[ RadSafe ] Nuclear battery could turn hazardous waste into lasting clean energy

[Ted de Castro]

Hmmm - maybe so - rereading the article and following their numbers says 
it would require 10 kg of c-14 "fuel" for a 1 watt output capacity.

It didn't go into the efficiency of the receptor itself.

I guess it needs further refinement <grin>

On 11/30/2016 11:46 AM, Jaro Franta wrote:
> Not so sure it's such a good idea.... seems more like pure hype to me.
>
> At about 1.3 tonnes of synthetic diamonds per Watt of electricity, who in
> their right mind would ever consider actually building such a ridiculous
> battery ?
>
> Some calculations:
>
> A Russian report gives approximately 8% energy conversion efficiency.
> http://www.naun.org/main/NAUN/circuitssystemssignal/2015/b182005-012.pdf
>
> Average Carbon-14 decay energy is 50keV (1eV = 1.6E-19 joules).
> Multiplying by 6.02E+23 and dividing by 14 gives 344MJ/g total decay energy.
> Half of that energy, 172MJ/g, is released in a 5730-year half-life, so the
> power per gram is 172E+6 J / (5730 x 365 x 24 x 60 x60 seconds) = 0.95 mW/g
>
> With an 8% energy conversion efficiency, that comes to about 0.076 mW/g of
> pure C14.
>
> If the graphite from decommissioned nuclear reactors contains 1% C14 (ie.
> all natural C13 gets converted to C14), then without isotopic separation,
> the expected electric output of the synthetic diamonds would be 0.00076 mW
> per gram.
> Or about 1.3 tonnes of synthetic diamonds per Watt of electricity.
>
> How much energy does it take to produce a tonne of synthetic diamonds ?
>
> -------------------------------
>
> PS.  I’m still trying to get at the C14 concentration in graphite moderator
> blocks.
>
> Pure C14 has a specific activity of 4.5 Ci/g or 0.167 TBq/g or 167,000
> TBq/tonne.
>
> If we take the Magnox graphite C14 production figure of 10.8 TBq/GWe-y and
> combine that with typical operating parameters (about 6.9 GWe-y lifetime) we
> get:
> 10.8 TBq/GWe-y x 6.9 GWe-y = 74 TBq of C14 total per Magnox reactor.
>
> With an inventory of 3,500 tons of graphite (3,175 metric tonnes), that
> comes to an average C14 activity of about 0.025 TBq/tonne of moderator.
> Therefore the average C14 concentration is:
> 0.025 TBq/tonne of moderator ÷ 167,000 TBq/tonne pure C14 = 1.5E-7 or
> 0.000015%
>
> That’s extremely low !
> Ten thousand times less than just assuming that all C13 (1.1%) gets
> converted to C14.
> Did I make a mistake somewhere in the algebra ?
>
>   Jaro
> ^^^^^^^^^^^^^^^^^^^^^^^^^
>
>
>
>
> -----Original Message-----
> From: radsafe-bounces at health.phys.iit.edu
> [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Ted de Castro
> Sent: Wednesday, November 30, 2016 2:22 PM
> To: The International Radiation Protection (Health Physics) Mailing List
> Subject: [ RadSafe ] Nuclear battery could turn hazardous waste into lasting
> clean energy
>
> Now here's a good idea!!!
>
> http://www.digitaltrends.com/cool-tech/diamond-battery-clean-energy/
>
>
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