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 2012 Sandia Corporation 

IMPORTANT NOTICE: The current official version of this document is available via the Sandia 

National Laboratories WIPP Online Documents web site. A printed copy of this document may 

not be the version currently in effect. 

SANDIA NATIONAL LABORATORIES

WASTE ISOLATION PILOT PLANT 

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Analysis Plan for the 2012 WIPP Panel Closure System Performance 

Assessment 

Task 1.4.1.2 

Effective Date: July 2, 2012 

Authored by: Chris Camphouse Original signed by Chris Camphouse 7/2/12 

 Print Name Signature Date 

 

Reviewed by: Bwalya Malama Original signed by Bwalya Malama 07/02/12 

 Print Name Signature Date 

 Technical Reviewer 

 

Reviewed by: Shelly Nielsen Original signed by Shelly R. Nielsen 7-2-12 

 Print Name Signature Date 

 Quality Assurance Reviewer 

 

Approved by: Janis Trone Original signed by Janis Trone 7/2/12 

 Print Name Signature Date 

 Department Manager 
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Table of Contents 

1 Introduction and Objectives ........................................................ 4

2 Approach .................................................................................... 7

2.1 ROMPCS Model .............................................................................................. 8 

2.2 Calculation Methodology ............................................................................... 10 

2.3 Reports and Documentation .......................................................................... 13

3 Tasks ........................................................................................ 14

4 Software.................................................................................... 15

5 Special Considerations ............................................................. 15

6 Applicable Procedures .............................................................. 16

7 References ............................................................................... 16
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List of Figures and Tables 

Figure 1: A Schematic of the “Option D” Panel Closure .............................................................. 5 

Figure 2. Schematic diagram of the revised panel closure design................................................ 6 

Table 1: PCS_T1, PCS_T2, and PCS_T3 Properties to be used in the PCS-2012 PA ................ 9 

Table 2: WIPP PA BRAGFLO Scenarios .................................................................................... 11 

Table 3: PA Intrusion Scenarios Used in Calculating Direct Brine Releases .............................. 12 

Table 4: Task List and Estimated Schedule for the PCS-2012 PA. ............................................ 14 

Table 5: Codes to be used for the PCS-2012 PA. ...................................................................... 15 

Table 6: WIPP PA Alpha Cluster ................................................................................................ 15 
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1 Introduction and Objectives 

The Waste Isolation Pilot Plant (WIPP), located in southeastern New Mexico, has been 

developed by the U.S. Department of Energy (DOE) for the geologic (deep underground) 

disposal of transuranic (TRU) waste. Containment of TRU waste at the WIPP is regulated by the 

U.S. Environmental Protection Agency (EPA) according to the regulations set forth in Title 40 of 

the Code of Federal Regulations (CFR), Part 191. The DOE demonstrates compliance with the 

containment requirements according to the Certification Criteria in Title 40 CFR Part 194 by 

means of performance assessment (PA) calculations performed by Sandia National Laboratories 

(SNL). WIPP PA calculations estimate the probability and consequence of potential 

radionuclide releases from the repository to the accessible environment for a regulatory period of 

10,000 years after facility closure. The models used in PA are maintained and updated with new 

information as part of an ongoing process. Improved information regarding important WIPP 

features, events, and processes typically results in refinements and modifications to PA models 

and the parameters used in them. Planned changes to the repository and/or the components 

therein also result in updates to WIPP PA models. WIPP PA models are used to support the 

repository recertification process that occurs at five-year intervals following the receipt of the 

first waste shipment at the site in 1999. 

WIPP waste panel closures comprise a feature of the repository that has been represented in 

WIPP PA regulatory compliance demonstration since the Compliance Certification Application 

(CCA) of 1996. Panel closures are included in the repository as a safety measure during the 

operational period. In particular, their presence in the repository is a means to protect workers 

from exposure to two potential hazards: 1) volatile organic compounds that may be present in 

emplaced waste materials and 2) an explosion which has been hypothesized to occur from gas 

generation causing methane concentration in the waste panels to reach a sufficiently high level. 

Panel closures were not developed to isolate radionuclides in the repository after closure. The 

DOE stated in the CCA (DOE 1996) that “The panel closure system was not designed or 

intended to support long-term repository performance.” Panel closures are included in WIPP 

PA models principally because they are part of the disposal system, not because they play a 

substantive role in inhibiting the release of radionuclides to the outside environment. 

The WIPP was certified to receive TRU waste in 1998. The 1998 rulemaking had several 

conditions. Condition 1 involved the design of the panel closure system (PCS) implemented in 

the repository. The DOE presented four design options in the CCA, and 

“The EPA based its certification decision on the condition that DOE 

implement the most robust design [referred to in the CCA as “Option D”]. 

The Agency found the Option D design to be adequate, but also determined 

that the use of a Salado Mass Concrete - using brine rather than fresh water - 

would produce concrete seal permeabilities in the repository more consistent 

with the values used in DOE’s performance assessment. Therefore, Condition 

1 of the EPA’s certification requires DOE to implement the Option D PCS at 

the WIPP, with Salado Mass Concrete” (EPA 1998). 
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The Option D panel closure system consists of three primary components: 1) a concrete block 

wall (the explosion wall), 2) open drift, and 3) a concrete monolith. The arrangement and 

dimensions of these components are illustrated in Figure 1. 

