Partitioning and Transmutation of Minor Actinides and Fission Products

Activities


The OECD-NEA programme on P&T involves the following activities: The P&T project is one example of horizontal activity within the Agency, involving several Divisions and Committees. Apart from the Nuclear Development Committee and the Nuclear Science Committee (Data Bank), the Radioactive Waste Management Committee is involved in the project and informed of its outcome as the potential application of Partitioning and Transmutation would have impacts on waste management and disposal not eliminating the need for geological disposal of high level waste but reducing the radiotoxic inventory to be disposed of. Also, whenever relevant, the NEA co-operates with the International Atomic Energy Agency (IAEA) and the European Commissions (EC) on specific topics of interest to the agencies.

Information Exchange Programme and Meetings

The objective of the Information Exchange Programme is to enhance the value of basic research in the subject areas by participating Organisations by facilitating the exchange of information on and discussion of programmes, experimental procedures and results. The scope of the programme includes information on all current and past research related to the areas set out to which participating Organisations have free access, subject to the Member Government's international non-proliferation obligations.

The subject areas set out are:

Nine International Information Exchange Meetings have already been held, differing in scope and findings as well as in attendance.

The first meeting (proceedings) was organised by JAERI and was held at Mito City (Japan) in November 1990. Various scientific and policy aspects of P&T were addressed and the presentations highlighted that a broad range of approaches were investigated, covering a variety of aqueous and non-aqueous chemical procedures and a number of different reactor and accelerator based transmutation schemes.

The second meeting (proceedings) took place in November 1992 at the Argonne National Laboratory (Illinois, USA). This meeting covered a broader scope and discussed issues such as legal background, incentives and implications of P&T for the whole fuel cycle according to different nuclear policies and the need for guidance on research priorities. One of the main conclusions was that a comparison of systems studies in the field of P&T, some of them already in progress, should form the core of the P&T activities carried out by the NEA under the auspices of the Nuclear Development Committee.

The third meeting (proceedings) was hosted by the French Atomic Energy Commission (CEA) in Cadarache in December 1994. It revealed an increased international interest in P&T and showed that dramatic progress was achieved throughout OECD countries in understanding its implications.

The fourth meeting (proceedings), held in September 1996 - again in Mito City (Japan), was hosted by the Science and Technology Agency (STA) in co-operation with JAERI, JNC and CRIEPI. The main findings of this meeting concerned the goals of and motivations for P&T, and guidance on future activities at the national and international level. Regarding the goals, it was clearly stated that P&T would not replace geological disposal but could reduce potential hazards associated with TRU elements and radiological impacts to humankind from mobile fission product radionuclides, such as 129I and 135Cs. The main motivations for P&T were revealed to be ethical, intergenerational equity principles and desire to address public concerns about radioactive waste disposal. The need to better define performance evaluation criteria, cut off period, optimal means for industrial implementation, and reasonable levels of extra costs was stressed. And, finally, the meeting highlighted the need to pursue technical studies and result evaluations, perform systems and strategic studies and undertake more thorough economic assessments.

The fifth meeting (proceedings, executive summary) in november 1998 was hosted by the Nuclear Research Center SCK·CEN in Mol (Belgium). About 120 participants attended this meeting and in total 43 oral papers and 13 posters were presented overing introductory papers, partitioning, fuel and target fabrication, cross-section data, reactor irradiations, comparisons between reactors and accelerator-driven systems as well as long-term radiological impact evaluations.

This fifth Information Exchange Meeting can be characterised by two main directions; first of all, a more integrative view on partitioning and transmutation was observed where consensus on the way how to perform P&T was achieved but where the questions of the added-value of P&T in the nuclear fuel cycle and the most appropriate way to achieve were raised. Secondly, the breakthrough in reprocessing of minor actinides achieving now the pre-set performances on lab-scale. During this meeting, the 'Status and Assessment Report on Actinide and Fission Product Partitioning and Transmutation' was presented as a result of the work of the expert group within the first phase of this P&T-project. This Information Exchange Meeting also highlighted issues for the nearby future. The comparative assessment of transmutation in fast reactors and accelerator-driven systems, addressing also the impact on the needed reprocessing, is one of the main issues to be studied in the nearby future to answer questions on performance and needed developments for P&T.

Proceedings of the 6th Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation
11-13 December 2000
Madrid, Spain

Seventh Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation
14-16 October 2002
Jeju, Republic of Korea

Eighth Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation
9-11 November 2004
Las Vegas, USA.

Ninth Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation
25-29 September 2006
Nîmes, France

Expert Groups and Status Reports

Expert Groups are established in order to conduct specific studies on P&T related topics. The Experts in such Expert Group are officially nominated by their respective Governments and cover specific fields as requested by the envisaged project.

