# DESIGN REPORT FOR A

REVISED PANEL CLOSURE SYSTEM AT THE WASTE ISOLATION PILOT PLANT

Revision 1

October 2002

Prepared for: 

## Westinghouse TRU Solutions, LLC

P.O. Box 2078 Carlsbad, New Mexico 88221

Prepared by: 

## RockSol Consulting Group , Inc


## .

848 Yellow Pine Avenue Boulder, Colorado 80304

## DESIGN REPORT FOR A

REVISED PANEL CLOSURE SYSTEM AT THE WASTE ISOL ATION PILOT PLANT

Revision 1

October 2002

Any comments or questions regarding this report should be directed to the U.S. Department of Energy

Carlsbad Field Office P.O. Box 3090 Carlsb ad, New Mexico 88221

Or to Westinghouse TRU Solutions, LLC

P.O. Box 2078 Carlsbad, New Mexico 88221

This report was prepared for Westinghouse TRU Solutions, LLC by RockSol Consulting Group, Inc., under Purchase Order Number 3164.ES

- 1 Rev. 1 10/3/2002



### Executive Summary
Scope. RockSol Consulting Group, Inc., under contract to Westinghouse TRU Solutions, prepared a detailed design for a panel closure system for the Waste Isolation Pilot Plant (WIPP). Preparation of this detailed design of an operational

- phase panel closure system is required to support the WIPP Hazardous Was te Facility Permit (HWFP). This report describes the detailed design for a panel closure system specific to the WIPP site. The recommended WIPP Panel Closure system (WPC) will adequately isolate the waste disposal panels from the active workings of the r epository for the required design life of 35 years.
Purpose. This report provides detailed design and engineering specifications for the construction of the WPC. The WPC design will ensure a nominal operational life of 35 years. The design provides assur ance that the mass release rate limits specified in the WIPP HWFP for the migration of volatile organic compounds (VOCs) will be met as specified in the relevant sections of the HWFP (e.g. Attachment N), for simplicity the point of compliance is referred t o hereafter as E

- 300 drift. The WPC will be located in the air

- intake and air

- exhaust drifts (Figure ES

- 1

- 1). The system components are designed to maintain their intended functional requirements under loads generated from salt creep and a postulated met hane explosion. The proposed design complies with regulatory requirements promulgated by Mine Safety and Health Administration (MSHA). The design uses common construction practices according to existing standards.
Background. The engineering design consi dered expected subsurface conditions at the location of the WPC. The geology is predominantly halite with inter

- bedded anhydrite at the repository horizon. During the operational period, the WPC will be subject to creep from the surrounding host rock. T he salt strata at the repository horizon are known to contain only trace amounts of brine.
The HWFP provides information in Module IV on Geologic Repository Disposal. The VOCs of concern in Table IV.F.2.c of the HWFP include carbon tetrachloride, chlorobe nzene, chloroform, 1,1

- dichloroethene, 1,2

- dichloroethane, methylene chloride, 1,1,2,2

- tetrachloroethane, toluene, and 1,1,1

- trichloroethane.
The primary intent of the WPC is to ensure that VOC releases are less than the regulatory limits specified in th e HWFP. The E

- 300 drift mass release rate limit equals the E

- 300 drift concentration limit as specified in Table IV.F.2.c of the HWFP times the minimum ventilation rate of 260,000 ft 3 /min (7,362 m 3 /min) required by the HWFP. This value establishes the cu rrent design mass release rate limits for flow of VOCs of concern from the waste disposal areas.ES

- 2 Rev. 1 10/3/2002 Room 7

Room 6

Room 5

Room 4

Room 3

Room 2

Room 1 A

A

B B

C C D D Panel Closure

System Reserved Area

UNDERGROUND WASTE DISPOSAL PANEL Air-Exhaust Drift Section D-D Air-Intake Drift Section C-C Panel-Access Drift Section B-B Disposal Room Section A-A

TYPICAL EXCAVATION SECTIONS DISPOSAL HORIZON STRATIGRAPHY Clay I

Anhydrite "a" Clay H

Disposal Horizon Envelope
Clay F

Orange Marker Bed

Marker Bed 139 Clay E Typical Disposal Room x x x x x

x x

x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x

x

x x x x x x x x x x x x x x

x x x x x

x x x x x

x

x

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x x x x x x x x x x x x x

x x x x x x x x x x x x x x x x

x

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x

x

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x Anhydrite "b"

Clay G

Figure ES
- 1
- 1 Typical Panel Layout with Drift Cross SectionsES

- 3 Rev. 1 10/3/2002

While no specific requirements exist for closing disposal ar eas under MSHA regulations, the intent of these regulations is to safely isolate abandoned areas from active workings using barricades of "substantial construction." A previous analysis (DOE, 1996a) examined the issue of methane gas generation from transu ranic waste and the potential consequences of a postulated methane explosion in closed waste disposal areas.
To demonstrate compliance with the E

- 300 drift mass release rate limits for the individual VOCs of concern, two air

- flow models were evaluated: (1) unrestricted flow and (2) restricted flow through the panel closure system. The unrestricted air

- flow model is defined as a model in which the gas pressure that develops is at, or very near, atmospheric pressure such that no back pressure exists in the d isposal areas. The restricted air

- flow model is defined as a model in which a back pressure develops in a closed waste disposal panel due to the restriction of flow through the panel closure system and the surrounding disturbed rock zone. The analyses we re based on an assumed approximate gas generation rate of 0.1 moles per drum per year due to microbial degradation, the expected volumetric closure rate due to salt creep, the expected headspace concentration for a series of nine VOCs of concern, and the e xpected air ventilation rate at the E

- 300 drift. The analyses showed that in both air

- flow models the release rate of each VOC at the E

- 300 drift is significantly below the permit limit. In the restricted case the release is further reduced.

Alternate D esigns. Various concepts were developed for evaluation. These concepts intentionally covered a broad range. A design review committee was convened and was requested to rank the various alternatives. The design review committee carefully discussed all th e alternatives, evaluated their potential performance, and recommended several of the concepts for further consideration. After further engineering evaluation and assessment, the explosion isolation wall with run of mine salt backfill was selected as the preferred alternative for the WPC. This alternative satisfies all performance specifications, is simple to construct, has a low impact on waste receipt, and is cost effective. WIPP Panel Closure System. The WPC has two components: a 30

- foot (9.1

- meter) co ncrete block wall and a run of mine salt backfill. Figure ES

- 1

- 2 illustrates these design components. The construction methods and materials to be used to implement the design have been proven in previous mining and construction projects. No other speci al requirements for engineered components beyond the normal requirements for fire suppression and methane explosion or deflagration containment exist for the WPC during the operational period.ES

- 4 Rev. 1 10/3/2002 Figure ES
- 1
- 2 Explosion Isola tion Wall in Combination with the Run of Mine Salt BackfillES

- 5 Rev. 1 10/3/2002

Design Evaluation. The evaluation of this design was performed to investigate several key design issues. This design evaluation can be divided into two components: (1) the operational requirement s of the system, and (2) the structural and material requirements of the system.
The conclusions reached from the evaluation addressing the operational requirements for the WPC design are as follows:

• The mass flow rate for different VOCs through the WPC (i ncluding flow through the disturbed rock zone [DRZ], the explosion isolation wall, and the run of mine salt backfill) were demonstrated to be at least two orders of magnitude below the limits specified in Table IV.F.2.c of the WIPP HWFP.

• The Monte Carlo Si mulation Method was used to assess the uncertainty of VOCs headspace concentrations, gas generation rate, and panel volume closure rate on the mass flow rate of carbon tetrachloride. The time required to reach the steady

- state mass flow rate of VOCs depen ds on the intrinsic permeability of the flow components. In some realizations in which the mass flow rate rises rapidly to the steady

- state mass flow rate, the flow is essentially unrestricted. In most cases, however, the WPC offers some resistance to fl ow and mass flow rates develop more slowly. In all cases, the explosion isolation wall with the run of mine salt backfill complies with the mass flow rate limit at the E

- 300 drift. The maximum mass flow rate through WPC calculated by this analysis was mo re than an order of magnitude below the mass flow rate limits specified in Table IV.F.2.c of the WIPP HWFP.

• The dimensions selected for the passive design components of the WPC are conservative, and thus ensure that these components will not require routin e maintenance during the operational life of 35 years.
The conclusions reached from the design evaluation addressing the structural and material requirements of the WPC are as follows:

• Thermal cracking due to heat of hydration effects does not apply to con crete blocks.

• The salt strata at the repository horizon are known to contain only trace amounts of brine that will not degrade the main concrete block wall over the nominal operational life of 35 years.

• Detailed axisymmetric FLAC models were developed to assess the state of stress in theES

- 6 Rev. 1 10/3/2002

concrete block wall and surrounding rock due to creep closure of the salt. The length selected for the explosion isolation wall provides for a substantial margin of safety against structural failure.

• Stress analysis showe d that the wall will withstand the forces of both creep closure and the postulated methane explosion. Further, at the likely time of a postulated explosion, the development of confining stress on the block wall would prevent fracturing around the block wa ll.
Design Components. Figure ES

- 1

- 2 illustrates the design components developed to satisfy the requirements for the WPC. The main barrier consists of a 30

- foot (9.1

- meter) long concrete block wall with construction joints. The concrete block wall design complies with MSHA requirements as it is made of incombustible materials of substantial construction. Surface treatment around the explosion isolation wall includes the removal of loose material to create a clean and regular surface for the construction of the block wall. The backfill consists of run of mine salt with a minimum length of 100 ft (30.5 m). Run of mine salt is a natural selection for backfill that is compatible with the environment.
The performance of the WPC design was evaluated against the performance specifications established for the panel closure system. The WPC design complies with all aspects of the performance specifications established for the panel closure system.i Rev. 1 10/3/2002



### Table of Contents_____________________________________________

E xecutive Summary ....................................................................................... ES

- 1 List of Tables .................................................................................................. iii List of Figures .................................................................................................. iv List of Acronyms ................................................................................................ v 1.0 Introduction

................................ ................................ ................................ ......................... 1

- 1 1.1 Scope

................................ ................................ ................................ ......................... 1

- 1 1.2 Regulatory Requirements

................................ ................................ .......................... 1

- 3 1.2.1 Hazardous Waste Regulations

................................ ................................ ..... 1

- 3 1.2.2 Mine Safety and Health Administration

................................ ...................... 1

- 3 1.3 Report Organization

................................ ................................ ................................ .. 1

- 3 2.0 Design Descriptions

................................ ................................ ................................ ............. 2

- 1 2.1 WPC Performance Specifications

................................ ................................ ............. 2

- 1 2.2 De sign Concept

................................ ................................ ................................ ......... 2

- 2 2.3 Design Components

................................ ................................ ................................ .. 2

- 2 2.3.1 Explosion Isolation Wall

................................ ................................ ............. 2

- 4 2.3.2 Backfill

................................ ................................ ................................ ........ 2

- 4 3.0 Design Evaluations

................................ ................................ ................................ .............. 3

- 1 3.1 Analyses Addressing Operational Requirements

................................ ...................... 3

- 1 3.1.1 Air

- Flow Analyses

................................ ................................ ....................... 3

- 1 3.1.1.1 Evaluation Procedure

................................ ................................ .... 3

- 1 3.1.1.2 Modeling Results

................................ ................................ .......... 3

- 6 3.1.1.3 Conclusions

................................ ................................ .................. 3

- 7 3.1.2 Advection Evaluation

................................ ................................ .................. 3

- 7 3.1.2.1 Evaluation P rocedure

................................ ................................ .... 3

- 7 3.1.2.2 Modeling Results

................................ ................................ ........ 3

- 13 3.1.2.3 Conclusion

................................ ................................ .................. 3

- 15 3.1 .3 Monte Carlo Simulation of VOC Release

................................ ................. 3

- 15 3.1.3.1 Evaluation Procedure

................................ ................................ .. 3

- 19 3.1.3.2 Modeling Results

................................ ................................ ........ 3

- 20 3.2 Analyses Addressing Material and Structural Requirements

................................ .. 3

- 20 3.2.1 Material Compatibility Evaluation

................................ ............................ 3

- 20 3.2.2 Heat Generation

................................ ................................ ......................... 3

