This is where it starts to become technobabble. There is a lot of stringing together of unrelated concepts to make it sound flashy. First, the weak interaction occurs at the nuclear level and primarly involves radioactive decay modes (e.g., beta decay), so heating at the macroscopic level would not influence it. Then there is the inference of a chain reaction, but no credible mechanism to explain it. Chain reactions in uranium and plutonium fission depend on the release of particles from the nucleus (neutrons) during the fission process. There is nothing here to indicate what the initiating particles are in this postulated process.
Transmutation of nickel to copper involves the gain of a proton, either by bombardment with protons or conversion of a neutron into a proton. You can get the latter by neutron bombardment of nickel to create a neutron-rich form of nickel, which will beta decay to copper, but there is no mention of this process and how you would do it (i.e., neutron source).
Don't assault kevmo with facts. He will either hide and remain unresponsive or he will start squawking something about seagulls...
Kevmo and rational, technical discussions of facts are like oil and water; you'll never find them occupying the same space...
Cue the seagulls in 10... 9... 8...
This is where it starts to become technobabble.
***I’m glad you see it that way, because here they are relying on the Widom-Larsen theory, which is bull shiite.