A Review of Opportunities and Methods for Recovery of Rhodium from Spent Nuclear Fuel during Reprocessing
Round 1
Reviewer 1 Report
The authors have prepared a well-arranged review, which, given the demand for rhodium and its current prices, will be beneficial for various scientific and later application purposes. I appreciate the logical and clear structure of the paper and the overview of extraction systems in tables S1-S4. I like the authors' additional comments on individual systems in these tables. I also like the partial conclusions of the authors, which they always draw from the available information (generalizations of known knowledge and conclusions and recommendations resulting from them). Regarding editing the manuscript, I propose only two formal minor changes that will make the manuscript better for the reader. Please recheck the abbreviations (indicate the full wording at the first occurrence and then use only the established abbreviations) and unify colours in lines in tables S1-S3 (sometimes poorly coloured). Thank you once again for preparing the review, and I wish the Journal of Nuclear Engineering many satisfied readers.
Author Response
RESPONSE:
We thank the reviewer for their kind comments.
We have checked the text for abbreviation omissions and amended accordingly where these were missing, and added a list of abbreviations at the start of the manuscript to aid readers.
The colours have been unified in the supplementary summary tables as requested, with gridlines added. This should make them easier to read.
Reviewer 2 Report
Fractionation of high-level waste generated after spent nuclear fuel reprocessing is a promising approach, firstly, to improving radiation safety in radioactive waste management due to the possible transmutation of long-lived nuclides, and secondly, to the use of valuable components, primarily platinoids. Fractionation is being studied by more and more researchers around the world. Selected and purified rhodium can be used for the needs of the nuclear industry. In addition, the isolation of platinoids is expedient, because these metals can lead to disruption of the glass structure and possible subsequent devitrification. For these reasons, the present review is of interest.
Remarks:
The review should sound more clearly what is its difference (or a new point of view to consider) from, for example, the review of 1. Verma, P. K.; Mohapatra, P. K.; Ruthenium speciation in radioactive wastes and state-of-the-art strategies for its recovery: A review. Sep. Purif. Tech. 2021, 275, 119148.
The review contains more than 60 references to literary sources - older than 15 years (about 39% of the total list). It is necessary to appreciate the importance of bringing so many references to relatively old papers.
Author Response
The majority of more classic references (older than 20 years) referring to Rh separation were covered in the previous reviews of around 2 decades ago (Refs 34 and 35), while Ru and Pd have received much more attention as we’re sure you’re aware.
The purpose of this work was to specifically address the state of the art in the the literature covering separation and recovery of Rh due to it’s high value and scarcity in light of recent geopolitical shifts which have rendered supplies of such critical elements unstable and thus prices highly volatile.
While we have primarily focused on newer literature, more classic examples older than 20 years have been included where these are relevant to the discussion in context of newer works.
The Verma and Mohapatra review is an excellent work covering Ru, but this is outside the scope of the work listed here, given our focus on Rh separations, unless collective PGM separations are being effected. While it would undoubtedly by beneficial to separate the PGMs early in reprocessing flowsheets (and thus remove the challenges presented by Ru), there are a great many challenges to overcome to achieve this. Similar separations to remove high-heat radionuclides (Cs and Sr) early on in reprocessing (pre-solvent extraction) is a similarly promising approach several of the authors have worked on, but is beyond the scope of the work presented here and thus warrants no further discussion. Here we are emphasising only the separations of valuable materials (Rh), not the management of problematic (but potentially valuable) ones (e.g. Ru)
Several modifications to the text have been made throughout to address these factors with reference back to the Verma and Mohapatra review where these are appropriate.