- 22 3.2.3 Explosion Evaluations

................................ ................................ ............... 3

- 22ii Rev. 1 10/3/2002 3.2.4 Stress Analysis

................................ ................................ ........................... 3

- 24 3.2.4.1 Block Wall Evaluation

................................ ................................ 3

- 24 3.2.4.2 Run of Mine Salt Backfill Evaluation

................................ ........ 3

- 26 3.2.5 Fract ure

- Propagation Evaluation

................................ ............................... 3

- 32 4.0 Design Calculations

................................ ................................ ................................ ............. 4

- 1 5.0 Technical Specifications

................................ ................................ ................................ ...... 5

- 1 6.0 Drawings

................................ ................................ ................................ .............................. 6

- 1 7.0 Conclusions

................................ ................................ ................................ ......................... 7

- 1 8.0 References

................................ ................................ ................................ ........................... 8

- 1

Appendix A

- Derivati on of Relationships for the Air

- Flow Models Appendix B

- Calculations of Panel Volume Closure Appendix C

- FLAC Modeling of the WIPP Panel Closure System Appendix D

- Technical Specifications Appendix E

- Design Drawingsiii Rev. 1 10/3/2002



### List of Tables___________________

______________________________
Table 3

- 1 Intrinsic Permeability of Flow Components

................................ ................................ . 3

- 5 Table 3

- 2 Air Conductance Through System Componen ts

................................ ........................ 3

- 12 Table 3

- 3 Ranges of Intrinsic Permeabilities in the Monte Carlo Simulation Analysis

............. 3

- 18 Table 5

- 1 Technical Specification s for the WIPP Panel Closure System

................................ ..... 5

- 1 Table 6

- 1 WIPP Panel Closure System Drawings

................................ ................................ ........ 6

- 1 Table 7

- 1 Compliance with Performance Spe cifications

................................ .............................. 7

- 3iv Rev. 1 10/3/2002



### List of Figures________________________________________________
Figure ES

- 1

- 1 Typical Panel Layout with Drift Cross Sections......................................ES

- 2 Figure ES

- 1

- 2 Explosion Isolation Wall in Combination with the Run of Mine Salt Backfill ..ES

- 4 Figure 1

- 1 Typical Panel Layout with Drift Cross Sections

................................ ......................... 1

- 2 Figure 2

- 1 Explosion Isolation Wall in C ombination with the Run of Mine Salt Backfill

.......... 2

- 3 Figure 2

- 2 Explosion Isolation Wall

................................ ................................ ............................. 2

- 5 Figure 3

- 1 Pressure Buildup with Time fo r a Single Panel

................................ .......................... 3

- 8 Figure 3

- 2 Migration Rates versus E

- 300 Drift Limit Values for the VOCs of Concern

............. 3

- 9 Figure 3

- 3 Breakthroug h Time for VOCs through Several Media

................................ ............. 3

- 14 Figure 3

- 4 Monte Carlo Simulation of Restricted Air

- Flow Analysis

................................ ........ 3

- 16 Figure 3

- 5 Mass Flow Rate for Carbon Tetrachloride

................................ ................................ 3

- 21 Figure 3

- 6 Creep Plus Explosion Model Geometry and Boundary Conditions

.......................... 3

- 25 Figure 3

- 7 Ver tical (Radial) Stress Profile at Top of Block Wall During an Explosion Occurring

10 Years after Emplacement

................................ ................................ ..................... 3

- 27 Figure 3

- 8 Horizontal (Axial) Stress Profile at Top of Block Wall During an Expl osion Occurring

10 Years after Emplacement

................................ ................................ ..................... 3

- 27 Figure 3

- 9 Vertical (Radial) Stress Contours in Block Wall During an Explosion Occurring 10

Years after Emplacement

................................ ................................ .......................... 3

- 28 Figure 3

- 10 Horizontal (Axial) Stress Contours in Block Wall During an Explosion Occurring 10

Years after Emplacement

................................ ................................ .......................... 3

- 28 Figure 3

- 11 Plasticity State in Block Wall at 35 Years

................................ .............................. 3

- 29 Figure 3

- 12 Vertical (Radial) Stress Profile at Top of Block Wall at 35 Years

......................... 3

- 29 Figure 3

- 13 Applie d Forces on a Longitudinal Element of Backfill

................................ .......... 3

- 33 Figure 3

- 14 Dynamic Displacement versus Distance from Explosion Face

............................... 3

- 33v Rev. 1 10/3/2002



### List of Acronyms___________________

__________________________

atm atmosphere CFR Code of Federal Regulations

cm centimeter(s) CQC Contractor Quality Control CQCP Contractor Quality Control Plan DOE Department of Energy DRZ Disturbed Rock Zone ft foot (feet) FLAC Fast Lagrangian Ana lysis of Continua g gram(s) HASP Health and Safety Plan HWFP Hazardous Waste Facility Permit K Kelvin kg kilogram(s)

m meter(s) mg milligram(s) min minute(s) MPa Mega Pascal(s) MSHA Mine Safety and Health Administration PCS Panel Closure System ppm part(s) per million psi pound(s) per square inch QA/QC Quality Assurance/Quality Control RCRA Resource Conservation and Recovery Act

s second(s) SNL Sandia National Laboratories TRU Transuranic VOC(s) Volatile Organic Compound(s) WIPP Waste Isol ation Pilot Plant WPC WIPP Panel Closure system yr year(s)1

- 1 Rev. 1 10/3/2002



### 1.0 Introduction
The Waste Isolation Pilot Plant (WIPP), a U.S. Department of Energy (DOE) facility located near Carlsbad, New Mexico, was established for the safe disposal of defense

- generated tr ansuranic (TRU) waste. The WIPP repository is approximately 2,150 feet (ft) (655 meters [m]) below the surface, in the Salado Formation.
One important aspect of repository operations at the WIPP is the activity associated with closure of waste disposal pa nels. Each panel consists of air

- intake and air

- exhaust drifts, panel

- access drifts, and seven rooms ( Figure 1

- 1 ). After completion of waste disposal activities in a panel, it will be closed at the same time that waste disposal may be occurring in the other panel(s). The closure of individual panels during the operational period will be accomplished in accordance with project

- specific health, safety, and environmental performance criteria.

The WIPP Panel Closure system (WPC) design is an explosion isolation wall with run of mine salt backfill. The original Panel Closure System (PCS) design was contained in DOE (1996a) and Appendix PCS of the WIPP Compliance Certification Application (CCA) (DOE, 1996b). A large portion of the design information contained in that appendix is applicable to the WPC design. This includes the application of the restricted and unrestricted flow models, heat transfer analyses, and analyses associated with the methane gas explosion. Th roughout this document, the CCA appendix is referred to as Appendix PCS.

1.1 Scope This report provides analyses of the WPC design for effectiveness of the explosion isolation wall as a gas barrier; the structural adequacy of the explosion isolation wall; an d the design description of the WPC for a nominal operational period of 35 years. The WPC design provides assurance that the limit for the migration of volatile organic compounds (VOCs) will be met as specified in the relevant sections of the HWFP (e.g. A ttachment N), for simplicity the point of compliance is referred to hereafter as the E

- 300 drift. The WPC will be located in the air

- intake and air

- exhaust drifts to each panel ( Figure 1

- 1 ). The WPC design maintai ns its intended functional requirements under loads generated from salt creep and a postulated methane explosion. The design complies with regulatory requirements promulgated by Mine Safety and Health Administration (MSHA).1

- 2 Rev. 1 10/3/2002 Room 7

Room 6

Room 5

Room 4

Room 3

Room 2

Room 1 A

A

B B

C C D D Panel Closure

System Reserved Area

UNDERGROUND WASTE DISPOSAL PANEL Air-Exhaust Drift Section D-D Air-Intake Drift Section C-C Panel-Access Drift Section B-B Disposal Room Section A-A

TYPICAL EXCAVATION SECTIONS DISPOSAL HORIZON STRATIGRAPHY Clay I

Anhydrite "a" Clay H

Disposal Horizon Envelope
Clay F

Orange Marker Bed

Marker Bed 139 Clay E Typical Disposal Room x x x x x

x x

x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x

x

x x x x x x x x x x x x x x

x x x x x

x x x x x

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x x x x x x x x x x x x x x x x

x

x

x

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x

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x

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x Anhydrite "b"

Clay G

Figure 1
- 1 Typical Panel Layout with Drift Cross Sections1

- 3 Rev. 1 10/3/2002

1.2 Regulatory Requirements

1.2.1 Hazardous Waste Regulations The Closure Plan in the WIPP HWFP was prepared in accordance with the requirements of 20.4.1. 500 New Mexico Administrative Code (incorporating 40 Code of Federal Regulations §264 Subparts G, I, and X). The WPC complies with the relevant portions of those requirements.

1.2.2 Mine Safety and Health Administration Under 30 CFR 57 “barriers and stopping” m ust be constructed of noncombustible materials appropriate for the specific mine category and must be of "substantial construction." Substantial construction implies construction of such strength, material, and workmanship that the barrier could withstand air blasts, methane detonation or deflagration, blasting shock, and ground movement expected in the mining environment. The WPC complies with the relevant portions of those regulations.

1.3 Report Organization This report presents evaluations of the WPC. Ch apter 2 presents the description of the design. Chapter 3 presents the design evaluations addressing the gas barrier effectiveness of the explosion isolation wall and the structural adequacy of the explosion isolation wall. Chapter 4 presents the design calculations. Chapters 5 and 6 present the technical specifications, and drawings respectively. Chapter 7 presents the conclusions to the report.2

- 1 Rev. 1 10/3/2002



### 2.0 Design Descriptions
This chapter describes how the concept for the WPC was developed and describes the expl osion isolation wall and run of mine salt backfill components of the WPC.

2.1 WPC Performance Specifications Original design criteria were presented in Table 7

- 1 of DOE (1996a) and were revised in Attachment I of the HWFP as issued. These criteria were review ed for continued applicability and only one of the performance specifications was modified, as italicized in the following list. The WPC performance specifications are:

• The panel closure system design shall limit VOC migration from a closed panel consiste nt with the limits found in Table IV.F.2.c of the HWFP.

• The panel closure system shall consider potential flow of VOCs through the disturbed rock zone (DRZ) in addition to flow through closure components.

• The panel closure system shall perform its intended functions under loads generated by creep closure of the tunnels.

• The panel closure system shall perform its intended function under the conditions of a postulated methane explosion.

• The nominal operational life of the closure system is thirty

- five (35) ye ars.

• The panel closure system for each individual panel shall not require routine maintenance during its operational life.

• The panel closure system shall address the most severe ground conditions expected in the waste disposal area.

• The design class of the panel closure system shall be IIIb (which means that it is to be built to generally accepted national design and construction standards).

• The design and construction shall follow conventional mining practices.

• Structural analysis shall use data acquired f rom the WIPP underground.

• Materials shall be compatible with their emplacement environment and function.2

- 2 Rev. 1 10/3/2002

• Treatment of surfaces in the closure areas shall be considered in the design.

• Thermal cracking of concrete shall be addressed.

• During construction, a Q uality Assurance/Quality Control (QA/QC) program shall be established to verify material properties and construction practices.

• Construction of the panel closure system shall consider shaft and underground access and services for materials handling.

Variou s concepts were developed for evaluation. These concepts intentionally covered a broad range. For each of these concepts, the estimated conductance was calculated and a preliminary construction cost was estimated. These were intended only as aids to fac ilitate ranking during the selection process.
A design review committee was convened and was requested to rank the various alternatives. The design review committee carefully discussed all the alternatives, evaluated their potential performance, and recom mended several of the concepts for further consideration. After further engineering evaluation and assessment, the explosion isolation wall with run of mine salt backfill was selected as the preferred alternative for the WPC. This alternative satisfies a ll performance specifications, is simple to construct, has a low impact on waste receipt, and is cost effective.

