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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

AP-161

Analysis Plan for the 2012 WIPP Pa nel 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 ManagerAP-161
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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 ............................................................................... 16AP-161
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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 ................................................................................................ 15AP-161
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## 1 Introduction and Objectives

The Waste Isolation Pilot Plant (WIPP), locat ed 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. Containmen t of TRU waste at the WI PP is regulated by the U.S. Environmental Protection Agency (EPA) accord ing 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 Certif ication Criteria in Ti tle 40 CFR Part 194 by means of performance assessment (PA) calculati ons performed by Sandia National Laboratories (SNL). WIPP PA calculations estimate the probability and cons equence of potential radionuclide releases from the repository to the accessible environment for a regulatory period of 10,000 years after facility closure. The models us ed 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 ch anges to the repository and/or the components therein also result in updates to WIPP PA mode ls. 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 de monstration since the Complian ce 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) volat ile 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 wa ste panels to reach a su fficiently high level. Panel closures were not develope d 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 th ey 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 re ceive TRU waste in 1998. The 1998 rulemaking had several conditions. Condition 1 involved the design of th e panel closure system (PCS) implemented in the repository. The DOE presented f our design options in the CCA, and

“The EPA based its certification d ecision on the condition that DOE implement the most robust design [referre d 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 certificati on requires DOE to implement the Option D PCS at the WIPP, with Salado Mass Concrete” (EPA 1998).AP-161
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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 7.9 m 9.1 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 th e “Option D” Panel Closure

Extensive refinement to WIPP panel closur e modeling in PA has occurred since the implementation used in the CCA (Vugrin an d 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 th e panel closure in WIPP, a PA was conducted in 2002 (Hansen 2002) with the aim of implementing an Option D panel closur e into the repository models used in WIPP PA, and to assess the im pacts of panel closur e design on long-term repository performance. Two panel closure cases were consid ered. 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 comple tion of the analysis, it was found that total normalized releases resulting from the two panel cl osure cases were nearly identical. Moreover, nearly identical distributions for each release co mponent 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 ne arly identical, indicating that repository performance is not si gnificantly 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 a nd 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 Rulema king for 40 CFR Part 194 (EPA, 1998) for the WIPP. Following the selection of the Opti on D panel closure desi gn in 1998, the DOE has reassessed the engineering of the panel closure a nd established a revised design which is simpler, easier to construct and equally effective at perf orming 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.)AP-161
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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 appro aching 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 betw een a ventilation bulkh ead & 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 desi gned to restrict air fl ows and prevent personnel access into waste-filled areas during the opera tional 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 ven tilation bulkhead will be the outer barrier, as shown in Figure 2b.

Panel closures are represented in PA by way of their material pr operties 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 incorp orated in PA. A material property with an associated uncertainty is assigned a distribution, and th is distribution is randomly sampled. This sampling process allows for repository performan ce 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, numer ous studies have been conducte d to date, often by way of full PA analyses, to quantify the impact of changes in panel clos ure material propert ies 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 incor porated 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 wallAP-161
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into the current PA baseline establishe d by the 2009 Performanc e 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 materi al parameters and timings to account for the following physical processes and rock mechanics principles:

1. Creep closure of the salt rock surrounding pa nel entries will cause consolidation of ROM salt emplaced in panel entries.
2. Eventually, the ROM salt comprising the clos ures will approach a condition similar to
intact salt.
3. As ROM salt reaches higher fractional densitie s during consolidation, back stress will be imposed on the surrounding rock mass leadin g to eventual heali ng 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 b een performed to develop material properties to be used in the PCS-2012 PA, and are documented in Camphous e (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 rele ase probabilities to those calculated in the
PABC-2009. Differences seen between the PA BC-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 demo nstrate compliance of the WIPP repository with the containment requirements according to the Cer tification 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 imp acted 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 be gins with an assessment that identifies and evaluates the features, events, and processes (F EPs) that are related to the changes introduced by the proposed panel closure design. The purpose of the FEPs ev aluation is to determine if the current FEPs baseline (currently the PA BC-2009 FEPs baseline) is suitable to evaluate the new closure design, or if changes to FEPs descriptions, screening ar guments, or decisions are necessary. The results of this assessment concluded that no change s are needed to the FEPs baseline (Kirkes 2011) 1 . It should be pointed out that the FEPs analysis on ly determines that the WIPP design features are

1 Note that Kirkes (2011) also evaluated changes associ ated with a proposed reconf iguration 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.AP-161
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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 change s proposed by the new PCS design and were the focus of the FEPs
assessment. These two FEPs have been screen ed 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 regulator y compliance will be determined by a direct comparison of PCS-2012 PA results to those ob tained 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 clos ure design changes will be captur ed in individual PA codes and
parameters.



