Department of Energy 

Carlsbad Field Office 

P. O. Box 3090 

Carlsbad, New Mexico 88221 

JAN 12	 2010 

Ms. Elizabeth Cotsworth, Director 

Office of Radiation and Indoor Air 

U. S. Environmental Protection Agency 

Washington D.C., 20460 

Subject:	 Response to the Environmental Protection Agency July 16, 2009 and 

October 19, 2009 Letters on the 2009 Compliance Recertification Application 

Dear Ms.	 Cotsworth: 

In response to the Environmental Protection Agency's (EPA) letters of July 16, 2009, 

and October 19, 2009, the U.S. Department of Energy (DOE) is providing information 

that answers some the questions included in the enclosures to those letters. DOE 

determined after review of EPA's letters that the response to many of the items noted in 

the October 19, 2009 letter required additional analysis or significant effort. In order to 

allow time for those additional analyses, while at the same time responding to the 

EPA's requests in a timely manner, DOE is providing responses to some of these 

issues and questions in this submittal. 

This submittal includes four enclosures. Enclosure 1 is a hard copy of the responses. 

Enclosure 2 (on compact disc) provides references that were not previously submitted 

with the CRA-2009. Enclosure 3 is a cumulative list of errata that have been identified 

and corrected up this point. An updated list will be submitted to EPA with future 

submittals. Enclosure 4 is a table with a summary of comments received, DOE 

responses in this submittal, responses previously submitted and responses still 

pending. 

If you have any questions, please contact Russ Patterson at 575-234-7457. 

Sincerely, 

David C. Moody 

Manager 

Enclosure(s) 

• Responses 

'. CDs JAN 111010 

• Errata 1000071 

• Tracking Summary Table MAll ROOM COpy 

CBFO:ORC:RP:GS: 10-0900: UFC 5486.00 
Ms. E. Cotsworth -2­

cc: 

V. Daub, CBFO * ED 

R. Nelson, CBFO ED 

G. Basabilvazo, CBFO ED 

R. Patterson, CBFO ED 

S. McCauslin, CBFO ED 

T. Peake, EPA ED 

C. Byrum, EPA ED 

R. Lee, EPA ED 

S. Kouba, WRES ED 

A. Chavez, WRES ED 

T. Klein,WRES ED 

C. Timm, PMS ED 

D. Kessel, SNL ED 

D. Reed, LANL ED 

B. Crawford, LANL ED 

CBFO M&RC 

*ED denotes electronic distribution 

JAN 1 2 2010
 

CBFO:ORC:RP:GS:1().()9OO:UFC 5486.00 
4th Response Submittal to the EPA Enclosure 1 

EPA Comment 

2-33-2 

40 CFR 194.33(c)(2) states: (c) Performance assessments shall document that in 

analyzing the consequences ofdrilling events, the Department assumed that... (2) 

Natural processes will degrade or otherwise affect the capability ofboreholes to transmit 

fluids over the regulatory time frame. Brine extraction wells in the vicinity ofWIPP have 

experienced significantfailures and collapse offormations near surface due to creation 

ofcavernousfeatures at depth. Recently, the Energy and Minerals Department Secretary 

Joanna Prukop directed the Oil Conservation Division to evaluate current rules and 

regulations governing brine wells, including an internal audit and well inspections. 

While brine wells are considered in the CRA-2009, it is unclear whether additional 

analysis was performed to determine whether any unforeseen elements that contributed 

to recent issues may impact CRA assumptions, and whether these should be further 

considered as part ofthe CRA-2009. That is, it is unclear whether these recent 

phenomenon have been considered, and how, or if, these may affect the transmissivity of 

formations above the solution collapse. Further, the root cause ofthese failures should· 

be assessed with respect to well completion practices to determine iffactors other than 

brine extraction (i. e. downwardflow offresh water within a poorly cemented annulus) 

may have impacted dissolution. Related to this, it is unclear whether the CRA-2009 has 

assessed injection well integrity for those wells within the 9-township boundary, as no 

references for this analysis were included in the CRA-2009. 

DOE Response 

The recent regional brine well collapses occurred after much ofthe CRA-2009 was 

prepared and therefore were not discussed or analyzed in the CRA-2009 documentation. 

The DOE has been evaluating these issues and presents related infonnation in this 

response. In summary, the DOE believes that these events do not change conclusions or 

positions presented in previous compliance applicatIons, although current infonnation 

will be updated to acknowledge these collapse events and discuss their relevance to 

WIPP screening arguments and decisions. The following presents a more in-depth 

discussion ofthe brine well collapses, the likelihood ofsimilar events occurring near the 

WIPP, and the status of brine and injection wells near the WIPP. 

For regulatory purposes, WIPP assessments of compliance must make clear distinctions 

regarding the regional extent ofthe area surrounding WIPP. Historically, the greater 

Delaware basin has been used for the calculation of drilling rate, and the nine-township 

area surrounding the WIPP has been deemed appropriate for identifying other likely or 

relevant activities, particularly those that relate to human activities such as drilling and 

the exploitation ofresources. These distinctions are relevant because most resource1 

January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

related activities are highly dependent upon geology and site-specific characteristics and 

also because these geologic characteristics may change dramatically in a relatively short 

distance. For example, the Capitan reef, which identifies the Delaware Basin's northern 

boundary, is only 7 miles from the WIPP, yet subsurface geology beyond it is quite 

different than that near the WIPP. 

WIPP personnel have been following the investigations undertaken by the New Mexico 

Oil Conservation Division (OCD) with great interest. In its investigation, the OCD has 

identified probable common causal factors for the recent collapses. These factors 

include: 1) operation of brine wells in shallow salt zones, 2) placement ofthe casing shoe 

near the top ofthe salt zone, 3) use of "reverse" circulation!, and 4) overproduction of 

brine, thereby creating a large cavern (OCD 2009). These failures have not been 

attributed to well completion techniques or hardware failures (packer, casing, cement, 

and/or tubular components). The OCD has identified other brine wells that may be at risk 

due to the existence ofthese common factors, and is taking precautionary measures at 

one well near Carlsbad in which failure may occur. 

Currently, the nearest brine solution well is approximately 20 miles from the WIPP (see 

Figure 2-33-2.1), and its operatiop poses no risk to the operation ofthe WIPP. Within the 

WIPP vicinity (nine-township area surrounding WIPP); there have been no brine wells 

developed or operated (past or current). As such, the WIPP is not affected in any way by 

currently operating brine wells. With respect to brine wells that may be established in the 

future, the DOE has studied the potential effects of solution mining as documented in the 

Third Set ofResponses to EPA's March 19, 1997 request for additional information dated 

14 May, 1997 (EPA Docket 11-1-31), where it concluded that the effects of solution 

mining for brine would not affect WIPP performance. In their Compliance Application 

Review Document (CARD) for Section 194.32.B.l, EPA (1998) concurred with the DOE 

where it stated that, " ...Based upon DOE's supplemental information, the restricted scale 

of brine extraction, and the distance involved, EPA concluded that while brine extraction 

(solution mining) occurs, its effects were appropriately screened out from consideration 

in the PA (due to low consequence)." The screening decision of "low consequence" 

continues for the CRA-2009. Appendix SCR-2009, FEP H59, "Solution Mining for 

Other Resources" discusses the potential effects of brine wells on the WIPP and 

concludes that these wells are screened out of performance assessment calculations on the 

basis of low consequence to the disposal system. 

Additional· to the conclusion of low consequence, there are two regulatory justifications 

that preclude consideration of solution mining at the WIPP. First, because brine wells 

I Reverse circulation is an injection method which injects fresh water down the casing/tubing annulus and 

removes saturated brine via the tubing. Because the fresh water contacts the salt at the top ofthe cavity, the 

solution cavity grows in an inverted cone shape, reducing the structural integrity ofthe roof. 

2 

January 11,2010 
4tit Response Submittal to the EPA Enclosure 1 

have not been developed near the WIPP site in the past or current time frames, the Future 

States Assumption provided in Section 194.25 would exclude such activities in 

performance assessment. Second, the EPA's own criteria place limits on the nature and 

scope offuture human activities that relate to drilling. As stated by the EPA (1998) in 

their CARD for 194.32.B.l, " ...The Agency fmds that the impact ofsolution mining on 

the PA does not need to be analyzed for boreholes drilled in the future as specified in 

Section 194.33(d).,,2 As a matter of practice, the WIPP project has screened speculative 

future processes such as this on low consequence, when a low consequence argument can 

be made. The low consequence arguments used in screening this FEP augments the 

regulatory exclusions that could be applied. 

