How do radioactive materials behave under extreme conditions?

Question

Radioactive decay releases alpha particles like Helium. But helium also has extreme states at cold & high pressures.

So if the conditions for the extreme states like 1GPa-525GPa & 1-20K are met; then what would radioactive decay behave like?

Example if helium is being given off by plutonium at 1GPA at 5K then it's a liquid or solid & would it serve to lay cracks in it.

If something decays tritium at 525GPa & 5K would it just immediately be superconducting while beside deep underground deposits of radioactive metal?

Assumptions: it's continuously cooled & can't heat up, & its under massive pressure to cause extreme states

Answer 1

Phenomena like liquid/solid phases, superconductivity, etc are effective states of a large number ("bulk", think Avogadro's number) of atoms acting together. Radioactive decay produces individual particles. Further, those particles in the case of alpha decay are nuclei, not atoms. For an alpha particle to become a helium atom, it would need to slow down drastically and then from somewhere capture two electrons. Taken together, radioactive decay products do not exhibit any such bulk phenomena.