### 2.1 ROMPCS Model

The PCS-2012 PA will replace th e PABC-2009 representation of the Option D panel closure with a representation of the ROMPCS within th e WIPP repository model. As discussed in relation to Figure 2, concrete block explosion wa lls have already been em placed in waste panels 1, 2, and 5. The ventilation bulkheads used in th e 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 sl abbing 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 emplaceme nt (Rocksol, 2006, Figures 7 and 10). No long term stress analyses have been carri ed 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-plast ic behavior of concrete. The ventilation bulkheads and explosion walls w ill therefore have no signif icant 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 tim e periods: from 0 to 100 years, from 100 years to 200 years, and from 200 years to 10,000 years. This is a re finement 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 20 11). Three time periods are ap propriate because the process
to consolidate the ROM salt occu rs 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 ofAP-161
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approximately 200 years. The ROM salt will theref ore be represented by three materials, denoted as PCS_T1 for the first 100 years, PCS_T2 fo r 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-consolid ated 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 a bove and below the ROMPCS will be modeled as having healed, and this sub-region of the DR Z will be represented by material DRZ_PCS. Material DRZ_PCS was developed during the TB M PA to represent healed DRZ above Option D panel closures (Stein 2002). Material DR Z_PCS has been used since the TBM PA to represent healed DRZ regions above and below pa nel 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 ROMP CS are the two parameters expected to have the greatest impact on calculations of pressure and brine saturati on in repository waste areas. Consequently, materials PCS_T1, PCS_T2, a nd PCS_T3 will be assigned porosities and permeabilities appropriate for representation of th e 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_T 1, 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 establis hed for materials PCS_T1, PCS_T2, and PCS_T3 is given in Table 1. In addition to the properties lis ted in Table 1, the initial brine saturation of the ROMPCS will be specified. This parameter co rresponds 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 Prop erties 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 Allo wable Capillary Pressure (PC_MAX = 1 x 10 8 Pa has been used for all BRAGFLO materials since the CCA) PCT_A Threshold Capill ary 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)AP-161
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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 regula tory 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 th e 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, intr usion scenarios, drilling rate and plugging pattern parameters, radionuc lide solubility parameters, and hydrologic transmissivity fields as were used in the PA BC-2009. The PCS-2012 PA will consist of a full set of PA compliance calculations. That is, three replicates of PA calcu lations, 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 potenti ally 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 spalling s releases as pressure changes yield changes in spallings volumes. Moreover, pressure changes in waste areas potentia lly alter the influx of brine into these regions, correspondi ng 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 paramete r in PA. Second, the repository pressure near the drilling location must exceed the hydrostatic pressure of the dr illing 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 inte rest 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 virtuall y no impact on total normali zed releases in the PABC-2009 (Clayton et al 2010). Implementa tion of the ROMPCS will not cha nge this result. In addition, hydrologic transmissivity fields are not be ing 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.AP-161
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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 wi ll 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_T 1, PCS_T2, and PCS_T3 and thei r corresponding properties. Distributions prescribed to these three mate rials are listed in Ca mphouse et al (2012).

2.2.3 Salado Flow: BRAGFLO

The two-phase flow code BRAGFLO simulates th e brine and gas flow in and around the WIPP repository and incorporates the effects of di sposal 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 fo r the subsequent calcula tion of Salado radionuclide transport, DBRs, and spallings releases. BRAGFLO scenario S6-BF is used in the calculation of radionuclide transport to the Culebra. The scen arios 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 BRAGF LO 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 DR Z 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-2009AP-161
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BRAGFLO grid will be modified slightly to account for the re duction in length of the ROMPCS as compared to Option D.