With regard to the consequences to formations above a solution collapse, the DOE 

believes that any effects caused by brine extraction at or near the WIPP are considered to 

be represented by the mining scenario in performance assessment. In their 

Supplementary Information to 40 CFR 194, EPA requires that performance assessments 

incorporate mining by significantly varying the hydraulic transmissivity within the 

overlying rock units (EPA 1996). This is because the most significant effect oftotal 

removal of an ore body is understood to be subsidence and disruption ofthe overlying 

rocks. The effects of subsidence due to brine extraction are therefore accounted for 

within the mining scenario in performance assessment. 

With respect to evaluating the integrity ofinjection wells within the vicinity ofthe WIPP, 

no such information was presented in the CRA-2009. The DOE has since gathered data 

on well configurations for the 55 wells currently permitted as injection wells within the 

nine-township area surrounding the. WIPP (WRES 2009). WRES (2009) shows that all 

55 ofthese injection wells are cased through the salt section to preclude dissolution ofthe 

salt should tubing and/or packer failure occur. Additionally, 53 ofthese have at least one 

.other casing and/or cement barrier to further isolate the salt from any potential tubing or 

packer leak. A representation ofthe wellbore configuration typical ofmost ofthese 

saltwater disposal wells is presented in Figure 2-33-2.2. It should also be recognized that 

salt water disposal wells such as these differ from brine solution wells in that the injected 

fluid is already near saturation and therefore would dissolve the salt very slowly should 

the necessary wellbore failures occur such that pressurized fluid were to be in 

communication with the Salado formation. Therefore collapse events such as those that 

have recently occurred in brine solution wells are not expected to occur in the salt water 

disposal or injection wells in the vicinity bfWIPP. 

In summary, the recent brine well collapses are not sufficiently near the WIPP to impact 

repository performance. Additionally, within the WIPP vicinity (nine-township area 

240 CFR 194.33 Cd) states: "With respect to future drilling events, performance assessments need not
 

analyze the effects oftechniques used for resource recovery subsequent to the drilling ofthe borehole."
 

3 

January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

surrounding WIPP), there have been no brine wells developed or operated (past or 

current). The DOE believes that these events do not change current screening arguments 

or decisions, that current performance assessment models appropriately address uncertain 

future human-initiated events, and that current positions are consistent with regulatory 

guidance and criteria.3 The DOE believes that it is important to monitor, analyze, and 

document the impacts of developing issues such as these recent brine well collapses, and 

will update compliance documentation as appropriate at each recertification cycle. 

3 The Future States Assumption of40 CFR 194.25(a) states that the DOE shall, " ... assume that 

characteristics ofthe future remain what they are at the time the compliance application is prepared 

provided that such characteristics are not related to hydrogeologic, geologic or climatic conditions." 

Therefore, because drilling for resources and conventional potash mining are currently occurring near the 

WIPP, the DOE assumes these activities will continue in the future and represents them in performance as 

appropriate. Alternatively, future human events such as solution mining have not been included in 

performance assessment because such activities have not occurred (nor presently occur) in the vicinity near 

WIPP. 

4 

January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

AC1lYE BRINE WELLS IN 'lEXAS 

AND N~ M!KICO LOCA1!D WIl11IN 11'£ DElAWAIlE IIASIN 

t ' 7 1 7 7 

, , '.'5' 

Reeves County 

Figure 2-33-2.1 Active Brine Wells in Texas and New Mexico Within the Delaware Basin 

5
 

January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

SURFACECASING SIZE 

(SEE TABLE) 

Surface Casing-­

HOLE SIZE 

(SEE TABLE) 

Tubing 

Base of Salt _. 

Intermediate Casing ­

HOLE SIZE 17 1/2" 

CASING SIZE 13 3/8"
 

HOLE SIZE 12 1/4"
 

CASING SIZE 8 5/8" PACKER
 

HOLE SIZE 7 7/8"
 

CASING SIZE 5 1/2" PERFORATIONS
 

PERFORATION ZONE -{ 

CIBP and Cement 

(Cast Iron Bridge Plug) 

NOT TO SCALE Total 

Figure 2-33-2.2 Typical Injection Well Design. 

6
 

January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

DOE References 

Environmental Protection Agency (EPA) 1996. Title 40 Code of Federal Regulation Part 194, 

February 9,1996. Supplemental Infonnation. Federal Register Volume 61, No. 28. pp.5224­

5245. Washington D.C. 

Oil Conservation Division (OCD) 2009. Brine Well Collapse Evaluation Report, June 18,2009. 

New Mexico Energy, Minerals and Natural Resources Department. OCD. Santa Fe, NM. 

Washington Regulatory and Environmental Services (WRES) 2009. Injection Well Design and 

Operation in the Nine Township Area. October 15,2009. Delaware Basin Drilling Surveillance 

Program. ERMS 552225. Carlsbad, NM. 

7 

January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

EPA Comment 

2-33-3 

Dakota Salts, LLC, is a Denver based company that has proposed the use ofDeep Salt Caverns 

for storage ofcompressed air generated by windfarms. Dakota Salts currently has eight salt 

caverns in North Dakota and, according to their website, is " ...prepared to enter the regulatory 

andpermitting stage and is working with the North Dakota Industrial Commission and North 

Dakota Department ofMineral Resources to establish the State's first regulatory control 

project" for storage ofcompressed air that would be released through windfarm operations 

during periods oflow wind generation. The CRA-2009, including the DBMR1

, does not address 

whether there are any known plans to use existing salt or potash minesfor this purpose. 

EPA References 

u.S. Department ofEnergy (DOE). 2007. Delaware Basin Monitoring Annual Report.
 

DOEIWIPP 07-2308. Carlsbad, NM: Carlsbad Field Office
 

·DOE Response 

Due to the speculative nature oftrying to predict future human activities, the Future States 

Assumption provided in 40 CFR §194.25 states that performance assessments should, " ... assume 

that characteristics ofthe future remain what they are at the time the compliance application is 

prepared... " Since salt caverns are not currently used within the vicinity ofthe WIPP (or the 

greater Delaware Basin) for compressed air storage, they have not been included in WIPP 

performance scenarios. Currently, there are no windfarms in the New Mexico portion ofthe 

Delaware Basin. Consequently, there are no known plans to use salt caverns for the storage of 

compressed air generated by windfarms at this time. Based on the DOE's wind resource map 

(see Figure 2-33-3.1) the area in the vicinity ofthe WIPP is listed as "marginal," rendering the 

development of wind resources near WIPP in the future questionable. It is acknowledged, 

however, that the economics ofthe future may be such that activities that are not profitable today 

may become more attractive in the future. WIPP monitoring programs will continue to monitor 

human activities to keep abreast of any technological advances used in current resource-related 

· activities and to identify the initiation of new activities not previously employed or attempted in 

the WIPP vicinity. 

· 1 DMBR - Delaware Basin Monitoring Annual Report (DOE 2007) 

8 

January 11,2010 
4th Response Submittal to the EPA	 Enclosure 1 

New Mexico - Wind Resource at 50 m 

108°	 106° 

34° 

32° 

108° 

Wind Power Classification 

WiBCI ResotJtce Wind F'ovMr Wind Speed" WiBCI 

Power Potential Oen$l~ alSO m at 60 m at 50 ri1 

Class Wlm2 m/s Il"4lI1 

Poor () - 200 0.0 - 5.9 0.0· 13,2 

Marginal 200 - 300 5,9 - 6.7 13.2 - 15.0 

Fait 300 - 400 6.7 - 7.4 15,0 - 16.6 

Good 400 - 500 7.4 - 7.9 16.6 - 17.7 

Excellenl 500 - 600 7.9 - 8.4 17.7 - 18.8 

Oulsl:sndlng 600- 800 8.4· 9.3 13.8- 20.8 

Superb :> 800 :> 9.3 :> 20,8 

·IIWlnd epeecIseM basad (Il'I a Welbull k or 2.0 at 1500 m elevation. 

104° 

Indian 

Reservation 

Navajo 

UtliMoumln 

Jloao'IIIIl~

Taos 

PicuIIs 

SlIn Juan 

!ialltaDal'il 

Sen lidelgnso 

POjOIltjue 

Nsmbe 

T'*"l.... 

