By Kelvin Kemm
Thankfully President Trump has issued Executive Order 143000 under which the Nuclear Regulatory Commission is undergoing restructuring and is reviewing the use of the Linear No-threshold (LNT) model. The Executive Order stated that the LNT model is flawed, and it instructs reviewers to use science-based measures. In June 2025 President Trump abruptly dismissed sitting NRC Chairman Chris Hanson. This marked the first time in the agency’s history that a sitting commissioner was removed. Before this happened, I had been told confidentially that the NRC had effectively become an anti-nuclear body, under the influence of the anti-nuclear lobby. Looking at the United States from other countries, it certainly had appeared like that. The NRC of the U.S. had become a major obstacle to the advance of nuclear power. Since mid-2025 a major NRC restructuring has been underway.
How did LNT happen, and what was the result?
What happened was that a scientist, Herman Mueller, discovered in 1927 that X-rays caused genetic mutations in fruit flies. Additional research in the 1920s and 1930s suggested a linear relationship between X-ray dose and fly mutations.
As the 1950s and 1960s of the Cold War era unfolded, the International Commission on Radiological Protection introduced this concept into nuclear radiation protection rules. They knew how much nuclear radiation would kill a person, and how much would seriously harm a person. At that point all was OK. But then people with political agendas extended the argument, (like the ice block story) and what they did was draw a straight line all the way to zero. But this was wrong. It implied that there was no dose under which nuclear radiation was harmless. The result was that huge costs were introduced into nuclear power plant construction, based on unrealistic assumptions of possible danger.
I asked a South African nuclear engineer, Andrew Kenny, to give a talk about this at a conference. Andrew did an excellent job and introduced the Falling Out Of Bed (FOOB) concept, as an amusing illustration of how silly LNT had become.
Andrew assembled real figures for injuries and death to people falling at industrial sites. The data was comprehensive. For example, for workers falling from, say, a four-storey building, death is virtually certain. From a two-storey building; very likely, but not certain, and so on. Andrew pointed out that falling from the height of a table would almost certainly not harm anyone, or at worst, break an arm. However, if you use the LNT nuclear radiation model, and foolishly extend the line all the way to zero, it would tell you that the chance of death was not zero. The law would then kick in, and require safety measures to be put in place to prevent anybody falling off a bar stool, from dying. Andrew took it further, and said that the mathematics would say that there was a chance of dying if a person fell out a bed. In the nuclear LNT scenario the law would then require that no bed could be higher than two bricks height, and that safety barriers would have to be built around the bed. This sounds silly but it is exactly what really happened in the nuclear industry.
Crazy cost escalation
As years went by, the application of the LNT model demanded hugely expensive safety measures be built into nuclear reactors, even though the real risks were negligible. These actions were enthusiastically encouraged by the anti-nuclear lobby who openly stated that they wanted to price nuclear power out of the market.
An interesting illustration was the Fukushima incident. The very old reactor complex was struck by the largest tsunami on record. It also turned out that Fukushima had a number of design faults and management faults as well, and yet the result was that not one single person was killed or injured by nuclear radiation. Additionally, no private property was harmed in any way by nuclear radiation. Fukushima was not a nuclear disaster. It was a conventional industrial incident which was very costly for the owners, and very damaging to the image and pride of the Japanese government. But it was not a nuclear disaster.
Air Disaster?
As a comparison, imagine if three large passenger aircraft were parked in a hangar at an airport, and the hangar catches fire. The hangar is burnt to the ground, and the three aircraft totally destroyed. Would you classify that as a major air disaster, merely because aircraft were involved? Not a chance…
Fukushima should have been hailed as an incredible illustration of just how safe nuclear power was. After all that went wrong, there was actually no nuclear problem. But the result of Fukushima internationally was that extra safety measures were demanded at reactors all over the world. Using the LNT model, ridiculously expensive additional safety measures were put in place, merely adding to the cost of nuclear power. So totally false LNT Index criteria were applied foolishly.