2.2 Design Concept The selected design for WPC is a combination of a mortared concrete block wall and a run of mine salt backfill. Figure 2

- 1 illustrates these design components. The construction methods and materials used to implement the design are well proven in previous mining and construction projects. This configuration satisfies the E

- 300 drift mass flow rate limits for the flow of VOCs of concern out of the panel. The selected design will resist the temperature transients and methane explosion pressure as discussed in Sections 3.2.2 through 3.2.4.

2.3 Design Components The following subsections presen t system and components design features.2

- 3 Rev. 1 10/3/2002 Figure 2
- 1 Explosion Isolation Wall in Combination with the Run of Mine Salt Backfill2

- 4 Rev. 1 10/3/2002

2.3.1 Explosion Isolation Wall The explosion isola tion wall consists of a 30

- foot (9.1

- meter) long, mortared, solid block wall as shown in Figure 2

- 2 . Detailed structural analyses have been performed (Section 3.2.4) to assess the development of stresses within the block wall. These analyses showed that a 30

- foot (9.1

- meter) long concrete block wall reduces the relative proportion of the compressive abutment zones near the ends of the wall to an acceptable level. Five construction joints were introduced to mitigat e the axial tensile stresses, which develop in the wall due to salt creep. The construction joints also eliminate the effects of potential differential displacements along the axis of the wall. Since the construction joints are normal to the direction of VOCs flow out of the closed panel they have minimal impact on flow conductance of the wall.
The blocks of the wall are 8x8x16 inches and have a minimum unconfined compressive strength equal to 5000 psi (34.5 MPa). The specifications include materials t esting to verify material properties and construction practices.
The concrete block wall design complies with MSHA requirements. It is made of incombustible materials and is of substantial construction. The block wall can also resist forces of a postula ted methane explosion under creep load from the surrounding rocksalt as discussed in Section 3.2.4. The surrounding salt surfaces will be prepared to create a smooth, clean surface for the placement of bricks and mortar.
The explosion isolation wall with the run of mine salt backfill separates the active ventilated underground workings from the closed panels. The restricted flow analysis presented subsequently (Section 3.1.1) shows an adequate design margin for meeting VOC release limits.

2.3.2 Backfill
The b ackfill consists of run of mine salt with a minimum length of 100 ft (30.5 m). Run of mine salt is a natural material for backfill that is completely compatible with the environment. In the absence of the block wall, run of mine salt backfill provides pr otection against a methane explosion. An analysis was conducted to assess the effect of methane gas explosion on the backfill. In this analysis, the explosion isolation wall was ignored and the run of mine salt backfill alone resisted the impact loading from the postulated methane explosion. The analysis showed that the backfill will absorb the explosion impact due to deflagration.2

- 5 Rev. 1 10/3/2002 Figure 2
- 2 Explosion Isolation Wall3

- 1 Rev. 1 10/3/2002



### 3.0 Desi

gn Evaluations
This chapter presents the evaluations that support the design of the WPC: (1) analyses addressing the operational requirements, and (2) analyses addressing the material and structural requirements. The first group includes air

- flow analyses , an advection analysis, and an uncertainty analysis of air

- flow. The second group includes material compatibility evaluation, heat generation, explosion evaluation, stress analysis and fracture

- propagation evaluation.

3.1 Analyses Addressing Operational Requ irements To evaluate the effectiveness of the WPC, air

- flow analyses were performed to examine the flow of VOCs through the WPC. The following sections address the air

- flow analyses, the advection analysis, and air

- flow uncertainty analysis. These analys es support the WPC design for both the overall protection of human health and the environment, and compliance at the E

- 300 drift as required by HWFP.

3.1.1 Air

- Flow Analyses The purpose of the air

- flow analyses is to evaluate the flow of VOCs through the WPC. T he effective intrinsic permeability of the WPC is evaluated and used as input to the air

- flow model (DOE, 1996a) to assess VOC(s) flow performance.
In this study, two air

- flow models are considered: (1) unrestricted flow, and (2) restricted flow through th e panel closure system. The unrestricted air

- flow model is defined as a model in which the gas pressure that develops is at, or very near, atmospheric pressure such that no back pressure exists in the disposal areas. The restricted air

- flow model is defi ned as a model in which a back pressure develops in a closed waste disposal panel due to the restriction of flow through the panel closure system and the surrounding disturbed rock zone. The analyses are based on an assumed gas generation rate of 8,650 mo les per panel per year (0.1 moles per drum per year [DOE, 1996a] for 86,500 drums per panel [HWFP]) due to microbial degradation, an average volumetric closure rate of 31,430 ft 3 (890 m 3 ) per year due to salt creep (Appendix B), the expected headspace

conc entration for nine VOCs (Appendix A), and the minimum mine ventilation rate of 260,000 ft 3 /min (7,362 m 3 /min) required by HWFP at E

- 300 drift.

3.1.1.1 Evaluation Procedure In the restricted flow model, the gases in the waste

- emplacement area are in part compresse d in the void space within a panel and in part flow into the main return air. The restricted flow model3

- 2 Rev. 1 10/3/2002

is based on the following assumptions:

• Gases (including VOCs) within the void space will obey the Ideal Gas Law. The gases will be generated at a rate of 0.1 moles per drum per year (DOE, 1996a) and will be stored by an increase in gas pressure. The rate of pressure buildup will be so gradual that it occurs at constant temperature.

• Volumetric reduction due to creep will reduce the void space at a rate of 31,430 ft 3 (890 m 3 ) per year (Appendix B) and will result in pressurization.

• Flow of gas out of the panel will obey Darcy's Law under quasi steady

- state conditions. Under quasi steady

- state conditions, the air pressure within the WPC will change so gra dually that the compressive storage of the air within the void space of the WPC could be neglected.

• Rates of gas generation, air outflow, and change in compressive storage will balance.

• Hydrodynamic dispersion through the barrier will be neglected.

• Analysi s will consider the superposition of flow rates from individual panels according to the operating schedule for a nominal operational life of 35 years.

The air

- flow under these assumptions follows a nonlinear system of two first

- order ordinary differential equations. The model is characterized by molar gas generation and reduction in void volume that together result in an increase in air pressure.
The problem can be solved using the system of nonlinear ordinary differential equations as derived in Appendix A:

2 )

(

V dt dV n V p p C RT p g T R dt dp atm

r −

⋅ −

⋅ ⋅ −

⋅ ⋅ = g (Equation 3

- 1 )

g atm r p

p C T R p g dt dn

−

⋅ ⋅

⋅ − = (Equation 3

- 2 )

where3

- 3 Rev. 1 10/3/2002 dt = Change in time (years)

R = Uni versal gas constant (atm . m 3 /(mole . K))

T = Absolute temperature (K)

n = Moles of gas in the panel

p = Pressure (atm)

atm p = Atmospheric pressure (atm)

C = Conduc tance (m 2 /s) of the panel closure system = L A K s ⋅

s K = Effective air conductivity of the panel closure system (m/s)

A = Cross sectional area of the panel closure system (m 2 )

L = Flow pat h length of the panel closure system (m)

g = Air density (kg/(m 2 . s 2 ))

r g = Gas generation rate (moles/yr)

V = Volume of the panel void space (m 3 )

dt dV

= Panel volumetric closure rate (m 3 /yr)

dt dp

= Panel pressure rate (atm/yr)

dt dn

= Panel molar storage rate (mole/yr).

The above relationships are subject to the following initial conditions: (1) the pressure in the panel will be atmospheric; and (2) the moles of gas in the panel equal the moles of gas occupying the initial panel void volume at the temperature of the repository at the time of panel closure.3

- 4 Rev. 1 10/3/2002

The effective air conductivity of the panel closure system ( s K ) can be expressed i n terms of the effective intrinsic permeability of the panel closure system ( s k ) and the fluid properties of air as (Freeze and Cherry, 1979):

m r g k K s s ⋅ ⋅ = (Equation 3

- 3 )
where

r = Air mass density (kg/m 3 )

g = Acceleration due to gravity (m/s 2 )

m = Absolute air viscosity (kg/(m . s))
The effective intrinsic permeability of the WPC ( s k ) can be evaluated by c onsidering the intrinsic permeabilities of the various flow components over their respective areas, as presented in Table 3

- 1

. Permeability measurements in salt were summarized in the original design report (DOE, 1996a). These dat a show a zone of increased permeability (10 - 18 to 10 - 20 ft 2 [10 - 19 m 2 to 10 - 21 m 2 ]) 3 to 42 ft (1 to 14 m) from the excavation surface. Based on these observations, the calculations assumed that the cross

- sectional area for flow through the DRZ and the WP C will equal nine times the air

intake and air

- exhaust drift area or that the DRZ extends out three radii from the center (DOE, 1996a).

As shown in Table 3

- 1 , a distinction is made between “dilated salt”, and “fractured salt”. Dil ated salt exhibits a higher permeability than intact salt due to relief of the lithostatic stresses, and this corresponds to the increased permeability zone observed by Case and Kelsall (1986). The more conservative value of 10 - 19 m 2 is used here for the intrinsic permeability of dilated salt. The fractured salt refers to the highly fractured zone in the immediate vicinity of the openings.
The intrinsic permeability of the concrete block wall was estimated from the intrinsic permeabilities of the concrete blocks and the interface zone between the mortar and concrete blocks that is tributary to each block. A parallel system was used to calculate the intrinsic permeability of the concrete block wall from the intrinsic permeabilities of its flow components ( concrete blocks and interface). It is assumed that the intrinsic permeability of mortar is the same as that of concrete block. For the concrete blocks an intrinsic permeability of c k = 1.0x10 - 19 m 23

- 5 Rev. 1 10/3/2002

(PCA, 2002) was used with a flow ar ea of c A = 8x16 in 2 = 128 in 2 = 0.083 m 2 . Further, the intrinsic permeability of the interface zone surrounding the concrete blocks was estimated using an interface zone aperture of 11 micron (Fernandez et al., 1994). For a smoothwal l aperture of b , the interface zone intrinsic permeability is equal to b 2 /12 (Fernandez et al., 1994). For an aperture of b = 11x10 - 6 m, the interface zone intrinsic permeability of i k = 1x10 - 11 m 2 is obtained. The area
of the interf

ace zone surrounding each concrete block is i A = 2(16 in + 8 in) b = 1.34x10 - 5 m 2

. The intrinsic permeability of the concrete block wall can be calculated using Equation A

- 14 of Appendix A as follows:

i c i i c c wall A

A A k A k k + ⋅

+ ⋅ = (Equati on 3

- 4 )

This results in an intrinsic permeability of 1.64x10 - 15 m 2 for the concrete block wall which is rounded to 2x10 - 15 m 2

. The run of mine salt backfill is placed in a loose state in the air

- intake and air

- exhaust drifts of each panel. Case et al. (1987) reports on an experiment on WIPP crushed salt that measured the relationship of hydraulic conductivities to porosity when subjected to confining pressure. The test results showed that the intrinsic pe rmeability might equal 0.01 darcy (10 - 14 m 2 ) at 15 percent porosity. For high porosities from 35 to 40 percent, the test results showed that the intrinsic permeability might equal 10 2 darcy (10 - 10 m 2 ). In the current analysis, an intrinsic permeability o f 10 darcy (10 – 11 m 2 ) was used. This is a reasonable value for the expected range of porosities.

Table 3
- 1 Intrinsic Permeability of Flow Components
Intrinsic Permeability Component ft 2 m 2 References Dilated salt 1x10 - 18 1x10 - 19 DOE, 1996a
Fractured salt 1x10 - 14 1x10 - 15 DOE, 1996a Clay seams 1x10 - 16 1x10 - 17 DOE, 1996a
Marker Bed 139 1x10 - 15 1x10 - 16 DOE, 1996a
Interface zone 1x10 - 10 1x10 - 11 DOE, 1996a Concrete block wall 2x10 - 14 2x10 - 15 Calculated
Run of mine salt 1x10 - 10 1x10 - 11 Case et al., 19873

- 6 Rev. 1 10/3/2002

Finally, for the clay seams, Marker Bed 139, and the interface zone between the concrete block wall and the surrounding rocksalt, the values from the previous design (DOE, 1996a) were used.