Jemez 

lia 

Cocl1ttl 

SatlID Oorniflgo 

Sen Felipe 

SantaMa 

Sarnllso 

Laguna 

Acoma 

1	 CinonclIO 

1&IeIa 

AlIImoNsvajo 

ZUni 

Ramah Navajo 

Mescale<o 

;".,,--=,.,.,,===-__... 100~=-,,150 200 Kllometllrs 

30 eo 90 120 Miles 

Transmission Une" 

Voltage (kV) 

- 115-136 

-230 

_. 345 

-500 

• Soun;e:	 POWERmap,@)Q002 

PlatIs, • DMlIon dIM McGtMo H1n~1es

u.s. Department of Energy 

National Renewable Energy Laboratory 

•

12·MA.Y-20031.2.1

Figure 2-33-301 New Mexico Wind Resources Map 

9 

January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

DOE References 

. DOE Energy Efficiency & Renewable Energy Website. 2009. Wind and Hydropower 

Technologies Program. Wind Resource Map at http://www.windpoweringamerica.gov Retrieved 

November 2, 2009. 

10 January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

EPA Comment 

2-33-4 

Carbon sequestration is being assessed on a nationwide basis, inCluding the Permian Basin 

(http://www.southwestcarbonpartnership.org/). The Southwest Regional Partnership (SWP), 

was selected by the u.s. Department ofEnergy and its National Energy Technology Laboratory 

(NETL) as one ofthe seven regional partnerships charged with evaluating available 

technologies to capture and to reduce the emissions intensity ofgreenhouse gases in the 

southwest region through a process known as carbon sequestration. The project includes 

several different analyses such as CO2 coalbed sequestration, saline aquifer CO2sequestration 

(i.e. injection into saline water-bearingformations), and terrestriallbiotic sequestration. New 

Mexico was included in the SWP evaluations, as the state contains several highly saline waterbearing intervals that may offer sequestration opportunities. While elements ofCO2 

sequestration are addressed in difftrent HI [human intrusion] scenarios, C02 sequestration is 

not specifically identified in the human intrusion analysis. 

DOE Response 

It is correct that CO2 sequestration is not represented in performance assessment. The following 

discusses the regulatory and technical bases for the content of WIPP performance scenarios as 

they relate to future human activities, both inside and outside the WIPP boundary. The WIPP 

performance assessment includes both disturbed and undisturbed performance scenarios. 

Disturbed performance scenarios include the effects ofinadvertent, intermittent human intrusion 

by exploratory drilling for resources, and include the effects of a "direct hit" of waste by the drill 

bit. This is consistent with the WIPP Certification Criteria at 40 CFR 194.33 (a)(I), where it 

states,_ "Inadvertent and intermittent intrusion by drilling for resources ... '" is the most severe 

human intrusion scenario." Also, 40 CFR 194.33 (d) limits the scope of drilling activities in 

these scenarios where it states: "With respect to future drilling events, performance assessments 

need not analyze the effects oftechniques used for resource recovery subsequent to the drilling 

ofthe borehole." Therefore, WIPP Human Intrusion scenarios do not include the direct effects 

of carbon dioxide (C02) sequestration (neither saline nor terrestrial). 

However, the effects of injection activities outside the WIPP boundary are not excluded from 

WIPP analyses by the explicit regulatory exemption provided in 40 CFR 194.33 (d). That is, 

while they may not be included explicitly in a direct intrusion scenario, such activities may 

warrant consideration indirectly through analyses of human activities outside the WIPP 

boundary. Such events are identified through the WIPP features, events, and processes (FEPs) 

identification and screening process detailed in Appendix SCR-2009. For example, humaninitiated events that relate to injection near the WIPP are FEP H27, "Liquid Waste DisposalOutside the WIPP Boundary (OB);" and FEP H28 "Enhanced Oil and Gas Production - OB." 

Both ofthese activities are currently practiced in the vicinity ofWIPP, and therefore cannot be 

11 January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

excluded on the grounds of 40 CFR 194.25, "Future States Assumption." As such, the potential 

effects of these processes were analyzed in Stoelzel and O'Brien (1996) and Stoelzel and Swift 

(1997) to determine their impact to WIPP performance. These studies analyzed out-of-zone 

water injection (whether for brine disposal or enhanced oil recovery (EaR)) near the WIPP 

boundary to determine if the repository would be adversely affected. Because properly 

functioning injection wells do not result in the migration of fluids beyond the target interval, 

failures were assumed to occur in the tubing packer, the casing, and cement sheath around the 

casing. Further, it was assumed that injection pressures above those typically permitted were 

reached. Even using these worst-case failure modes, the analyses concluded that hypothetical 

injection failures would not adversely affect WIPP performance. Therefore, FEPs H27 and H28 

(liquid waste disposal outside the WIPP boundary and enhanced oil and gas production outside 

the WIPP boundary) have been excluded from performance assessment calculations due to low 

consequences to the disposal system. These arguments also hold true ifCO2 were being injected 

instead ofwater or brine. 

.Currently, the WIPP baseline does not include a FEP which specifically addresses CO2 

sequestration, although aspects ofthis proposed activity are discussed in WIPP FEPs H29, 

"Hydrocarbon S!orage - OB," and H59, "Solution Mining for Other Resources." Appendix 

SCR-2009, Section SCR-5.2.2.4.6, Solution Miningfor Gas Storage states that " ...No gas 

st~~ag~~avities have been solution mined within the NewMexico portion ofthe Delaware 

Basin." No further examination is provided for this activity, due to the Future State Assumption 

provided at 40 CFR 194.25. Appendix SCR-2009, Section SCR-5.2.2.4.7 Solution Miningfor 

Disposal states, " ...Solution mining can be used to create a disposal cavity in bedded salt. Such 

disposal cavities can be used for the disposal ofnaturally occurring radioactive material or other 

wastes. No stich cavities have been mined or operated within the vicinity of the WIPP." Such 

disposal would be analogous to a solution cavity being used for the storage or disposal of 

greenhouse gases. However, because no such activity has occurred or is occurring in the vicinity 

ofWIPP, no further consideration has been given (although the effects are not thought to be 

significantly different than those represented in the previous analyses offluid injection). 

The DOE believes that the periodic recertification ofthe WIPP's performance is an opportunity 

to take into account advances in technology and changes and updates to human activities. Such 

is the case for CO2 injection (whether for sequestration or enhanced oil recovery [EORD. 

Therefore, CO2 sequestration is a potential activity that is being monitored in WIPP human 

activities monitoring. For example, in Appendix SCR-2009, CO2 sequestration is recognized as 

an activity that could occur in the future, should political and economic forces merit. In a 

supporting reference to Appendix SCR-2009, Melzer (2008) evaluates the potential for CO2 

sequestration to be utilized as an EaR technique. Melzer illustrates that while CO2 flooding is a 

viable EaR technique in certain reservoirs, the potential to use captured carbon from industrial 

processes may make CO2 injection even more attractive in the future. While such techniques are 

currently not being employed, WIPP monitoring activities will continue to keep abreast of any 

12 January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

advancements and project start-ups that may affect the current state of human industrial practices 

as they pertain to the WIPP vicinity and WIPP performance. 

DOE References 

Melzer, L.S. 2008. An Assessment of the C02-Enhanced Oil Recovery Potential in the Vicinity 

of the Waste Isolation Pilot Plant (June). ERMS 550502. Midland, TX: Melzer Consulting. 

Stoelzel, D.M., and D.G. O'Brien. 1996. The Effects of Salt Water Disposal and Waterfloo~ing

on WIPP. Summary Memorandum of Record for NS-7a. ERMS 240837. Albuquerque: Sandia 

National Laboratories. 

Stoelzel, D.M., and P.N. Swift. 1997. Supplementary Analyses of the Effect of Salt Water 

Disposal and Waterflooding on the WIPP. ERMS 244158. Albuquerque: Sandia National 

Laboratories. 

13 January 11,2010 
4th Response Submittal to the EPA	 Enclosure 1 

EPA Comment 

2-33-5 

In the CRA-2009, DOE changed the maximum time a DBR can occurfrom 11 days to 4.5 days. 

