Radioactivity_Sim’s first use: Feasibility of a radiation battery with unprocessed waste
I have proposed some concepts in past posts (Deeper understanding of mechanisms of fission waste radiation in the generating storage unit, Raw Fission Waste Photo-Generative Storage Unit) for the use of raw unprocessed fission reactor waste as a type of battery. Since then I’ve created the Radioactivity_Sim program to help with the calculation of energy output rates for radioactive elements. That program has reached the point where it can assist with some basic feasibility calculations for the photo-generative storage unit.
To see how much total energy is output by the waste, I created the following batch file which calculates the radiation decays during a 500g sample of wastes first year after creation (note that U238 and U235 daughter nuclei are presumed to be negligible in the sample due to fuel refinement):
Constructing a sample of uranium reactor waste (4% enriched uranium reacted with 80% efficiency): new PSample 1.2145E24 U238 0 31556908.8 365 add PSample 1.012096E22 U235 add PSample 1.1578E20 KR85 add PSample 5.275E20 305KR85 add PSample 2.3197E21 SR90 add PSample 2.6323E21 ZR95 add PSample 2.6306E21 NB95 add PSample 2.4825E21 MO99 add PSample 2.4825E21 TC99 add PSample 1.2562E21 RU103 add PSample 1.6598E20 RU106 add PSample 1.6598E20 RH106 add PSample 1.7311E21 TE132 add PSample 2.8582E20 I129 add PSample 1.651E21 I131 add PSample 2.6679E21 I133 add PSample 2.5869E21 I135 add PSample 2.6719E21 XE133 add PSample 2.676E21 XE135 add PSample 2.5185E21 CS137 add PSample 2.5561E21 BA140 add PSample 2.4837E21 LA140 add PSample 2.3724E21 CE141 add PSample 2.2161E21 CE144 add PSample 2.2165E21 PR144 add PSample 9.036E20 ND147 add PSample 9.036E20 PM147 add PSample 4.2629E20 PM149 add PSample 1.7019E20 PM151 add PSample 1.7019E20 SM151 add PSample 5.9795E19 SM153 get PSample energy all > /home/user/git/Radioactivity_Sim/WasteEnergyCalcs get PSample energy 0 86400 > /home/user/git/Radioactivity_Sim/WasteEnergyCalcs get PSample energy 15552000 15638400 > /home/user/git/Radioactivity_Sim/WasteEnergyCalcs get PSample energy 31449600 31536000 > /home/user/git/Radioactivity_Sim/WasteEnergyCalcs
I then ran the batch file with the Radioactivity_Sim_Terminal “read batch” command and got the following output:
Executing...: get PSample energy all > /home/user/git/Radioactivity_Sim/WasteEnergyCalcs PSample Total Energy = 9.346707029909215E22 [MeV] Executing...: get PSample energy 0 86400 > /home/user/git/Radioactivity_Sim/WasteEnergyCalcs PSample Energy = 1.7076296176152554E22 [MeV], between t_start = 0.0 and t_end = 86400.0 Executing...: get PSample energy 15552000 15638400 > /home/user/git/Radioactivity_Sim/WasteEnergyCalcs PSample Energy = 1.3419729369180246E19 [MeV], between t_start = 1.5552E7 and t_end = 1.56384E7 Executing...: get PSample energy 31449600 31536000 > /home/user/git/Radioactivity_Sim/WasteEnergyCalcs PSample Energy = 7.8613820627348849E18 [MeV], between t_start = 3.14496E7 and t_end = 3.1536E7
Those are big numbers that look promising, but with some quick calcs I find: Total energy: 9.3467E22[MeV/year]/6.21E18[MeV/J] = 15051[J/year] First Day energy: 1.70763E22[MeV/year]/6.21E18[MeV/J] = 2749.8[J/day] = 31.83[mW](average power output) Midyear energy: 1.34197E19[MeV/year]/6.21E18[MeV/J] = 2.161[J/day] = 0.025[mW](average power output) End of year energy: 7.8614E18[MeV/year]/6.21E18[MeV/J] = 1.2659[J/day] = 0.01465[mW](average power output)
Even at the highest daily average energy output during the first day (31.83[mW]) the total power is too low for any practical harnessing, but even if it were a higher number, it would still include heat generation and other unharness-able output. in order for that original conceptual design to be feasible, there would probably need to be on the order of 1000[W] of power output. So what does all this mean? Basically, it is very unlikely that there will be a battery of this type that could generate enough energy during its life to recuperate its cost. Certain types of waste processing could be incorporated to maximize power output, but isotope separation techniques tend to require a lot of energy input which further decreases the overall lifetime utility of such types of batteries. I’m not willing at this time to say that researching better designs is futile, but it seems likely that such things might be better used in smaller applications where a long term battery is needed in the dark where PV’s can’t be used to charge a standard battery type.
