Characterization of Compacted Ca- and Na-Bentonite with Copper Corrosion Products in the KAERI Underground Research Tunnel
Round 1
Reviewer 1 Report
The authors have conducted a study to determine the mineralogical and chemical reactions of bentonite due to copper corrosion products under aerobic conditions. The findings reported in this work are relevant in understanding the behavior of engineered barriers in contact with waste canisters, which are relevant in evaluating the long-term safety of stored radioactive nuclear waste. The article is well written and I recommend it for publication with minor corrections.
Comments
1. Page 7 lines 222-225: It is not clear from figure 5 which peak corresponds to the (001) peak. Please label this for clarity.
2. Is there any justification as to why there is a lower penetration rate of Cu cations in Na bentonite? This should be mentioned in the discussion/conclusions.
Author Response
Response 1 : We revised the figure 5.
Response 2 : We added the explain about Cu penetration. (line 300-307)
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear Editor,
I recommend the paper for publication after minor corrections:
1) Abstract; line 18 …,,bentonite (KJ-I), swelling was observed...” Change to …,,bentonite (KJ-I), the swelling was observed...”
2) 1. Introduction; line 28 …,,and hole in a deep...” Change to …,, and the hole in a deep...”
Line 37 …,,to suppress material movement...” Change to …,,to suppress the material movement...”
Line 49-50 …,,while simultaneously experiencing a temperature rise owing to radioactive decay of the waste...” Please add a reference that would relate to this claim.
Line 70 …,,The aim of this study is to understand...” Change to …,,This study aims to understand...”
3) 2. Materials and Methods; 2.1. Sample; line 83…,,in depth, so...” Please remove the comma.
Line 98-99 …,,was 600 °C, powder preheating temperature 98 was 400 °C, and injection pressure...” Change to …,, was 600 °C, the powder preheating temperature 98 was 400 °C, and the injection pressure...”
2.3. KURT Groundwater; line125 …,,of the 30°C chamber used...” Please remove the definite article and change to …,,of 30°C chamber used...”
4) 3. Results; line 179 …,,the corrosion products of rolled plate (RP) Cu (A) ...” Please add the indefinite article and change to …,, the corrosion products of a rolled plate (RP) Cu (A) ...”
Line 184 …,,the corrosion products of rolled plate (RP) Cu (A) ...” Please add the indefinite article and change to …,, the corrosion products of a rolled plate (RP) Cu (A) ...”
Line 188 …,,Concentration of copper (Cu)...” Please add the definite article and change to …,,The Concentration of copper (Cu) ...”
Line 192 …,,The changes in Cu concentration analyzed based on the thickness in RP and CSC Cu...” Change to …,, The changes in Cu concentration analyzed based on the RP and CSC Cu thickness...”
Line 196 …,,However, the Cu concentration was decreased to that found 2 mm from the interface…,, Change to …,,However, the Cu concentration decreased to 2 mm from the interface...”
Line 235 …,,The main constituent minerals were montmorillonite, quartz, cristobalite, albite, and calcite...” Please put next to each listed mineral type the space group and the number in which the listed mineral type crystallizes, for example, SG(12), and the number of the card you used for its identification, for example, ICSD#112233.
Line 266 …,,and heulandite...” Please put next to the listed mineral type the space group and the number in which the listed mineral type crystallizes, and the number of the card you used for its identification.
Great article, just pay attention to the definite article and the indefinite article.
Author Response
Response 1 : We revised that. (line 18)
Response 2 : We revised that. (line 34)
We revised that. (line 43)
We added the reference (line 56)
We revised that. (line 76)
Response 3 : We revised that. (line 89)
We revised that. (line 104-105)
We revised that. (line 131)
Response 4 : We revised that. (line 186)
We revised that. (line 191)
We revised that. (line 195)
We revised that. (line 200)
We revised that. (line 203)
We revised that. (line 245-246)
We revised that. (line 284)
Author Response File: Author Response.docx
Reviewer 3 Report
The work studies the characterization of mineralogical and chemical reactions of bentonite buffer material caused by copper corrosion in a deep geological disposal system. Here are a few suggestions for improvement.
The opening sentence mentions that the study aims to characterize the mineralogical and chemical reactions of bentonite caused by copper corrosion. It would be helpful to provide a clear statement of the study's overall objective or its significance in the context of deep geological disposal systems. The draft contains several technical details and findings, making it dense and potentially challenging to understand for non-experts. Consider breaking down the information into more digestible sections or bullet points to enhance readability. Some abbreviations, such as KJ-I and MX-80, are used without prior explanation. It's advisable to define these abbreviations upon their first use or provide a glossary for readers to easily understand the terms and follow the study. While the text describes the observations and measurements made during the study, it would be beneficial to discuss the significance of these findings. What are the implications of the observed d-spacing expansions and copper penetration depths? How do these results contribute to our understanding of the long-term stability and safety of deep geological disposal systems? The inclusion of clear and meaningful figures, diagrams, or tables related to the study's findings can greatly enhance understanding and engagement. Visual representations of the d-spacing expansions, copper distribution, or other relevant data can aid readers in comprehending the results.
Author Response
Response 1 : We added the explain of that. (line 28-34)
Response 2 : We revised that. (line 137, 147, 159, 164, 214, 226)
Response 3 : We revised that. (line 83)
Response 4 : We revised that. (line 294-297, 307-311)
Response 5 : We revised that. (line 330-334)
Author Response File: Author Response.docx