The P&T programme of work has currently been covered by two Expert Groups:

Second Phase P&T Study 'Comparative Study of ADS and FR in Advanced Nuclear Fuel Cycles'

In advanced fuel cycles, fast reactors (FRs) and accelerator-driven systems (ADSs) are most interesting for their potential to permit transmutation of long-lived radionuclides. The concept of advanced nuclear fuel cycles, incorporating those ADS and FR, represents an important step towards more sustainable nuclear power because it could improve not only waste management but also uranium resource utilisation.

The first phase report "Status and Assessment Report on Actinide and Fission Product Partitioning and Transmutation" discussed only briefly those ADSs. The past five years have shown a major change in the general interest in ADSs and related R&D-programmes are now being conducted in several OECD Member countries. This renewed interest stems from the fact that some major breakthroughs in knowledge on partitioning and transmutation related technologies have been booked in recent years and new insights on the integral performance of P&T become apparent, addressing mainly the topic in today's discussion on the back-end of the fuel cycle, i.e.:

and the subsequent relevant question to this study becoming:

The answer to this question does not cover solely the technological requirements of each part of the P&T-scheme, but especially addresses the complete optimisation of the fuel cycles possibly covering P&T as a separate or integrated part. For example, current partitioning methods envisage the ultimate separation of the fission products and minor actinides in the waste stream, intending the fabrication of specific targets to be used in a heterogeneous transmutation scheme. New partitioning methods (pyrochemistry) and dedicated fast neutron devices (FR, ADS, molten salt fast reactors) could possibly perform better as integrated systems based on shorter out-of-core residence times and higher P&T efficiencies, but could be burdened by technological and economical limits. Both questions are also relevant in the context of an ever increasing interim storage of spent fuel, especially if nuclear deployment will be continued (in developing countries), and final waste disposals are delayed or even absent in some countries.

This study aims to address these various facets of P&T in advanced nuclear fuel cycles, focusing especially the ADS comparison with FR as transmutation devices and the respective partitioning methods supporting the integration in an advanced fuel cycle. In principal, the different fuel cycle schemes under consideration are based on the different options one could develop, i.e.:

The increasing interest in ADS has resulted in some studies focusing an overview of existing projects but none has considered in detail the added value and role of such ADS in advanced nuclear fuel cycles and the comparison with better-known systems as FR. As such, this study addresses the feasibility, requirements and reliability of ADS and the evaluation of the specific added value and role that both ADS and FR can offer in the fuel cycle.

The following preliminary list of topics could be used as a guideline to this study, and could serve as indication for the contents of the final report.

  1. Nuclear fuel cycle scenarios involving TRU, MA and FP burning/transmutation
  2. Advanced nuclear fuel cycles as shown in the figure 1 below.
  3. Role of FR and ADS in symbiosis with other reactors
    • Aspects of homogeneous and heterogeneous recycling methods
    • Aspects of partitioning technologies: aqueous and/or dry reprocessing
    • Criteria to which P&T should respond in advanced nuclear fuel cycles
  4. Comparison of the scenarios with emphasis on the potential of the systems to supply radiological 'clean' nuclear energy
    • Neutron economy considerations
    • Radiotoxic inventory and mass flows
    • Impact on requirements for HLW repositories
    • Fuel cycle impacts in front- and back-end
  5. Technologies involved
    • FR technology issues
      • Current status of FR technology
      • History of FR development and main issues
      • R&D Expenditure and future R&D programmes on FRs
    • ADS technology issues
      • Accelerator technology, e.g. high power and reliability issues
      • Spallation target, concepts, material problems, …
      • Core design for solid fuels, effect of higher MA contents, …
      • Molten salt concepts, advantages and drawbacks
  6. Fuel cycle issues
    • Fabrication of fuel and targets, fuel handling (shielding)
    • Fuel behaviour, achievable burn-up
    • Reprocessing options, advantages/drawbacks with regard to the different scenarios, necessary/achievable recovery factors
    • Secondary waste arising from the reprocessing
  7. FR and ADS Safety
    • Influence of MA-dominated fuel composition on safety parameters, comparison of different coolants, benefits from subcriticality
    • Safety strategies, defence in depth, active/passive and preventive/mitigative safety measures, classical and ADS specific accident initiators
    • Safety of the fuel cycle
  8. Cost/benefit consideration and life cycle assessment
    • Recovery costs and additional fabrication costs
    • Investments and operational costs for new facilities, uncertainties and risks
    • Economic, environmental and sociological benefits related to the front and back-end of the fuel cycle
  9. Principal R&D issues and priorities, R&D programmes and expenditures
  10. Overview and timing of Demo and research reactor projects
  11. International co-operation, status and needs.

Additional information on this specific study can be obtained from the NEA Secretariat.

Next to these specific Expert Groups, other working parties and task groups were established by the NSC.

Related links

P&T projects and links

P&T activities

P&T publications and documents

P&T contacts

Partitioning explained (general introduction)