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The FuTure oF nuclear Fuel cycle - MIT Energy Initiative

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Figure A.3 plots Eq (2), where advantage has been taken of the fact that it is a straight line<br />

on log×log paper. Values of Cr = 100 $/kg and Gr = 10 4 GWe-yr are assigned based on 2005<br />

as the reference year. Trend lines for three values of q are shown, based on the probabilistic<br />

assessment described in Section 3.C. <strong>The</strong> plot is to be interpreted as the probability (e.g.,<br />

85%) that the cost (e.g., 200 $/kg) will be less than the value on the trace plotted (in this<br />

example supporting ~10 × 10 4 GWe yr). Note that the 100% probability line (not shown)<br />

is given by q = 0.5, which matches the 0.40 1 0.52 values in four of the (non-probabilistic)<br />

models surveyed by Schneider (5). Our value of 0.29 matches his “optimistic” value of 0.30.<br />

Points are plotted on Figure 3A.3 corresponding to 2007 Red Book values for identified<br />

and identified-plus-undiscovered resources at under 130 $/kg: 5.5 and 13.0 million metric<br />

tons. Also shown are cumulative consumption indicators for 100 years at one, five and ten<br />

times today’s rate. <strong>The</strong>se benchmarks support the expectation that uranium production<br />

costs should be tolerable for the remainder of the 21 st century — long enough to develop<br />

and smoothly transition to a more sustainable <strong>nuclear</strong> energy economy.<br />

Sample Applications<br />

To employ this figure in scenario analysis one merely integrates under a postulated GWe vs<br />

time history (starting at 2005), divides by 10 4 , adds 1 (to include pre-2005 consumption),<br />

and reads off the projected cost of natural uranium in 2005 dollars as (C/Cr) × 100 $/kg.<br />

Values for different values of q are readily plotted. In the following, the “conservative” 85 th<br />

percentile value (i.e., median plus approximately-one sigma) of q = 0.29 is used.<br />

For example:<br />

A scenario gives 50,000 GWe yr between 2005 and 2050, Hence (G/Gr) = 5 + 1 = 6. For q =<br />

0.29, Figure 3A.3 gives (C/Cr) = 1.7, thus C = 170 $/kg in 2005 dollars as of 2050.<br />

Scenarios are often based on simple exponential growth:<br />

E(t) = Er e γt , Gwe<br />

Thus cumulative energy generation over a period of T years is:<br />

`<br />

G<br />

Gr<br />

1<br />

Er cT<br />

j = + c e - 1<br />

cGr<br />

m6 @<br />

For example:<br />

<strong>The</strong>n<br />

Let Er = 400 GWe<br />

Gr = 10 4 GWe yr<br />

g = 0.04 per yr<br />

T = 80 years<br />

146 <strong>MIT</strong> STudy on <strong>The</strong> <strong>FuTure</strong> <strong>oF</strong> <strong>nuclear</strong> <strong>Fuel</strong> <strong>cycle</strong>

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