Skip to content
Australian Government - Department of Foreign Affairs and Trade

Advancing the interests of Australia and Australians internationally

Australian Government - Department of Foreign Affairs and Trade

Advancing the interests of Australia and Australians internationally

Australian Safeguards and Non-Proliferation Office

Annual Report 1999-2000

The Nuclear Non-Proliferation RegimeInstitutional and Technical Aspects

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.

Return to the ASNO Annual Report IndexNuclear Waste ManagementPartitioning And Transmutation

Department of Foreign Affairs and Trade