The maximum DBR duration is represented in PA by the parameter MAXFLOW and used in the 

code BRAGFLo. The CRA-2009 states "Kirkes (2007) documents that this change is in keeping 

with current drilling practices within the Delaware Basin and the previous assumption of11 

days was incorrect. Kirkes and Clayton (2008) document the impacts ofreducing the maximum 

duration ofDBR and show that this change has a very minor impact upon performance 

predictions. Appendix PA-2009, Section PA.9.3 discusses the contribution ofDBR to total 

releases for the CRA-2009 performance calculations. Therefore, DOE continues to comply with 

40 CFR §194.33(c). " 

Review ofKirkes (above, 2007) raised the following completeness questions: 

a.	 The South Culebra BluffBlowout is cited as an inappropriate analogyfor a WIPP brine 

release based on the formation encountered, downhole pressures anticipated, gas 

content/ignition, etc. The document does not address whether there are analogies 

elsewhere (e.g. unanticipated brine pockets encountered at relatively shallow depths in 

saltformations) that are more representative ofpotential conditions anticipated at the 

WIPP. 

EPA References 

Kirkes, G.R 2007. Evaluation ofthe Duration ofDirect Brine Release in WIPP Performance 

Assessment (Revision 0). ERMS 545988. Carlsbad, NM: Sandia National Laboratories. 

Kirkes, R, and D. Clayton. 2008. Impact Analysis of Decreased Duration ofDirect Brine 

Release in WIPP Performance Assessment, Revision O. (March 10). 2008. ERMS 548313. 

Carlsbad, NM: Sandia National Laboratories. 

DOE Response 

While there are limited reported occurrences of brine flows from units above the Delaware 

Mountain Group, there are no cases of catastrophic well control loss, as in the South Culebra 

.Bluff. As documented in Kirkes (2007), conversations with drillers indicate that occurrences of 

pressurized brine flows are quite rare in the vicinity ofWIPP, and when they do occur, drilling 

progress is seldom interrupted. In cases when the driller chooses to shut in the well, it is done 

due to the presence of gas or to determine the presence of gas. If no gas is present, then drilling 

14	 January 11,2010 
4th Response Submittal to the EPA Enclosure I 

resumes. Gas kicks 1 are more difficult (and dangerous) to handle because gas entrained in the 

mud returns lightens the mud column and may threaten well control. Therefore, the majority of 

drillers surveyed in the analysis state that they would shut in a gas kick, but would let a brine 

kick flow, once the absence of gas was confirmed (allowing the flow ofbrine does not slow 

drilling, casing, and cementing procedures as discussed further in response to comments 2-33-5c 

and 2-33-5d). Unmitigated flow from the repository to the surface is represented by the DBR 

scenarIO. 

The DOE believes that the hypothetical scenario posed to the drillers in the survey (Kirkes 2007) 

accurately represents downhole conditions representative of a pressurized repository. The survey 

responses effectively reflect how a driller would react to a pressurized brine flow originating 

from the Salado and represents current practice in the area. The drillers' responses to the 

hypothetical scenario are consistent with what is documented in EPA's Background Information 

Document (BID) for 40 CFR 194 where the Cedar Breaks "2" State (API 30-015-27406) 

intercepted a pressurized brine flow in the McNutt potash zone ofthe Salado Formation May 1, 

1993. New Mexico Oil Conservation Division (OCD) records show that this well was 

temporarily shut in for four hours, flow rates were determined and the absence of gas was 

verified. Drilling then continued uninterrupted while brine was allowed to flow until the target 

depth for the intermediate string was reached (1,555 ft below ground surface). The casing was 

then set and cemented without interruption. The driller's reaction to this unexpected water flow 

is very consistent with the answers provided by the drillers interviewed in Kirkes (2007a). While 

the Cedar Breaks "2" well is outside the Delaware Basin, it does provide a useful analog 

regarding a driller's reaction to an unexpected pressurized brine flow and is consistent with both 

the most recent driller's survey and the assumptions used in the current DBR model. 

DOE References 

Kirkes, G.R. 2007. Documentation ofPersonal Interviews with WIPP Area Drilling Personnel. 

April 26, 2007. ERMS 545980. Carlsbad, NM: Sandia National Laboratories. 

1 A "kick" is an entry ofwater, gas, oil, or other formation fluid into the wellbore during drilling. It occurs because 

the pressure exerted by the column of drilling fluid is not great enough to overcome the pressure exerted by the 

fluids in the formation drilled. 

15 January 11,2010 
4th Response Submittal to the EPA	 Enclosure 1 

EPA Comment 

2-33-5 

b.	 Review ofdrillers' comments (Memorandum, Document Number 545844) indicates that 

many drillers have never encountered a situation that would require mitigation ofa brine 

release or blowout at shallow depths in the Delaware Basin. Kirkes (2007) takes this 

into account by calculating the anticipated time it would take· to acquire appropriate 

materials, but it is unclear whether the actual response time from the crew takes into 

account this lack ofexperience. Please indicate whether there are any other 

considerations short ofmaterial availability, that were considered when evaluating this 

circumstance. 

EPA References 

545844 (Kirkes, G.R. 2007). Documentation of Personal Interviews with WIPP Area Drilling 

Personnel. April 26, 2007. ERMS 545844 (Superseded by ERMS 545980). Carlsbad, NM: 

Sandia National Laboratories. 

Kirkes, G.R. 2007. Evaluation ofthe Duration of Direct Brine Release in WIPP Performance 

Assessment. April 27, 2007. ERMS 545988. Carlsbad, NM. Sandia National Laboratories. 

DOE Response 

Conservative assumptions (such as maximum repository pressures) were used when developing 

the hypothetical scenario represented to the drillers in the survey. When evaluating the 

responses from the drillers, other consid~rations such as bad weather and conservative travel 

times were used in the development of the response time. However, while it is correct that most 

drillers have not encountered a situation similar to the hypothetical scenario presented in the 

questionnaire in Kirkes (2007a), this should not be interpreted as a lack of knowledge of 

common well control techniques. All the drillers interviewed were very familiar with kill 

techniques 1 and state that the primary safety feature on the drilling rig is the blow-out preventer 

(BOP). All drillers interviewed state that they have BOPs rigged up and that these BOPs are 

routinely tested. In addition to BOPs, mud additives such as weight agents (barite) are either on 

site or readily available from local vendors. One driller stated that they may not yet have such 

additives on site while drilling the intermediate section ofthe borehole, because over-pressurized 

brine or gas is so rare at such a shallow depth. Therefore, in this case, weight additives would be 

brought to the site prior to drilling deeper zones where overpressure is more common. Another 

driller in the survey stated that barite or other additives are always on hand at his rig. 

1 "Kill techniques" are methods used to overcome pressure in a well by use ofmud or heavy drilling fluids such that 

the hydrostatic pressure within the wellbore (as exerted by the drilling fluid) exceeds formation pressure, thus 

prohibiting formation fluids or gas from entering the wellbore. 

16	 January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

The mitigation scenario in the DBR Report (Kirkes 2007b) conservatively assumed that mud 

weighting additives would not be present on site and therefore would be trucked in after the high 

pressure zone was encountered. In the case of a high pressure kick that threatens losing control 

of the well, the BOPs would be activated (closed), thus shutting in the well. During this shut-in 

period, weight additives could be mixed (if on hand), or dispatched from the nearest vendor if 

not available on site. 

DOE References 

Kirkes, G.R. 2007a. Documentation of Personal Interviews with WIPP Area Drilling Personnel. 

April 26, 2007. ERMS 545980. Carlsbad, NM: Sandia National Laboratories. 

Kirkes, G.R. 2007b. Evaluation ofthe Duration ofDirect Brine Release in WIPP Performance 

Assessment. April 27, 2007. ERMS 545988. Carlsbad, NM: Sandia National Laboratories. 

17 January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

EPA Comment 

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). 

While this may be improbable under the assumed downhole pressure conditions, the 

consequences that a lack ofrelease detection would have with respect to release 

scenarios or performance assessment has not been addressed in the references reviewed 

or in Kirkes (2007). Please provide this information. 

EPA References 

545844 (Kirkes, G.R. 2007). Documentation of Personal Interviews with WIPP Area Drilling 

Personnel. April 26, 2007. ERMS 545855 (Superseded by ERMS 545980). Carlsbad, NM: 

Sandia National Laboratories. 

Kirkes, G.R. 2007. Evaluation ofthe Duration ofDirect Brine Release in WIPP Performance 

Assessment (Revision 0). ERMS 545988. Carlsbad, NM: Sandia National Laboratories 

DOE Response 

There would be no impacts upon the current DBR modeling assumptions if a driller failed to 

detect that a brine flow was occurring. In fact, this is precisely what the DBR model assumes. 

