WIPP CRA‐2009 Comments and Responses Enclosure 4

EPA Comment

Included in

this Submittal

Previously

Submitted Pending

Comments Received May 21, 2009

1‐G‐1 Stakeholder‐Water Flow Model Concerns ‐ ext from the Citizens

for Alternatives to Radioactive Dumping (CARD) news release on

March 25, 2009, raises questions...

9

1‐G‐2 Shielded Containers ‐ The shielded container planned change

request has been an ongoing activity that was not completed before

the CRA‐2009 was received by EPA.

9

1‐G‐3 Inventory‐ As outlined in the Executive Summary of DOE/TRU‐

2008‐3379, Rev. 1 (ATWIR 2007), DOE has proposed that ATWIR 2008

be used as the inventory source...

9

1‐23‐1 New Compliant Performance Assessment ‐ EPA believes it is

necessary to perform a new performance assessment to capture

changes since the last recertification...

9

1‐23‐2 Chemistry PA ‐ References from Appendix SOTERM‐2009: ‐ 

References from Appendix SOTERM‐2009: Borkowski...; Lucchini...;

Reed...; Richmann...

9

1‐23‐3 Chemistry PA‐ DOE summarizes thermodynamic data for the

+111, +IV, and +V actinides that have become available since the CRA‐

2004 PABC in Appendix SOTERM...

9

1‐23‐4 Chemistry PA‐ AP‐137 (Clayton 2008), includes the statement

on pages 17 and 18 that the ligand concentrations were expected to

increase from the 2004 to 2007 inventories.

9

1‐23‐5 Chemistry PA‐ In Appendix SOTERM‐2009, Section 3.3.2 and

SOTERM‐2009, Section 3.6.2, DOE states that the pcH of the WIPP

brines is expected to be approximately 8.7...

9

1‐23‐6 Chemistry PA‐ DOE reports uranium (VI) solubility experiments

in the absence of carbonate and ligands (Appendix SOTERM‐2009,

Section 3.3.2).

1‐23‐6 a. If the experimental results in GWB are extrapolated to pcH

9.64, the Nd (III) solubility could be approximately two orders of

magnitude greater (~4 x 10‐5 M) than the value...  

9

1‐23‐6 b. ‐Given the evidence that borate complexation appears to

affect the +111 and +VI actinide solubilities, DOE should address

whether the +IV actinide solubilities...

9

1
WIPP CRA‐2009 Comments and Responses Enclosure 4

EPA Comment

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this Submittal

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1‐23‐6 c. ‐The current actinide solubility conceptual model includes

the assumption that "The important ions in WIPP brines are H+, Na+,

K+, Mg2+, OH‐, CL‐, CO32‐, SO42‐and Ca2+.

9

1‐C‐1 Chemistry Issues‐ DOE states that the characterization data for

the Martin Marietta MgO has been obtained from a single lot

(SL2980076) of this material (Appendix MgO‐2009...

9

1‐C‐2 Chemistry Issues‐ The reactivity test used for MgO material

acceptance was developed in 1997. At that time, the MgO used as

backfill had a lower reactivity, but was...

9

1‐C‐3 Chemistry Issues‐ Appendix PA‐2009, Section 7.1.1 attributes

slower changes in repository pressure after 2,000 years to cessation

of room closure, slowing of brine inflow...

9

1‐C‐4 Chemistry Issues‐ Appendix MASS‐2009 and Appendix SOTERM‐

2009 do not address the current assumption that plastic and rubber

degradation (if occurring)...

9

1‐C‐5 Chemistry Issues‐ It is stated in Appendix PA‐2009, Section

2.3.1, that water is neither created nor consumed by microbial

reactions.

9

1‐C‐6 Chemistry Issues‐ DOE should provide justification for the

statement in Appendix SOTERM‐2009, Section 3.7 that "Of the four

organic chelating agents considered, only citrate...

9

1‐C‐7 Chemistry Issues‐ Appendix SOTERM‐2009, Table SOTERM‐l,

provides an incomplete list of the current chemistry model

assumptions.

9

1‐C‐8 Chemistry Issues‐ The fourth paragraph of Appendix SOTERM‐

2009, Section 2.3.2 states: "the expected pH, when little or no

carbonate is present, is 8.69 in GWB brine and...

9

1‐C‐9 Chemistry Issues‐ DOE states that carbonate complexation of

Nd(III) is unimportant at conditions expected in WIPP brines

(Appendix SOTERM‐2009, Section 3.6.2).

9

1‐C‐10 Chemistry Issues‐ n Appendix SOTERM‐2009, Section 4.4, DOE

states that the chemical potential (μo/RT) for Th(OH)4(s) was

changed in the FMT database since the...  