Waste disposal Open Drift

Concrete

Monolith

9.1 m 7.9 m

Explosion

Wall

3.7 m

40 m

2.4 or 2.7 m

2.4 m

DRZ

DRZ

Open Drift

Figure 1: A Schematic of the “Option D” Panel Closure 

Extensive refinement to WIPP panel closure modeling in PA has occurred since the 

implementation used in the CCA (Vugrin and Wagner 2006). In the CCA and the PAVT 

(MacKinnon and Freeze 1997) that followed, regulatory compliance was demonstrated with a 

generic panel closure that was not Option D. Following certification of the WIPP in 1998, and 

the mandate that Option D be implemented as the panel closure in WIPP, a PA was conducted in 

2002 (Hansen 2002) with the aim of implementing an Option D panel closure into the repository 

models used in WIPP PA, and to assess the impacts of panel closure design on long-term 

repository performance. Two panel closure cases were considered. The first was modeled upon 

the mandated Option D panel closure design. The second was the generic panel closure design 

implemented in the CCA and PAVT. Upon completion of the analysis, it was found that total 

normalized releases resulting from the two panel closure cases were nearly identical. Moreover, 

nearly identical distributions for each release component were calculated in the two panel closure 

cases. A more granular representation of the Option D panel closure was developed during the 

2002 – 2003 Technical Baseline Migration (TBM) PA. Upon completion of the TBM PA, it was 

again found that the TBM and PAVT produced releases that are nearly identical, indicating that 

repository performance is not significantly affected by changes in the panel closure properties 

(Dunagan 2003). The Option D panel closure representation developed during the TBM was 

used for the panel closure representation in the 2004 and 2009 Compliance Recertification 

Applications (CRA-2004 and CRA-2009, respectively). 

The DOE has submitted a planned change request (PCR) to the EPA requesting that EPA modify 

Condition 1 of the Final Certification Rulemaking for 40 CFR Part 194 (EPA, 1998) for the 

WIPP. Following the selection of the Option D panel closure design in 1998, the DOE has 

reassessed the engineering of the panel closure and established a revised design which is simpler, 

easier to construct and equally effective at performing its operational-period isolating function. 

Accordingly, the PCR submitted to EPA requested that Condition 1 be changed, and that a 

revised design for the panel closures be approved for use in all panels (DOE, 2011). The revised 

design of the PCS, known as the Run-of-Mine Panel Closure System (ROMPCS), comprises 100 

feet of run-of-mine (ROM) salt with barriers at each end (Figure 2). The ROM salt is generated 

from ongoing mining operations at the WIPP and may be compacted and/or moistened as it is 

emplaced in a panel entry. The ROM salt will be emplaced to all salt surfaces (back, walls, etc.) 
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as completely as practicable. After emplacement, creep closure of the panel entries will cause 

the ROM salt to consolidate to a condition approaching intact salt, with low porosity and low 

permeability. 

(a) Panel closure with 100 feet of ROM salt between two ventilation bulkheads 

(b) Panel closure with 100 feet of ROM salt between a ventilation bulkhead & explosion wall 

Figure 2. Schematic diagram of the revised panel closure design 

The barriers will consist of ventilation bulkheads, similar to those currently used in the panels as 

room closures. The ventilation bulkheads are designed to restrict air flows and prevent personnel 

access into waste-filled areas during the operational phase. In Panels 1, 2, and 5, where 

explosion walls fabricated from concrete blocks have already been emplaced in the panel entries, 

an explosion wall is the inner barrier and a ventilation bulkhead will be the outer barrier, as 

shown in Figure 2b. 

Panel closures are represented in PA by way of their material properties and spatial extent. Due 

to the regulatory time scale of 10,000 years for which regulatory compliance must be 

demonstrated, there are uncertainties associated with panel closure material properties. These 

uncertainties in material properties are incorporated in PA. A material property with an 

associated uncertainty is assigned a distribution, and this distribution is randomly sampled. This 

sampling process allows for repository performance to be quantified over a range of material 

conditions, as well as an analysis of performance sensitivity to changes in material properties. 

As briefly described above, numerous studies have been conducted to date, often by way of full 

PA analyses, to quantify the impact of changes in panel closure material properties on regulatory 

compliance. In addition, several PA analyses have been performed (Hansen 2002, Vugrin & 

Dunagan 2006, Camphouse et al 2011) with the aim of determining the impact of panel closure 

redesigns on repository performance. Regulatory compliance has been met in all PA analyses 

performed to date, including those that incorporated changes to panel closure modeling. 

Regulatory compliance has been repeatedly shown to be primarily insensitive to panel closure 

material properties. An additional PA is to be executed that incorporates the ROMPC design 

Concrete

block wall
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into the current PA baseline established by the 2009 Performance Assessment Baseline 

Calculation (PABC-2009) (Clayton et al., 2010). The name given to this new panel closure PA 

is PCS-2012. 

The PCS-2012 PA will quantify impacts of the ROMPCS design by comparing total normalized 

releases to those found in the PABC-2009 where Option D was implemented as the panel 

closure. The PCS-2012 PA will incorporate material parameters and timings to account for the 

following physical processes and rock mechanics principles: 

1. Creep closure of the salt rock surrounding panel entries will cause consolidation of 

ROM salt emplaced in panel entries. 