Current DBR conditions are such that a DBR will occur if: 1) repository pressure exceeds 8 

megapascals (MPa), and 2) the repository contains sufficient mobile brine. The DBR model then 

assumes that flow will continue until one ofthe following occurs: 1) repository pressure drops 

below 8 MPa, 2) available brine is depleted, or 3) the 4.5 day maximum DBR duration is 

reached. In the case where the driller does not notice that a flow is occurring, the intermediate 

section ofthe borehole would be 'completed, cased and cemented within three days, according to 

current practices in the vicinity (Leonard, 1996). Because the minimum duration for DBR has 

been set at three days, failure to detect is represented by allowing flow while normal drilling, 

casing, and cementing operations continue (unless one ofthe limiting assumptions above occurs 

first). Ifrepository conditions merit, flow may continue, although this is a conservative 

assumption and ignores the fact that the driller would complete this section ofthe borehole in 

three days or less. This three-day minimum duration is based on previous WIPP surveys and 

information in Section 9.3.1.2 ofEPA's Background Information Document (BID) for 40 CFR 

194 (EPA 1996). 

DOE References 

Environmental Protection Agency (EPA). 1996. Criteria for the Certification and ReCertification ofthe Waste Isolation Pilot Plant's Compliance with the 40 CFR Part 191 Disposal 

18 January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

Regulations. Background Information Document for 40 CFR Part 194. EPA 402-R-96-002. 

Environmental Protection Agency, Office of~adiation and Indoor Air, Washington, DC. 

Leonard, R.J. 1996. "Commonality of Pressurized Brine Encounters within the Delaware 

Basin." Memorandum from R. Leonard to M. Marietta. July 31, 1996. ERMS 240850. 

Carlsbad, NM: Westinghouse Electric Corporation. 

19 January 11,2010 
4th Response Submittal to the EPA	 Enclosure 1 

EPA Comment 

2-33-5 

d	 One driller interviewed in reference 545844 indicated that ifa brine kick was 

encountered, he would probably let brine flow to surface without any attempt at 

mitigation. However, Kirkes (2007) and other references examined do not appear to 

address the likely duration ofunmitigatedflow and impact on PA assumptions. Please 

provide or cite references that address this occurrence. 

EPA References 

545844 (Kirkes, G.R. 2007). Documentation of Personal Interviews with WIPP Area Drilling 

Personnel. April 26, 2007. ERMS 545855 (Superseded by ERMS 545980). Carlsbad, NM: 

Sandia National Laboratories. 

Kirkes, G.R. 2007. Evaluation ofthe Duration ofDirect Brine Release in WIPP Performance 

Assessment (Revision 0). ERMS 545988. Carlsbad, NM: Sandia National Laboratories 

DOE Response 

As stated in the response to EPA question 2-33-5c, there would be no impacts upon the current 

DBR modeling assumptions if a driller failed to detect that a brine flow was occurring. As 

identified in Kirkes (2007), not all drillers state that they would react in the same manner to the 

hypothetical conditions presented in the questionnaire. Reactions vary based on personal 

experience, training, and other personal factors such as risk aversion, etc. It is clear, however, 

that most drilling decisions are based on maximizing drilling efficiency and continued progress 

towards target depth. Some drillers state that only when a fluid flow is sufficient to exceed pit 

capacity (thus requiring excess brine to be trucked away for disposal), would shutting in the well 

become necessary. Otherwise stated, only when the flow becomes an obstacle to drilling 

progress, or presents a safety or environmental concern, would mitigation techniques be sought. 

Therefore, under these circumstances, the flow would continue until the intermediate interval 

was drilled, cased, and cemented. These procedures would take no more than three days, which 

is the minimum duration for direct brine release (Leonard 1996). Therefore, unmitigated flow 

has no impact on performance assessment assumptions, and is represented by the three-day 

minimum duration used in performance assessment. 

DOE References 

Kirkes, G.R. 2007. Documentation of Personal Interviews with WIPP Area Drilling Personnel. 

April 26, 2007. ERMS 545980~ Carlsbad, NM: Sandia National Laboratories. 

20	 January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

Leonard, R.J. 1996. "Commonality ofPressurized Brine Encounters within the Delaware 

Basin." Memorandum from R. Leonard to M. Marietta. July 31, 1996. ERMS 240850. 

Carlsbad, NM: Westinghouse Electric Corporation. 

21 January 11, 20iO 
4th Response Submittal to the EPA	 Enclosure 1 

EPA Comment 

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 that 

surface shut in (prior to brine kill) would have on downhole conditions below the surface 

casing, assuming that surface casing is set to approximately 900ft with the remainder of 

the hole open. (At that point, intermediate casing would not have been set.) 

DOE Response 

If pressures were sufficient to cause the well to be shut-in, flow from the w~llbore into the casing 

(and upwards to the surface) would cease. The following excerpt from Kirkes (2007) provides 

an explanation of flow and relative downhole pressures: 

" ...Should a high pressure kick occur (approaching an SIDPP [Shut-in Drillpipe 

Pressure] of 1,000 psi), it is standard procedure for the driller to shut-in the well. 

Such is the case during the "wait and weight" method ofwell control (Grace, 

2003). During this shut-in period, no flow to the surface occurs. Only during the 

actual kill procedure, when the kill-weight mud is being pumped down the 

drillpipe, can formation fluids (in this case contaminated brine from the 

repository) flow to the surface. During the kill procedure, mud returns are 

regulated through a choke until kill fluids have been circulated down the drill 

string and back up the drillpipe/c~ing annulus. Once the kill-weight mud has 

been circulated completely throughout the well, there should be zero surface 

pressure on the drillpipe and the drillpipe/casing annulus, indicating zero flow 

into the wellbore (Grace, 2003). In such a scenario, fluid from the repository 

could only flow into the wellbore during the kill procedure, and then only at a 

very slow rate, due to the choking and regulating process used in the kill 

procedure. This may result in flow to the surface of only one-half hour or less; 

the period oftime it takes to circulate the kill fluid (Grace, 2003). Once the flow 

has been killed, normal drilling operations would continue until the target depth 

for the intermediate string is reached. The kill-weight mud would continue to be 

used throughout the remainder,ofthis interval, thus keeping high pressure 

formation fluids in place. Finally, when setting the intermediate casing string, the 

heavy mud would continue to be used until the casing is set and cemented. It is 

likely that very little flow from the repository would occur, once the kill-weight 

mud was in circulation." 

The point of this observation is that should a driller encounter pressure sufficient to warrant 

shutting in the well while a kill-weight mud was prepared, the duration offlow to the surface 

would be even less (perhaps significantly less) than if the flow was undetected, and allowed to 

22	 January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

continue until the intermediate string interval was cased and cemented. That is, when 

considering real-world drilling techniques (not those used in a hypothetical model), higher 

pressures do not necessarily result in increased flow or duration. The current DBR model 

employed in WIPP performance assessment conservatively ignores the fact that a shut-in well 

does not flow to the surface. 

DOE References 

Grace, R. D. 2003. "Blowout and Well Control Handbook." Elsevier Science, 2003. 

Kirkes, G.R. 2007. Evaluation ofthe Duration of Direct Brine Release in WIPP Performance 

Assessment. April 27, 2007. ERMS 545988., Carlsbad, NM: Sandia National Laboratories. 

23 January 11,2010 
4th Response Submittal to the EPA Enclosure 1 

EPA Comment 

3-23-9 FEPs (194.23) 

EPA supports the systematic approach required by SP 9-4 and believes that it will improve the 

maintenance, accuracy, and traceability ofDOE's FEPs baseline. In reviewing SP 9-4, EPA 

found discrepancies in the identification ofdocumentation that should be resolved. Section 3.0 of 

SP 9-4 identifies three QA Records: a FEPs Assessment Analysis Report, a Document Review 

Commentformper NP 6-1, and a Revised Baseline FEPs List (BFL). The FEPs Assessment 

Analysis Report appears to be the report documenting the results and recommendations ofthe 

baseline FEPs assessment mentioned in Section 2.4.8 ofSP 9-4, however, Section 2.4.9 ofSP 9-4 

states that the PA Manager is to sign the cover sheetfor the FEPs Impact Assessment Report. If 

the FEPs Impact Assessment Report is differentfrom the FEPs Assessment Analysis Report, it 

should also be included as part ofthe QA record. Ifthese are the same reports, they should be 

given the same name. DOE should clarify these different documents when including them in the 

future. 