This is like creating a silly; Falling Out Of Bed Index (FOOBI) and applying it all over society to anything of any height, even your bed and barstool, supposedly to save lives on a massive scale.
So, the FOOBI concept shows that you can’t just extrapolate some data without actually checking if the extrapolation is valid.
In the case of LNT, it is not valid. Small doses of nuclear radiation are harmless and there’s no need for any concern. As much as you can safely sleep on a normal bed, you can safely sleep next door to a modern nuclear reactor.
Very nice. People have gotten mad at me for stating no one died from nuclear radiation at Fukushima. But it is clear we need regulations for the regulators. They are out of control.
Yep.
More people died at Chappaquiddick than from Fukushima.
And from Three Mile Island 2, The “worst nuclear accident in U.S. history.”
And I recall a show on PBS mentioning a woman living near post-accident TMI who would walk around the area near the plant with a Geiger counter, looking for radiation “leaks.” She was told she got more radiation from the radon in her basement than anyone got from TMI. She said that was OK, because it was “natural” radiation.
Radiation is radiation, no matter the source. What a maroon.
Pierre Pellerin famously said, regarding the Chernobyl accident (Lenin plant):
“poses no risk to public health” and “poses absolutely no threat to anyone.”
He said it was possible the radioactive material reaching France would be so diluted that “there will be little or almost nothing left”.
And when L-NT was proposed, there was no awareness of DNA repair.
There is a good argument to be made for Radiation Hormesis.
The idea that small doses cause the body to strengthen its defenses.
That the net overall effect is good.
https://pmc.ncbi.nlm.nih.gov/articles/PMC2477686/
Radiation is a natural phenomena and cannot be escaped. All life on earth evolved in the presence of radiation from natural sources. In the US, natural background levels range over a factor of 5 in various locations, largely lower in the east, higher in the midwest and highest in the southwest. Research has revealed no correlation between the various radiation levels and mortality from cancers of all kinds. Dr. T. D. Luckey to researched radiation hormesis for many years by exposing fruit flies very low background doses in heavily shielded enclosures, as close to zero as he could get, and higher doses using radiation sources. He found a u-shaped curve of fly fecundity – flys with very little radiation exposure had shorter lives than those with natural background levels. At higher doses fly lifetime began to decline. Dr. Luckey was an odd man and for that reason his research received little acknowledgement. Search for T. D. Luckey for his work.
Radiation Hormesis
Greens persistently allege that there is no such thing as a “safe” level of radiation as an argument against nuclear power.
Research into whether or not there is a “safe” level of radiation made a surprising discovery – that not only is there a safe level, there is a desirable level ! An optimum level of radiation where higher and lower levels of radiation about this optimum led to greater morbidity.
https://en.wikipedia.org/wiki/Radiation_hormesis
This has been confirmed several times by different research groups.
Unsurprisingly this radiation level is just slightly more than the natural background radiation level – presumably because that is what we evolved in, and levels are diminishing as geological time goes by.
We are surrounded by radioactive rocks and bombarded by cosmic and solar radiation. That big bright light in the sky called the Sun – is a gigantic nuclear explosion – delivering the power of 5700 Hiroshima bombs per second to target Earth ! That is our “natural” environment.
“The fact that we live at the bottom of a deep gravity well, on the surface of a gas covered planet going around a nuclear fireball 90 million miles away and think this to be normal is obviously some indication of how skewed our perspective tends to be.”
― Douglas Adams, The Salmon of Doubt: Hitchhiking the Galaxy One Last Time
And there was apparently no awareness that all life on the planet arose and exists in a sea of cosmic radiation.
I am aware of this. I sometimes wonder if I could feel or detect a complete absence of radiation, in all the forms we are constantly bathed in. I don’t know how you could remove all or most of the radiation. If you could, I imagine it would be a very subtle, probably undetectable, difference.
I have experiences where I was in conditions of altered world activity in which I became aware of something different. The first were climbing trips to a remote part of Baja in the late 70’s. There simply was nothing around, including airplanes. There was a difference in the background. The other time was the first few days after 9/11. I was out in the Naval Weapons Center East Range, and I felt again, that silence.
