The k0 method has been introduced at the 30 kW miniaturized neutron source reactor (MNSR) at the Pakistan Institute of Nuclear Science & Technology (PINSTECH). It involved the full energy peak efficiency calibration of the HPGe detector for different counting geometries and the characterization of the neutron flux at four inner irradiation channels. The latter involved the determination of the thermal to the epithermal flux ratio, epithermal flux shape factor, the modified spectral index, Westcott’s g-factor, the Maxwellian neutron temperature and the fast flux. The method was validated by analyzing IAEA-SL1 (Lake Sediment) and NIST-SRM-1572 (Citrus Leaves) reference materials. All calculations were performed in Excel, including the optimization step. The results revealed that most of the elements were estimated with less than 10% relative deviation from the certified value.