Radionuclides are important in the diagnosis and treatment of, amongst others, cancer. A promising therapy is targeted radionuclide therapy, where the radionuclide is brought to the tumor by a targeting specific vector. Bringing the radionuclide directly to the tumor, should reduce the dose to the healthy tissue. For targeted radionuclide therapy, a radionuclide with a high specific activity is required. Some radionuclides, with promising half-lives and decay energies, are currently not produced with the required specific activity. This problem occurs mainly for radionuclides that are produced via (n,γ) reactions in nuclear reactors. For radionuclides that are produced via this reaction, it is nearly impossible to do a chemical separation between the target material and the produced radionuclide, because these are of the same element. This is why new production routes have to be investigated. In this thesis a feasibility study has been done for a new production method, which should increase the specific activity of radionuclides that are produced via a (n,γ) reaction. For this production method, the target material is labeled with a chelator. Due to the Szilard-Chalmers effect the bond with the chelator will be broken, when the target material is activated by a neutron. This enables the separation of the produced radionuclide from the target complex and therefore, the extraction of the radionuclide. The production method will be loop-based, in order to enable continuous activation of the target material and extraction of the radionuclide. Furthermore, the loop-based design should minimize the effect of radiolysis and relabeling. The loop will be placed close to the reactor core. In this thesis, the elements holmium and lutetium have been used. It has been determined which chelator is most suitable to label with holmium and lutetium. Furthermore, the stability of this complex has been investigated for: higher temperatures, time and the effect of the γ-radiation. The effect of the γ-radiation was determined because this results in radiolysis. The extraction of the radionuclide has also been investigated. These parameters have been used in the calculation of the possible achievable specific activity of 166Ho and 177Lu, when using this loop-based production method. Labeling was possible with the chelator DOTA, which resulted in a stable complex, even for higher temperatures. Labeling happened fast, which also results in fast relabeling. The effect of radiolysis, due to the γ-radiation, was determined by fitting the experimental data. The fit gave negative values for short irradiation times, which is not possible. Therefore, two possible fits were made, which did not give negative results. The first fit was shifted over the y-axis and for the second fit the negative values were assigned to be zero....