To calcula te the void space volume of the panel ( V ), the analysis assumed that the volume of the waste is equal to the total waste capacity of a panel (600,000 ft 3 [16,990 m 3 ]) (DOE, 1994) times the assumed average solid volume of the waste drums (23 percent) (IT, 1994). The analysis uses a solid waste volume equal to 138,000 ft 3 (3,908 m 3 ) for the panel and this volume remains constant during the operational life of the panel.

The waste

- emplacement capacity of a panel includes the seven rooms an d the panel access drifts from Room 1 to Room 7. Field data from geotechnical engineering measurements were used to determine creep closure rates for 35 years as presented in Appendix B.
A model for unrestricted flow of VOCs was also developed to predict the mass flow rates of VOCs (Appendix A). The results of unrestricted flow analysis are used for comparison with the restricted flow case.

3.1.1.2 Modeling Results The HWFP provides information in Module IV on Geologic Repository Disposal. Table IV.F.2.c of this module presents the E

- 300 drift concentration limits for VOCs of concern. These limits are shown on appropriate figures. The VOCs of concern in Table IV.F.2.c of the HWFP include carbon tetrachloride, chlorobenzene, chloroform, 1,1

- dichloroethene, 1,2

- d ichloroethane, methylene chloride, 1,1,2,2

- tetrachloroethane, toluene, and 1,1,1

- trichloroethane.

The E

- 300 drift mass release rate limit equals the E

- 300 drift concentration limit as specified in Table IV.F.2.c of the HWFP times the minimum mine ventilati on rate of 260,000 ft 3 /min (7,362

m 3 /min) required by HWFP. This value establishes the current design mass release rate limits for flow of VOCs of concern from the waste disposal areas.
Comparisons are made of the expected mass release rate of VOCs of con cern to the E

- 300 drift mass release rate limits. The calculation of the expected mass flow uses the product of (1) an estimate of the actual headspace concentrations for each of the VOCs of concern, and (2) an estimate of the actual gas flow rate from t he restricted flow model as presented previously.3

- 7 Rev. 1 10/3/2002

The sources of information for the actual VOCs headspace concentrations (Appendix A) include Table A

- 2 of DOE (1996a), and the WIPP Waste Information System Headspace Gas Concentration Report (2002). Th e maximum values for actual mass concentrations from the two sources of information are used in the present analysis.
Figure 3

- 1 shows the expected pressure buildup in a single panel after closure. The pressure

w ithin the panel builds up gradually due to the large compressibility of the panel void space relative to the air

- flow rate out of the panel. The restricted air

- flow rate also builds up gradually to a steady

- state flow rate.
Figure 3

- 2 presents the expected mass release rates for the VOCs of concern versus time for comparison to the E

- 300 drift mass release limits for the repository. In these analyses, the current panel closure schedule (Westinghouse, 2002) is con sidered, and the expected mass release rates from individual panels as they are closed are superimposed in time. The analyses show that in every case, the expected mass release rate from the repository is much lower than E

- 300 drift mass release rate limi t for the VOCs of concern.

3.1.1.3 Conclusions
The air

- flow model (DOE, 1996a) was used to predict the expected mass flow rate for VOCs of concern through a panel closure system consisting of a concrete block wall with run of mine salt backfill. The analysis sugg ests that VOC flow over the operational period will be at least two orders of magnitude below the HWFP limits established at the E

- 300 drift ( Figure 3

- 2 ).

3.1.2 Advection Evaluation The purpose of the advection evaluation is to assess contaminant transport time through various media. As panel pressure develops with time, gases will travel through the panel closure system. The restricted air

- flow model considered that the VOC concentration front will instantaneously devel op in the active underground workings and the gases would then flow by advection. The more detailed analysis presented below considers the flow distribution in different components.

3.1.2.1 Evaluation Procedure The relative significance of each of the air

- flow zones can be evaluated by studying flow conductance. The flow conductance through a parallel system is calculated as follows (Freeze and Cherry, 1979):3

- 8 Rev. 1 10/3/2002 0.0 0.5 1.0 1.5 2.0

5 10 15 20 25 30 35 T ime ( y ears)Pressure (atm)

Figure 3
- 1 Pressure Bu ildup with Time for a Single Panel3

- 9 Rev. 1 10/3/2002 Carbon Tetrachloride

1.E-05 1.E-03 1.E-01 1.E+01

5 10 15 20 25 30 35 Time (years)Mass Flow Rate (g/min)

Chlorobenzene

1.E-07 1.E-05 1.E-03 1.E-01 1.E+01

5 10 15 20 25 30 35 Time (years)Mass Flow Rate (g/min) Chloroform

1.E-06 1.E-04 1.E-02 1.E+00 1.E+02

5 10 15 20 25 30 35 Time ( years)Mass Flow Rate (g/min)

1,1-Dichloroethene

1.E-07 1.E-05 1.E-03 1.E-01 1.E+01

5 10 15 20 25 30 35 Time (years)Mass Flow Rate (g/min) 1,2-Dichloroethane

1.E-08 1.E-06 1.E-04 1.E-02 1.E+00 1.E+02

5 10 15 20 25 30 35 Time (years)Mass Flow Rate (g/min)

Figure 3
- 2 Migration Rate s versus E
- 300 Drift Limit Values for the VOCs of Concern Restricted Flow Unrestricted Flow Limit at E

- 300 Drift3

- 10 Rev. 1 10/3/2002 Methylene Chloride

1.E-05 1.E-03 1.E-01 1.E+01 1.E+03

5 10 15 20 25 30 35 Time ( years)Mass Flow Rate (g/min) 1,1,2,2-Tetrachloroethane

1.E-07 1.E-05 1.E-03 1.E-01 1.E+01

5 10 15 20 25 30 35 Time ( years)Mass Flow Rate (g/min)

Toluene

1.E-06 1.E-04 1.E-02 1.E+00 1.E+02

5 10 15 20 25 30 35 Time (years)Mass Flow Rate (g/min) 1,1,1-Trichloroethane

1.E-06 1.E-04 1.E-02 1.E+00 1.E+02

5 10 15 20 25 30 35 Time (years)Mass Flow Rate (g/min)

Figure 3
- 2 (continued) Migration Rates versus E
- 300 Drift Limit Values for the VO Cs of Concern Restricted F low Unrestricted Flow Limit at E

- 300 Drift3

- 11 Rev. 1 10/3/2002 

## ∑ ⋅ = i i i L A K C (Equation 3

- 5 )
where

C = Flow conductance of the system (m 2 /s)

i K = Air conductivity of the th i component (m/s)

i A = Cross sectional area of the th i component (m 2 )

i L = Length of the th

i component (m)
The conductance through the WPC will depend on the air conductivity and cross

- sectional area of the flow components. Table 3

- 2 summarizes these values for each component. Since the conductance of run of mine salt is at least four orders of magnitude higher than that of any other component, the breakthrough of VOCs throu gh run of mine salt occurs very rapidly. Therefore, in the advection analysis the effect of run of mine salt is neglected. The calculations show that flow through the block wall and fractured salt will dominate the conductance.

In Table 3

- 2 , the flow area of the interface zone between the 14 ft x 21 ft concrete block wall and surrounding rocksalt is based on an interface zone aperture of b = 11x10 - 6 m (Fernandez et al., 1994). This results in an interface flow are a of i 

### A = 2(14 ft + 21 ft) b = 2.34x10 - 4 m 2 . For a smoothwall aperture of b , the interface zone intrinsic permeability is equal to b 2 /12 (Fernandez et al., 1994). For an aperture of b = 11x10 - 6 m, the interface zone intrinsic permeab ility of i k = 1x10 - 11 m 2 is obtained. The interface zone air conductivity can be calculated from Equation 3

- 3. Using the air density of 

### g = 

### g ⋅ r = 0.0735 lbf/ft 3 (11.55 kg /(m 2 . s 2 )) and air vis cosity of 

### m = 3.85x10 - 7 lbf s/ft 2 (1.84x10 - 5 kg/(m . s)) (Lindeburg, 1986), the interface zone air conductivity is obtained equal to 6.26x10 - 6 m/s.
The breakthrough of VOCs through the WPC under the assumption of advection will occur when the VOC front has traversed its length. The average linear velocity equals the Darcy flux divided by the effective porosity for the various flow components. The average linear velocity, neglecting compressibility effects of the gas, is given by (Fr eeze and Cherry, 1979):

g ⋅ ⋅ ⋅ = L n p t p K t p V

e atm

i i avg )

- ) ( ( )) ( ( (Equation 3

- 6 )3

- 12 Rev. 1 10/3/2002

where

i

avg t p V )) ( ( = Average linear velocity for the th i component (m/s)

i K = Air conductivity of t he th i component (m/s)

) ( t p = Panel internal pressure as a function of time (atm)

atm p = Atmospheric pressure (atm)

L = Length of the barrier (m)

g = Air density (kg/ (m 2 . s 2 ))

e n = Effective porosity
The following assumptions were made in this advection model:

• The air

- flow velocity will be constant along the panel closure system.

• The gases (including VOCs) within the void space will obey the Ideal Ga s Law.

Table 3
- 2 Air Conductance Through System Components
Component Effective Porosity Air Conductivity

(m/s) Approximate

Cross

- Sectional Area (m 2 ) Conductance per

Unit Length (m 3 /s)

Dilated salt 1 0.001 6.2 6x10 - 14 170 1.0x10 - 11
Fractured salt 1 0.040 6.26x10 - 10 16 1.0x10 - 8 Clay seams 1 0.400 6.26x10 - 12 0.09 5.6x10 - 13
Marker Bed 139 1 0.040 6.26x10 - 11 11 6.9x10 - 10
Interface 2 1.000 6.26x10 - 6 2.34x10 - 4 1.5x10 - 9
Concrete block wall 2 0.200 1.25x10 - 9 27 3.4x10 - 8
Run of mine salt 3 0.440 6.26x10 - 6 27 1.7x10 - 4

1 DOE, 1996a 2 Calculated 3 Case et al., 19873

- 13 Rev. 1 10/3/2002

• The flow of air out of the panel will obey Darcy's law under quasi steady

- state conditions. Under quasi steady

- state conditions, the air pressure within the pa nel closure system will change so gradually that the compressive storage of air within the void space of the panel closure system will be neglected.

• The two

- phase flow and interactions between air and brine will be neglected, although the

re

- saturation of salt would tend to reduce the flow of VOCs through the panel closure system.

The air

- flow average linear velocity as a function of time was calculated for each component of the WPC using the maximum pressure determined from the air

- flow model (DOE, 1996a). The breakthrough time for advective transport was then determined for each of the WPC components (fractured salt, MB 139, clay seams, and the explosion isolation wall).

3.1.2.2 Modeling Results In the model presented for air

- flow, the pressure varies as a functi on of time for flow through the WPC. This will result in a change in the average linear velocity as a function of time that was calculated for each of the various components (fractured salt, MB 139, clay seams, and the explosion isolation wall).

Breakth rough times for a WPC due to advection were computed and are shown in Figure 3

- 3 . The advection analysis suggests that for fractured salt and the mortared block wall, average linear velocities will be high due to h igh permeability, and low porosity, and that VOC breakthrough may occur within one to several years.
Previous analysis (DOE, 1996a) evaluated the effects of hydrodynamic dispersion on VOC transport through the WPC, using a one

- dimensional dispersion model (Freeze and Cherry, 1979). This analysis showed that since breakthrough due to advection occurs rapidly through the dominant flow paths within several years, the effects of hydrodynamic dispersion are negligible. The analysis presented in this report als o shows a similar rapid breakthrough through fractured salt in one to several years, as was the case in the previous analysis.3

- 14 Rev. 1 10/3/2002 1.E-03 1.E-01 1.E+01 1.E+03 1.E+05

1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Time (years)Distance Traveled (m)

Fractured Salt

MB 139 Path Length

1.E-05 1.E-03 1.E-01 1.E+01 1.E+03 1.E+05

1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Time (years)Distance Traveled (m)

Dilated Salt

Clay Seams Block Wall Path Length

Figure 3
- 3 Breakthro ugh Time for VOCs through Several Media3

- 15 Rev. 1 10/3/2002

3.1.2.3 Conclusion
The restricted air

- flow analysis of Section 3.1.1 showed that the mass flow rates of VOCs of concern will remain well below the HWFP required E

- 300 drift limit. The results of advection analysis suggest the appropriateness of the restricted flow model (DOE, 1996a) for the instantaneous breakthrough of VOCs. The advection analysis showed that for fractured salt and the mortared block wall, average linear velocities will be high due to high permeability, a nd low porosity, and that VOC breakthrough may occur within one to several years. While it may appear that this breakthrough time is short, the quantities involved are so small that, as was concluded in Section 3.1.1.3, VOC flow over the operational perio d will be at least two orders of magnitude below the HWFP required limit in the E

- 300 drift.

