Re: [Vo]:Enriching Ni - actually quite cheap

[Axil Axil]

In the far future, tungsten and molybdenum could be used to replace nickel
in the cold fusion hydrogen reactor to take advantage of the higher thermal
efficiencies made possible by using these metals.

Doing so will enable very high temperature applications to replace heat
sources like coal and natural gas in the cement, glass, metals and smelting
business. The transmutation waste products derived from these refractory
metals will produce some of the rarest precious industrial metals to be
found on earth in the platinum family whose price per Kilo might reach up
to $5,000.






On Wed, Feb 15, 2012 at 12:03 PM, Robert Lynn <
robert.gulliver.l...@gmail.com> wrote:

> I know this has been discussed before, but I thought there might be some
> interest in rough estimates of energy costs of Ni enrichment, just in case
> it turns out to be critical for improving power density or decreasing
> radioactivity of products.
>
> With Ni it appears you are most interested in Ni62 and Ni64 as these will
> create stable Cu63 and Cu65 with proton capture, and together amount to
> 4.5% of Ni, you are wanting to separate off the Ni58, Ni60 and Ni61. Nickel
> tetracarbonyl  is a
> gas at 315K (Uranium gas centrifuges operate at 310-320K) and with natural
> Ni isotope blend (mass 58.6) has a molecular weight of 170.   Assuming
> isotopically pure C and O, (which can be recycled) you are looking to
> separate molecules with an average weight of almost 174, so about 2.3%
> heavier.
>
> Uranium hexafluoride has a molecular weight average 352 and you are trying
> to separate compounds molecules with about 0.8% mass differences.
>
> The energy required to separate different weight molecules scales with the
> square of the mass difference so separating the nickel from the same level
> of concentration appears to require (0.0085/0.0235)² = 13% of the energy of
> separating uranium isotopes given the same starting concentration. (In
> reality it will be more than that due to presence of Ni60 and Ni61, and the
> harder work to separate them, but this is only a rough calculation)
>
> But the starting concentration is a huge factor too.  Using the SWU
> calculations  enriching
> U235 from 0.7% to 95% with 0.2% U235 tailings takes 245 SWU(U235 from
> natural U), whereas enriching 4.5% Ni62+Ni62 to 99% with 4% tailings takes
> just 30 SWU(Ni62,64 from natural Ni).   It doesn't matter as much if you
> don't extract all of the Ni62 and Ni64 because the slightly depleted Ni has
> almost the same value (note that SWU is different for separating the Ni
> isotope vs the uranium isotope)
>
> Assuming I have those numbers roughly correct then enriching Ni62+65 to
> 99% would need only about about 30 SWU(Ni62,64 from natural Ni) x 0.13 =
> equivalent energy to 4 SWU(U235 from natural U), vs the 250SWU(U235 from
> natural U) required for producing 95% U235.  Or as another comparison
> enriching the nickel to 99% Ni62+Ni64 needs less than half the 9 SWU(U235
> from natural U) required to create reactor grade 5% U235 Uranium, with no
> waste products because Ni is a useful metal for other purposes.
>
> Now 1 SWU(U235 from natural U) is about 
> 50kWh so
> ignoring equipment and operating costs to produce 1kg of 95% U235 requires
> about 12500kWh ($0.1/kWh) and 190kg Uranium (~$165/kg) = $32000/kg, 1kg of
> 5% U235 requires about 450kWh and 9.6kg Uranium for total cost of about
> $1600/kg (note that the waste metal cost is dominant over almost irrelevant
> electricity cost).
>
> But because there is no wasted metal from the process so 99% Ni62+Ni64
> needs about 200kWh, or only about $20/kg + the price of 1kg nickel (about
> $20/kg) for a total of $40/kg for 99% Ni62+Ni64.  If that nickel can
> produce 100kW output for 6 months then the cost is so small it is
> irrelevant - and we can also expect power costs to go down making
> enrichment costs even lower.
>
> 1 AC100 gas centrifuge can deliver about 330 SWU(U235 from natural
> uranium) per year.  So each of those centrifuges can probably contribute
> the equivalent of about 80kg of highly enriched 99% Ni64+Ni62 per year, or
> about double the uranium fuel that is produced.
>
> Global uranium production is currently about 80,000 tonnes per year,
> producing about 8,000 tonnes of reactor fuel.  If shifted to Nickel (that
> could produce 100kW/kg) then there is sufficient capacity in the world to
> make about 16,000 tonnes of highly enriched Ni for about 800GW output
> (assuming 6 month fuel life).  Not that far off being sufficient for
> current requirements.
>
> I can now see how enriching the Ni might not be a significant cost factor,
> Rossi was probably not wrong to think that cheap enrichment was possible.
>  Once large scale enrichment processes are utilised, and if uranium
> separation equipment were modified to process Nickel then it could produce
> almost 

[Vo]:Enriching Ni - actually quite cheap

[Robert Lynn]

I know this has been discussed before, but I thought there might be some
interest in rough estimates of energy costs of Ni enrichment, just in case
it turns out to be critical for improving power density or decreasing
radioactivity of products.

