Introduction

From the outset of the nuclear era,
non-proliferation of nuclear weapons has been an objective of the highest
priority. The almost universal
adherence to the non-proliferation regime has been possible because of the
realisation by the overwhelming majority of States that their security
interests would not be furthered by the acquisition of nuclear weapons. Hence most States have joined the NPT as
non-nuclear-weapon States, and have accepted comprehensive IAEA safeguards,
currently being strengthened by the introduction of the Additional Protocol and
related measures. While the political
commitment against proliferation has been the decisive factor, curbing nuclear
proliferation has also been helped by the relatively limited spread of
proliferation-sensitive technologies (enrichment and reprocessing) and the
limited availability in civil programs of weapons-grade nuclear materials.

In the early days of the development of
nuclear technology, efforts were made to find an inherent technical barrier to
proliferation, i.e. some way of spiking reactor fuel to render it incapable
of being used to produce nuclear weapons material. However, no practicable solution was found, and attention turned
to institutional barriers to proliferation. In considering whether technical barriers are now becoming
practicable, or desirable, it is worthwhile to review the institutional context
in which nuclear energy operates.

Institutional measures in support of
Non-proliferation

Limiting the spread of
sensitive technology The manufacture of nuclear weapons requires
either:

• uranium at very high enrichment
  levels (while the high enriched uranium (HEU) category starts at 20% U-235, weapons-grade uranium comprises 93% or
  more U-235), produced in enrichment plants designed and operated for this
  purpose; or
• plutonium preferably with a very
  high proportion of Pu-239 (weapons-grade
  plutonium comprises less than 7% Pu-240), produced in reactors designed and
  operated to produce low burn-up plutonium, and separated from spent fuel or
  irradiation targets in reprocessing plants or plutonium extraction plants.

These
materials are very different to those normally produced in civil programs: low
enriched uranium (LEU) typically used in light water reactors (LWRs) is in the
range of 3-5% U-235, and reactor-grade
plutonium from the operation of LWRs is typically around 25% Pu-240. The history of nuclear weapons development
shows that those States that have acquired nuclear weapons have established
dedicated facilities for this purpose, rather than using civil power programsindeed, in
some of these States nuclear power remains insignificant or non-existent. Nonetheless, because enrichment or
reprocessing are indispensable for the production of weapons material, the
earliest institutional barrier against proliferation was control over the
supply of enrichment and reprocessing technologies, and this remains a key
element in the non-proliferation regime.
Most States with nuclear power programs have neither enrichment nor
reprocessing facilities, instead contracting with others for these services.

Political and legal commitments
As more and more States sought to share in the benefits of nuclear
science and technology, the focus of non-proliferation efforts turned to
establishing legally binding peaceful use commitments, with a verification
mechanism in the form of safeguards inspections. Initially this was on a bilateral basis, but in the late 1950s
and the 1960s this was multilateralised, culminating in the conclusion of the
NPT in 1968, and the introduction of comprehensive (full scope) IAEA safeguards soon after.

The
non-proliferation regime that has evolved, with the NPT as its centrepiece, is
multi-layered, with several elements complementing and reinforcing each
otherthus providing defence-in-depth.
Of fundamental importance is the political commitment of almost every
State against acquiring nuclear weapons.
This political commitment is reinforced by treaty commitments,
particularly membership of the NPT. The
NPT is now almost universalthe only significant non-Parties being Israel,
India and Pakistan (Cuba is also a non-Party, but all its existing nuclear
activities are under safeguards).
Political and legal commitments are further reinforced by
confidence-building measures, the most important being IAEA safeguards, which
provide assurance through verification.
As has been discussed, restraint both in supply and in acquisition of
sensitive technology continues to be an essential element in the regime.

Future institutional developments
An important area of development is the promotion of transparency
in nuclear programsthat the extent of national nuclear programs,
and the policies behind them, should be clearly open and comprehensible to
others. While the present focus is on
transparency through IAEA safeguards, there are other transparency mechanisms,
both existing and potential, directly between States, at the bilateral and the
regional level.

Another
area for further evolution is in relation to access to sensitive
technology. Clearly it remains prudent
to limit the States operating enrichment and reprocessing facilities. This is not to say that current
non-proliferation and safeguards arrangements are inadequate, but rather, to
recognise the benefits of mutually reinforcing mechanisms. Containing the spread of sensitive
technologies may come under challenge, however, as nuclear power programs grow,
and as more States aspire to technological independence and equality. For the limitation of sensitive technology
to continue to be effective, it will be necessary to address the commercial
terms on which enrichment and reprocessing services are made available, and
especially to address the issue of security of supply.