3.1.3 Monte Carlo Simulation of VOC Release This section presents a Monte Carlo Simulation Analysis (Hahn and Shapiro 1967) for mass flow rate of carbon tetrachloride ov er 35 years of operation. Carbon tetrachloride is used as a surrogate for all VOCs of concern since it is likely to be present in the greatest concentration in a closed panel. In the Monte Carlo Simulation Method, uncertain input parameters are represent ed by separate probability distribution functions. Each of the uncertain input parameters is sampled to develop multiple realizations. It is assumed that the uncertain input parameters are independent of each other and that the covariance between the inp ut parameters can be neglected. A deterministic function or model is then used to evaluate the output parameter (in this case, the mass flow rate of carbon tetrachloride) for each set of realization of input parameters.
In an analysis of the flow of VOC s from a panel, a number of uncertain input parameters can be identified. For example, the concentration of VOCs can vary within and between panels, so the actual headspace concentration can be considered as uncertain input for calculation purposes. The migration of VOCs depends on the panel volumetric closure rate and the molar gas generation rate, both of which are uncertain parameters. Finally, in the case of restricted flow, the intrinsic permeabilities of the WPC (for both closure components and the surrounding disturbed rock zone) also are a source of uncertainty.
In the current Monte Carlo Simulation, only the restricted flow of VOCs is considered. A schematic representation of the Monte Carlo Simulation for restricted flow analysis is shown in Figure 3

- 4 . Each of the uncertain inputs is discussed in the following sections:
Headspace concentratio n : The VOC inventory perhaps represents the most significant source of uncertainty. WIPP receives waste from multiple facilities with multiple waste streams. Both the3

- 16 Rev. 1 10/3/2002

Figure 3
- 4 Monte Carlo Simulation of Restricted Air
- Flow Analysis Intrinsic Permeability

Gas Generation Rate

Volume Closure Rate Restricted Air Flow Analysis

Headspace Concentration Output Input

VOCs Mass Flow Rate3

- 17 Rev. 1 10/3/2002

unrestricted and restricted flow models assume that the heads pace concentrations serve as a constant source of VOCs. This assumption is conservative because most containers only have trace quantities of VOCs, either trapped in the headspace or on the surfaces of the various waste components. It is likely that only a small number of waste containers have a significantly greater source of VOCs such as a solvent

- soaked rag. Only this small number of waste containers have a realistic likelihood of maintaining a constant headspace VOC concentration as gas generation
pr oceeds.
The current project baseline uses a headspace concentration of 3625.77 mg/m 3 for carbon tetrachloride (DOE, 1996a). To account for the uncertainty, it is assumed that the headspace concentration for carbon tetrachloride ranges from 0 to 7250 mg/m 3 with a uniform distribution.
Gas generation rate: The next uncertain parameter is the gas generation rate. The current project baseline uses a gas generation rate of 0.1 moles per drum per year. In the current uncertainty analysis it is assumed that th e gas generation rate ranges from 0 to 0.2 moles per drum per year with a uniform distribution. The uniform distribution provides an estimate of variance that is higher than that for a normal distribution. It is therefore conservative to assume that the molar gas generation rate is uniformly distributed.

Volumetric closure rate: Another uncertain parameter is the volumetric closure rate. In the original design the panel closure rate was based upon data from Panel 1. Since that time, Panel 2 has been excavated, and data are available for assigning the uncertainty. The air

- flow analysis presented in Section 3.1.1 used an average volumetric closure rate of 890 m 3 (31,430 ft 3 ) per year (Appendix B). For the purpose of uncertainty analysis, it is assumed that the volumetric closure rate is uniformly distributed between 600 (21,200) to 1200 m 3 (42,400 ft 3 ) per year.
Intrinsic permeabilities: The remaining uncertain parameters are the intrinsic permeabilities of the various flow components. Log uniform d istributions are used in this analysis for intrinsic permeabilities of various flow components. The ranges of intrinsic permeabilities selected for the Monte Carlo Simulation Analysis are presented in Table 3

- 3

. The intrinsic perm eability of salt in the disturbed rock zone includes the intrinsic permeability of dilated salt and fractured salt. Within the first meter of most excavations, some fractures parallel to the drift are observed from boreholes at the midheight of the rib (D OE, 1995). In this region, the permeabilities are generally greater than at any other location in the salt. Between 3 and 6 ft (1 and 2 m) into the rib, permeabilities decrease to about 10 - 19 m 2 and below; beyond 6 ft (2 m), the permeabilities rapidly de crease to the value associated with intact salt (10 - 22 m 2 ). Based on3

- 18 Rev. 1 10/3/2002

these observations, the analysis assumes that the dilated salt has a range of intrinsic permeabilities from 10 - 20 to 10 - 17 m 2 . Also, the analysis assumes the fractured salt intrinsic pe rmeability ranges from 10 - 17 to 10 - 12 m 2 . Thus the combined range of the dilated salt and fractured salt values is exceptionally broad and covers the extreme range of values commonly used in various other WIPP

- related assessments.
Freeze and Cherry (197 9, p. 29) present a range of intrinsic permeabilities for clay, which can be used to estimate values for the clay seams. The range selected here is from 10 - 19 to 10 - 16 m 2

. Single

- phase brine and nitrogen permeabilities were measured in the laboratory fo r specimens of MB 139 taken from the underground workings at the WIPP (DOE, 1995). Permeabilities to gas ranged from approximately 1.8x10 - 19 to 2.5x10 - 17 m 2 , and the Klinkenberg

- corrected equivalent liquid permeabilities ranged from 1.4x10 - 18 to 1.6x10 - 17 m 2 . Measured permeabilities to brine ranged from 4.4x10 - 20 to 9.7x10 - 17 m 2 . Based upon these values, the range of intrinsic permeability for the MB 139 is selected as from 1x10 - 20 to 1x10 - 16 m 2

. The intrinsic permeability for the interface zone between t he concrete block wall and the surrounding rocksalt is estimated based on a smoothwall aperture range from b = 2 to b = 16 microns (Fernandez et al., 1994). For a smoothwall aperture of b , the interface zone intrinsic permeability is equal to b 2 /12 (Ferna ndez et al., 1994). The results range from 3.33x10 - 13 to 2.13x10 - 11 m 2 for the interface zone intrinsic permeability.

Table 3
- 3 Ranges of Intrinsic Permeabilities in the Monte

Carlo Simulation Analysis

Med ian Lower Value (m 2 ) Upper Value (m 2 ) Dilated Salt 1.00x10 - 20 1.00x10 - 17
Fracture Salt 1.00x10 - 17 1.00x10 - 12 Clay Seams 1.00x10 - 19 1.00x10 - 16
Marker Bed 139 1.00x10 - 20 1.00x10 - 16
Interface Zone 3.33x10 - 13 2.13x10 - 11 Explosion Isolation Wall 1.00x10 - 1 7 1.00x10 - 13
Run of Mine Salt Backfill 1.00x10 - 14 1.00x10 - 103

- 19 Rev. 1 10/3/2002

The intrinsic permeability of the concrete block wall was estimated in Section 3.1.1.1 as 2x10 - 15 m 2 . To account for uncertainty, a range of permeability of four orders of magnitude for the e xplosion isolation wall was selected from 10 - 17 m 2 to 10 - 13 m 2

. The run of mine salt backfill is placed in a loose state in the air

- intake and air

- exhaust drifts of each panel. Case et al. (1987) reports on an experiment on WIPP crushed salt that measured the relationship of hydraulic conductivities to porosity when subjected to confining pressure. The test results showed that the intrinsic permeability might equal 0.01 darcy (10 - 14 m 2 ) at 15 percent porosity. For high porosities from 35 to 40 percent, t he test results showed that the intrinsic permeability might equal 10 2 darcy (10 - 10 m 2 ). Therefore, the range of intrinsic permeability is selected from 10 - 14 m 2 to 10 – 10 m 2

.

3.1.3.1 Evaluation Procedure In order to combine information on assessing the mass fl ow rate of carbon tetrachloride from a single panel, MathConnex (MathSoft, Inc., 1999) was used. MathConnex tm is an environment for visually integrating and linking applications and data sources to create heterogeneous computational systems. MathConnex p rovides a means of connecting MathCad and EXCEL files together in a network. In the MathConnex file entitled Monte Carlo Simulation for Restricted Flow, the uncertain parameters are implemented in four MathConnex components:

• Headspace Concentration of CCl 4 is an EXCEL file that generates a random sample for the headspace concentration of carbon tetrachloride as discussed above.

• Volumetric Closure Rate is an EXCEL file that generates a random sample of the panel volumetric closure rate as discussed above.

• Gas Generation Rate is an EXCEL file that generates a random sample of the gas generation rate as discussed above.

• Intrinsic Permeabilities is an EXCEL file that generates a random sample of the intrinsic permeabilities for each of the flow components as discussed above.
For a single realization of the randomly sampled parameters, the outputs from each of these components is input to the MathCad file entitled Restricted Flow Model. The restricted flow model is used to develop a time history for the mass flow rate of CCl 4 out of the panel. The output from the Restricted Flow Model is then input to an EXCEL file Monte Carlo Simulation. This file develops the time histories for multiple realizations of the input parameters.3

- 20 Rev. 1 10/3/2002

3.1.3.2 Modeling Results
A Monte Carlo Simulation was performed for the restricted flow analysis of VOCs. The results of this simulation for 40 different realizations are presented in Figure 3

- 5 . The figure shows the variation of mass flow rate for ca rbon tetrachloride during the operational life of the WPC. The mass flow rate limit for CCl 4 is calculated as the mass concentration limit at E

- 300 drift times the minimum underground ventilation flow rate of 260,000 ft 3 /min (7,362 m 3 /min) required by HWF P.
In general, the magnitude of the unrestricted steady

- state mass flow rate of CCl 4 reflects the uncertainty in VOCs concentration rates, panel gas generation rate, and panel volumetric closure rate. The time required to reach the restricted steady

- sta te VOC mass flow rate depends on the intrinsic permeability of the flow components. In some restricted realizations, the mass flow rate rises rapidly to the unrestricted steady

- state mass flow rate, so the flow is essentially unrestricted. In the large m ajority of cases, however, the WPC offers some resistance to flow and the mass flow rates develop much more slowly. In all cases the WPC complies with the mass flow rate limit at the E

- 300 drift as required by HWFP.

3.2 Analyses Addressing Material and Struct ural Requirements This section presents evaluations relating to the material and structural requirements for the WPC.

