LENR has showed to be real in experiments but it is not widely accepted science because of the absence of a reliable hypothesis about the mechanism behind the nuclear fusion. This shortcoming of LENR cannot be a surprise because there is no theoretical frame of reference in physics to understand the creating of nuclear fusion at low temperatures.
So we have to conclude that the understanding of LENR needs “new physics”. However, most people who are fascinated by “cold fusion” are not familiar with the foundations of physics so they try to find the mechanism with the help of complicated presumptions.
When someone wants to understand LENR, he/she has to understand quantum field theory. Unfortunately, quantum field theory is partly a mystery for physicists. They can calculate all kinds of interactions between elementary particles (Standard model of particle physics) but the models are awkward and counter intuitive. So there is a lot of uncertainty about “the foundations”.
I have tried to translate the mathematical mechanism behind LENR in understandable physics (see http://vixra.org/pdf/1610.0141v1.pdf).
The conclusion is the conservation of quanta transfer in space (quantum fields) and the constant velocity of quanta transfer (speed of light).
More in detail – in relation to cold fusion – is the description at https://xzplo.blogspot.nl/2016/11/introduction.html.
However, there is not one way to get nuclear fusion. A nickel-hydrogen reactor can also be stimulated by an alternating high frequency. And probably there are chemical compounds that can adsorb hydrogen in an easy way and are a conductor for high frequency currents too. So I hope that people who want to DIY an experimental LENR reactor have some hold on the descriptions.