In 1980 the IAEA-coordinated International
Nuclear Fuel Cycle Evaluation (INFCE) recommended that sensitive facilities be owned and
operated on a multi-nation basis. In
some ways the further privatisation of the nuclear industry and the process of
globalisation are leading towards the INFCE model: the operation of sensitive
facilities by the private sector rather than governmentsall the
more so where this is by corporations crossing national boundariesclearly
brings benefits in terms of transparency and confidence-building. In the future, the governments concerned may
wish to consider establishing enrichment and reprocessing facilities, as well
as plutonium storage and fuel fabrication facilities, on a regional basisservicing
the needs of industries in the region, and operated by regional partnership
involving governments and the private sector.
This approach would limit the overall number of sensitive facilities, would maintain them under
multilateral control, and would remove the economic motivation for establishing
such facilities on a national basis.

Technical measures in support of Non-proliferation

The
institutional elements of the non-proliferation regime have proven very
effective. It is timely to consider
whether these can be complemented through technical developments. Technical measures could add to the
difficulty of diversion of nuclear material useable for weapons, and enhance
the international communitys capability for timely detection of such
diversion. While the choice of future
nuclear power systems will depend on factors including economic
competitiveness, energy security, safety standards, and waste disposal options,
opportunities to address proliferation-related aspects should also be taken
into account, preferably at an early stage in the decision-making process.

Developments prompting renewed consideration of
these issues include:

• the fact that reprocessing is well
  established in a number of countries, and there are substantial quantities of
  separated plutonium in civil programs;
• the accumulation of separated plutonium has been exacerbated by the delay
  of commercialisation of fast breeder reactors (FBRs)this in turn has led to increasing
  utilisation of MOX (mixed uranium/plutonium oxide) fuel in thermal reactors;
• the end of the Cold War has brought about the need to dispose of
  ex-weapons plutonium and HEU;
• for the future, the prospect of the introduction of the plutonium
  breeding cycle.

Current
research

Currently
R&D in this area is proceeding in two broad directions:

• technical approaches predicated on the
  once-through cycle, to create a technical barrier to the recovery of
  plutonium, and minimise plutonium production, and to consume/degrade plutonium
  released from weapons programs;
• technical approaches predicated on
  plutonium recycle, under which recycle could proceed in
  non-proliferation-friendly ways, e.g. recovery and recycle of plutonium
  without separation.

Proliferation-resistant
Fuels (PRFs)
PRFs are an example of the first approach mentioned above. PRFs have been proposed in several
countries, including France, Italy, Switzerland, Japan and the US, as a means of
disposing of excess military and civil plutonium. PRFs would encapsulate plutonium and burnable poisons in a
non-uranium matrix. PRFs are designed
to behave like standard, low-enriched uranium fuel, able to be used in standard
LWR fuel cycles without reactor modification.
Because they do not contain uranium or thorium, PRFs do not produce
plutonium or U-233. Consequently, PRFs
can consume more plutonium than MOX over identical reactor cycles. The results of extensive theoretical studies
are extremely promising. However,
deployment of PRFs will require a significant fuel development and
qualification program.

Radkowsky Thorium Fuel (RTF) concept
This is another approach to a proliferation-resistant fuel. The RTF concept assumes a once-through fuel
cycle with no reprocessing. The fuel
comprises uranium enriched to a maximum of 20% and a thorium blanket,
incorporated in a seed-blanket unit fuel assembly. Compared to an LWR, the partial replacement of uranium by thorium
results in a major reduction in plutonium production. U-233 produced through irradiation of the thorium is mostly
consumed in the reactor, and the residual U-233 in the spent fuel is denatured
by non-fissile uranium isotopes.

Of more significance, given the likelihood of
greater plutonium recycle in the future, are approaches which directly address
plutonium recycle issues:

Co-processing of FBR material
A simple approach to avoiding the separation of the high Pu-239
plutonium produced in FBR blankets is to avoid the separate reprocessing of
blanket assemblies, instead reprocessing blanket and core assemblies together,
or blending blanket material with LWR fuel in-process, so as to dilute the
fissile content of the plutonium before it reaches the separated stage. This approach has been adopted by JNC (Japan Nuclear Cycle Development Institute) for its RETF facility.

DUPIC An interesting example of
plutonium recycle without separation is the DUPIC process^[10] being developed through collaboration between the ROK, Canada, and the US. By direct re-fabrication of spent PWR fuel
into fresh CANDU reactor fuel, the DUPIC fuel cycle can reduce natural uranium requirements and spent fuel
arisings. The basis of DUPIC is that
the fissile content of spent PWR fuel (residual U-235 and produced plutonium)
is well suited for use in heavy-water moderated CANDU reactors. No separation of plutonium is involved: dry
thermal-mechanical processes are used to reduce spent PWR fuel to a fine
powder, which is subject to high temperature to drive off volatile fission
products (around 40% of total fission products), pressed into pellets, and fabricated into CANDU fuel bundles.

