Can the rate of a nuclear reaction be changed by an increase of temperature?

Answer 1

Fusion reactions are affected by temperature. High temperatures are the only way to make fusion reactions go. Fission reactions are not as temperature dependent, especially those that depend only upon the decay of a nucleus, but total fission reaction may be somewhat dependent upon T as a result of the moderator used.

Answer 2

Could the rate of a nuclear reaction be changed by adding a catalyst or decreasing the pressure?

Answer 3

I really don't know what kind of a nuclear reaction you are talking about. In general, if we are talking about say the decay of a readioactive substance, I don't know that the temperature has much effect at all. And I don't know what kind of catalyst one needs to change the rate of decay of say a Ra atom. Likewise, I wouldn't think chaning the pressure would have much effect. However, if you are talking about a nuclear pile where a moderator is present, then all that might change. Your question is too generic to focus on an answer.