9

1‐C‐11 Chemistry Issues‐ In Appendix SOTERM‐2009, Section 4.4, DOE

should explain what is meant by their statement that, "The effects of

hydromagnesite and calcite...

9

2
WIPP CRA‐2009 Comments and Responses Enclosure 4

EPA Comment

Included in

this Submittal

Previously

Submitted Pending

1‐C‐12 Chemistry Issues‐ n the caption for Appendix SOTERM‐2009,

Figure SOTERM‐11, DOE states that the Eh‐pH diagram demonstrates

that Pu(IV) species would be...

9

1‐C‐13 Chemistry Issues‐ DOE should provide the carbonate

concentration, total americium concentration, and assumed ionic

strength for generation of Appendix SOTERM‐2009...

9

1‐C‐14 Chemistry Issues‐ DOE states in Appendix SOTERM‐2009,

Section 4.6 that organic ligands do not significantly affect actinide

solubilities, despite data presented in Appendix...

9

1‐C‐15 Chemistry Issues‐ n Appendix SOTERM‐2009, Table SOTERM‐

21, the parameter descriptions for PHUMCIM and PHUMSIM indicate

"actinide solubilities are inorganic only...  

9

1-C-16 Chemistry Issues- In Appendix SOTERM-2009, Section 

2.4.1.1, DOE cites "degradation of solubilizing organic ligands, leading 

to lower actinide solubility" as a possible... 

9

1-C-17 Chemistry Issues - In Appendix SOTERM-2009, Section 2.3.2, 

Brush et al. (2006) is cited as part of the documentation for the CRA2004 PABC, but this report was... 

9

1-C-18 Chemistry Issues - In Appendix MgO-2009, Section 4.2.2, 

DOE claims that hydromagnesite will completely convert to magnesite 

during the 10,000 year WIPP regulatory time... 

9

1-C-19 Chemistry Issues - In Appendix MgO-2009, Section 5.1, DOE 

states that the actinide solubilities in WIPP brines calculated for the 

CRA-2004 PA and CRA-2004 PABC 

9

1-C-20 Chemistry Issues - In the discussion of MgO uncertainties 

(Appendix MgO-2009, Section 6.2.4.4), DOE does not include the 

uncertainties associated with the... 

9

1-C-21 Chemistry Issues- Appendix PA-2009, Table PA-10 does not 

include units for the concentrations, which should be moles/L. 9

1-C-22 Chemistry Issues - Appendix PA-2009, Section 4.9 includes a 

statement that releases are controlled almost entirely by direct 

releases to the surface as cuttings, cavings... 

9

1-C-23 Chemistry Issues - To facilitate EPA's technical review, DOE 

should provide EPA with copies of all FMT input and output files used 

to update the actinide solubility uncertainty... 

9

3
WIPP CRA‐2009 Comments and Responses Enclosure 4

EPA Comment

Included in

this Submittal

Previously

Submitted Pending

Comments Received July 16, 2009

2-G-4 Inventory-Quality Assurance Sign-offs - While reviewing some 

of the quality assurance documents used by the LANL-CO inventory 

team to develop, manipulate and... 

9

 CARD 2009 Recertification Comments (as noted in the 1st

completeness letter) The group, Citizens Against Radioactive Dumping 

(CARD), has submitted a report entitled, "Proof of Rapid Rainwater 

Recharge at the WIPP Site, 

9

2-15-CARD-l page 1, last line- CARD states, "This is why the 

proponents of WIPP deny the existence of karst at the WIPP site. 

They argue, in effect, that WIPP is a karst-free island... 

9

2-15-CARD-2 page 2, first line- CARD states, "The supposed reliability 

of the Rustler Formation as a barrier to the migration of contaminated 

water hangs upon a postulated... 

9

2-15-CARD-3 page 2, third paragraph- CARD states, "Proof of 

rainwater recharge at the WIPP site would constitute proof that WIPP 

is part of the regional karstland of the Pecos River... 

9

2-15-CARD-4 page 3, third paragraph- CARD states, "This is the very 

definition of karst. Simply stated, if rainwater recharge does reach the 

Culebra dolomite, the Culebra is not a... 

9

2-15-CARD-5 page 4, paragraph 2-CARD states, "But the point to 

remember is this: none of this rainwater recharge is supposed to be 

happening. This invalidates the groundwater... 

9

2-15-CARD-6 page 14 last line-CARD states, "This strongly suggests 

that the water table will continue to rise at the WIPP site. Thus the 

Culebra is not in hydraulic steady state, as... 

9

2-15-CARD-7 page 30, first paragraph-CARD states, "If groundwater 

is supposed to be flowing from north to south, as DOE contends, how 

then did dissolved halite appear in these... 