2. Eventually, the ROM salt comprising the closures will approach a condition similar to 

intact salt. 

3. As ROM salt reaches higher fractional densities during consolidation, back stress will 

be imposed on the surrounding rock mass leading to eventual healing of the disturbed 

rock zone (DRZ). 

4. DRZ healing above and below the ROM salt panel closures will reduce DRZ porosity 

and permeability in those areas. 

Calculations and analyses have been performed to develop material properties to be used in the 

PCS-2012 PA, and are documented in Camphouse (2012), DOE (2012), and Herrick (2012). 

Potential regulatory compliance impacts resulting from the use of the ROMPCS design in WIPP 

will be determined by way of a comparison of release probabilities to those calculated in the 

PABC-2009. Differences seen between the PABC-2009 and the PCS-2012 PA will be a direct 

consequence of the revised design of the PCS. This document details how SNL will conduct the 

compliance decision analysis for the PCS-2012 PA. 

2 Approach 

The PCS-2012 PA analysis will be used to demonstrate compliance of the WIPP repository with 

the containment requirements according to the Certification Criteria in Title 40 CFR Part 194. A 

focused set of PA calculations will be executed to determine the impact of the panel closure 

changes being proposed. The results of PCS-2012 PA calculations will be compared to those 

obtained in the PABC-2009. The PCS-2012 PA will examine all aspects of repository 

performance that are potentially impacted by the panel closure design. 

The approach used for the PCS-2012 PA will be very similar to that used for PABC-2009 

(Clayton 2009). The PCS-2012 PA begins with an assessment that identifies and evaluates the 

features, events, and processes (FEPs) that are related to the changes introduced by the proposed 

panel closure design. The purpose of the FEPs evaluation is to determine if the current FEPs 

baseline (currently the PABC-2009 FEPs baseline) is suitable to evaluate the new closure design, 

or if changes to FEPs descriptions, screening arguments, or decisions are necessary. The results 

of this assessment concluded that no changes are needed to the FEPs baseline (Kirkes 2011) 1. It 

should be pointed out that the FEPs analysis only determines that the WIPP design features are 

 

1

 Note that Kirkes (2011) also evaluated changes associated with a proposed reconfiguration of the repository 

layout; the PCS changes are a subset of this FEP evaluation. Only the elements (and FEPs) relating to the PCS 

redesign are germane to this Analysis Plan and resulting analyses. 
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appropriately identified, described, and screened according to established FEPs screening 

methods. WIPP FEPs W109 Panel Closure Geometry and W110, Panel Closure Properties, are 

directly related to the changes proposed by the new PCS design and were the focus of the FEPs 

assessment. These two FEPs have been screened in (represented) as part of previous 

performance assessments in all scenarios, and continue to be so in the PCS-2012 PA. Any 

differences in the representation of these FEPs within the WIPP repository model is described in 

this analysis plan, and proper parameterization of the PCS elements that represent these FEPs is 

described in Camphouse et al. (2012). 

The impacts of the ROMPCS design on regulatory compliance will be determined by a direct 

comparison of PCS-2012 PA results to those obtained in the PABC-2009. The FEPs baseline 

utilized in the PABC-2009 will also be applied to the PCS-2012 PA, as no changes were 

recommended in Kirkes (2011). As such, this will enable a “like for like” comparison between 

the two analyses, with any compliance impacts seen in the PCS-2012 being solely attributable to 

the ROMPCS closure design and its material parameters. 

The following sections detail the implementation of the PCS-2012 PA with particular attention 

being given to the way panel closure design changes will be captured in individual PA codes and 

parameters. 

2.1 ROMPCS Model 

The PCS-2012 PA will replace the PABC-2009 representation of the Option D panel closure 

with a representation of the ROMPCS within the WIPP repository model. As discussed in 

relation to Figure 2, concrete block explosion walls have already been emplaced in waste panels 

1, 2, and 5. The ventilation bulkheads used in the ROMPCS are designed to provide isolation 

only during the operational period. These bulkheads are not expected to remain intact 100 years 

after repository closure because of creep closure of the panel entries. The explosion wall is also 

designed for the operational period. These walls are inspected on a regular basis, and their 

anticipated condition is also assessed through numerical modeling (e.g. RockSol, 2006). 

Installed explosion walls show surface spalling or slabbing of the concrete blocks as a result of 

the loading caused by inward creep of the salt. Numerical stress analysis of the concrete 

explosion wall has demonstrated that the free faces and the rib contacts will be in a condition of 

plastic yield with an unyielded core by 7 years after emplacement (Rocksol, 2006, Figures 7 and 

10). No long term stress analyses have been carried out; however, it is expected that the spalling 

and yield will be progressive, and that the walls will not be significant structures after the initial 

100 year time period, due to the brittle, non-plastic behavior of concrete. The ventilation 

bulkheads and explosion walls will therefore have no significant impact on long-term 

performance of the panel closures and are therefore not included in the PCS-2012 PA 

representation of the ROMPCS. Consequently, the ROMPCS will be modeled as consisting of 

100 feet of ROM salt. 

