TRS435_web

1. INTRODUCTION
1.1. WORLD NUCLEAR ENERGY SITUATION
The worldwide electronuclear capacity is about 350 GW(e), which can be
subdivided into three blocks, each 100–120 GW(e): the USA, the European
Union and the rest of the world. For strategic evaluations, a block of
100 GW(e) is therefore a representative portion of the electronuclear output
on the world scale. Two fuel cycle options have reached industrial maturity: the
once through fuel cycle (OTC) and the reprocessing fuel cycle (RFC) with
recycling of plutonium and some uranium. Worldwide some 10 500 t HM of
spent fuel is discharged annually from nuclear power plants and is either stored
or reprocessed. Currently, the industrial reprocessing capacity amounts to
3900 t HM/a, which means that only one third of the discharged spent fuel can
be reprocessed. This situation led to the total inventory of stored spent fuel
increasing to 130 000 t HM by 2000, while only 70 000 t HM has been
reprocessed and transformed into high level waste (HLW) or used in light
water reactor (LWR) mixed oxide (MOX) fuel. Only a small fraction of
recovered uranium has been recycled, and constitutes, together with the
depleted uranium inventory, an additional radiotoxic waste type, which has to
be stored or disposed of safely. Owing to the relatively low price of uranium,
this evolution is expected to continue for some decades. Increasing amounts of
repository space will become necessary to cope with these high inventories of
spent fuel. On a worldwide scale two repositories of the size of Yucca Mountain
need to be licensed for spent fuel, and one of the same size for HLW [1].
In some States the safety case of an underground repository has been
thoroughly evaluated. Adequate engineering designs have been found and
sometimes accepted by the regulatory authorities. However, it has been
difficult to obtain public acceptance of a repository installation. Whichever
strategy is followed, a repository for radioactive waste will need to be established,
whether direct disposal, reprocessing or partitioning and transmutation
(P&T) is pursued.
This report addresses the potential impact of P&T on the long term
disposal of nuclear waste and evaluates how realistic P&T scenarios can lead to
a reduction in the time required for the waste to reach an acceptable activity
level.
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