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Procedings
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50 e n e r g y + p r o c e e d i n g s time of existing
plants
, thus pushing the new capacity need ahead until the capability for adding new
plants
has become better. in the range of 550 to 700 nuclear power
plants
are needed world wide in 2030 assuming that they will produce somewhere between 4000 and 5000 twh/ year (see figure 8). since about 100
plants
may have to be shut-down between now and then for age rea- sons, the number of new
plants
to be built between now and 2030 is in the range of 210-360. on the average this means 10-17 per year. more may have to be built during the last part of the period because of increased number of
plants
being shut down, and also because fewer will be built in the beginning of the period. it should be noted that this will not suffice to substantially reduce the co 2 releases. generation iv-
reactor
s making nuclear power a sustainable energy source
fuel
for light water
reactor
s may become costly once the easily accessible resources of uranium have been exploited. a transition to advanced
reactor
s permit- ting the breeding (generation) of fissile material from 238u or 232th may then increase available
fuel
resources by a factor of 100-300. according to the gen-iv international forum a new set of so-called generation-iv
reactor
s should, be- sides being able to increase available
fuel
resources, permit reduction in long-lived high level waste inven- tories, be economically competitive, exhibit excellent safety and reliability characteristics, eliminate the need for off-site emergency response, and be the least at- tractive route for theft of weapon materials. six reac- tor types were selected as having the best potential for fulfilling these objectives: 1) the sodium cooled fast
reactor
2) the lead cooled fast
reactor
3) the gas cooled fast
reactor
4) the very high-temperature
reactor
5) the supercritical water
reactor
6) the molten salt
reactor
out of these systems, the three latter operate on a thermal spectrum, and would therefore only be able to support a sustainable
fuel
cycle by using thorium
fuel
s, requiring the development of new
fuel
cycle facilities for reprocessing and refabrica- tion of th-bearing
fuel
. further, as reprocessing of the coated particle
fuel
foreseen for the very high- temperature
reactor
is exceedingly difficult, only the first three
reactor
types are in practice able to fulfil all of the gen-iv requirements in a short to medium term. if fully implemented, gen-iv
reactor
s would allow the use of economically competitive nuclear power for tens of thousands of years, i.e. for all practical purposes it would become sustainable. the waste stream also would be radically changed, with the residual high level waste inventory being reduced by a factor of 100 in countries not having already vitri- fied parts of their waste. the time scale for reposi- tory function until the long-term radiotoxic inventory has decayed to acceptable levels could similarly be reduced to less than 1000 years. as the efficiency in conversion from heat to electricity may reach 40-45%, the economical impact of gen-iv may be fully viable in a world where demand for electricity will continue to increase. if a fully closed
fuel
cycle is to be implemented, the
fuel
fabrication, recycling, and reprocessing facilities would be of such character that they would preferably serve regions rather than countries, making socio- political acceptance of free movement for spent
fuel
a necessity. furthermore, it opens for the possibility of regional repositories to be constructed in more suita-
snetp-research-figure-53.html
