They are the Libertarian medical equivalent of the Marshall Institute's physical science "experts".
They're called Doctors For Disaster Preparedness.
I'm not going to link to them (you can easily find them), but on their website is an e-book dealing with surviving radiation and other emergencies.
It is written by Allen Brodsky, who provides his many credentials (deniers always do!). Here is one paragraph from page 17:
"Moreover, these ICRP and NCRP estimates do not take into account the evidence for hormetic effects at lower dose ranges (protective, adaptive, and beneficial effects observed at acute dose levels below about 20 rem, and at low and much higher levels spread over long time intervals). Dr. T. Donald Luckey in 1980 and 1991 published comprehensive reviews of thousands of references to published scientific articles in which lower level radiation exposures were found to be beneficial to the life of organisms consisting of only single cells up to animals and humans (Luckey 1991). He coined the term “hormesis,” which is derived from the same Latin word as hormone, because Dr. Luckey found that lower doses stimulated beneficial biochemical and physiological reactions in many species. Dr. Luckey was Chairman of Biochemistry at the University of Missouri. (Bless his soul, Don Luckey just passed away at 94 in March 2014.)"
Um, no Brodsky...the ICRP and NCRP have evaluated the "evidence for hormetic effects" and have concluded that it is not persuasive.
P.S. The evidence for the existence of souls isn't persuasive either.
The late T.D. Luckey who seriously compared hormesis to homeopathy as an argument. Seriously!