Nanoscale metal-based tunneling junction (MTJ) devices were fabricated using the electromigration method, and their electrical properties were studied after exposure to γ- and β-radiation. Irradiation caused the set threshold voltage (V_set) of the MTJ devices to increase, leading to a transition from a low-resistance state (LRS) to a high-resistance state (HRS). This shift in V_set was due to atom displacement from high-energy electrons excited by γ- and β-radiation. Unlike semiconductor devices, MTJ devices showed resilience to permanent damage and could be restored in-situ through multiple I−V (I is the drain current; V is the drain voltage) sweeps with appropriate configurations. This ability to recover suggests that MTJ devices have promising potential under irradiation. The reparability of irradiated MTJ devices is closely related to nothing-on-insulator (NOI) their structure, providing insights for other NOI and metal-based micro-nanoscale devices.