Groundshine: LNT vs SNT
Figure 1. GKG worst case public dose rate profile at Fukushima, no evacuation. Only first two years shown. Just about all Fukushima evacuees would have experienced far less harmful dose rate profiles had they not evacuated.
David MacQuigg is one of our more troublesome choristers. He starts arguments, and then claims neutrality as a Citizendum editor. If you are a male, you ran into that type on the playground. His latest squabble is into the effects of groundshine.
This is a subject that the GKN has talked about over and over. For example, SNT versus LNT at Fukushima, Yes, we could have another Chernobyl, and The Taipei Apartment Dweller Exposure. The Karunagappally dose rate profiles are mainly groundshine. But perhaps these epistles were too long for the likes of Facebook. Here’s another shorter try.
Groundshine is external photon radiation from material deposited on and in surfaces, Groundshine has been extensively studied at Chernobyl. The seminal paper is Golikov-2002.1
MacQuigg is also concerned about resuspension. The best way to resuspend absorbed particles is a fire. We had a fire in the Chernobyl exclusion zone in 2015. This was studied by Evangeliou et al. The ambient air dose rates in the exclusion zone peaked at about 1 mSv per year.2 Resuspension, unlike groundshine, is a phony issue.
Groundshine has been even more carefully studied after Fukushima.3 A key focus of these authors has been cesium weathering. Their findings have been incorporated into the GKG model. We have a pretty good idea of the groundshine dose rates at both Chernobyl and Fukushima.
The issue is the harm associated with these dose rate profiles. This comes down to LNT vs SNT. Due to Cesium-137’s 30 year life, groundshine lasts a lifetime. If you assume no evacuation, as all the GKG analyses of both Chernobyl and Fukushima do, and LNT, you can accumulate 40 year doses of more than1000 mSv. For example, GKG’s worst hit Okumans at Fukushima got 812 mSv over 40 years. Figure 1 shows the GKG dose rate profile for these people. The LNT mortality is a scary 3.9%.
The worst case profile starts of at about 1.6 mSv/d, which is less than the pre-1950 ICRP 2 mSv/d tolerance dose rate. The profile falls rapidly to about 0.4 mSv/d, and then starts declining very slowly. After two years, the dose rate is down to about 0.2 mSv/d. Now we are at Karunagappally numbers. The high dose cohort in that population showed a slight decrease in cancer. The SNT mortality for the high end Fukushima group is 0.0027%. Under LNT you can make an argument for evacuating the worst hit areas around Fukushima. Under SNT, you are clearly better off evacuating no one. 50 nearly immediate murders would have been avoided, plus something like 2000 premature deaths during exile.
A corollary of using LNT is that due to the slow Cs-137 decay, evacuations end up as exiles. The shape of Figure 1 is typical of just about all public dose rate profiles in a NPP release, rapid decline for a couple of months, followed by very slow decline during which the cumulative dose just keeps building. In the case of Chernobyl, even under SNT you can made a case for evacuating the Pripyat kids and moms for maybe 60 days. But after that they can come back. Under LNT, they cant.
MacQuigg has stumbled on the core issue. If we can’t repair DNA damage as LNT claims, nuclear power is so hazardous that it is a Faustian bargain. If we can repair DNA damage as SNT claims, then a providential Nature has twice blessed humanity.
a) She has given us a nearly pollution free source of dispatchable electricity with an insane energy density and all the blessings thereof.
b) She has provided us with a DNA repair system that can handle the unique hazard associated with this magical source.
The only way we can screw this up is by denying (b), which results in rejecting (a). That would be auto-genocidal.
Golikov, V. and Balonov, M. and Jacob, P., External exposure of the population living in areas of Russia contaminated due to the Chernobyl accident, Radiation Environmental Biophysics, 2002, 41, 185-193.
Evangeliou, N. et al, Resuspension and atmospheric transport of radionuclides due to wildfires near the Chernobyl Nuclear Plant in 2015, Scientific Reports, 2016, May, Vol 6, p 1-34.
Ishikawa, T. et al, The Fukushima Health Management Survey: estimation of external doses to residents in Fukushima Prefecture, Scientific Reports, 2015, 5.
Kinase, T. et al, Temporal variations of Sr-90 and Cs-137 in atmospheric depositions after the Fukushima Daiichi Nuclear power plant accident”, Scientific Reports, 2020, 10, 21627.
Yoshimura, K. et al, Initial decrease in the ambient dose equivalent rate after the Fukushima accident and its difference from Chernobyl”, Scientific Reports, 2020, 10, 3859,
That's rather a holy hyperbole Friday there Jack.
Cohen showed, rather convincingly, in his book, The Nuclear Energy Option, that even using LNT, nuclear power is very safe, indeed much safer than any other means of generating reliable power. It is on par with wind and solar, and those aren't reliable. Cohen also showed that using LNT and long time frames, what anti-nukes do regularly to score points, nuclear power has very big net health benefits, due to reduced radon from using the uranium up.
Cohen's book is a real eye opener. Still one of the best books ever written on nuclear energy risks.
Jack, this is excellent. I will ignore the ad hominem (I get worse from the anti's) and read the articles you have cited.
You may have misunderstood the question. There is no argument over LNT (I have not "stumbled on the core issue"). The worry about groundshine is easy to quantify (a few microwatts per square meter). The question was about Cs-137 in the dust long after the plume has blown over.
I think you are right that it is not a problem, but just calling it a "phony issue" won't convince the anti's on FaceBook. Why should you care what they think? Because these are the people who control public opinion. Your NRA proposal will get nowhere if all you do is preach to the choir.
Keep up the good work. Your articles are by far the best on the nuclear debate. Let me and others engage with the morons. Be more tolerant when we come back with a question.