3.2.1 Material Compatibility Evaluation The purpose of the material compatibility evaluations is to select suitable materials for the WPC. The materials must be chemically compatible with the host rock and brine without chemical degradation. This section presents information on brine

- cement interactions at the locations of the WPC.
WIPP brines were initially studied when evidence of some minor c oncrete deterioration in the Waste Shaft key was noted (DOE, 1996a). The cause was geochemical alteration of the concrete shaft liner and shaft grout by the brine present at the Rustler

- Salado contact. Chemical constituents detected in brine samples incl uded both organic and inorganic compounds that probably originated from dissolution of the concrete liner and grout materials used in the shaft construction. The presence of large amounts of organics that likely originated from the chemical grout appeared to have complexed the calcium present in the brine, interfering with the inorganic chemistry of the naturally occurring brine. The brines in contact with the Waste Shaft key were3

- 21 Rev. 1 10/3/2002 1.E-07 1.E-05 1.E-03 1.E-01 1.E+01 1.E+03

5 10 15 20 25 30 35 T ime (Years)CCl4 Mass Flow Rate (g/min)

Figure 3
- 5 Mass Flow Rate for Carbon Tetrachloride E

- 300 Drift Mass Flow Rate Limit3

- 22 Rev. 1 10/3/2002

also found to be significantly higher in both chlorides and magnesium than the Salado Formation brine.
Several other studies investigated the effect of the high

- magnesium brine interactions on vario us candidate barrier materials (DOE, 1996a). However, the original PCS design concluded that two extremely different service environments can be inferred between the Waste Shaft key and the underground repository horizon.

The WPC consists of concrete blo ck wall and run of mine salt backfill. Blocks will be pre

- cast in a factory setting and no organic grout compounds are used in the design. The magnesium level in the brines is much lower at the repository horizon. Further, only trace amounts of brine wo uld contact the explosion isolation wall over the operational period due to the relative impermeability of the surrounding halite. For these reasons, significant brine

- cement interactions are not anticipated and the block walls will perform their function within this time period. Run of mine salt backfill is entirely compatible with the underground environment.

3.2.2 Heat Generation The WPC uses concrete blocks for explosion isolation wall. The concrete blocks will be pre

- cast and cured in a factory setting. They will then be transported to the site and taken underground as convenient. Note that for these small blocks (8x8x16 inches), the volume to surface ratio is smaller than for large monolithic emplacements of concrete. Thus the temperature rise due to the heat of hydration can be dissipated without the development of tensile strains within the blocks before emplacement. Quality control testing of the blocks will assure strength and serviceability. Therefore cement heat generation is not an issue for t he WPC.

3.2.3 Explosion Evaluations The evaluation of the postulated methane explosion consists of evaluating the pressure and thermal effects of such an explosion on the explosion isolation wall. A methane explosion would generate an initial pressure transient that would impinge on the explosion isolation wall. Subsequently, temperature would rise in the panel as well as in the explosion isolation wall.
Two analyses are necessary to evaluate methane

- explosion effects: (1) effect of explosion pressure, and (2) effect of explosion heat. After an explosion, the explosion isolation wall would be subjected to short

- term dynamic loading. The design pressure can be calculated as the maximum pressure times the dynamic load factor (Biggs, 1964). The dynamic load fact or will3

- 23 Rev. 1 10/3/2002

depend on the shape of the pressure

- time transient. An explosion will result in a transient pressure pulse that will rise instantaneously and then drop gradually.
The second effect requires a thermal analysis with a heat

- transfer model. The res ults of the heat transfer model calculations (DOE, 1996a) are valid under the postulated explosion. The heat transfer model under the postulated explosion within the panel considered the heat balance between the gas and the walls of the panel for a stoich iometric mixture of methane. The rate at which the gas temperature will rise within the panel depends on (1) the number of moles of methane, (2) the specific heat capacity of the gas and the heat transfer to the salt and the walls through radiation, (3) c onvection along the vertical and horizontal surfaces, and (4) conduction within the salt and walls. The thermal analysis result (DOE, 1996a) showed that the elevated temperature due to explosion would propagate a maximum of 6 inches (15 cm) through the wa ll.
In the event of a hydrocarbon explosion either (1) deflagration will result in a rapid rise of pressure, with no transition to a detonation, or (2) a detonation wave front will propagate as a supersonic shockwave. The transition to a detonation is a f unction of two parameters: (1) the methane concentration at the time of the explosion, and (2) the ability for a wave front to form. In underground excavations, the latter condition typically requires a reasonably long passage through which the combustio n wave travels and transforms to a detonation. The probability of occurrence of a detonation in an air

- gas mixture also depends strongly upon the type of air

- gas mixture. In the case of WIPP, the open passages above the waste stack will reduce in size du e to creep closure so it is unlikely that a long passage with open geometry will exist. As a result the occurrence of detonation in underground excavation at WIPP is very unlikely. Therefore this analysis will only consider deflagration.
The peak explosi ve pressure arising from a deflagration is about eight times (DOE, 1996a) the ambient pressure at the time of explosion. The ambient pressure at the time of explosion depends on panel volume reduction rate, gas flow rate from WPC, and gas generation rate. In the current analysis the ambient pressure will reach a steady value of 1.41 atmosphere in a short time after panel closure. This results in a peak explosion pressure of 164 psi (1.14 MPa).
The dynamic load factor will depend on the natural frequency of the explosion isolation wall. The value for the dynamic load factor approaches a maximum value of 2, with increased natural frequency for a variety of exponential curves (DOE, 1996a). Based upon this loading, the block wall will be subjected to an equ ivalent uniform pressure of 328 psi (2.28 MPa). The result of the stress analysis is presented in the next section.3

- 24 Rev. 1 10/3/2002

3.2.4 Stress Analysis The purpose of the stress analysis was to evaluate the interaction of the block wall and run of mine salt backfill of the W PC with the surrounding salt. Stresses are expected to develop in the block wall component due to continued creep closure of the air

- intake and air

- exhaust drifts after installation of the block wall. Stresses are also expected to develop in the run of m ine backfill, although at a very much slower rate than in the block wall. It is also shown that each component can individually withstand the postulated methane explosion.

3.2.4.1 Block Wall Evaluation
Detailed two

- dimensional axisymmetric representations of the WPC were developed using the FLAC (Itasca, 2000) computer code. The properties used in these models are presented in Appendix C.
FLAC has been used since 1991 to model underground excavations at the WIPP. FLAC is a two

dimensional explicit finite differe nce code that simulates the behavior of rock and soil

- like structures. The WIPP Reference Creep Law is built into the code and has been verified against the WIPP Second Benchmark Problem (Kreig, 1984). The following sections describe the geometry and bou ndary conditions of the models used in the FLAC analysis.
Model Development. A detailed axisymmetric model was developed to investigate the barrier under creep loading and combined creep and explosion loading. The geometry of this model is shown in Figure 3

- 6 . There are five construction joints in this case, which are spaced evenly in the block wall. The construction joints have no cohesion (see Appendix C). The concrete is modeled as a Mohr

- Coulomb material wit h a tension cut

- off. Three cases were run with different loading and strength properties as called for by the ACI Ultimate Strength Design Method (ACI 318

- 02):

1.4 W

1.2 W + 1.6 E

0.9 W + 1.6 E

where W and E denote the dead load (far

- field stress) and exp losion load, respectively. All three cases used a strength reduction factor of 0.8. In addition to these three cases, a service load case3

- 25 Rev. 1 10/3/2002 concrete 5 m

Figure 3
- 6 Creep Plus Explosion Model Geometry and Boundary Conditions3

- 26 Rev. 1 10/3/2002

was run with all loading and strength properties set to their nominal values. In all cases with an explosion load, the explosive force was applied instantaneously, equilibrium was reached, and then the force was re moved.
Modeling Results. The results from the ultimate strength design cases showed that while some compressive failure occurs near the ends of the block wall, the wall maintains a sizable intact confined core in every case, thus validating the design. O nly the results from the service load case are presented here. Profiles of the stress in the block wall caused by an explosion after ten years of creep loading are shown in Figure 3

- 7 and Figure 3

- 8 . The vertical (radial) loading is not significantly changed, while the axial loading is actually improved since the stress goes slightly compressive rather than tensile. Figure 3

- 9 and Figure 3

- 10 show contours of stress in the wall and in the rock during the explosion. Figure 3

- 11 shows the plasticity state in the wall at 35 years. This figure shows a limi ted tensile fracture zone near the rocksalt

- concrete interface. Like the construction joints, these fractures are normal to the direction of the VOC flow through the WPC and have minimal impact on the flow conductance. Figure 3

- 12 shows a vertical stress profile in the block wall at 35 years, the required design life. These figures show that the block wall will perform its required function throughout the nominal operational design life.

3.2.4.2 Run of Mine Salt Backfill Evaluation The run of mine salt backfill also provides a barrier to resist explosion pressure. To show the effectiveness of the salt backfill as an explosion barrier, a simple analytical model was developed. The following simplifying assumptions were ma de to conduct a conservative analysis.

• The run of mine backfill was subjected to all of the explosion loading.

• The explosion pressure is assumed to reach the maximum value of 1.14 MPa (Section 3

- 2

- 3) instantly and remains constant with negligible decay.

• Th e confining pressures on the salt backfill due to creep closure of the surrounding rocksalt are ignored.

• The geometric and material dampings are ignored.

• The only resistance mechanism is the frictional contact between backfill and rocksalt.

• Backfill materi al is assumed to be elastic.3

- 27 Rev. 1 10/3/2002 Explosion to Right

-24 -22 -20 -18 -16 -14 -12 -10

-5 -4 -3 -2 -1 0 1 2 3 4 5 Distance from center of barrier (m)Sxx at top of wall (MPa)

Sxx at 10 yr Sxx Explosion at 10 yr

Figure 3
- 7 Vertical (Radial) Stress Profile at Top of Block Wall During an Explosion Occurring 10 Years after Emplacement

Explosion to Right

-2.5 -2 -1.5 -1 -0.5 0 0.5 1

-5 -4 -3 -2 -1 0 1 2 3 4 5 Distance from center of barrier (m)Sxx at top of wall (MPa)

Syy at 10 yr Syy Explosion at 10 yr

Figure 3
- 8 Horizontal (Axial) Stress Profile at Top of Block Wall During an

Explosion Occurring 10 Years after Emplacement3

- 28 Rev. 1 10/3/2002

Figure 3
- 9 Vertical (Radial) Stress Contours in Block Wall During an Explosion

Occurr ing 10 Years after Emplacement

Figure 3
- 10 Horizontal (Axial) Stress Contours in Block Wall During an Explosion Occurring 10 Years after Emplacement3

- 29 Rev. 1 10/3/2002 Figure 3
- 11 Plasticity State in Block Wall at 35 Years

-35 -30 -25 -20 -15 -10

-5 -4 -3 -2 -1 0 1 2 3 4 5 Distance from center of barrier (m)Sxx at top of wall (MPa)

Sxx 30 years after wall installed

Figure 3
- 12 Vertical (Radial) Stress Profile at Top of Block Wall at 35 Years3

- 30 Rev. 1 10/3/2002

The strain

- stress relations for a general three

- dimensional body can be writ ten as (Fung, 1965):

        

− − = − − = − − =

E

E E E E E E E E

y

x z z z

x y y z

y x x

s

u s u s e s

u s u s e s

u s u s e
(Equation 3

- 7 )

where x s , y s and z s are the normal stress components in the x , y and z directions, respectively, x

e , y e and z e are the corresponding normal strain components, and E and n are the Young’s modulus and Poisson’s ratio respectively.
By taking the x axis as the longitudinal axis along the salt backfill ) 0 ( ∞ < < x and setting

y e = z e = 0, Equation 3

- 7 reduces to the following one

- dimensional form:


## ( ) E K x o x s u e 2 1

− = (Equation 3

- 8 )

where

u u

− = 1 o K

By substituting Equation 3

- 8 into the one

- dimensional strain

- displacement relation of dx du x / = e and defining p

x − = s one obtains:


## ( ) E p K dx du

o

u 2 1

− − = (Equation 3

- 9 )

where )

, ( t x u u = is the axial displacement along the x a xis at time t

. The applied forces on a longitudinal backfill element of length dx are shown in Figure 3

- 13

. Equilibrium of these forces along the x axis results in :

dx Q p K A dp p dx A t u A p o m r +

+ + ∂ ∂

= )

( 2 2 ) 0 , , ( > t x u (Equation 3

- 10 )3

- 31 Rev. 1 10/3/2002

in which:

r = mass density

m = coefficient of friction

A = cross

- sectiona l area of backfill
Q = perimeter of backfill in cross section

dx A t u 2 2 ∂ ∂ r = inertia force

dx Q p K o m = friction force along the perimeter of backfill
Using Equation 3

- 9, Equation 3

- 10 can be further simplified as:

0 2 2 2 2
2 2 2 =

∂ ∂ + ∂ ∂

− ∂ ∂

x

u C t u

x u C l ) 0 , , ( > t x u (Equation 3

- 11 )

where

)

2 1 ( o K E C u r

− =

A Q K o 2 m l =

Equation 3

- 11 is subjected to zero displacement and veloc ity as initial conditions. Also, from Equation 3

- 9, the following boundary condition is applied: 

## ( ) )

( 2 1 ) , 0 ( t

P E K t x u o

u

−

− = ∂ ∂ (Equation 3

- 12 )

where ) ( t P is the explosion pressure at the expl osion face. By ignoring the reflected wave effect from the far end of the backfill, Equation 3

- 11 is solved using the central finite difference method. The elastic parameters for run of mine salt ( = E 20.1 MPa, =

u 0 .25) were adopted from Callahan and DeVries (1991). A conservative value of 25 degrees similar to loose silt or silty sand (Bowls, 1982) was used for the friction angle of run of mine salt.3

- 32 Rev. 1 10/3/2002

Figure 3

- 14 shows the re sult of the analysis. Based on this figure, the displacement of the salt at the explosion face is 13.8 inches (0.350 m) when the maximum displacement at the opposite end is about 0.4 inches (0.01 m). This verifies that the run of mine salt backfill perfo rms as an effective explosion barrier.