DOE Response 

The EPA is correct in identifying the inco11.sistency in nomenclature in sections 2.5.9 and 3.0 of 

Sandia Procedure (SP) 9-4 (Kirkes 2009). The terms, "FEPs Impact Assessment Report" and 

"FEPs Assessment Analysis Report" are in fact referring (in generic terms) to the unique report 

generated for each FEP assessment, not a specific FEPs assessment report. In SP 9-4, these 

terms are used generically, since each FEP assessment is named with a specific title indicating 

the scope ofthe assessment (e.g., "Features Events and Processes Assessment for the Panel 

Closure System Redesign"), however the inconsistency is not appropriate and will be corrected 

via revision of SP 9-4. 

DOE References 

Kirkes, G.R. 2009. Activity/Project Specific Procedure SP 9-4, Performing FEPs Baseline 

Impact Assessments for Planned or Unplanned Changes, Revision 2. August 24,2009. ERMS 

551859.Carlsbad, NM: Sandia National Laboratories. 

24 January 11,2010 
Enclosure 3 

eRA 2009 ErrataTracking 

Error # 

1 

.. 

Error Description 

EPA comment 1-C-15 

In Appendix SOTERM-2009, Table SOTERM-21, 

the parameter descriptions for PHUMCIM and 

PHUMSIM indicate "actinide solubilities are 

inorganic only (complexes with man-made organic 

ligands are not important); solubilities were 

calculated assuming equilibrium with Mg-bearing 

minerals (brucite and magnesite)." DOE should 

correct these statements to clarify that organic 

ligands were considered during calculation of the 

solubilities used with these proportionality 

constants for the CRA-2004 PASC, and that the 

solubilities were calculated assuming equilibrium 

with brucite and hydromagnesite. 

. . 

Correction 

The description for PHUMCIM in Appendix 

SOTERM-2009, Table SOTERM-21 should 

be changed to "Proportionality constant for 

concentration of actinides associated with 

mobile humic colloids; in Castile brine; 

actinide solubilities include organics 

(complexes with man-made organic ligands); 

solubilities are calculated assuming 

equilibrium with Mg-bearing minerals (brucite 

and hydromagnesite)." 

. ',' .. :... 

Originator 

EPA 

, .. , ':.:';:.:' ..':"" 

Responsibility 

LANL-Reed 

:'., 

Status 

Revised text 

included in 1st 

Response 

Submittal to the 

EPA 

.. 

Date of 

Completion 

Submitted to EPA 

in 1st Response 

Aug 24,2009 

2 EPA comment 1-C-15 

In Appendix SOTERM-2009, Table SOTERM-21, 

the parameter descriptions for PHUMCIM and 

PHUMSIM indicate "actinide solubilities are 

inorganic only (complexes with man-made organic 

ligands are not important); solubilities were 

calculated assuming equilibrium with Mg-bearing 

minerals (brucite and magnesite)." DOE should 

correct these statements to clarify that organic 

ligands were considered during calculation of the 

solubilities used with these proportionality 

constants for the CRA-2004 PASC, and that the 

solubilities were calculated assuming equilibrium 

with brucite and hydromagnesite. 

The description for PHUMSIM in Appendix 

SOTERM-2009, Table SOTERM-21 should 

be changed to "Proportionality constant for 

concentration of actinides associated with 

mobile humic colloids; in Salado brine; 

actinide solubilities include organics 

(complexes with man-made organic ligands); 

solubilities are calculated assuming 

equilibrium with Mg-bearing minerals (brucite 

and hydromagnesite)." 

EPA LANL-Reed Revised text 

included in 1st 

Response 

Submittal to the 

EPA 

Submitted to EPA 

in 1st Response 

Aug 24, 2009 

. 

Page 1 of 11 
Enclosure 3 

3 EPA comment 1-C-18 The following statementshould be added at EPA SNL-Brush Revised text . Submitted to EPA 

In Appendix MgO-2009, Section 4.2.2, DOE claims the end of Subsection 4.2.2 of Appendix included in 1st in 1st Response 

that hydromagnesite will completely convert to MgO 2009 to clarify the text in this Response Aug 24, 2009 

magnesite during the 10,000 year WIPP regulatory subsection: "Based on the evidence Submittal to the 

time period. However, DOE's evaluation of the discussed above, the DOE concludes that it EPA 

likely conversion of hydromagnesite to magnesite is still unclear whether hydromagnesite will 

ignores information about this issue presented in persist or convert to magnesite during the 

SCA (2008). As part of a thorough evaluation of 1O,OOO-year WIPP regulatory period. 

the likely conversion rate for hydromagnesite to However, the EPA has specified that the 

magnesite, SCA (2008) cited data from Vance et brucite-hydromagnesite (5424) reaction be 

al. (1992) that showed hydromagnesite can persist used to buffer the C02 fugacity for 

for as long as 6,200 years. In addition, DOE does compliance-related actinide-solubility 

not consider that slow CPR degradation will result calculations since the CCA PAVT (Trovato, 

in continuous brucite carbonation during the 1997; U.S. EPA, 1998)." 

10,000-year regulatory period, rather than 

hydromagnesite formation that occurs only for a 

short time following repository closure. 

Consequently, even if hydromagnesite formed in 

the repository converts to magnesite within a few 

thousand years, hydromagnesite is likely to remain 

in the repository and would be likely to influence 

carbon dioxide fugacity for the entire 10,000-year 

regulatory period. DOE should revise this 

discussion to show that hydromagnesite is likely to 

be present in the backfill throughout the WIPP 

-

regulatory period. 

Page 2 of 11 
Enclosure 3 

4 EPA comment 1-C-19 

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 differed because of "changes in the 

thermodynamic databases for the An(III), An(IV), 

and An(V) models." The thermodynamic database 

for the An(IV) model changed between these two 

PA calculations when the chemical potential 

(IJO/RT) for Th(OH)4(aq) was revised. On the other 

hand, the An(III) and An(V) solubility results 

changed because of a recalculation of ligand 

concentrations. EPA was not informed of any 

changes to the thermodynamic data for the An(lll) 

and An(V) oxidation states. DOE should either 

correct this statement or document the revised 

thermodynamic data. 

The statement that, 'The An(III), An(IV), and 

An(V) solubilities predicted for the CRA-2004 

PA and PABC calculations are different for· 

both brines because of changes in the 

thermodynamic databases for the An(III), 

An(IV), and An(V) models between these 

calculations" (U.S. DOE, 2009, Appendix 

MgO, Subsection 5.1, p. MgO-32), is 

incorrect. It should state, "The An(III) 

solubilities predicted for the CRA-2004 PA 

and PABC calculations are different for both 

brines because of an increase in the 

concentration of EDTA (compare Brush and 

Xiong, 2005, Table 4, columns labeled "CRA2004 PA" and "PABC"). The An(IV), 

solubilities predicted for the CRA-2004 PA 

and PABC calculations are different for both 

brines because of changes in the 

thermodynamic database for An(IV). The 

An(V) solubilities predicted for the CRA-2004 

PA and PABC calculations are different for 

both brines because of the inclusion of the 

solubility-limiting phase whewellite (Ca 

oxalate·2H20) in the FMT database, which 

decreased the dissolved oxalate 

concentration despite an increase in the 

concentration of oxalate prior to precipitation 

of whewellite (compare Brush and Xiong, 

2005, Table 4, columns labeled "CRA-2004 

PA" and "PABC"). 

EPA SNL-Brush· Revised text 

included in 1st 

Response 

Submittal to the 

EPA 

Submitted to EPA 

in 1st Response 

Aug 24, 2009 

Page 3 of 11 
Enclosure 3 

5 EPA comment 1-C-20 

In the discussion of MgO uncertainties (Appendix 

MgO-2009, Section 6.2.4.4), DOE does not include 

the uncertainties associated with the chemical 

composition of the cellulose, plastics, and rubber 

in the WIPP inventory. DOE should acknowledge 

this uncertainty in the discussion. 

The following statement should be added at 

the end of the first paragraph of Subsection 

6.2.4.4.1 of Appendix MgO-2009, "Vugrin et 

al. (2006) did not include uncertainties 

associated with the chemical compositions of 

the CPR materials in the WIPP inventory. 

However, the DOE acknowledges that there 

are uncertainties associated with the 

EPA SNL-Brush Revised text 

included in 1st 

Response 

Submittal to the 

EPA 

Submitted to EPA 

in 1st Response 

Aug 24, 2009 

chemical compositions of these materials." 

6 EPA comment 1-C-21 

Appendix PA-2009, Table PA-1O does not include 

units for the concentrations, which should be 

moles/L 

The units moles/L should be added to 

Appendix PA-2009, Table PA-1O. 