9

2-15-CARD-8 page 36, 6th paragraph-CARD states in conclusion, 

Proof of rapid rainwater recharge at the WIPP site renders invalid the 

hydrologic model of the Culebra by which... 

9

2-C-24 Inventory-Chemistry ‐ The PA team requested data on the 

cement inventory as documented in PAIR 2008 (Crawford et al 2009, 

Section 3.1). The scaled mass of cement was... 

9

4
WIPP CRA‐2009 Comments and Responses Enclosure 4

EPA Comment

Included in

this Submittal

Previously

Submitted Pending

2-23-7 Adequacy of Minimum Brine Calculations for Actinide Solubility 

Determinations The minimum brine volume is the volume of brine 

needed for a direct brine release (DBR) to... 

9

2-33-1 Please provide the following reference... RL. Resources, 

Monthly Injection & Saltwater Report for ... 9

2-33-2 40 CFR 194.33(c)(2) states: (c) Performance assessments 

shall document that in analyzing the consequences of drilling events, 

the Department assumed that. ..(2) Natural... 

9

2-33-3 Dakota Salts, LLC, is a Denver based company that has 

proposed the use of Deep Salt Caverns for storage of compressed air 

generated by wind farms. Dakota Salts... 

9

2-33-4 Carbon sequestration is being assessed on a nationwide basis, 

including the Permian Basin 

(http://www.southwestcarbonpartnership.org). The Southwest... 

9

2-33-5 In CRA-2009, DOE changed the maximum time a DBR can 

occur from 11 days to 4.5 days. The maximum DBR duration is 

represented in PA by the parameter MAXFLOW... 

9

2-33-5 a. The South Culebra Bluff Blowout is cited as an inappropriate 

analogy for a WIPP brine release based on the formation 

encountered, downhole pressures anticipated... 

9

2-33-5 b. Review of drillers' comments (Memorandum, Document 

Number 545844) indicates that many drillers have never encountered 

a situation that would require mitigation of... 

9

2-33-5 c. Several drillers (reference 545844) indicated that they may 

never detect a brine release from the repository given the hypothetical 

release conditions posed by Kirkes (2007) 

9

2-33-5 d. One driller interviewed in reference 545844 indicated that if a 

brine kick was encountered, he would probably let brine flow to 

surface without any attempt at mitigation... 

9

2-33-5 e. Additionally, it is unclear what effect brine shut-in would have 

with respect to duration of flow and downhole conditions. Please 

provide references that address the effects.. 

9

Comments Received October 19, 2009

5
WIPP CRA‐2009 Comments and Responses Enclosure 4

EPA Comment

Included in

this Submittal

Previously

Submitted Pending

3-24-1 Inventory (194.24) Table 5-4 of PAIR 2008 provides without 

comment a comparison of waste material parameters used in the 

PABC and PABC09 (the 2009 PABC). 

9

3-C-25 Chemistry (C) Issues The Kd values used to model matrix 

actinide sorption during transport through the Culebra were based on 

the consideration of experimental data... 

9

3-23-8 FEPs (194.23) The screening argument for FEP W45 is 

combined with that for FEPs W44 (Degradation of Organic Material) 

and W48 (Effects of Biofilms on Microbial Gas Generation),... 

9

3-23-9 EPA supports the systematic approach required by SP 9-4 and 

believes that it will improve the maintenance, accuracy, and 

traceability of DOE's FEPs baseline. In reviewing SP 9-4,... 

9

3-23-10 Parameters (194.23) The focus of EPA's review of the CRA09 

input files was on changes that occurred since the PABC 2004. 

Identified changes involving hard-coded numerical inputs included... 

9

3-23-11 Appendix PA-2009 states in Section PA-4.2.2, Initial 

Conditions, last paragraph, that the initial waste disposal area 

pressure is 1.01325 x 105

 Pa, rather than the value of ... 

9

3-23-12 Computer Codes A number of secondary computer codes are 

used to support CRA-2009. Please provide QA documentation for 

these codes that demonstrate they are reasonably qualified for use in 

PA. 

9

January 25, 2009 Follow‐up questions to issues first raised in EPA's

May 21, 2009 letter, comment 1‐23‐6

1. There seems to be a disconnect between the previous (CRA-2004 

PABC) FMT modeling results and the experimental investigation of 

Nd(III) solubilities. Borkowski et al. (2008) assumed that the stable 

Nd(III) phase in the carbonate system would be NdOHCO3(s). 

9

2. The observed differences in the concentrations at similar pcH in 

GWB and ERDA-6 brine are attributed to borate complexation. GWB 

has approximately 2.5 times the borate concentration of ERDA-6.