The ROMPCS properties will be based on three time periods: from 0 to 100 years, from 100 

years to 200 years, and from 200 years to 10,000 years. This is a refinement to the granularity of 

panel closure modeling undertaken in the 2006 PCS PA (Vugrin and Dunagan 2006) and the 

2011 PC3R PA (Camphouse et al 2011). Three time periods are appropriate because the process 

to consolidate the ROM salt occurs over a primary time scale of approximately 100 years, while 

the process to heal fractures in the DRZ surrounding the PCS occurs over a longer time scale of 
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approximately 200 years. The ROM salt will therefore be represented by three materials, denoted 

as PCS_T1 for the first 100 years, PCS_T2 for 100 to 200 years, and PCS_T3 for 200 to 10,000 

years. Analyses and calculations have shown (Camphouse et al 2012) that the time-dependent 

back stress imposed on the DRZ by the re-consolidated ROM salt panel closure does not become 

appreciable until roughly 200 years after emplacement of the ROM salt in the drift. As a result, 

it is reasonable and appropriate to maintain the same properties for the DRZ above and below the 

ROMPCS for the first 200 years after closure as are specified to the DRZ surrounding the 

disposal rooms. After 200 years, the DRZ above and below the ROMPCS will be modeled as 

having healed, and this sub-region of the DRZ will be represented by material DRZ_PCS. 

Material DRZ_PCS was developed during the TBM PA to represent healed DRZ above Option 

D panel closures (Stein 2002). Material DRZ_PCS has been used since the TBM PA to 

represent healed DRZ regions above and below panel closures, and will be used in the PCS-2012 

to maintain consistency in material names with prior analyses. 

The effective permeability and porosity of the ROMPCS are the two parameters expected to have 

the greatest impact on calculations of pressure and brine saturation in repository waste areas. 

Consequently, materials PCS_T1, PCS_T2, and PCS_T3 will be assigned porosities and 

permeabilities appropriate for representation of the ROMPCS. Properties specified for material 

DRZ_PCS will be identical to those used in the PABC-2009 PA. BRAGFLO calculations 

require that two-phase flow properties be specified for all materials. A brief discussion of the 

two-phase flow parameters used for PCS_T1, PCS_T2, and PCS_T3, particularly their 

implementation in regard to BRAGFLO capillary pressure modeling, is given in Camphouse 

(2012). A full list of properties to be established for materials PCS_T1, PCS_T2, and PCS_T3 is 

given in Table 1. In addition to the properties listed in Table 1, the initial brine saturation of the 

ROMPCS will be specified. This parameter corresponds to property SAT_IBRN for material 

PCS_T1. With the exception of these parameters, the PCS-2012 PA will use the same 

parameters and parameter values that were used for the PABC-2009 (Clayton 2009).

Table 1: PCS_T1, PCS_T2, and PCS_T3 Properties to be used in the PCS-2012 PA 

Property Description 

CAP_MOD Capillary Pressure Model Number 

(CAP_MOD = 1 or 2 has been used in every PA to 

date for all materials in BRAGFLO) 

COMP_RCK Bulk Compressibility 

KPT Flag to Enable Dynamic Updating of Threshold 

Capillary Pressure as a Function of Permeability 

(KPT = 0 has been used in every PA to date for all 

materials in BRAGFLO) 

PC_MAX Maximum Allowable Capillary Pressure 

(PC_MAX = 1 x 108

 Pa has been used for all 

BRAGFLO materials since the CCA) 

PCT_A Threshold Capillary Pressure Linear Parameter 

PCT_EXP Threshold Capillary Pressure Exponential 

Parameter 

PO_MIN Minimum Brine Pressure for Capillary Model 3 

(CAP_MOD = 3 has never been used in PA) 
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Property Description 

PORE_DIS Brooks-Corey Pore Distribution Parameter 

POROSITY Effective Porosity 

PRMX_LOG Log of Intrinsic Permeability, X-Direction 

PRMY_LOG Log of Intrinsic Permeability, Y-Direction 

PRMZ_LOG Log of Intrinsic Permeability, Z-Direction 

RELP_MOD Relative Permeability Model Number 

SAT_RBRN Residual Brine Saturation 

SAT_RGAS Residual Gas Saturation 

2.2 Calculation Methodology 

2.2.1 Rationale 

The aim of the PCS-2012 PA is to quantify regulatory compliance impacts associated with the 

ROMPCS design. Impacts will be determined by direct comparison of PCS-2012 PA results to 

the current compliance baseline established by the PABC-2009. To enable the direct comparison 

of results obtained in the two analyses, the PCS-2012 PA is constructed so that the structure of 

calculations performed are as similar as possible to that used in the PABC-2009. To that end, the 

PCS-2012 PA will utilize the same waste inventory information, intrusion scenarios, drilling rate 

and plugging pattern parameters, radionuclide solubility parameters, and hydrologic 

transmissivity fields as were used in the PABC-2009. The PCS-2012 PA will consist of a full set 

of PA compliance calculations. That is, three replicates of PA calculations, each replicate 

consisting of 100 vectors, will be performed. The random seeds from the PABC-2009 will be 

preserved so that results from the PCS-2012 PA analysis can be compared to those from the 

PABC-2009 on a vector-by-vector basis. 