I suffer from pollen allergies. I became aware of this when as a young USN sailor I spent longish times at sea and my symptoms (the usual) disappeared. I was so used to my chronic condition it was the sudden absence of the irritant that led me to this awareness.
One way to reduce your dose would be to live on a barge floating on a lake. Fresh water normally contains very little natural radioactivity and serves to shield anyone on or in the water from radioactive emissions from the sediments below.
Here’s a (mad) thought, but is evolution driven in part by radiation?
Yes.
Cosmic radiation adds to the total we all get each year but amounts at present times to no more than 10% of all that we get. The rest is from natural radioactive materials in the rocks, soils and air we breath.
What’s the ice block story?
https://en.wikipedia.org/wiki/Ice_block_expedition_of_1959
Thanks. I had seen that in my googling, but didn’t see any connection to radiation or LNT.
All food is radioactive and contains carbon-14 and potassium-41. These nuclides emit low energy beta particles. The air we breath in contains radioactive CO2.
And because of cosmic radiation, to be logically consistent, no one should be allowed to live above sea level, and those wanting to see the Rocky Mountains, or any mountains for that matter, should be required to obtain a permit, be issued a dosimeter, and be limited to an annual dosage as with medical imaging. Visitations to places with granite basement rocks, such as Pikes Peak or Yosemite, would be doubly dangerous, and generally prohibited for even short visitations. Flying in aircraft should be prohibited for all but the most extreme situations. It is important that people be prevented from harming themselves. [Note: If you are humor impaired, read the above carefully and give yourself 24 hours to think about it before complaining.]
You would also have to ban granite counter tops.
That depends on the granite. In South Dakota, the pink granite there is very low in radioactivity. Elsewhere its higher.
Commercial airplane staff receive the highest radiation exposure of any other worker in the world. This is because of elevated cosmic radiation at high altitudes.
Yes, all food is indeed radioactive as is practically everything else. Bananas, because of being rich in potassium, will give an easily measurable gamma reading above background when measured by a simple scintillator in a lead lined container. Many years ago I gave talks titled “Radioactivity in Nature” to elementary school students during a few-day retreat they had a State park. I had enough lead bricks to assemble a reasonable shielded cave and had the kids gather pebbles of all one color, some white, some black some of other colors, sorted them by appearance and measured them in the lead cave. Some were more radioactive than others and some showed no detectable radiation (as measured by my feeble detector). we also measured bananas. I showed them the large fireplace in the covered area where all the talks were being given had higher radiation levels because of the white firebricks lining the back and sides of the fire enclosure (they contain thorium as do the original Coleman lantern mantles.) I had a small orange fiestaware bowl that drove the detector nuts – the glaze was made from a compound of uranium. We walked down a path to a small lake holding the detector. It registered different values depending on what we held it close to. In a rabbit hole it read much higher. Out on a dock extending into a small lake, it read very low because the water was shielding the radiation coming from the sediments below. Some of the parents thought I was cheating by controlling the click rate of the detector so I let them hold it next to various materials so they could see for themselves. I think at that point, some concluded that I was a sorcerer.
I always chuckled when someone came in for a chest x-ray with a beautiful tan and started worrying about the radiation they were getting!
I always chuckle when passengers get on 12 hour flights to go see buildings in far off countries.
It’s not just nuclear since the no-linear threshold fails elsewhere. Something not always recognized called hormesis occurs where low concentrations have positive effects despite greater ones negative. I heard that this concept was too long not appreciated and applied. Calabrese, E. J. 2008. Hormesis: Why it is important to toxicology and toxicologists. Environmental Toxicology and Chemistry. 27(7):1451-147.
https://doi.org/10.1897/07-541.1 OPEN ACCESS
For one example and certainly more common than recognized which seems a more common occurrence nowadays. Living species aren’t the fool they are made out to be. Stebbing, A. R. D. 1981. Hormesis – stimulation of colony growth in Campanularia flexuosa (Hydrozoa) by copper, cadmium and other toxicants. Aquatic Toxicology. 1:227-228. https://doi.org/10.1016/0166-445X(81)90017-5
Good points. Old ‘hormesis’ saying, applicable in my experience to a lot more than just radiation and chemical exposures:
”What doesn’t kill you makes you stronger’.
