Streamlines Based Stochastic Methods and Reactive Transport Simulation Applied to Resource Estimation of Roll-Front Uranium Deposits Exploited by In-Situ Leaching

Round 1

Reviewer 1 Report

Please see the attached review file.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

This manuscript contains numerous grammatical errors. The nomenclature in Table 1 is quite confusing, particularly Cred, Cox, Ce, and Cpr. I also think that the generalization of redox reactions in equation 2 is an oversimplification of a complex chemical system. 

My main complaint is over the amount of modeling completed. I do not believe that you can prove that your method is an improved method over ordinary kriging methods by only showing a single simulated deposit. To demonstrate a statistical improvement, you need to model numerous systems. 

For certain tests, ordinary kriging appears to be at the same level or even better than your new approach, such as shown in figures 17 and 18, which was not discussed. 

This manuscript discussed a different strategy for simulating uranium roll-front deposits using a streamline-based approach. The paper discussed how this streamlines approach compared to a standard kriging approach for a single simulated roll-front deposit. The manuscript did a decent job of explaining how the streamline method was utilized. However, my main complaint is over the amount of modeling completed. I do not believe that you can prove that your method is an improved method over ordinary kriging methods by only showing a single simulated deposit. To demonstrate a statistical improvement, you need to model numerous systems. For certain tests, ordinary kriging appears to be at the same level or even better than your new approach, such as shown in figures 17 and 18, which was not discussed. For these reasons, I do not believe that your manuscript illustrates that a streamline approach provides an advantage over standard kriging strategies, and I think that the paper should be rejected. 

In addition, the manuscript contains numerous grammatical and wording errors. For example, on lines 25-27, you state: "Reactions occurring at the redox front force precipitation of dissolved species from groundwater stream, while oxygen rich meteoritic water continuously dissolves solid minerals creating redeposition and advance of the roll-front." This sentence should probably state: "Reduction reactions of aqueous uranium, selenium, and molybdenum occurring at the redox front lead to precipitation of solid minerals. Oxygen-rich meteoric water continuously dissolves these solid minerals at the upgradient side of the roll-front, allowing the roll-front to advance downgradient." On lines 39-40, you state: "Kazakhstan, for instance, multiplied by six its annual production since 2009 now accounting for almost 40% of World’s total production [4]." This sentence should probably state: " Kazakhstan, for instance, has increased its annual uranium production by a factor of six since 2009, now accounting for almost 40% of global production." These types of grammatical and wording errors are found throughout the manuscript. The nomenclature in Table 1 is quite confusing, particularly Cred, Cox, Ce, and Cpr. 

I also think that the generalization of redox reactions in equation 2 is an incorrect oversimplification of a complex chemical system. Molybdenum and selenium do not typically complex with carbonate. This type of error will likely negatively affect modeling of the system.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Line 96- change “the coffinite and the pitchblende” to “coffinite and pitchblende”

Line 125- change “on the basis of the work” to “on the basis of previous work”

Line 127- change “Similar experiment was conducted” to “Similar experiments were conducted”

Line 205- change “Evidently, chosen algorithm” to “The chosen algorithm”

Line 209- change “ordinary kriging algorithm” to “the ordinary kriging algorithm”

Line 220- change “Darcy Law” to “Darcy’s Law”

Line 229- change “the Pollock’s method” to “Pollock’s method”

Line 270- change “Variogram” to “The variogram”

Line 281- change “is well collected” to “is collected”

Line 326- change “extract concentration” to “extract U”

Line 327- delete “little more less than”

Line 327- change “the kriging has shown significant overestimation” to “the kriging method significantly overestimated U resources”

Line 329- change “the proposed method” to “the streamline method”

Line 330- add a quick discussion about how the number of exploratory wells affects resource estimation for both the original kriging method and the streamline method

Lines 330-331- delete “with true resources equal to 688 tons of uranium”

Lines 333-334- rewrite this sentence. Are you discussing how including a greater number of exploratory wells improves the accuracy of the original kriging model of total U resources?