 

The design of the ROMPCS potentially alters pressure profiles in repository waste regions as 

compared to Option D design implemented in the PABC-2009. Pressure changes in the waste 

panels translate directly to changes in spallings releases as pressure changes yield changes in 

spallings volumes. Moreover, pressure changes in waste areas potentially alter the influx of 

brine into these regions, corresponding to changes in brine saturation. Direct brine releases are a 

function of pressure and brine saturation at the time of intrusion. Two conditions must be met 

for a DBR to occur. First, the brine saturation in the intruded panel must exceed the residual 

brine saturation of the waste, a sampled parameter in PA. Second, the repository pressure near 

the drilling location must exceed the hydrostatic pressure of the drilling fluid, which is specified 

in PA to be 8 MPa. The combined impact of pressure and brine saturation changes resulting 

from implementation of the ROMPCS potentially alters the released brine volume associated 

with a particular intrusion event as compared to the PABC-2009. The potential for changes to 

released brine volumes translates directly to changes in DBRs. For these reasons, spallings and 

DBRs are the primary release mechanisms of interest in the PCS-2012 PA. Changes to the panel 

closure design have no impact on releases due to cuttings and cavings. Transport releases 

through the Culebra had virtually no impact on total normalized releases in the PABC-2009 

(Clayton et al 2010). Implementation of the ROMPCS will not change this result. In addition, 

hydrologic transmissivity fields are not being updated as part of the PCS-2012 PA. 

Consequently, Culebra transport results obtained in the PABC-2009 will also be used in the 

PCS-2012 PA. 
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The calculations to be conducted for the PCS-2012 PA are listed below. Results generated from 

the PABC-2009 will be used for codes not discussed below. 

2.2.2 Parameter Sampling: LHS 

Three replicates of 100 vectors will be created using the computer code LHS. LHS version 2.42 

will be used for the PCS-2012 PA, which is the same code used for the PABC-2009. The 

random seed and parameter ordering from the PABC-2009 will be used for the PCS-2012 PA. 

Use of the PABC-2009 random seeds and ordering will result in identical sampled parameter 

values for parameters that are common to both the PCS-2012 PA and the PABC-2009. This 

approach enables comparison of the PCS-2012 PA and the PABC-2009 on a vector-by-vector 

basis. 

PA material CONC_PCS was used in the PABC-2009 to represent the concrete monolith 

component of the Option D panel closure. In the PCS-2012 PA, material CONC_PCS will be 

replaced by materials PCS_T1, PCS_T2, and PCS_T3 and their corresponding properties. 

Distributions prescribed to these three materials are listed in Camphouse et al (2012). 

2.2.3 Salado Flow: BRAGFLO 

The two-phase flow code BRAGFLO simulates the brine and gas flow in and around the WIPP 

repository and incorporates the effects of disposal room closure, gas generation, brine 

consumption, and inter-bed fracturing in response to gas pressure. The results of BRAGFLO 

scenarios S1-BF to S5-BF are used as input for the subsequent calculation of Salado radionuclide 

transport, DBRs, and spallings releases. BRAGFLO scenario S6-BF is used in the calculation of 

radionuclide transport to the Culebra. The scenarios modeled in BRAGFLO are listed in Table 

2. 

Table 2: WIPP PA BRAGFLO Scenarios 

Scenario # of Drilling 

Intrusions 

Time of Intrusion 

(Years) 

Castile Brine Pocket 

encountered 

S1-BF 0 (Undisturbed) NA NA 

S2-BF 1 350 Yes 

S3-BF 1 1,000 Yes 

S4-BF 1 350 No 

S5-BF 1 1,000 No 

S6-BF 2 1,000 and 2,000 Only at 2,000 

Implementation of the ROMPCS will slightly alter the BRAGFLO computational grid and 

material map that were used in the PABC-2009. In particular, Option D panel closures 

represented in the PABC-2009 BRAGFLO grid will be replaced by panel closures consisting of 

ROM salt for the PCS-2012 PA. Healing of the DRZ directly above and below redesigned panel 

closures as discussed in Section 1 will also be captured in PCS-2012 PA calculations. Finally, 

the Option D panel closure implemented in the PABC-2009 is 40 meters long (Figure 1) while 

the ROMPCS modeled in the PCS-2012 is 100 feet (30.48 meters) long. The PABC-2009 
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BRAGFLO grid will be modified slightly to account for the reduction in length of the ROMPCS 

as compared to Option D. 

A complete suite of BRAGFLO calculations will be executed for the PCS-2012 PA. These 

calculations will consist of 3 replicates, 100 vectors per replicate, and 6 scenarios (see Table 2) 

per vector. The codes PREBRAG version 8.0, BRAGFLO version 6.0 and POSTBRAG version 

4.00A will be used for the PCS-2012 PA, which are the same codes used for PABC-2009. 

