Developing a new target design for producing ⁹⁹Mo in a MTR reactor

Highlights: • An investigation is performed for producing more efficient of ⁹⁹Mo in Tehran research reactor. • Stochastic code MCNPX along with CFD code ANSYS are used to perform the calculations. • The proposed design satisfied all the neutronic, safety and operational constraints. • The new target gives rise to a higher production of ⁹⁹Mo enough for the local demand. • The proposed design causing a reduction in nuclear waste, process and operating difficulties. - Abstract: ⁹⁹Mo is an important radioisotope and mainly produced using uranium fission reaction in a nuclear reactor. Investigation for probable improvements, especially on target geometry and in-core location of target is the main goal of this research. This is for producing more efficient of ⁹⁹Mo in a typical Material Testing Reactors (MTRs). A parametric investigation is done focused on the target characteristics such as geometry, location, material, density, heat flux (power density) and also usability in Tehran Research Reactor (TRR) as a MTR case study. Stochastic code MCNPX 2.6.0 along with CFD code ANSYS are used to perform neutronic and thermal-hydraulic analyses. A target with plate type design is specified and proposed as a final and most favorable design. Taking into account the safety criteria, the production yield, the chemical process and radioactive waste, it is demonstrated that the new target design meets the key design requirements without compromising the reactor safety. This research results indicate that the new target gives rise to a higher production of ⁹⁹Mo using less amount of initial material causing to a reduction in nuclear waste and process difficulties.