3.2.5 Fracture
- Propagation Evaluation
The fracture

- propagation studies evaluate the potential for fracture propagation, using the results of previous analyses. The results of the thermal analysis suggest that elevated temp eratures within an explosion isolation wall and salt will be a localized phenomenon. During an explosion two phenomena could affect the potential fracturing of the salt: (1) the expansion of the explosion products into existing fractures, and (2) the pote ntial reflection of sonic waves off free surfaces around the barrier. The fractures in the roof and floor could be affected by the expansion of the gas products on the order of 164 psi (1.14 MPa), which decay rapidly with time and attenuate with distance. Around the wall, the confining stress on the order of 2,100 psi (15 MPa) will develop. Horizontal fracture propagation could occur around the barrier only if the internal gas pressure exceeds confining pressure. Because the peak internal pressure from deflagration is less than ten percent of the confining pressure, fractures would not propagate through or around the main wall.
Following an explosion, the wall would be subject to sonic waves that would impinge on the wall. As the sonic wave encounters a contrast in wall stiffness, a portion of the sonic wave would be refracted, and a portion would be reflected (Jaeger and Cook, 1972). This would result in minor tensile spalling of the isolation wall. The salt backfill causes a partial wave transmission and damping which in turn reduces the reflected tensile wave. At the time of a potential explosion, the development of confining stress relative to the explosion pressure would prevent fracturing around the block wall. The block wall can safely withstan d the pressure from the postulated methane gas explosion.3

- 33 Rev. 1 10/3/2002 Figure 3
- 13 Applied Forces on a Longitudinal Element of Backfill

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40

0 5 10 15 20 25 30

Distance from Explosion Face (m)Displacement (m) Explosion

Face Run of Mine Salt

Figure 3
- 14 Dynamic Displacement versus Distance from Explosion Face Inertia Force Friction Force

p p + dp

dx4

- 1 Rev. 1 10/3/2002



### 4.0 Design Calculations
All calculations were performed in accordance with the RockSol Consulting Group, Inc., Quality Assurance Program and comply with Westinghouse TRU Solutions requi rements. The documentation for the codes and calculations, as well as related documents such as verification and validation tests, constitute quality records and are maintained in accordance with WIPP procedures.
The bases for all calculations are prese nted in Chapter 3 and Appendices A, B, and C. All software for the design calculations have been documented, verified and validated in accordance with the RockSol Consulting Group, Inc. Quality Assurance Program. This program complies with the requiremen ts of the Westinghouse TRU Solutions QA Program.5

- 1 Rev. 1 10/3/2002



### 5.0 Technical Specifications
The specifications are in the engineering file room at the WIPP and are the property of Westinghouse. These specifications are included as an attachment in Appendix D and are

sum marized in Table 5

- 1

.

Table 5
- 1 Technical Specifications for the WIPP Panel Closure System

Division 1
- General Requirements
Section 01010 Summary of Work
Section 01090 Reference Standards
Section 01400 Contractor Quality Control
Section 01600 Material and Equipment Division 2
- Site Work
Section 02010 Mobilization and Demobilization
Section 02222 Excavation Division 3
- Masonry

Section 03100 Morta r Section 03300 Unit Masonry System

Section 03400 Masonry Explosion Isolation Structure
Division 4
- Salt Backfill
Section 04100 Salt Backfill6

- 1 Rev. 1 10/3/2002



### 6.0 Drawings
The Drawings (Appendix E) are in the engineering file room at the WIPP and are summarized in Table 6

- 1

.

Table 6
- 1 WIPP Panel Closure System Drawings

Drawing Number Title
110

- CD001 Panel closure system, title sheet
110

- CD002 Panel closure system, underg round waste disposal panel
110

- CD003 Panel closure system, construction details7

- 1 Rev. 1 10/3/2002



### 7.0 Conclusions
This chapter presents the conclusions for the detailed design activities for the WPC. Table 7

- 1 sh ows the performance specifications for the WPC and the compliance of the design with the performance specifications. The design configuration and essential features for the WPC include an explosion isolation wall constructed of 5000 psi (34.5 MPa) unconfi ned compressive strength blocks that is 30 ft (9.1 m) long, and a run of mine salt backfill section that is 100 ft (30.5 m) long. Surface treatment around the explosion isolation wall includes the removal of loose material to create a clean, regular surfa ce for construction of the block wall.
The design is presented in this report as performance specifications, a series of calculations, and engineering Drawings and Specifications. Structural analyses used to select the design length and other design featu res are based upon data acquired from the WIPP underground. The Drawings illustrate and describe the construction and details for the system. The Specifications cover the general requirements of the system, quality assurance and quality control, site wor k, masonry, and run of mine salt backfill. Information on the proposed construction method is also presented. The WPC can be built to generally

- accepted national design and construction standards.
The design complies with all aspects of the design basis established for the WPC. The design can be constructed in the underground environment with no special requirements at the WIPP. To investigate several key design issues and to implement the design, design evaluations were performed. The conclusions reac hed from the evaluations are as follows:

• The mass flow rates for different VOCs through the WPC (including flow through the DRZ, the explosion isolation wall, and run of mine salt backfill) are substantially below the limits established in the HWFP for the E

- 300 drift.

• The Monte Carlo Simulation Method was used to assess the uncertainty of VOCs headspace concentrations, gas generation rates, and panel volume closure rates on the mass flow rate of carbon tetrachloride. The time required to reach the steady

- state mass flow rate of carbon tetrachloride depends on the intrinsic permeability of the flow components. In some realizations the mass flow rate rises rapidly to the steady

- state mass flow rate and the flow is essentially unrestricted. In most cases, h owever, the WPC offers resistance to flow, and mass flow rates would develop more slowly. In all cases, the explosion isolation wall with the run of mine salt backfill complies with the mass flow rate limit at the E

- 300 drift.

• The passive design component s of the WPC do not require routine maintenance during the7

- 2 Rev. 1 10/3/2002

nominal operational life of 35 years.

• Thermal cracking due to heat of hydration effects does not apply to concrete blocks.

• The trace amounts of brine from the salt at the repository horizon would not degrade the main concrete barrier for at least 35 years.

• Detailed axisymmetric models were developed to assess the state of stress in the block wall and surrounding rock due to creep closure of the salt. The length selected for the explosion isolation wall provides for a substantial margin of safety against structural failure due to creep loading.

• Stress analysis shows that the wall will withstand both the forces of creep and the postulated methane explosion. Further, at the time of a potential expl osion, the development of confining stress would prevent fracturing around the block wall.

• The heat

- transfer analysis in the previous PCS design (DOE, 1996a) showed that elevated temperatures would occur within the salt and the explosion isolation wall; ho wever, the elevated temperatures will be isolated by the PCS. Temperature gradients will not significantly affect the stability of the wall.

• The WPC provides for flexibility over the 35

- year operational life in construction scheduling and construction mat erial transportation and therefore minimizes the effect on waste receipt.
In addition to the design requirements presented above, the design includes a QA/QC program to verify material properties and construction practices. The existing shafts and under ground access can accommodate the construction of the WPC.7

- 3 Rev. 1 10/3/2002 Table 7
- 1 Compliance with Performance Specifications

Requirement Design Report Section Compliance

with Requirement Notes on Compliance

The panel clo sure system design shall limit VOC migration from a closed panel consistent with the limits found in Table IV.F.2.c of the HWFP. 3.1 Complies Gas

- flow modeling shows that the VOC flow is substantially less than the E

- 300 drift limit specified in the HWFP.

The panel closure system shall consider potential flow of VOCs through the disturbed rock zone (DRZ) in addition to flow through closure components. 3.1 Complies Restricted gas

- flow model considers flow through the DRZ.

The panel closure system shall per form its intended functions under loads generated by creep closure of the tunnels. 3.2.4 Complies Stress analyses and design calculations show that the WPC performs as intended under creep closure. The panel closure system shall perform its intended funct ion under the conditions of a postulated methane explosion. 3.2.3 3.2.4 3.2.5 Complies The methane explosion studies, fracture propagation studies, and supporting design calculations show that the WPC performs as intended. The nominal operational life of the closure system is thirty

- five (35) years. 3.1 3.2 Complies Gas

- flow modeling and stress analyses shows satisfactory performance for 35 years. The panel closure system for each individual panel shall not require routine maintenance during its operation al life. 2.2 Complies Passive design components require no routine maintenance.

The panel closure system shall address the most severe ground conditions expected in the waste disposal area. 3.1 3.2 Complies Design is based upon flow and structural analyse s of the most severe ground conditions. The design class of the panel closure system shall be IIIb (which means that it is to be built to generally accepted national design and construction standards). 2.3 Complies The construction sequence for the design followed conventional mining practices.

The design and construction shall follow conventional mining practices. 2.2 2.3 Complies The specifications include normal construction practices used in the underground at WIPP and according to the most
current mo rtar and concrete block specifications.7

- 4 Rev. 1 10/3/2002 Table 7
- 1 (Continued) Compliance with Performance Specifications

Requirement Design Report Section Compliance

with Requirement Notes on Compliance

Structural analysis shall use data acquired from the WIPP undergr ound. 3.2.4 Complies The structural analysis uses properties that model creep closure for stress analyses from data acquired in the WIPP Geotechnical Monitoring Program. Materials shall be compatible with their emplacement environment and function. 3.2.1 Complies The material compatibility studies showed no degradation of materials and no need for surface treatment.
Treatment of surfaces in the closure areas shall be considered in the design. Appendix D Complies Design specifications address surface trea tment

Thermal cracking of concrete shall be addressed. 3.2.2 Complies Thermal cracking due to heat of hydration effects do not apply to concrete blocks. During construction, a Quality Assurance/Quality Control (QA/QC) program shall be established to veri fy material properties and construction practices. Appendix D Complies The specifications include materials testing to verify material properties and construction practices.

Construction of the panel closure system shall consider shaft and underground acc ess and services for materials handling. Appendix D Complies The specifications allow construction within the capacities of underground access.8

- 1 Rev. 1 10/3/2002



### 8.0 References
American Concrete Institute (ACI), 2002, "Building Code Requirements for Structural Concrete and Commentaries," ACI 318

- 02, American Concrete Institute, Farmington Hills, Michigan.
American Concrete Institute (ACI), 2002, "Building Code Requirements for Masonry Structures & Specification for Masonry Structures & Commentaries," ACI 530.1

- 02, American C oncrete Institute, Farmington Hills, Michigan.
American Society for Testing and Materials (ASTM), 2002, "Standard Practice for Laboratories Testing Concrete and Concrete Aggregates for Use in Construction and Criteria for Laboratory Evaluation," ASTM C 107 7

- 02 , American Society for Testing and Materials, West Conshohocken, Pennsylvania.
American Society for Testing and Materials (ASTM), 2002, "Standard Practice for Agencies Performing Nondestructive Testing," ASTM E 543

- 02 , American Society for Testing and Materials, West Conshohocken, Pennsylvania.
American Society for Testing and Materials (ASTM), 2002, "Standard Specification for Aggregate for Masonry Mortar," ASTM C 144

- 02, American Society for Testing and Materials, West Conshohocken, Pennsylvania.

