Development of neutron activation analysis protocol for low power research reactors: The case of GHARR-1 miniature...

We present an improved neutron activation analysis (NAA) protocol tailored for low-power (34 kW) Ghana Research Reactor-1 (GHARR-1), a miniature neutron source reactor (MNSR). This protocol is designed for routine multi-elemental analysis of sediment/soil samples. It requires 150 mg of analyte per irradiation section, and strategically adjusts irradiation and counting schemes based on radionuclide half-lives. The approach prioritizes operational efficiency and repeatability over reliance on advanced detection systems or elaborate gamma interference corrections. Despite operating without Compton suppression, coincidence counting, or dead-time correction systems, the protocol supports accurate quantification of over 40 elements. Performance validation was conducted through participation in international Interlaboratory Comparison exercises organized by the IAEA (PTNATIAEA series) and its Marine Environmental Studies Laboratory (MESL). Out of 156 submitted data points, 88 % yielded z-scores within |z|≤2, confirming analytical accuracy and international comparability. This work demonstrates that robust analytical outcomes can be achieved in low-power NAA laboratories using standard HPGe detectors and thoughtful experimental design. By combining effective protocol, optimized sample mass, and strategic timing, the method significantly extends the practical capabilities of low-power research reactors in environmental and geochemical applications, without the need for auxiliary hardware upgrades. These results reinforce relevance of low-power neutron sources in contributing to reliable trace element analysis, especially, resource-constrained settings.