With Ni it appears you are most interested in Ni62 and Ni64 as these will
create stable Cu63 and Cu65 with proton capture, and together amount to
4.5% of Ni, you are wanting to separate off the Ni58, Ni60 and Ni61. Nickel
tetracarbonyl  is a gas
at 315K (Uranium gas centrifuges operate at 310-320K) and with natural Ni
isotope blend (mass 58.6) has a molecular weight of 170.   Assuming
isotopically pure C and O, (which can be recycled) you are looking to
separate molecules with an average weight of almost 174, so about 2.3%
heavier.

Uranium hexafluoride has a molecular weight average 352 and you are trying
to separate compounds molecules with about 0.8% mass differences.

The energy required to separate different weight molecules scales with the
square of the mass difference so separating the nickel from the same level
of concentration appears to require (0.0085/0.0235)² = 13% of the energy of
separating uranium isotopes given the same starting concentration. (In
reality it will be more than that due to presence of Ni60 and Ni61, and the
harder work to separate them, but this is only a rough calculation)

But the starting concentration is a huge factor too.  Using the SWU
calculations  enriching U235
from 0.7% to 95% with 0.2% U235 tailings takes 245 SWU(U235 from natural
U), whereas enriching 4.5% Ni62+Ni62 to 99% with 4% tailings takes just 30
SWU(Ni62,64 from natural Ni).   It doesn't matter as much if you don't
extract all of the Ni62 and Ni64 because the slightly depleted Ni has
almost the same value (note that SWU is different for separating the Ni
isotope vs the uranium isotope)

Assuming I have those numbers roughly correct then enriching Ni62+65 to 99%
would need only about about 30 SWU(Ni62,64 from natural Ni) x 0.13 =
equivalent energy to 4 SWU(U235 from natural U), vs the 250SWU(U235 from
natural U) required for producing 95% U235.  Or as another comparison
enriching the nickel to 99% Ni62+Ni64 needs less than half the 9 SWU(U235
from natural U) required to create reactor grade 5% U235 Uranium, with no
waste products because Ni is a useful metal for other purposes.

Now 1 SWU(U235 from natural U) is about
50kWh so
ignoring equipment and operating costs to produce 1kg of 95% U235 requires
about 12500kWh ($0.1/kWh) and 190kg Uranium (~$165/kg) = $32000/kg, 1kg of
5% U235 requires about 450kWh and 9.6kg Uranium for total cost of about
$1600/kg (note that the waste metal cost is dominant over almost irrelevant
electricity cost).

But because there is no wasted metal from the process so 99% Ni62+Ni64
needs about 200kWh, or only about $20/kg + the price of 1kg nickel (about
$20/kg) for a total of $40/kg for 99% Ni62+Ni64.  If that nickel can
produce 100kW output for 6 months then the cost is so small it is
irrelevant - and we can also expect power costs to go down making
enrichment costs even lower.

1 AC100 gas centrifuge can deliver about 330 SWU(U235 from natural uranium)
per year.  So each of those centrifuges can probably contribute the
equivalent of about 80kg of highly enriched 99% Ni64+Ni62 per year, or
about double the uranium fuel that is produced.

Global uranium production is currently about 80,000 tonnes per year,
producing about 8,000 tonnes of reactor fuel.  If shifted to Nickel (that
could produce 100kW/kg) then there is sufficient capacity in the world to
make about 16,000 tonnes of highly enriched Ni for about 800GW output
(assuming 6 month fuel life).  Not that far off being sufficient for
current requirements.

I can now see how enriching the Ni might not be a significant cost factor,
Rossi was probably not wrong to think that cheap enrichment was possible.
 Once large scale enrichment processes are utilised, and if uranium
separation equipment were modified to process Nickel then it could produce
almost twice as much output as current uranium fuel for nuclear power.
 Even including the capital and operations costs the highly enriched Nickel
might only cost on the order of $100/kg.