Pyro-electro-chemical reprocessing
One possibility for simpler reprocessing is adoption of
pyro-electro-chemical processes originally developed in the US and Russia. These processes can be applied for many different
types of fuel. A key feature is that
there is no separation of plutonium from uranium. A number of countries are pursuing research in this area.

Russian
BREST Reactor Russian researchers are working on an
innovative concept of a transmutational
fuel cyclebased on a fast neutron lead-cooled reactor, BREST. The proposed reactor has a number of design
features that make it proliferation-resistant.
The reactor features full plutonium reproduction in the core-uranium blankets
are not used to breed plutonium, thus precluding production of weapons-grade
plutonium. With a small reactivity
margin in the core, it is not feasible to load targets into the reactor for
undeclared plutonium production.

The
design eliminates the need for plutonium separation from spent fuel. Spent fuel reprocessing will be reduced to
removing the bulk of fission products and actinides from the uranium/plutonium
mix. To adjust fuel composition,
further U-238 is added to compensate for fuel burn-up. A decision on the reprocessing method has
yet to be taken, but it will probably be a pyro-electrolytic technique, as
discussed above. A small proportion of
fission products still remaining in the fuel after incomplete purification will
create a radiation barrier facilitating physical protection of the fuel. Spent fuel can be cooled for 3 to 12 months
in an in-vessel storage facility-reprocessing and fuel fabrication would take place
at the power plant site, eliminating any physical protection issues associated with long-distance
shipments of fuel.

The concept also offers major advantages
for waste management: fission products and minor actinides would be recycled
for transmutation, substantially reducing the period of high radiotoxicityit
is envisaged that the resulting high level waste would decay to levels
comparable with natural uranium within about 200 years. Russia hopes to build a 300 MWe prototype
BREST reactor in 2002, for completion in 2007.
Provided use of lead coolant proves viable, this concept appears very
promising.

Super-PRISM Reactor While the BREST concept appears particularly attractive, there are
other fast neutron reactor concepts which avoid plutonium separation. For example, in the US General Electric is developing a modular liquid
sodium-cooled fast reactor called Super-PRISM.
This concept uses a dry pyro-processing system that does not separate
plutonium from minor actinides, thus enhancing the proliferation resistance of
the S-PRISM fuel cycle. Due to the
compact nature of the dry pyro-processing system, on site processing of the
spent metal fuel is a design option. In
this case, the fresh and spent fuel storage and receiving facilities would be
replaced by a compact co-located Spent Fuel Recycle Facility that integrates
spent fuel storage, processing and waste storage and conditioning operations
into a single facility.

Conclusions

Developments
in the nuclear industry and in nuclear technology should be considered in the
context that the overwhelming majority of countries have given political and
legal commitments against the acquisition of nuclear weapons. These commitments are reinforced by the
institutional arrangements of the non-proliferation regime, especially by IAEA
safeguards, and also by limits on the supply of sensitive technology. Institutional aspects of the
non-proliferation regime continue to evolve, e.g. through strengthened
safeguards and enhanced transparency.
Further developments are likely to include closer regional links.

The
non-proliferation regime can be further strengthened through technical
barriers, such as proliferation-resistant features at relevant stages of the
fuel cycle. This has not been a priority to date, because containing the spread of
sensitive technology has been largely effective, and because there is very
little weapons-grade material in civil nuclear programs. However, the increasing use of plutonium
fuels, and particularly the development of the plutonium breeding cycle, is
prompting renewed interest in technical approaches in support of
non-proliferation objectives.

Introduction of the plutonium breeding
cycle has been delayed by a number of factors, especially economics, brought
about by the slowdown in the growth of nuclear energy and by depressed uranium
prices. This delay provides an
important opportunity for the international community to ensure that
non-proliferation aspects are properly addressed at an early stage in the
development of new fuel cycle concepts.
While plutonium recycle could present a substantial challenge to
non-proliferation objectives, some of the approaches outlined above show that,
if developed in an appropriate way, plutonium recycle could actually bring
major non-proliferation advantages.

This will continue to be a major area of
interest to ASNO, ensuring that the Government is kept appraised of
developments and that Australia is able to play a constructive role in support
of non-proliferation objectives.

[10]. DUPIC stands for Direct
Use of spent PWR fuel in CANDU reactors.

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