A complete suite of BRAGFLO calculations w ill be executed for the PCS-2012 PA. These
calculations will consist of 3 replicates, 100 vectors per repl icate, 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: DRS PALL and CUTTINGS_S

Repository pressures may be affected by the imp lementation of the ROMPCS design. Changes in repository pressures have the potential to imp act 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 in itial repository pressures of 10, 12, 14, and 14.8

MPa. DRSPALL calculations that were utilized to genera te 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 in terpolate between thes e DRSPALL volumes to calculate spallings volumes corresponding to a particular drilling intrus ion. The initial repository pressure for a given scenario, time, location, an d 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 combina tion by interpolating betw een 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 t ool 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 pressure s and brine saturations in waste-containing repository regions, DBR calculati ons will be performed as pa rt of the PCS-2012 PA. The numerical grid and material map used to calcula te 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 PR EBRAG version 8.0, BRAGFLO version 6.0 and
POSTBRAG version 4.00A will be used for th e 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 1 st ) 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, 10000AP-161
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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 indi vidual vectors for total normalized releases using Culebra release re sults calculated in the PABC-2009. The PCS-2012
PA will calculate CCDFs of individual vectors fo r total normalized releases, cuttings and cavings releases, spallings releas es, and DBRs. (The use of the ROMP CS design will have no impact on cuttings and cavings releases. Nonetheless, ne w 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 replicat es 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 analys es for results from the major codes in a manner consistent with those employed for th e PABC-2009. Specifically, global sensitivity analyses will be conducted on the results from CCDFGF usi ng 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 co rresponding PABC-2009 calculations; and 2) analysis of results relevant to the long term performance of the re pository. Th e 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 suppor t of a rulemaking decision to replace the current WIPP Option D panel closure design with the ROMPCS design. As such, itAP-161
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is likely that additional analyses and calculati ons will be performed as part of the regulatory review and approval process. These addition al tasks and documentation, if they become necessary, will also fall under AP-161.



## 3 Tasks

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

Table 4: Task List and Estima ted 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 LongAP-161
Revision 0 Page 15 of 17



## 4 Software

The major WIPP PA codes to be used for this analys is 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®, MA TLAB®, MATHCAD®, Excel®, Access®, Grapher®, or Kaleidagraph® may be utilized. Th e use of any COTS applic ation 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-2 001 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-20 05 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

NoneAP-161
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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 a ccordance 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 th e 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 ove rview of the BRAGFLO two-phase flow parameters used to model the run-of-mine salt pane l 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 La boratories, 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 th e CRA-2009 Performance Assessment Baseline
Calculation

, Revision 1. Sandia National Laboratorie s. 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. Pane l Closure System Design, Planned Change Request to the EPA 40 CFR Part 194 Certificati on of the Waste Isolation Pilot Plant. U.S. Department of Energy, Carlsbad Fiel d Office. Carlsbad, New Mexico.

DOE (U.S. Department of Energy), 2012. Respons e to First Set of EPA Questions to DOE, December 22, 2011

. Letter from Mr. Juan Franco, Manage r, Carlsbad Area Field Office, U.S. Department of Energy, to Mr. Jonathan Edwards, Director, Radiation Pr otection Division, U.S. Environmental Protection Agency, dated April 17, 2012.AP-161
Revision 0 Page 17 of 17

Dunagan, S. C. 2003. Complementary Cumulati ve Distribution Functions (CCDFs) for the Technical Baseline Migration (T BM), Revision 0. Sandia Nationa l 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: Certifi cation 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 Pa nel Closure Impact Assessment. Sandia National Laboratories, Carlsbad, NM. ERMS 523935.

Herrick, C.G. 2012. JAS3D Calculations Perfor med in Support of the PCS-2012 PA Parameter
Selections. Sandia National Laborat ories, Carlsbad, NM.

Kirkes, G. R. 2011. Features, Events, and Pr ocesses 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 Replicat es) and Comparison with the Compliance Certification Application Calculations, Sandi a National Laboratories, Carlsbad, NM. ERMS 414880. (EPA Docket A-93-02, II-G-28.)

RockSol Consulting Group, Inc. 2006. Further Asse ssment of the Short-term Stability of the 12 Foot Explosion Isolation Wall. Report pr epared for Washington TRU Solutions, LLC.

Stein, J.S. 2002. Parameter values for new ma terials CONC_PCS and DRZ_PCS. Memo to Kathryn Knowles dated February 13, 2002. Sandia National Labor atories, 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 Cl osure Summary Report. Sandia National Laboratories. Carlsbad, NM. ERMS 544802.AP-161
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