1/ν (n, γ) reaction based on the Westcott formalism using k0-neutron activation analysis (k0-NAA) method at the Malaysian Nuclear Agency (MNA) research reactor. The r(α) was determined by the bare bi-isotopic monitor method using measurement of radionuclides of 97Zr and 95Zr. The 176Lu as non-1/ν and 197Au as 1/ν monitors were utilized for determination of gLu(Tn). The r(α) and gLu(Tn) values ranged from 0.0715 to 0.1417 with a RSD of 15.24% and from 1.7832 to 2.0149 with a RSD of 3.58%, respectively. The accuracy of the method was evaluated based on the calculated absolute neutron temperature (Tn) value. The calculated average value of Tn was 40.56±9.32°C while the value reported by MNA was 40°C, which represents an acceptable level of consistency.