2.2.4 Spallings: DRSPALL and CUTTINGS_S 

Repository pressures may be affected by the implementation of the ROMPCS design. Changes 

in repository pressures have the potential to impact spallings results. Consequently, spallings 

releases for the PCS-2012 PA may differ from those found in the PABC-2009 due to differences 

in repository pressures calculated by BRAGFLO. Spallings volumes from a single borehole 

intrusion are calculated by code DRSPALL at initial repository pressures of 10, 12, 14, and 14.8 

MPa. DRSPALL calculations that were utilized to generate spallings volumes at these pressures 

in the PABC-2009 will also be used in the PCS-2012 PA. The PCS-2012 PA will use the same 

procedure as was used for the PABC-2009 to interpolate between these DRSPALL volumes to 

calculate spallings volumes corresponding to a particular drilling intrusion. The initial repository 

pressure for a given scenario, time, location, and vector will be retrieved from the BRAGFLO 

results, and CUTTINGS_S will use this initial pressure to calculate a spallings volume for each 

scenario, time, location, and vector combination by interpolating between DRSPALL results. 

The code CUTTINGS_S version 6.02 will be used for the PCS-2012 PA, which is the same code 

used for the PABC-2009. 

2.2.5 Direct Brine Releases: BRAGFLO 

In addition to its role as a tool used to simulate brine and gas flow in and around the WIPP 

repository, BRAGFLO is also used in PA to calculate DBR volumes. As the implementation of 

the ROMPCS design potentially impacts pressures and brine saturations in waste-containing 

repository regions, DBR calculations will be performed as part of the PCS-2012 PA. The 

numerical grid and material map used to calculate DBRs will be updated to reflect the ROMPCS 

design. Conditions required for the initiation of a DBR release will remain unchanged from the 

PABC-2009, and the DBR volumes will be calculated for the same scenarios and times (Table 3) 

used in that analysis. The codes PREBRAG version 8.0, BRAGFLO version 6.0 and 

POSTBRAG version 4.00A will be used for the PCS-2012 PA, which are the same codes used 

for the PABC-2009. 

Table 3: PA Intrusion Scenarios Used in Calculating Direct Brine Releases 

Scenario 

Conditioning (or 1st) 

Intrusion Time (year) and 

Type 

Intrusion Times – Subsequent 

(year) 

S1-DBR None 100, 350, 1000, 3000, 5000, 10000 

S2-DBR 350, E1 550, 750, 2000, 4000, 10000 

S3-DBR 1000, E1 1200, 1400, 3000, 5000, 10000 

S4-DBR 350, E2 550, 750, 2000, 4000, 10000 

S5-DBR 1000, E2 1200, 1400, 3000, 5000, 10000 
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2.2.6 CCDF Construction: CCDFGF 

Implementation of the ROMPCS design will have a negligible impact on potential releases from 

the Culebra. As a result, the PCS-2012 PA will calculate CCDFs of individual vectors for total 

normalized releases using Culebra release results calculated in the PABC-2009. The PCS-2012 

PA will calculate CCDFs of individual vectors for total normalized releases, cuttings and cavings 

releases, spallings releases, and DBRs. (The use of the ROMPCS design will have no impact on 

cuttings and cavings releases. Nonetheless, new cuttings and cavings release volumes will be 

calculated in the PCS-2012 PA as a by-product of the spallings calculation.) Mean CCDFs for 

each release pathway will be calculated by replicate and across all replicates. The 95% 

confidence limit on the mean across all replicates will also be calculated. The codes 

PRECCDFGF version 1.01 and CCDFGF version 5.02 will be used for the PCS-2012 PA, which 

are the same codes used for the PABC-2009. 

2.2.7 Sensitivity Analysis: STEPWISE 

The PCS-2012 PA will implement sensitivity analyses for results from the major codes in a 

manner consistent with those employed for the PABC-2009. Specifically, global sensitivity 

analyses will be conducted on the results from CCDFGF using the linear regression code 

STEPWISE version 2.21. Since the Salado flow results from the BRAGFLO calculations are 

used as input to many other codes, additional sensitivity analyses may be performed using 

BRAGFLO results. WIPP PA codes such as PCCSRC, as well as Commercial Off-The Shelf 

(COTS) statistical software, may be used to assess the sensitivity of BRAGFLO results to input 

parameters. 

2.3 Reports and Documentation 

Several reports will be generated as a result of this analysis plan. Each set of calculations 

discussed in Section 2.2 and its subsections will be documented in an analysis report. These 

reports will include: 

1) discussion of any implementation changes (parameters, modeling assumptions, etc.) 

relative to the corresponding PABC-2009 calculations; and 

2) analysis of results relevant to the long term performance of the repository. The analysis 

will include comparisons of PCS-2012 PA results with PABC-2009 results. 

A summary report describing the major results of the PA will also be written. The summary 

report will include the run control record as an appendix. This appendix will contain: 

1. A description of the hardware platform and operating system used to perform the 

calculations. 

2. A listing of the codes and versions used to perform the calculations. 

3. A listing of the scripts used to run each calculation. 

4. A listing of the input and output files for each calculation. 

5. A listing of the library and class where each file is stored. 

6. File naming conventions. 

The analyses performed under this analysis plan are in support of a rulemaking decision to 

replace the current WIPP Option D panel closure design with the ROMPCS design. As such, it 
AP-161 

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is likely that additional analyses and calculations will be performed as part of the regulatory 

review and approval process. These additional tasks and documentation, if they become 

necessary, will also fall under AP-161. 

3 Tasks 

The tasks, responsible personnel and estimated task schedule are summarized below in Table 4. 

Table 4: Task List and Estimated Schedule for the PCS-2012 PA. 