Line 335- discuss how maximum and average error were calculated

Lines 335-343- I actually would move this entire discussion on error estimates to the discussion section- near line 396

Line 368- change “is appears” to “appears”

Lines 392-394- You can’t just write one sentence on your other modeling study. Add at least a couple graphs (similar to figure 15) and a discussion on resource estimation for this other deposit

Line 396- change “show” to “demonstrate”

Line 399- change “with increased number of wells maximum” to “with an increased number of wells, the maximum”

Line 399- isn’t it the kriging model where the maximum error sharply decreases with an increased number of wells, not the streamline method

Lines 399-401- add a discussion of maximum errors for the streamline method and a discussion of the  average error for the original kriging method versus the streamline method

Line 402- if the kriging model is more precise overall, why are you using the streamline model? I would reword this

Line 425- delete “in realty”

Lines 433 and 434- change “reduced environment” to “the reduced environment”

Line 435- change “Darcy law” to “Darcy’s Law”

Line 436- change “are not be critical” to “are not critical”

Line 437- change “are used as” to “may be used as”

Line 442- change “account for” to “account”

Line 446- change “well log hard data” to “well log data”

Line 449- change “better picture in terms of” to “improved”

Line 451- change “and additional” to “additional”

Author Response

Line 96- change “the coffinite and the pitchblende” to “coffinite and pitchblende”
Fixed
Line 125- change “on the basis of the work” to “on the basis of previous work”
Fixed
Line 127- change “Similar experiment was conducted” to “Similar experiments were conducted”
Fixed
Line 205- change “Evidently, chosen algorithm” to “The chosen algorithm”
Fixed
Line 209- change “ordinary kriging algorithm” to “the ordinary kriging algorithm”
Fixed
Line 220- change “Darcy Law” to “Darcy’s Law”
Fixed
Line 229- change “the Pollock’s method” to “Pollock’s method”
Fixed
Line 270- change “Variogram” to “The variogram”
Fixed
Line 281- change “is well collected” to “is collected”
Fixed
Line 326- change “extract concentration” to “extract U”
Fixed
Line 327- delete “little more less than”
Fixed
Line 327- change “the kriging has shown significant overestimation” to “the kriging method significantly overestimated U resources”
Fixed
Line 329- change “the proposed method” to “the streamline method”
Fixed
Line 330- add a quick discussion about how the number of exploratory wells affects resource estimation for both the original kriging method and the streamline method
Appropriate sentence has been added.
Lines 330-331- delete “with true resources equal to 688 tons of uranium”
Fixed
Lines 333-334- rewrite this sentence. Are you discussing how including a greater number of exploratory wells improves the accuracy of the original kriging model of total U resources?
Sentence has been rewritten
Line 335- discuss how maximum and average error were calculated
Explanation has been added.
Lines 335-343- I actually would move this entire discussion on error estimates to the discussion section- near line 396
Moved
Line 368- change “is appears” to “appears”
Fixed
Lines 392-394- You can’t just write one sentence on your other modeling study. Add at least a couple graphs (similar to figure 15) and a discussion on resource estimation for this other deposit
A chart has been added together with a discussion.
Line 396- change “show” to “demonstrate”
Fixed
Line 399- change “with increased number of wells maximum” to “with an increased number of wells, the maximum”
Fixed
Line 399- isn’t it the kriging model where the maximum error sharply decreases with an increased number of wells, not the streamline method
The sentence has been corrected.
Lines 399-401- add a discussion of maximum errors for the streamline method and a discussion of the  average error for the original kriging method versus the streamline method
Appropriate discussion has been added.
Line 402- if the kriging model is more precise overall, why are you using the streamline model? I would reword this
The sentence has been corrected.
Line 425- delete “in realty”
Deleted
Lines 433 and 434- change “reduced environment” to “the reduced environment”
Fixed
Line 435- change “Darcy law” to “Darcy’s Law”
Fixed
Line 436- change “are not be critical” to “are not critical”
Fixed
Line 437- change “are used as” to “may be used as”
Fixed
Line 442- change “account for” to “account”
Fixed
Line 446- change “well log hard data” to “well log data”
Fixed
Line 449- change “better picture in terms of” to “improved”
Fixed
Line 451- change “and additional” to “additional”
Fixed