fixed unit price simulation for disposal of spent fuel ... - Greenpeace UK

Research Report
Model Parameter Initial Value Technical Comment
NDA Contingency Cost
for Hotter Spent Fuel
0% Depending on their storage period, high burn-up EPR
and AP1000 spent fuel assemblies radiate more heat than
standard burn-up AGR spent fuels, and so may need
physically spacing wider apart inside repository tunnels.
In order to accommodate high burn-up spent fuels,
greater spacing of tunnels or fewer fuel assemblies per
storage canister might be necessary. The marginal cost of
disposing of EPR spent fuels is likely to be slightly larger
than AGR spent fuels because the tunnels need to be
longer to accommodate this extra spacing. These longer
tunnels will cost more (per tU) to excavate than standard
AGR tunnels. To correct for this, FUPSIM can add a
contingency cost to the scaled-up cost of the extra repository
space needed for new build spent fuel. For example,
if the EPR tunnels need to be twice as long as
standard AGR tunnels then FUPSIM could add a 100%
cost increase. However this correction factor should be
used cautiously depending on expert judgement by a
mining engineer. FUPSIM sets the default correction
factor to zero %, meaning that the cost of disposing of
EPR fuel is the same as AGR fuel. However FUPSIM
allows a contingency cost correction of up to 300% if this
is judged necessary. The correction factor is not likely to
be needed if the EPR spent fuel cooling and storage time
is greater than 75 years. NDA Disposability Assessment
concludes that 100 years cooling would be needed for
65,000 MWd/tU burn-up EPR spent fuel to maintain a
repository temperature limit of 100 o C. For lower burnups,
75 years cooling would be needed for 50,000
MWd/tU burn-up EPR fuel, to meet the same repository
temperature limit of 100 o C. A correction factor is only
likely to be needed for early disposal of high burn-up
spent fuels with less than 75 years cooling, but the % is a
matter of judgement. The authors are grateful to Mr
Hugh Richards for discussions on this issue.
Jackson Consulting 24