”What doesn’t kill you makes you stronger’.
And according to my girlfriend, fatter 🙂
Ha. George Carlin had a bit where he said as a kid he and his pals swam in sewage in the Hudson River, strengthening his immune system. None of his pals died from polio.
Many places, such as the springs in Hot Springs (AR) became famous because of people ‘taking the waters,’ which are slightly radioactive.
Did some quick research. Muller’s Nobel Prize winning research used high energy X-rays (equivalent to low energy gamma rays from radioactive decay) in total doses from 200,000 to millions of roentgens (r). Others later extended his fruit fly mutation work down to a total dose of 400r at a rate of 0.01r per minute, or 0.6r per hour. Still some fruit fly mutations, still in a roughly linear dose response fashion.
By comparison, natural background gamma in high gamma ray areas (granitic rock releasing radon, such as out on elevated portions of the Canadian Shield where it is about half extraterrestrial gamma r and half radioactive decay gamma r) is about 0.0000072 r/hr.
So a huge gap between LNT assumptions and some unknown threshold below which we already know there is no harm—altho fruit flys do have a very hard time surviving Canadian winters.
“altho fruit flys do have a very hard time surviving Canadian winters”
But not the ones in my kitchen!
Since the early 1980s France has the highest number of nuclear power plants scattered around the country with around one per one million persons so there ought to be sufficient empirical data available to assess health effects if any.
For instance leukemia, one of the main cancers related to radiation exposure, France records 5.2 cases per 1000 while Australia with no nuclear power plants ever records 4.9 per 1000, not much to see there.
My cancer rates are out X 100.
No living tissue on earth is protected against all radiation damage.
There is no zero dose in reality!
Is it always bad. No.
There is a DNA repair mechanism well established scientifically which is ancient in origin and allows damage from background radiation to be kept at a minimum from generation to generation.
It may well be that background radiation contributed to evolution, especially in the early Eons when the activity was greater.
Fun fact from Australian Institue of Health –
Moral – stay away from ladders. Should be laws against them!
As a practically lifelong rock climber, and certifiably old guy, I recognize ladders as the treacherous things they are.
We have a friend that went over backwards on a one of those tall restaurant chairs. She suffered serious brain trauma, and she probably will not fully recover.
And I have sneezed myself off a high bar stool and suffered nothing but embarrassment.
Old men who can’t get up ladders fo to the ED?
(someone had to recognize the combination of terms)
Kevin, I had to think about that – I wondered if your “fo to the ED” was a typo, or a cunning play on words.
I’ve go with a typo. I hope that was it!
A different observation, disagreeing a bit with this post, which said, paraphrasing,
‘hugely expensive safety measures against negligible real risks.’
Depends on what is meant by ‘real risks’. Without adequate costly containment, Chernobyl was a real disaster. With adequate costly containment, 3 Mile Island wasn’t. With adequate reactor containment but inadequate spent fuel storage cooling, Fukushima was real bad but not a total disaster.
So clearly some level of ‘expensive safety measures’ IS warranted. The debate spectrum ranges from ‘no nucs’ (think Germany) to ‘minimum necessary’ (think SMR advocates).
I am not expert enough to hazard a result guess other than ‘somewhere in the middle’.
Rud,
After about the 1960s, the Geiger Counter or scintillation counter in hand-held form became a common, cheap and effective way to scare yourself. Later radiation detectors using typically Sodium Iodide detectors gave everyone access to a highly sensitive piece of gear. Some models even came with sound that grew more alarming at higher levels.
