"Benign" is the best word, much less need for debate compared to "harmless" or "perfectly safe". This is the best writing on the topic I have ever seen. I have been thinking our audience is college educated. We really need to focus on the average level, 8th grade.
I've been introducing the words "recovered fuel" instead of "waste" or "spent fuel" or "used fuel". We willl eventually use it for future fuel, but not until we exhaust the much larger stores of ample, benign, U-238 tailings left over from U-235 enrichment of natural uranium. And there's no hassle with radioactive fission products. We'll need more experience with fast neutron reactors.
"recovered fuel" Excellent. I will revise our articles at Citizendium. I have long bemoaned the phrase "nuclear waste", trying to correct it every time I see it, trying to persuade people to say "spent nuclear fuel". Recovered fuel is better, as it makes clear that the fuel is far from "spent", and we don't need to persuade people that there really is 95% of the energy left in the recovered fuel.
I also have a problem trying to get people to say "storage facility" instead of "nuclear waste dump".
The graph shows alpha particles as lasting thousands of years with the dose being orders of magnitude higher than the other components of radiation. This needs explanation. Maybe that the dose per kg is so large, because the distance is so short. Alternatively, show total absorption in a human body. Then it needs less explanation. Also, if we could make the curves smoother, maybe from an actual simulation, it wouldn't look like just a rough guess.
The alpha dose is high because there is so much heavy metal: U, Np, Pu, etc. The alphas and betas are all absorbed in the cask, even by a few inches of air.
Grays measure the absorption per kg of tissue. We really need to say something about the assumed absorption, e.g. 10% of total energy for gammas absorbed in 100kG of tissue, vs 100% of total energy for alphas absorbed in 1 kg of tissue for ingested material.
Getting from here to dose in mG/hr involves a lot of assumptions.
I can easily get to mW per cm2 at a distance of 1 meter, assuming no shielding. If we assume the fuel bundle itself will block alphas and betas, then we just need to total all the gamma emitters and make one further assumption - the ratio of mG/hr to mW/cm2.
"Benign" is the best word, much less need for debate compared to "harmless" or "perfectly safe". This is the best writing on the topic I have ever seen. I have been thinking our audience is college educated. We really need to focus on the average level, 8th grade.
I've been introducing the words "recovered fuel" instead of "waste" or "spent fuel" or "used fuel". We willl eventually use it for future fuel, but not until we exhaust the much larger stores of ample, benign, U-238 tailings left over from U-235 enrichment of natural uranium. And there's no hassle with radioactive fission products. We'll need more experience with fast neutron reactors.
"recovered fuel" Excellent. I will revise our articles at Citizendium. I have long bemoaned the phrase "nuclear waste", trying to correct it every time I see it, trying to persuade people to say "spent nuclear fuel". Recovered fuel is better, as it makes clear that the fuel is far from "spent", and we don't need to persuade people that there really is 95% of the energy left in the recovered fuel.
I also have a problem trying to get people to say "storage facility" instead of "nuclear waste dump".
https://citizendium.org/wiki/Nuclear_waste_management
PragerU is doing a good job of educating the public about nuclear power. If you haven't seen any of their videos, do a search for it on their site.
The graph shows alpha particles as lasting thousands of years with the dose being orders of magnitude higher than the other components of radiation. This needs explanation. Maybe that the dose per kg is so large, because the distance is so short. Alternatively, show total absorption in a human body. Then it needs less explanation. Also, if we could make the curves smoother, maybe from an actual simulation, it wouldn't look like just a rough guess.
The alpha dose is high because there is so much heavy metal: U, Np, Pu, etc. The alphas and betas are all absorbed in the cask, even by a few inches of air.
The figure on recovered fuel from Jack Devanney shows 3% fission products and 1% each for U-235 and Pu-239. https://citizendium.org/wiki/File:Devanney_Fig_2.3_Spent_Fuel.png
Grays measure the absorption per kg of tissue. We really need to say something about the assumed absorption, e.g. 10% of total energy for gammas absorbed in 100kG of tissue, vs 100% of total energy for alphas absorbed in 1 kg of tissue for ingested material.
But look at all the U-238! decaying. I don't know where Jack was counting gammas. I'll learn more.
U-238 decay is very weak. Here is the activity over time for all the nuclides in recovered fuel: https://citizendium.org/wiki/File:Radioactive_waste_decay.png
Getting from here to dose in mG/hr involves a lot of assumptions.
I can easily get to mW per cm2 at a distance of 1 meter, assuming no shielding. If we assume the fuel bundle itself will block alphas and betas, then we just need to total all the gamma emitters and make one further assumption - the ratio of mG/hr to mW/cm2.
Here is a work in progress:
https://docs.google.com/spreadsheets/d/1PQG56havjmnBeEHp2oU-Vx7CgW3bR9olpB1xqNdbAHo/edit?usp=sharing