Abstract
The results of an international review of separation processes for spent nuclear fuel (SNF) recycling in future closed fuel cycles are reported. This study was made by the Expert Group on Fuel Recycling Chemistry (EGFRC) organised by the Nuclear Energy Agency (NEA) of the Organisation for Economic Co-operation and Development (OECD). A unique feature of this study was that processes were classified according to a hierarchy of separations aimed at different elements within spent fuel (uranium; uranium-plutonium co-recovery; minor actinides; high heat generating radionuclides) and also the Head-end processes, used to prepare the SNF for chemical separation, were included. Separation processes covered both wet (hydrometallurgical) and dry (pyro-chemical) processes. A bespoke methodology suitable for assessing the technological maturities of separation processes for SNF recycling was then designed based on the well-established Technology Readiness Level (TRL) scale but adapted for spent nuclear fuel separations. The innovative feature of this was the use of a matrix approach that enabled information on both the scale of testing and materials used in testing to be combined in the evaluation of the TRL. TRLs for the Head-end, hydrometallurgical and pyrochemical processes that had been reviewed by the study have been evaluated. It is clear that, whilst more R&D is needed in most cases to raise TRLs, suitable options exist to enable the recovery of all actinide elements plus the HHRs by wet or dry processes, even up to the extraordinarily difficult isolation of americium alone. The technology readiness levels (TRL) for most processes fall in the ‘proof of principle’ range with TRLs between 4 and 6, although this is an evaluation at the system level and some gaps in the individual process steps may still exist that strictly would reduce the overall TRL. That is, flowsheets have been proposed for processes and tested with active materials under increasingly relevant conditions, through to initial hot tests with small quantities of SNF. The results of this work were shown to be comparable to a parallel European study that evaluated TRLs for minor actinide partitioning processes.
Original language | English |
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Article number | 103091 |
Journal | Progress in Nuclear Energy |
Volume | 117 |
DOIs | |
State | Published - Nov 2019 |
Funding
This paper was based on a study organised by the Expert Group on Fuel Recycling Chemistry under the mandate of the Working Party on the Fuel Cycle, for the OECD-NEA, and chaired by P. Baron. The NEA are thanked for permission to publish the findings of this study in the present paper. Further details of the study are reported in ref. (Collins et al. 2018). The authors of this paper wish to thank and acknowledge a wide range of additional contributions made to the study, under the auspices of the EGFRC, that are synthesised in this paper; specifically key contributions were made by: V.I. Beznosyuk; S. Delpech; C. Hill; R.T. Jubin; A.B. Kolyadin; C.J. Maher; R. Malmbeck; E. Mendes; M. Miguirditchian; V.F. Saprykin; J. Serp; C. Sorel. B.B Spencer is thanked for his contributions to the study and review of the draft paper. C. Mason and R. Hughes are also thanked for reviewing the draft paper.
Keywords
- Fuel cycle
- Hydro-metallurgy
- Pyro-processing
- Reprocessing
- Separations
- Technology readiness