It was such a good device that people who were novices at using scientific gear found a new hobby. Unhappily, it was part of the development of nuclear phobia and it possibly helped some people to become anti-nuclear activists. As well as its value for improving radiation safety management, it became used as a demonstration that radiation was everywhere and some places were more radioactive than others. Some of this was happening at the same time as activist Ralph Nader was publishing his automobile book “Unsafe at Any Speed”, adding to the growing nuclear feeling of “Unsafe at Any Dose”.
In hindsight, I wish that the Geiger Counter had not been so sensitive.
Also, I would prefer that measurement of nuclear radiation injury was occasionally expressed as annual counts of death certificates, which is zero or near zero for nuclear radiation in most countries most years.
Geoff S
“occasionally expressed as annual counts of death certificates”
Bruce Ames investigated the toxicity of natural versus synthetic pesticides in foods. He found little to distinguish them.
He suggested the toxicity of dietary synthetic pesticides be measured in units of peanut butter sandwiches (aflatoxin).
At SLAC, we had an amusing incident. The health physics guy had been called to certify an X-ray beamline after use of a radioactive sample.
On strolling out, he off-handedly swiped a bottle of potassium permanganate (KMnO₄).
His Geiger counter responded with rapid clicks, set off by the natural potassium-40. He was shocked by the unexpected danger signal.
If it had been anything but a standard reagent, they’d have roped off the BL and called in a decontamination crew. As it was, there was a tense moment of uncertainty.
When I bought a used Ludlum scintillometer, I bought a fresh 40-lb bag of KCl water softener to check the sensitivity. Just think how much radioactive water I have been drinking for the last 20 years to avoid elevating my sodium intake.
Scary!
Chernobyl and TMI are too different to draw lessons by contrasting.
Kevin,
A common factor is that few or nil people were killed.
Geoff S
True for TMI but Chernobyl released a large portion of the radioactive content of a 1000 megawatt (electric) reactor core to the environment. It was a big reactor. Russia’s official death count is, I believe, around 80 workers, some within a week or two of receiving extremely high doses, well above the LD50 level (sufficient radiation exposure to kill 50% of those exposed). It is quite probable that some thousands of others nearby and down wind of the accident have also died in later years of the exposure they received. Chernobyl was an incredibly large release of radioactive materials handled in an incredibly incompetent manner in the beginning.
A reactor containment is a very logical way to limit the potential consequences of a release of radiation and radioactive elements from a loss of reactor coolant. It is an essential part of the accident analyses required of nuclear plant designs. The release limits are detailed in 10CFR20 and it is recognized some releases will happen, since it is not practical (or dangerous) at low enough levels. However, the LNT theory was added on top to keep non-accident releases “as low as reasonably achievable,” or ALARA. That added a lot of additional expense in plant design and operations. I know, because I was part of a team that quantified the difference in $$ at one plant. It was 100’s of millions of dollars.
The Trump Administration is working hard to replace LNT and ALARA with more realistic methods for estimating harm from radiation. This will have some benefit for reducing the burden of excessive design requirements on nuclear power.
However …. the most substantial impact of NRC regulation on the costs of nuclear power come from 10CFR50 Appendix B, the quality assurance requirements.
It takes a well-tuned nuclear industrial base to implement the NRC’s quality assurance requirements and to deliver QA-compliant systems and components on time and on cost.
And so at present, we don’t have anything close to the kind of well-tuned industrial base needed to run a cost-efficient nuclear construction effort.
The NRC’s quality assurance requirements are not going away. Not today, not tomorrow, not ever. Until the investments are made to rebuild America’s nuclear industrial base into a QA-compliant cost-effective delivery system, we will not see a substantial reduction in nuclear’s capital costs.
For additional and supporting information on LNT, in July 2023 WUWT kindly published my article linked here.
Corruption Of Science By Money And Power – Watts Up With That?
Geoff S
“ As much as you can safely sleep on a normal bed, you can safely sleep next door to a modern nuclear reactor.”
Although in fact there are risks associated with sleeping on a normal bed and they increase as you get older. A recent study found that:
“This retrospective analysis found that, among the 164 patients admitted to the emergency department over a five-year and eight-month period due to falling from beds, 143 were classified as elderly, aged 65 and above. The mean age of those admitted was 76, whereas those not admitted had a mean age of 71. A significant majority, 87%, were hospitalized; within this group, 16% required intensive care. Surgical intervention was necessary for 27 individuals, and there were three fatalities.”