EPA SNL-Clayton Revised text 

included in 1st 

Response 

Submittal to the 

EPA 

Submitted to EPA 

in 1st Response 

Aug 24, 2009 

7 EPA comment 1-C-22 

Appendix PA-2009, Section 4.9 includes a 

statement that releases are controlled almost 

entirely by direct releases to the surface as 

cuttings, cavings, and slJallings. DOE should 

correct this statement to include cuttings, cavings, 

and direct brine release, as explained in Appendix 

In Appendix PA-2009, Section 4.9, page PA162, line 2, the phrase "cuttings, cavings, 

and spallings" should be changed to 

"cuttings, cavings, and direct brine releases". 

EPA SNL-Claytcin Revised text 

included in 1st 

Response 

Submittal to the 

EPA 

Submitted to EPA 

in 1st Response 

Aug 24, 2009 

PA-2009, Section 9.0. 

8 EPA Comment 1-C-10 Chemistry Issues 

In Appendix SOTERM-2009, Section 4.4, DOE 

states that the chemical potential (!lo/RT) for 

Th(OH)4(s) was changed in the FMT database 

since the CRA-2004 PA. However, only the 

chemical potential for Th(OH)4(aq) changed 

between the CRA-2004 PA and the CRA-2004 

PABC (Xiong et al. 2005). DOE should correct this 

The DOE agrees with this comment - this is 

a typographical error in the text. The text will 

be corrected to read Th(OH)4 (aq). Note that 

this is correctly stated in Figure SOTERM-17 

and Equation SOTERM. 48. 

EPA LANL-Reed Revised text 

included in 2nd 

Response 

Submittal to the 

EPA 

Submitted to EPA 

in 2nd Response 

Oct, 2009 

statement 

-. 

Page 4 of 11 
Enclosure 3 

9 EPA Comment 1-C-11 

In Appendix SOTERM-2009, Section 4.4, DOE 

should explain what is meant by their statement 

that, "The effects of hydromagnesite and calcite 

precipitation were added..." to the FMT database 

for the CRA-2004 PABC, because hydromagnesite 

and calcite thermodynamic data have been 

included in the database at least since the CCA 

PAVT. In addition, SOTERM-4.4 states that the 

version of the code used was 

FMT_050405.CHEMDAT, which is the database 

version, not the code. DOE should correct this 

misstatement. 

The EPA is correct in their statement that 

hydromagnesite and calcite precipitation 

were included in the FMT calculations at 

least since the time of the CCA PAVT. The 

second bullet inSOTERM-2009, Section 4.4 

should be replaced with, "The dimensionless 

standard chemical potential for whewellite 

(CaC204oH20) was added to the database 

(Xiong 2004)." 

The first sentence in SOTERM-2009, Section 

4.4 should read, "The version of the 

database used with the FMT code for the 

CRA-2004 PABC was 

FMT_050405.CHEMDAT (Xiong 2005)." 

These corrections will be added to the errata 

list for Appendix SOTERM-2009. 

EPA LANL-Reed Revised text 

included in 2nd 

Response 

Submittal to the 

EPA 

Submitted to EPA 

in 2nd Response 

Oct, 2009 

10 EPA Comment 1-C-17 Chemistry Issues - Proper The DOE agrees with this comment. Brush EPA LANL-Reed Included in 2nd Submitted to EPA 

ReferenCe for Brush (2005) in Section 2.3.2 2005 is the correct reference. This will be Response in 2nd Response 

In Appendix SOTERM-2009, Section 2.3.2, Brush added to the errata list for Appendix Submittal to the Oct, 2009 

et al. (2006) is cited as part of the documentation SOTERM-2009. EPA 

for the CRA-2004 PABC, but this report was 

prepared after the CRA-2004 PABC. DOE should 

replace it with the correct reference (Brush 2005). 

Page 5 of 11 
Enclosure 3 

11 EPA Comment 1-23-5 Chemistry IssuesInconsistencies in pH in SOTERM 

In Appendix SOTERM-2009, Section 3.3.2 and 

1) Change the following in Appendix 

SOTERM Section 3.3.2: 

"At the expected pCH+ in the WIPP (-8.7), 

EPA LANL-Reed Included in 3rd Submitted to EPA 

Response in 3rd Response 

Submittal to the Nov 2009 

SOTERM-2009, Section 3.6.2, DOE states that the the measured uranium solubility was EPA 

pcH of the WIPP brines is expected to be between 10-7 M and 10-6 M." 

approximately 8.7 or 8.5. Based on FMT modeling To: 

performed for the CRA-2004 PABC, however, the 

pcH of GWB and ERDA-6 are expected to be 9.39 "At the expected pCH+ in the WIPP (-9.5), 

and 9.64, respectively. The pcH values cited by the measured uranium solubility was 

DOE seem to reflect the pH values of 8.69 and between 10-7 M and 10-6 M." 

8.94. DOE should correct the cited pcH values and 

reinterpret the solubility data in light of the correct 2) Change the following in Appendix 

. values. SOTERM Section 3.6.2: 

"The WIPP-relevant data summarized in this 

report support current PA calculations 

performed with the use of the Pitzer model 

(U.S. Department of Energy 2004, Appendix 

PA, Attachment SOTERM) for the values of 

3 x 10-7 M and 1.7 x 10-7 M in GWB and 

ERDA-6, respectively, at pCH+-8.5." 

To: 

"The WIPP-relevant data summarized in this 

report support current PA calculations 

performed with the use of the Pitzer model 

(U.S. Department of Energy 2004, Appendix 

PA, Attachment SOTERM) for the values of 3 

x 10-7 M and 1.7 x 10-7 M in GWB and 

ERDA-6, respectively, at pCH+-9.5." 

Page 6 of 11 
Enclosure 3 

12 IEPA Comment 1-C-8 Chemistry Issues -Issue of lin Section 2.3.2, Page 10, line 12-16 of IEPA LANL-Reed Included in 3rd Isubmitted to EPA 

pH in microbial and non-microbial vectors Appendix SOTERM change: Response in 3rd Response 

"Under these repository-relevant conditions, Submittal to the Nov 2009 

The fourth paragraph of Appendix SOTERM-2009, Ithe expected pH, when little or no carbonate EPA 

Section 2.3.2 states: is present, is 8.69 in GWB brine and 8.94 for 

ERDA-6 brine. In both cases, this pH is 

"the expected pH, when little or no carbonate is established/buffered by the brucite 

present, is 8.69 in GWB brine and 8.94 for ERDA-6 dissolution reaction. The presence of 

brine. In both cases, this pH is . microbial activity will potentially contribute 

established/buffered by the brucite dissolution significant amounts of carbon dioxide and 

reaction. The presence of microbial activity will leads to a model-predicted pH of 8.69 and 

potentially contribute significant amounts of carbon 9.02 for GWB and ERDA-6 brine, 

dioxide and leads to a model-predicted pH of 8.69 respectively." 

and 9.02 for GWB and ERDA-6 brine, respectively. To: 

DOE also states that the ERDA-6 pH is 9.02 in the "Under these repository-relevant conditions, 

text immediately following equation SOTERM.4. the model-predicted pH is 8.69 in GWB brine 

These statements appear to confuse the results of and 8.94for ERDA-6 brine. In both cases, 

FMT modeling for the CRA-2004 PABC and the this pH is established/buffered by the brucite 

CRA-2004 PA. The pH values of 8.69 and 8.94 for dissolution reaction." 

GWB and ERDA-6 brine, respectively, were 

obtained for microbial vectors with organic ligands 

for the CRA-2004 PABC. The pH values of 8.69 

and 9.02 for GWB and ERDA-6 brine, respectively, 

were obtained for microbial vectors with organic 

ligands for the CRA-2004 PA. DOE should clarify 

this statement, in light of the fact that all vectors for 

the PABC were assumed to include microbial 

degradation of cellulose or cellulose, plastics, and 

rubber 

Page 7 of 11 
Enclosure 3 

And on page 10, line 36 to page 11 line 2 

change: 

"Consideration of the possibility of high C02 

levels leads to a calculated pH of 8.69 and 

9.02 for GWB and ERDA-6 brine, 

respectively. This is a relatively small 

change in the predicted pH with no change 

predicted in GWB brine and only a 0.08 pH 

shift in ERDA-6 brine. These values of fco2 

and pH were used in the actinide speciation 

and solubility calculations for all CRA-2004 

PABC vectors (Brush 2005)." 

