Cold Fusion breaks the laws of Physics? A Primer:

I have been interested in this topic since 1989. For people unfamiliar with this, the various theories would not violate the laws of physics. Hot fusion uses high energy to force particles together past the "coulomb barrier" There is a force called the weak nuclear force that keeps atom nucleolus' apart. Its the nature repellent of ++ or-- forces we learn about in 3rd grade. There is another force called the strong nuclear force. It is strong, it attracts, but its range is very short. Imagine a magnetic train. Magnets repulse stronger than gravity, but the force drops off faster than gravity, so there is this natural neutral "boyancy" that allows near frictionless movement. Well there is a point where the strong nuclear force falls off, and the weak nuclear force takes over. It is very very close to the nucleus: Between the nucleus and the places where the first electron is typically found.

The idea of cold fusion does not force particles past the coulomb barrier, rather, it "coaxes" protons to snuggle up with a nickle nucleus. That can only happen if there was a way to neutralize the positive charge of the proton. In the 1950s a study was published that saw that happen by essentially "putting" a muon onto the proton. This eliminates the weak nuclear force, and enables the proton to get close enough for the strong nuclear force to grab it.

That is one idea. It breaks no laws. There are a few others, too complex to share here. There are problems with all the theories, and the study of the phenomena is far from complete. This is partially because of the way the Ivy League Universities have shut any study down, by sheer derision. With probable obscurity, what young scientist would want to go down this path? Any published peer reviewed papers in the past 20 years have had inordinate burdens of proof placed on them. The Ivy Leagues, 100 years ago derided the Write brothers and pronounced to the world man could never fly. The inventor went before the science, and the Ivy leagues ate crow and scrambled to catch up. It is possible this is happening again...