I viewed the answers to the non repliable post https://www.physicsforums.com/threads/is-radioactive-decay-reversible-in-time.673735/, but I have doubts. In particular, the last claim by nugatory: "the overall decay of the sample is as irreversible as the transfer of heat from a hotter body to a cooler one." Given that there is no heat inside the nucleus, and knowing that temperature doesn't influence half-life time in radioactive deacay of, let's say, a neutron or a tritium nuclid, we must agree that heat transfer here can be not more than an analogy. On the other hand, if the process can be reverted, we should get a dynamic equilibrium between nuclei and dacay products by putting protons and electrons in a gravitationally confined volume with enough kinetic energy (that is the same of high temperature). In that system we expect that the probability of decay in the collection of neutrons would be temperature dependent.