See
https://www.cureus.com/articles/230597-falls-from-beds-among-elderly-outpatients-injuries-and-outcomes#!/
So in fact sleeping next to a modern nuclear reactor is likely to be safer than sleeping
in a normal bed. But that is only due to the safety regulations that have been imposed.
Attribution is a lot more straight forward for obvious trauma than for radiation because the potential for radiation damage is based on models — such as LNT — and one ends up with estimates that are probably on the high side because it is almost impossible to remove the confounding influences after decades of exposure to background radiation and shoe stores offering free X-rays of customer’s feet. I’m old enough to remember the experience, yet have no abnormalities in my feet.
But that is because the damage caused by low doses of radiation is probabilistic in nature. A single x-ray photon has a low but non-zero chance of hitting a DNA strand and damaging it. There there is a small but again non-zero chance that the usual repair mechanisms don’t work (DNA repair is never 100% successful) and so the probability that a single x-ray causes cancer is very small (multiple two small numbers together and you get a smaller one) but it is not zero. The question is whether the benefits outweighs the risks. For a correct fitting shoe the answer is no. For a broken arm the answer is yes.
I recall reading about researchers examining the effect of radiation on mice. They had a control group which they shielded from all radiation by using a lead surround. At the end of the experiment these mice were very sick and emaciated whilst those in a normal environment were healthy. The lesson being that people need a minimum radiation level to stay healthy.
It is worth noting that whilst the bombing of Hiroshima and Nagasaki killed many people the predictions about likely cancer deaths and other effects were far below predictions. This was known by Mueller but he was very successful in using his status to suppress publication of arguments counter to his LTM for most of the 20th century.
The ongoing health problems at Hiroshima and Nagasaki that were alleged to be the lingering effects of the bombs were actually heavy metal poisoning of the harbours and coastal waters getting into the locally caught fish that were a prominent part of the local diet.
That was discovered when someone bothered to compare the health records of Hiroshima and Nagasaki with other heavy industry coastal cities like Yokohama.
The lesson being that … light is radiation.
The weird part of this is radioactive material is freely available over the counter. Smoke alarms contain radioactive material, and some welding tungstens are surprisingly radioactive – enough so that it would probably trigger an alarm if released in a nuclear facility.
https://youtube.com/shorts/celo_udub4s?si=1bbN0WfJ8ti5hi1Q
A school in Perth, West Australia, wanted to teach about radioactivity by using a Geiger counter, but they had no source to raise the counts above background. I bought them a couple of glass slides for teaching, that were mildly active and parcel posted them Melbourne to Perth. Next day, a strained voice on the phone was saying “We cleared the building as soon as we saw the radioactive symbol on the packet, we have called emergency services like Fire Brigade and Ambulance. What should we do next?”
I suggested they go home for a sex session with wifey or to the pub for a beer to relax them, then to arrange to attend a course in nuclear safety before returning to work as pig ignorant as yesterday intent on teaching innocents about nuclear materials.
Geoff S
“pig ignorant”
I like that one.
Read https://atomicinsights.com/muller-and-linear-no-threshold/
Rod Adams is a lefty BTW. But he is a straight shooter.
This article by Jack Devanney at the Gordian Knot News on substack describes a proposed alternative to LNT, the Sigmoid No Threshold (SNT) model of radiation harm.
Rate SNT: the continuous version of SNT
LNT models greatly overestimate the harm from low doses of radiation. But that harm is not zero.
In his article, Jack Devanney argues for a particular version of SNT, Rate SNT, which does recognize that harm from low dose radiation is not zero, but which is much more realistic than LNT in estimating what harm might actually occur.
It is factual that adding more and more safety measures actually makes things less safe.
The fractional person model. If there is 1 in a million chance falling out of bed will kill you, that is 400 deaths in the US alone.