The FuTure oF nuclear Fuel cycle - MIT Energy Initiative

Stockpiling
If supply interruption (or price run-up faster than interest rates) should become an important
concern, stockpiling of either natural uranium or fuel-ready LEU would not be an
onerous burden, requiring only 200 MT U NAT or 20 MT of 4.5% enriched uranium per GWe
year. The latter mass is more than 10 5 smaller than equally potent coal, oil, or natural gas
storage amounts. Hence a strategic uranium reserve could be contemplated.
If one values the current U.S. Strategic Petroleum Reserve of 7.27 × 10 8 barrels (~ 70 days of
imports) at 50 $/bbl, the same investment in natural uranium at 100 $/kg U would support
100 reactors for nearly twenty years. Hence a stockpile a factor of 5 smaller would provide
more than ample protection against short term supply interruption. Alternatively, at about
double the cost per kilogram of natural uranium, one can stockpile 5% enriched uranium.
This reduces the time delay prior to fuel fabrication and reduces the fuel-ready stockpile
mass by a factor of ten. However, the other 90% must still be stored as depleted uranium. As
discussed in Chapter 8, a fuel bank is being developed through the IAEA to provide security
of supply as part of a nonproliferation strategy.
De facto stockpiles of other types are available:
p U.S. enrichment plant tails (in excess of 700,000 metric tons [20] containing about 1400
MT U-235 – enough to support up to 14 LWR reactors for 100 years if fully recovered.
Cheaper uranium enrichment services should eventually permit cost-effective access to
some of this material. World depleted uranium stores are probably comparable.
p U.S. in situ ore reserves are of on the order of 2 x 10 6 MT U NAT (see Table 3.1), not currently
being mined because of cheaper supplies from the international market, principally
Canada. If eventually recovered, these could sustain 100 reactors for 100 years.
p In December 2008 the U.S. DOE announced a program to release for commercial use,
over a period of 25 years, a variety of excess uranium types totaling roughly 60,000 MT
of natural uranium equivalent: i.e., about 300 reactor years’ worth [20].
The above considerations buttress the contention that natural uranium resources will not be
a major constraint for the remainder of the 21 st century.
Effects of Weapon Stockpile Reduction [21]
The United States and Russia reached an agreement in 1993 to blend down 500 tons of
90% enriched uranium for consumption by U.S. LWRs through 2013. One metric ton of
HEU can sustain a 1 GWe LWR for approximately 1 year. Hence, the 500 tons of HEU can
support five reactors for 100 years – useful but not a major factor when considerably more
than 500 reactors could be operational within a few decades (there are currently about 360
operating LWRs globally).
Russia and the U.S. have retained a stockpile of 600 – 1200 MT of HEU, which could again
easily be absorbed by the world uranium market. IPFM estimates more than 1700 tons total
worldwide. [21]
40 MIT STudy on The FuTure oF nuclear Fuel cycle