TRS435_web

3. NON-PROLIFERATION ASPECTS OF PARTITIONING
AND TRANSMUTATION
As previously discussed, P&T has been considered by some States as a
technical option for long term HLLW management strategies. P&T technologies
involve the separation (partitioning) of MAs such as neptunium and
americium from HLW to reduce its radiotoxicity. Thus the application of P&T
techniques to a nuclear fuel cycle could result in increased inventories of
separated neptunium and americium, which, prima facie, could pose a proliferation
risk, because these materials could be used for nuclear explosive devices.
At the very least, partitioning and subsequent transmutation of these materials
through irradiation in dedicated nuclear facilities (FRs or ADSs) would
certainly have an impact on safeguards implementation at facilities involved in
P&T. Given the potential proliferation risk associated with a P&T strategy, the
non-proliferation aspects of P&T should be carefully addressed at an early
stage of development.
An evaluation of the proliferation risks potentially posed by P&T developments
and applications and of their impact on IAEA safeguards implementation,
and studies of proliferation resistance measures, needs to be an integral
part of the investigation and assessment of P&T strategies and techniques.
3.1. PROLIFERATION POTENTIAL OF NEPTUNIUM AND
AMERICIUM
It has been recognized for many years that some TRUs other than
plutonium, in particular neptunium and americium, if available in sufficient
quantities, could be used for nuclear explosive devices. Their respective critical
masses are estimated to be of the same order as those of some other fissile
actinides (i.e. ~50 kg). Owing to its long half-life (2 140 000 years), neptunium
has no heat or radiation emissions that would complicate its use in a nuclear
explosive device. Americium, however, produces high levels of heat and
radiation, which would greatly complicate its use in a nuclear weapon; it would
therefore require considerably more skill and resources to handle and use
americium to manufacture a nuclear device. Other transuranics formed in fuel
during the operation of a nuclear reactor (e.g. curium, berkelium and
californium) also have fissionable isotopes. However, their more limited availability,
high thermal output, short half-lives and other nuclear properties make
them unsuitable for use in nuclear explosive devices. The results of an extensive
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