Task Description Guiding 

Document 

Approximate 

Completion 

Date 

Responsible 

Individual(s) 

1 Parameters 

1a Development of ROMPCS parameters SP 9-5 7/11/12 

Camphouse 

Gross 

Herrick 

Kicker 

Thompson 

1b Entry of ROMPCS parameters into 

PAPDB SP 9-5 7/12/12 Long 

2 Preparation Tasks 

 2a Input files prepared AP-161 7/25/12 Camphouse 

Clayton 

Kicker 

Kirchner 

Malama 

2b Input file review AP-161 8/1/12 Camphouse 

3 Code Run Environment Preparation 

 3a Libraries Update AP-161 8/1/12 Long 

 3b Run Control Script Update AP-161 9/14/12 Long 

4 Calculations 

 4a Parameter Sampling: LHS AP-161 8/2/12 Long 

 4b BRAGFLO Testing with new 

parameters and por/perm relationship 

AP-161 8/10/12 Camphouse 

Malama 

 4c Salado Flow: BRAGFLO AP-161 8/17/12 Long 

 4d Cuttings & Cavings, Spallings: 

CUTTINGS_S 

AP-161 8/24/12 Long 

 4e Direct Brine Releases: BRAGFLO AP-161 8/31/12 Long 

 4f CCDF Construction: CCDFGF AP-161 9/7/12 Long 

 4g Sensitivity Analysis: STEPWISE AP-161 9/14/12 Kirchner 

5 Analysis & Documentation 

 5a Parameter Sampling: LHS AP-161 9/6/12 Kirchner 

 5b Salado Flow: BRAGFLO AP-161 9/21/12 Camphouse 

Malama 

 5d Spallings: CUTTINGS_S AP-161 9/28/12 Kicker 

 5c Direct Brine Releases: BRAGFLO AP-161 10/5/12 Malama 

Camphouse 

 5d CCDF Construction: CCDFGF AP-161 10/12/12 Kicker 

 5e Sensitivity Analysis: STEPWISE AP-161 10/19/12 Kirchner 

 5f Summary Report with Run Control as 

Appendix 

AP-161 11/9/12 Camphouse 

Long 
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4 Software 

The major WIPP PA codes to be used for this analysis are listed in Table 5. These codes will be 

executed on the WIPP PA Alpha Cluster, which is listed in Table 6. Additionally, COTS 

software, such as MATHEMATICA®, MATLAB®, MATHCAD®, Excel®, Access®, 

Grapher®, or Kaleidagraph® may be utilized. The use of any COTS application will be verified 

per NP 9-1 Appendix C as appropriate. 

Table 5: Codes to be used for the PCS-2012 PA. 

Code Version Build Date Executable 

ALGEBRACDB 2.35 31-JAN-1996 ALGEBRACDB_PA96.EXE 

BRAGFLO 6.0 12-FEB-2007 BRAGFLO_QB0600.EXE 

CCDFGF 5.02 13-DEC-2004 CCDFGF_QB0502.EXE 

CUTTINGS_S 6.02 9-JUN-2005 CUTTINGS_S_QA0602.EXE 

GENMESH 6.08 31-JAN-1996 GM_PA96.EXE 

ICSET 2.22 1-FEB-1996 ICSET_PA96.EXE 

LHS 2.42 18-JAN-2005 LHS_QA0242.EXE 

MATSET 9.10 29-NOV-2001 MATSET_QA0910.EXE 

PCCSRC 2.21 23-MAY-1996 PCCSRC_PA96.EXE 

POSTBRAG 4.00A 28-MAR-2007 POSTBRAG_QA0400A.EXE 

POSTLHS 4.07A 25-APR-2005 POSTLHS_QA0407A.EXE 

PREBRAG 8.00 8-MAR-2007 PREBRAG_QA0800.EXE 

PRECCDFGF 1.01 7-JUL-2005 PRECCDFGF_QA0101.EXE 

PRELHS 2.30 27-NOV-2001 PRELHS_QA0230.EXE 

RELATE 1.43 6-MAR-1996 RELATE_PA96.EXE 

STEPWISE 2.21 2-DEC-1996 STEPWISE_PA96_2.EXE 

SUMMARIZE 3.01 21-DEC-2005 SUMMARIZE_QB0301.EXE 

Table 6: WIPP PA Alpha Cluster 

Node Hardware Type CPU Operating System 

CCR HP AlphaServer ES45 Alpha EV68 Open VMS 8.2 

TDN HP AlphaServer ES45 Alpha EV68 Open VMS 8.2 

BTO HP AlphaServer ES45 Alpha EV68 Open VMS 8.2 

CSN HP AlphaServer ES45 Alpha EV68 Open VMS 8.2 

GNR HP AlphaServer ES47 Alpha EV7 Open VMS 8.2 

MC5 HP AlphaServer ES47 Alpha EV7 Open VMS 8.2 

TRS HP AlphaServer ES47 Alpha EV7 Open VMS 8.2 

TBB HP AlphaServer ES47 Alpha EV7 Open VMS 8.2 

5 Special Considerations 

None 
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6 Applicable Procedures 

All applicable WIPP QA procedures will be followed when conducting these analyses. 

 Training of personnel will be conducted in accordance with the requirements of NP 2-1, 

Qualification and Training. 

