Can a radioactive element ever lose its radioactivity under certain conditions?

Hypothetically if "cold fusion" was proven unquestionably possible the process could be used to ameliorate radioactive elements. Other than that chemical reactions don't change one element into another. Chemical reactions just rearrange the electrons to create different chemical compounds due to the law of conservation of matter.

The modern understanding of changing one element into another is bombarding a radioactive element with neutrons or simply waiting as the passage of time causes one element to slowly transmute due to half-life decay.

The "aid of a machine" you are probably thinking of in this question's description to make an element inert would require a level of femtotechnology that modern science hasn't reached yet.