According to Axil Axil here
Someone will test the plasma type LENR reaction for muon generation, and when the government finds out that muons are being produced in massive amounts, then the government will take over the LENR tech and produce a thorium based large scale centralized gigawatt level fission power station connected to the power grid. All the LENR developers […] and all their associated investors will lose everything that they have invested in this LENR tech. Before all these developers and investors proceed, it would be prudent to test their systems for muon production.
Muons generate a potpourri of nuclear reactions including muon decay, fusion, fission from muons, and fission from catalyzed neutrons. The trick is to capture those muons so that the energy that they carry can be turned into heat. Currently, most of the energy produced by a LENR reactor is broadcast for miles in all directions with little of that energy being converted to heat. Heavy elements capture muons a million times better than hydrogen, water, your body or air so surrounding a muon source with a lot of heavy elements will produce lots of nuclear reactions generated from sub atomic particle reactions.
In LENR, most of the energy produced is not captured by the reactor. That energy escapes as sub atomic particle emissions and atomic fragments. So capturing this energy will increase the COP from LENR reactors by many orders of magnitude.
We are exposed to muons from space every day and we get along just fine. But as the number of LENR reactors increase, the density of muons broadcast around the countryside will become problematic. Background radiation produced by those excess muons will begin to exceed acceptable limits. This radiation increase will force the government to restrict the prolific use of unshielded LENR reactors. There comes a point where muon pollution just becomes too much. This is why LENR reactors must be shielded by a large amount of heavy elements.