 Analyses will be conducted and documented in accordance with the requirements of 

NP 9-1, Analyses. 

 All software used will meet the requirements laid out in NP 19-1, Software Requirements

and NP 9-1, as applicable. 

 The analyses will be reviewed following NP 6-1, Document Review Process. 

 All required records will be submitted to the WIPP Records Center in accordance with 

NP 17-1, Records. 

 New and revised parameters will be created as discussed in NP 9-2, Parameters.

7 References 

Camphouse, R.C. 2012. An overview of the BRAGFLO two-phase flow parameters used to 

model the run-of-mine salt panel closures implemented in the PCS-2012 PA. Memo to Paul 

Shoemaker dated June 7, 2012. Sandia National Laboratories, Carlsbad, NM. ERMS 557653. 

Camphouse, R.C., Gross, M., Herrick, C.G., Kicker, D.C., and Thompson, B. 2012. 

Recommendations and Justifications of Parameter Values for the Run-of-Mine Salt Panel 

Closure System Design Modeled in the PCS-2012 PA. Memo to WIPP Records Center dated 

May 3, 2012. Sandia National Laboratories, Carlsbad, NM. ERMS 557396. 

Camphouse, R.C., Clayton, D.J., Kicker, D.C., and Pasch, J.J. 2011. Summary Report for the 

AP-151 (PC3R) Performance Assessment, Revision 1. Sandia National Laboratories, Carlsbad, 

NM. ERMS 555489. 

Clayton, D.C., Camphouse, R. C., Garner, J. W., Ismail, A. E., Kirchner, T. B., Kuhlman, K. L., 

and Nemer, M. B.. 2010. Summary Report of the CRA-2009 Performance Assessment Baseline 

Calculation, Revision 1. Sandia National Laboratories. Carlsbad, New Mexico, ERMS 553039. 

DOE (U.S. Department of Energy). 1996. Title 40 CFR Part 191 Compliance Certification 

Application for the Waste Isolation Pilot Plant. DOE/CAO-1996-2184. U.S. Department of 

Energy, Waste Isolation Pilot Plant, Carlsbad Area Office. Carlsbad, NM. 

DOE (U.S. Department of Energy), 2011. Panel Closure System Design, Planned Change 

Request to the EPA 40 CFR Part 194 Certification of the Waste Isolation Pilot Plant. U.S. 

Department of Energy, Carlsbad Field Office. Carlsbad, New Mexico. 

DOE (U.S. Department of Energy), 2012. Response to First Set of EPA Questions to DOE, 

December 22, 2011. Letter from Mr. Juan Franco, Manager, Carlsbad Area Field Office, U.S. 

Department of Energy, to Mr. Jonathan Edwards, Director, Radiation Protection Division, U.S. 

Environmental Protection Agency, dated April 17, 2012. 
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Dunagan, S. C. 2003. Complementary Cumulative Distribution Functions (CCDFs) for the 

Technical Baseline Migration (TBM), Revision 0. Sandia National Laboratories, Carlsbad, NM. 

ERMS 525707. 

EPA (U.S. Environmental Protection Agency). 1998. Criteria for the Certification and 

Re-Certification of the Waste Isolation Pilot Plants Compliance with the 40 CFR Part 191 

Disposal Regulations: Certification Decision; Final Rule, Federal Register, Vol. 63, No. 95, 

pp. 27353-27406. U.S. Environmental Protection Agency, Office of Air and Radiation, 

Washington, D.C. 

Hansen, C. W. 2002. Analysis Report for the Panel Closure Impact Assessment. Sandia National 

Laboratories, Carlsbad, NM. ERMS 523935. 

Herrick, C.G. 2012. JAS3D Calculations Performed in Support of the PCS-2012 PA Parameter 

Selections. Sandia National Laboratories, Carlsbad, NM. 

Kirkes, G. R. 2011. Features, Events, and Processes Assesssment for Changes Described in 

Analysis Plan – 151, Revision 0. March 2011. Sandia National Laboratories, Carlsbad, NM. 

ERMS 555237. 

MacKinnon R. and G. Freeze, 1997. Supplemental Summary of EPA-Mandated Performance 

Assessment Verification Test (All Replicates) and Comparison with the Compliance 

Certification Application Calculations, Sandia National Laboratories, Carlsbad, NM. ERMS 

414880. (EPA Docket A-93-02, II-G-28.) 

RockSol Consulting Group, Inc. 2006. Further Assessment of the Short-term Stability of the 12 

Foot Explosion Isolation Wall. Report prepared for Washington TRU Solutions, LLC. 

Stein, J.S. 2002. Parameter values for new materials CONC_PCS and DRZ_PCS. Memo to 

Kathryn Knowles dated February 13, 2002. Sandia National Laboratories, Carlsbad, NM. ERMS 

520524. 

Vugrin, E.D. and S.C. Dunagan. 2006. Analysis Package for the Impact Assessment of the 

Redesigned Panel Closure System, Rev. 0. Sandia National Laboratories. Carlsbad, NM. ERMS 

543865. 

Vugrin, E., and S. Wagner. 2006. Panel Closure Summary Report. Sandia National 

Laboratories. Carlsbad, NM. ERMS 544802. 
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