9

3. The ”shoulder" in the Nd concentration in ERDA-6 brine as a 

function of increasing pcH was attributed by Borkowski et al. 2008 to 

borate complexation. However, the reason for the decreasing Nd 

complexation as a function of pcH above about 9.75 was not clear.

9

4. If the trend in Nd concentrations in GWB (Figure 4-8) is simply 

extrapolated up to pcH 9.4 (the pcH predicted by FMT modeling for 

GWB brine in the repository), the Nd concentration could be as high 

as 4 x 10-5 M, which is much higher than the concentrations... 

9

6
WIPP CRA‐2009 Comments and Responses Enclosure 4

EPA Comment

Included in

this Submittal

Previously

Submitted Pending

5. When discussing possible effects of increased +III actinide 

solubilities on PA during our call, a LANL staff member said that he 

thought the increased ligands concentrations predicted for the CRA2009 PABC FMT calculations might have increased the +III... 

9

6. Figure 4-9 presents Nd(III) solubility data in GWB as a function of 

pcH in the absence of carbonate. At pcH values of approximately 7.3 

and 8.0, the concentrations measured in experiments approached 

from undersaturation are higher by approximately an order of... 

9

7. DOE's response to 1-23-6c dated November 25, 2009 statement 

that "For the III actinides, the complexation of borate effectively 

substitutes for the calculated effect of carbonate presently in the WIPP 

model." 

9

8. DOE should perform FMT calculations to predict the concentrations 

of Nd(III) under the conditions of the Nd(III) solubility experiments in 

the NaCl, GWB, and ERDA-6 brines. 

9

9. Another question is related to the carbonate concentrations in the 

experiments that they conducted. I understand that they spiked an 

initial carbonate concentration into the solutions and used "gas-tight 

polypropylene bottles" for the experiments. 

9

Comments Received February 22, 2010

4-C-26 On page 12 of Borkowski et al. (2008), the americium-borate 

species is represented as AmB(OH)4 +, but on page 46, the 

neodymium-borate species are represented as NdB40 7+ and 

Nd(B407)2-. DOE should address whether there is any basis for 

9

4-C-27 DOE should address whether transformation of the initial 

NdOHC03(s) in their experiments to Nd(OH)3(s) could have 

substantially changed the carbonate concentrations during the 

undersaturation experiments, including whether it was possible that 

9

4-C-28 Figure 3-4 of Borkowski et al. (2008) shows the solution 

concentrations of americium(lII) as a function ofpcH in the absence 

and presence ofCO2, and the data are attributed to Kim et al. (1984). 

However, examination of this reference shows that the reported 

9

4-C-29 Figure 4-7 of Borkowski et al. (2008) shows the neodymium 

concentration as a function of time in the undersaturation experiments 

with GWB and carbonate. The data in this figure show that 

neodymium concentrations increased rapidly after the start of the 

9

4-C-30 On page 46 of Borkowski et al. (2008), it is stated that the 

addition of carbonate to modeling calculations performed with 

Geochemists Workbench led to a slight increase in the 

d i t ti b fth f ti f th Nd2(C03)l

9

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WIPP CRA‐2009 Comments and Responses Enclosure 4

8

EPA Comment

Included in

this Submittal

Previously

Submitted Pending

4-C-31 On page 46 of Borkowski et al. (2008), it is stated that the 

addition of carbonate to modeling calculations performed with 

Geochemists Workbench led to a slight increase in the 

d i t ti b fth f ti f th Nd2(C03)l

9

4-C-32 On page 29 of Borkowski et al. (2008), it was stated that XRD 

analysis ofNdOHC03(s) synthesized for the purpose of the 

experiments confirmed the "predominance" of a neodymium mixed 

hydroxy-carbonate phase. DOE should discuss whether any XRD 

9

4-C-33 On page 35 of Borkowski et al. (2008), it was stated that 

neodymium solubility was studied in 5 M NaCI at 10-2M total 

carbonate concentration. DOE should explain why this carbonate 

concentration was not listed in the test matrices 

9

4-C-34 Because the data in Figure 4-5 (neodymium(III) solubility in 5 

M NaCI in the presence of carbonate) were obtained over different 

time periods and had different initial carbonate concentrations, it is 

difficult to interpret these data. 

9

4-C-35 A review of the recent literature regarding aqueous thorium 

speciation in carbonate solutions indicates that the speciation selected 

by the OECD critical review (Rand et al. 2009) is the most consistent 

with the available data. 

9

4-C-36 An experimental investigation reported by Altmaier et al. 

(2004) has indicated that intrinsic thorium colloids (eigencolloids) can 

form and remain stable at high ionic strength (up to 5 M NaCI or 4.5 M 

MgCh). 

9