In order to support the utilization of Power Ramp Test Facility (PRTF) at RSG-GAS reactor, the investigation of safety parameters both on the target and the reactor during the irradiation of natural UO2 has been conducted. The PARET/ANL and MCNP6 codes are integrated for thermal-hydraulic and neutronic analysis under the reactivity insertion phenomenon. In the MCNP6 code, the reactivity insertion and Linear Heat Rate (LHR) are analyzed to confirm that the maximum value is still below the safety limits. In addition, the code computes kinetic parameters to provide inputs for the PARET/ANL code to evaluate the reactor response due to the target movement at the PRTF. The target moves from the farthest position to the nearest one traveling 440 mm, and then moves back to the original position. The result of the irradiation target simulation is satisfying, both maximum reactivity insertion and LHR values do not exceed the safety limit allowed. The pin target induces maximum reactivity insertion of 0.023%dk/k and produces the maximum LHR of 137.27 watt/cm and 274.54 watt/cm; when the reactor operates at 15 MW and 30 MW, respectively. In addition, the PARET/ANL simulation indicates that the reactor power oscillates due to the target movement. In order to avoid the reactor scram, the recommended pin target maximum velocities are 170 mm/s and 80 mm/s for reactor power of 15 MW and 30 MW, respectively.