Very large-scale integrated circuit design, based on today's CMOS technologies, are facing various challenges. Shrinking transistor dimensions, reduction in threshold voltage, and lowering power supply voltage, cause new concerns such as high leakage current, and increase in radiation sensitivity. As a solution for such design challenges, hybrid MTJ/CMOS based design can resolve the issue of leakage power and bring the advantage of nonvolatility. However, radiation-induced soft error is still an issue in such new designs as they need peripheral CMOS components. As a result, these magnetic-based circuits are still susceptive to radiation effects. This paper proposes a radiation hardened and low power magnetic full-adder (MFA) for advanced microprocessors. Comparing with the previous work, the proposed MFA is capable of tolerating any particle strike regardless of the induced charge. Besides, our MFA circuit offers a lower energy consumption in write operation as compared with previous counterparts. We also suggest an incremental modification to the proposed MFA circuit to give it the advantage of full nonvolatility for future nonvolatile microprocessors.