To: 

"This value of fco2 and a pH of 8.69 and 8.94 

for GWB and ERDA-6 brine, respectively, 

were used in the actinide speciation and 

solubility calculations for all CRA-2004 PABC 

vectors (Brush 2005)." 

Page 8 of 11 
Enclosure 3 

13 EPA Comment 1-C-12 Chemistry Issues- In Appendix SOTERM, page 51, figure EPA LANL-Reed Included in 3rd Submitted to EPAI 

Stability and likelihood of Pu(lII) in Brine legend for Figure 11, change: Response in 3rd Response 

Submittal to the Nov 2009 

In the caption for Appendix SOTERM-2009, Figure "Speciation Diagram for Plutonium in EPA 

SOTERM-11, DOE states that the Eh-pH diagram Carbonated Low-Ionic-Strength Groundwater 

demonstrates that Pu(lV) species would be stable (Based on Data Presented in Runde et al. 

at near-neutral pH. However, at the reducing 2002). This Illustrates the Expected Lower 

conditions expected in the repository (near the Solubility of Reduced Pu, Shows Pu(lV) 

lower stability limit for water), Pu(lIl) species Rather Than Pu(lll) Species at Near-Neutral 

appear to be the most stable (PuC03+ and pH, and Suggests That the Dominant Pu 

Pu(C03)2-). DOE should explain this apparent Species in the pH 8-9 Range are Hydrolytic 

discrepancy. Species with Lesser Contributions From 

Carbonate." 

To: 

"Speciation Diagram for Plutonium in 

Carbonated Low-Ionic-Strength Groundwater 

(Based on Data Presented in Runde et al. 

2002). This Illustrates the Expected Lower 

Solubility of Reduced Pu(lll) and Pu(lV), and 

Suggests That the Dominant Pu Species in 

the pH 8-9 Range are Hydrolytic Species 

with Lesser Contributions From Carbonate." 

I 

Page 9 of 11 
Enclosure 3 

14 IEPA Comment 1-C-13 Chemistry Issues - Data IThe specifics used to generate Figure 

request for Figure SOTERM-16 and error in Figure SOTERM-16 are discussed in more detail in 

reference Richmann et al. (2008) provided to 

DOE should provide the carbonate concentration, the EPA. The concentrations used in 

total americium concentration, and assumed ionic generating this Figure are the predicted 

strength for generation of Appendix SOTERM- solubility of III actinides in the CRA-2004 

2009, Figure SOTERM-16. In addition, DOE should PABC for reacted GWB brine. 

correct a typographical error in the figure, where 

the subscript "3" was omitted from Am(OH)3(s). IThe DOE agrees that the "3" was 

inadvertently omitted from Am(OH)3(s) in 

Figure SOTERM-16. 

In Appendix SOTERM, page 72, Figure 

SOTERM-16, change: 

IEPA LANL-Reed Included in 3rd ISubmitted to EPA 

Response in 3rd Response 

Submittal to the Nov 2009 

EPA 

I 

w 

i -,~

!--?~~~---'-_.-..... _.".-_........ ­ o , • 6 & \D 

oH 

To: 

i 

i

-'t 2S"C -.... 

, , , 

Page 10 of 11 
Enclosure 3 

15 EPA Comment 1-C-14 Chemistry IssuesInconsistencies in Description of Organic Ligand 

Effects 

DOE states in Appendix SOTERM-2009, Section 

4.6 that organic ligands do not significantly affect 

actinide solubilities, despite data presented in 

Appendix SOTERM-2009, Table SOTERM-19 

showing that ligands increased the calculated +111 

actinide solubilities by factors of 1.71 (GWB) and 

3.32 (ERDA-6) and +V actinide solubilities by 

factors of 1.50 (GWB) and 1.53 (ERDA-6). This 

statement is also at odds with the assertion in 

SOTERM-3.7 that EDTA and citrate could 

potentially affect actinide solubilities in WIPP 

brines. DOE should correct this statement, 

especially in light of the data indicating that ligand 

concentrations in the inventory have increased 

significantly since the CRA-2004 PABC. 

In Appendix SOTERM, Section 4.6, page 79, 

line 27 change: 

'The FMT calculations (Brush 2005) 

demonstrate that the solubility of the III and 

IV actinides was not significantly enhanced 

by complexation with acetate, citrate, EDTA, 

and oxalate at their maximum potential 

concentrations (Table SOTERM-19)". 

To: 

"The FMT calculations (Brush 2005) 

demonstrate that the solubility of the III and 

IV actinides are only slightly affected by 

organic complexation (Table SOTERM-19). 

The solubility of the III actinides was 

increased by a factor of 1.7 in GWB and 3.3 

in ERDA-6 brine. In both brines the solubility 

of the IV actinides was decreased by organic 

complexation. The overall effect of these 

changes on the release of actinides is not 

considered significant." 

EPA LANL-Reed Included in 3rd 

Response 

Submittal to the 

EPA 

Submitted to EPA 

in 3rd Response 

Nov 2009 

Page 11 of 11 
WIPP CRA-2009 Comments and Responses Enclosure 4 

EPA Comment 

Included in 

this Submittal 

Previously 

Submitted Pending 

Comments Received May 21, 2009 

1-G-l Stakeholder-Water Flow Model Concerns - ext from the Citizens 

for Alternatives to Radioactive Dumping (CARD) news release on 

March 25, 2009, raises questions... 

./ 

17G-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. 

./ 

1-G-3 Inventory- As outlined in the Executive Summary of DOE/TRU2008-3379, Rev. 1 (ATWIR 2007), DOE has proposed that ATWIR 2008 

be used as the inventory source... 

./ 

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... 

./ 

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

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

Reed...; Richmann... 

./ 

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

+111, +IV, and +V actinides that have become available since the CRA2004 PABC in Appendix SOTERM... 

./ 

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. 

./ 

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... 

./ 

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... 

./ 

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... 

./ 

1 
WIPP CRA-2009 Comments and Responses Enclosure 4 

EPA Comment 

Included in 

this Submittal 

Previously 

Submitted Pending 

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-, C032-, S042-and Ca2+. 

../ 

1-~-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... 

../ 

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... 

../ 

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... 

../ 

1-C-4 Chemistry Issues- Appendix MASS-2009 and Appendix SOTERM2009 do not address the current assumption that plastic and rubber 

degradation (if occurring)... 

../ 

l-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. 

../ 

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... 

../ 

l-C-7 Chemistry Issues- Appendix SOTERM-2009, l:able SOTERM-I, 

provides an incomplete list of the current chemistry model 

assumptions. 

../ 

1-C-8 Chemistry Issues- The fourth paragraph of Appendix SOTERM2009, Section 2.3.2 states: "the expected pH, when little or no 

carbonate is pres~nt, is 8.69 in GWB brine and... 

../ 

1-C-9 Chemistry Issues- DOE stat~.s that carbonate complexation of 

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

(Appendix SOTERM-2009, Section 3.6.2). 

../ 

1-C-1O Chemistry Issues- n Appendix SOTERM-2009, Section 4.4, DOE 

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

changed in the FMT database since the... 

../ 

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... 

../ 

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-ll, DOE states that the Eh-pH diagram demonstrates 

that Pu(lV) species would be... 

./ 

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

concentration, total americium concentration, and assumed ionic 

strength for generation of Appendix SOTERM-2009... 

./ 

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... 

./ 

1-C-15 Chemistry Issues- n Appendix SOTERM-2009, Table SOTERM21, the parameter descriptions for PHUMCIM and PHUMSIM indicate 

"actinide solubilities are inorganic only... 

./ 

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... 

./ 

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... 

./ 

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... 

./ 

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 

./ 

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... 

./ 

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

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

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... 

./ 

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... 

./ 

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 Slgn-offs - While reviewing some 

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

team to develop, manipulate and... 

./ 

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, 

./ 

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

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

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

./ 

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 ... 

./ 

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. .. 

./ 

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... 

./ 

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. .. 

./ 

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... 

./ 

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... 

./ 

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... 

./ 

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

cement inventory as documented in PAIR 2008 (Crawford et al2009, 

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

./ 

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... 

./ 

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

Monthly Injection &Saltwater Report for ... ./ 

2-33-240 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... 

./ 

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... 

./ 

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

including the Permian Basin 

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

./ 

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... 

./ 

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 ... 

./ 

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... 

./ 

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) 

./ 

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... 

./ 

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.. 

./ 

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). 

../ 

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... 

../ 

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), ... 

../ 

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, ... 

../ 

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... 

../ 

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 ... 

../ 

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. 

../ 

6