This paper describes the utility of mesoporous alumina (MA), a high capacity nanomaterial based sorbent, for the development of a clinical grade Mo-99/Tc-99m generator using (n,gamma)Mo-99. Synthesis of MA was performed using a glucose template in an aqueous system. Structural characterization of the nanosorbent was carried out by analytical techniques such as X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), atomic force microscopy (AFM), scanning electron miscroscopy (SEM), transmission electron microscopy (TEM), thermogravimetry-differential thermal analysis (TG-DTA), Fourier transform infrared (FTIR) spectroscopy, and Brunauer-Emmett-Teller (BET) surface area analysis. The material synthesized was mesoporous and nanocrystalline, with average crystallite size of 2-3 nm with a large surface area of 230 +/- 10 m(2) g(-1). In order to evaluate the surface charge of MA in aqueous solution, the zeta potential was determined at different pH environments. Adsorption characteristics of the sorbent such as time course of the adsorption, distribution ratios of Mo-99 and Tc-99m ions, Mo sorption capacity under static and dynamic conditions, Mo-99 adsorption pattern and Tc-99m elution pattern were determined to assess its effectiveness in the preparation of Mo-99/Tc-99m generator. The measured distribution ratio values indicate that Mo-99 is both strongly and selectively retained by MA at acidic pH and Tc-99m could be readily eluted from it, using 0.9% NaCl solution. The static sorption capacity and practical sorption capacity under dynamic conditions of MA was determined to be 225 +/- 20 and 168 +/- 12 mg Mo per gram of sorbent, respectively. With a view to realize the scope of developing clinical scale generator, a novel tandem column generator concept was used in which two Mo-99 loaded columns were connected in series. In this method Tc-99m eluted from the first column was fed to the second column to achieve higher radioactive concentration (RAC) as well as purity of Tc-99m. A 26 GBq (700 mCi) Mo-99/Tc-99m generator was developed using (n,gamma)Mo-99 having specific activity of similar to 18.5 GBq (500 mCi)/g of Mo. The Tc-99m eluted from the generator possessed high radionuclidic, radiochemical, and chemical purity and was amenable for the preparation of Tc-99m-labeled radiopharmaceuticals. The technology can be adapted by those countries having research reactors with flux >1 X 10(14) n.cm(-2).s(-1) to produce Mo-99 by (n,gamma) route. The capacity of the generator can be scaled up to 260 GBq (7 Ci) using (n,gamma)Mo-99 produced from a reactor with flux >1 X 10(15) n.cm(-2).s(-1)