Amer ican Society for Testing and Materials (ASTM), 2002, "Standard Specification for Portland Cement," ASTM C 150

- 02 , American Society for Testing and Materials, West Conshohocken, Pennsylvania.
American Society for Testing and Materials (ASTM), 2002, "Standar d Test Method for Compressive Strength of Masonry Prisms," ASTM C 1314

- 02a , American Society for Testing and Materials, West Conshohocken, Pennsylvania.
American Society for Testing and Materials (ASTM), 2002, "Standard Test Method for Preconstruction and Construction Evaluation of Mortars for Plain and Reinforced Unit Masonry," ASTM C 780

- 02 , American Society for Testing and Materials, West Conshohocken, Pennsylvania
American Society for Testing and Materials (ASTM), 2002, "Standard Test Methods for Sampli ng and Testing Concrete Masonry Units and Related Units," ASTM C 140

- 02 , American Society for Testing and Materials, West Conshohocken, Pennsylvania.8

- 2 Rev. 1 10/3/2002

American Society for Testing and Materials (ASTM), 2001, "Standard Practice for Accreditation of Testing A gencies for Unit Masonry," ASTM C 1093

- 95 , American Society for Testing and Materials, West Conshohocken, Pennsylvania.
American Society for Testing and Materials (ASTM), 2001, "Standard Specification for Extended Life Mortar for Unit Masonry," ASTM C 1142

- 95 , American Society for Testing and Materials, West Conshohocken, Pennsylvania.
American Society for Testing and Materials (ASTM), 2001, "Standard Specification for Concrete Brick," ASTM C 55

- 01a , American Society for Testing and Materials, West Conshoho cken, Pennsylvania.
American Society for Testing and Materials (ASTM), 2001, "Standard Specification for Agencies Engaged in the Testing and/or Inspection of Materials Used in Construction," ASTM E 329

- 01a , American Society for Testing and Materials, West Conshohocken, Pennsylvania.
American Society for Testing and Materials (ASTM), 2001, "Standard Specification for Mortar for Unit Masonry," ASTM C 270

- 01a , American Society for Testing and Materials, West Conshohocken, Pennsylvania.
American Society for Tes ting and Materials (ASTM), 2001, "Standard Specification for Masonry Cement," ASTM C 91

- 01, American Society for Testing and Materials," West Conshohocken, Pennsylvania.
American Society for Testing and Materials (ASTM), 2000, "Standard Specification for Ready

Mixed Concrete," ASTM C 94

- 00 , American Society for Testing and Materials, West Conshohocken, Pennsylvania.
American Society for Testing and Materials (ASTM), 1997, "Standard Specification for Hydrated Lime for Masonry Purposes," ASTM C 207

- 91 , Ameri can Society for Testing and Materials, West Conshohocken, Pennsylvania.
American Society for Testing and Materials (ASTM), 1994, "Standard Guide for General Criteria Used for Evaluating Laboratory Competence," ASTM E 548

- 94 , American Society for Testing an d Materials, West Conshohocken, Pennsylvania.
Biggs, J., 1964, Introduction to Structural Dynamics, McGraw Hill, New York, New York.8

- 3 Rev. 1 10/3/2002

Bowles, E., 1982, Foundation Analysis and Design , McGraw

- Hill, New York, New York.
Callahan, G. D., and K. L. DeVries, 199 1, "Analyses of Backfilled Transuranic Wastes Disposal Rooms," SAND91

- 7052, Sandia National Laboratories, Albuquerque, New Mexico.
Case, J. B., and P. C. Kelsall, 1986, "Shaft

- Seal Modeling and Analysis of the Small Scale Seal Performance Tests at the Wast e Isolation Pilot Plant," IT Corporation, Albuquerque, New Mexico.
Case, J. B., P. C. Kelsall, and J. L. Withiam, 1987, "Laboratory Investigation of Crushed Salt Consolidation," Rock Mechanics: Proceedings of the 28 th US Symposium , Edited by: I. W. Farmer, J. J. K. Daemen, C. S. Desai, C. E. Glass, and S. P. Neuman, Tucson, Arizona, pp189

- 196.
Daemen, J. J. K., J. C. Stormont, N. I. Colburn, D. L. South, S. A. Dischler, K. Fuenkajorn, W. Greer, G. S. Adisoma, D. E. Miles, B. Kousari, and J. Bertucca, 1983, "Rock Mass Sealing Experimental Assessment of Borehole Plug Performance," NUREG/CR3483 , University of Arizona, Tucson Arizona.
Fernandez, J. A., J. B. Case, C. A. Givens, and B. C. Camey, 1994, "A Strategy to Seal Exploratory Boreholes in Unsaturated Tuff, " SAND93

- 1184, Sandia National Laboratories, Albuquerque, New Mexico.
Freeze, A., and J. Cherry, 1979, Groundwater, Prentice Hall, Inc., Englewood Cliffs, New Jersey.
Fung, Y. C., 1965, Foundations of Solid Mechanics , Prentice

- Hall, Inc., Englewood Cliffs, New Jersey.
Hahn, G. J., and S. S. Shapiro, 1967, Statistical Models in Engineering , John Wiley & Sons, New York, New York.
IT Corporation (IT), 1994, "Backfill Engineering Analysis Report," report prepared for Westinghouse Electric Corporation, Carlsbad, New Mexico.
Itasca Consulting Group, Inc. (Itasca), 2000, "FLAC User's Manual," Itasca Consulting Group, Inc., Minneapolis, Minnesota.
Jaeger, J. C., and N. G. W. Cook, 1972, Fundamentals of Rock Mechanics, John Wiley and Sons, New York, New York.8

- 4 Rev. 1 10/3/2002

Krieg, R. D., 1984, "Reference Stratigraphy and Rock Properties for the Waste Isolation Pilot Plant," SAND83

- 1908 , Sandia National Laboratories, Albuquerque, New Mexico.
Lindeburg, M. R., 1986, Civil Engineering Reference Manual , Professional Publications, Inc.
MathSoft, 1999, Mathcad 2000 User’s Guide, MathSoft, Inc., Cambridge Massachusetts.
Mine Safety and Health Administration (MSHA), 2002, "Safety Standards for Methane in Metal and Nonmetal Mines," Title 30, Code of Federal Regulations (CFR), Part 57 (30 CFR 57), U.S. Department of Labor, Mine Safety and Health Administration, Washington, D.C.
New Mexico Environment Department, 2000, "Adoption of 40 CFR Part 264," Title 20 (Environmental Protection) of the New Mexico Administrative Code, Chapter 4 (Hazardous Waste), Part 1 (Hazardous Waste Management) , New Mexico Hazardous and Radioactive Materials Bureau, Santa Fe, New Mexico.
Portland Cement Association (PCA), 2002, "Fundamentals of Concrete, " ISO54 , Portland Cement Association, Skokie, Illinois.
U.S. Depar tment of Energy (DOE), 1996a, "Detailed Design Report for an Operational Phase Panel Closure System," DOE/WIPP 96

- 2150 , U.S. Department of Energy, WIPP Project Office, Carlsbad, New Mexico.
U.S. Department of Energy (DOE), 1996b, " WIPP Compliance Certifica tion Application 40 CFR 191 Subpart B and C. " CD

- ROM Version prepared by the Carlsbad Technical Assistance Contractor, Roy F. Weston, Carlsbad, New Mexico.
U.S. Department of Energy (DOE), 1995, "Conceptual Design for Operational Phase Panel Closure Syste ms," DOE

- WIPP

- 95

- 2057, U.S. Department of Energy, WIPP Project Office, Carlsbad, New Mexico.
U.S. Department of Energy (DOE), 1994, "Panel 1 Utilization Plan." WIPP/WID

- 94

- 2027, Westinghouse Electric Corporation, Carlsbad, New Mexico.

U.S. Environmental Pr otection Agency (EPA), 2001, " Standards for Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities, " Title 40 (Protection of Environment) of the Code of Federal Regulations, Part 264 , U.S. Government Printing Office.8

- 5 Rev. 1 10/3/2002

WIPP Wast e Information System, 2002, "Headspace Gas Concentration Report," Report RP0430, 4/25/2002.
WIPP Hazardous Waste Facility Permit, NM 4890139088

- TSDF, Aug. 31, 2001, Module IV

- Geologic Repository Disposal.
Westinghouse TRU Solutions, 2002, "Mining/Emplace ment Schedule," June 1 st 2002 update.

## APPENDIX A

DERIVATION OF RELATIONSHIPS FOR THE

AIR
- FLOW MODELSA

- 1 Rev. 1 10/3/2002 

### APPENDIX A DERIVATION OF RELATIONSHIPS FOR THE

AIR
- FLOW MODELS

A.1.0 Introduction This appendix presents the derivation of unrestricted and restricted air

- flow models used to dete rmine the performance of the panel closure system. These derivations were used in the analyses in Section 3.1 to determine gas flow from a panel. These analyses provide an estimate of the volume of gas that might flow through the panel closure systems at the Waste Isolation Pilot Plant (WIPP).


### A.2.0 Model for Unrestricted Flow of VOCs A model for the unrestricted flow of volatile organic compounds (VOCs) was developed to predict the mass flow rates of VOCs and to compare these mass flow rates with the de sign migration limits for VOCs. Over time, a mixture of gases containing VOCs flows from each waste container. It is assumed for the unrestricted flow model that the headspace concentrations serve as a constant source of VOCs. This assumption is conserv ative because most containers only have trace quantities of VOCs, either trapped in the headspace or on the surfaces of the various waste components. It is likely that only a small number of waste containers have a significantly greater source of VOCs suc h as a solvent

- soaked rag. Only this small number of waste containers have a realistic likelihood of maintaining a constant headspace VOC concentration as gas generation proceeds.
The VOCs originating from the waste containers can migrate from the panel d ue to volumetric creep closure of the panel void space and to gas generation due to microbial degradation of the waste. Because flow is unrestricted, the VOCs migrate under a pressure of one atmosphere. Other assumptions in the unrestricted flow model ar e as follows:

• Any gases released into the mine atmosphere would be reduced in concentration by the minimum ventilation rate of 260,000 ft 3 /min (7,362 m 3 /min) required by HWFP at E

- 300 drift. The mass flow rate of individual VOCs from individual panels fol lowing their closure is summed to determine the mass flow rate of VOCs at E

- 300 drift.

• The analysis uses the schedule for closure of individual panels (Westinghouse, 2002) as illustrated in Table A

- 1 during the oper ational life of the panel closure system.A

- 2 Rev. 1 10/3/2002

• Open panels of waste are not considered as a source contributing to the emissions of VOCs.
Considering only advection in the migration of VOCs, the mass

- balance relationship is (DOE, 1996):

300 300 E E p p Q C Q C

⋅ = ⋅ (Equation A

- 1 )

where

p C = Headspace concentration for an individual VOC

p Q = Flow rate of VOCs from the panel

300 E C = Concentration of VOCs at the E

- 300 drift

300 E Q = Underground ventilation f low rate at the E

- 300 drift

Table A

- 2 presents the maximum headspace concentrations for different VOCs of concern. The total flow rate of VOCs from the panel can be obtained as follows (DOE, 1996):

c gr p Q Q Q + = (Equation A

- 2 )

where

gr Q = Volumetric flow rate due to gas generation

c Q = Volumetric flow rate due to panel volumetric closure The volumetric flow rate due to gas generation is calculated as the gas generation rate (0.1 moles per drum per year) times the number of drums within a panel times the specific volume under atmospheric pressure. The VOCs concentrations at the E

- 300 drift must be restricted to the limits found in Table IV.F.2.c of the HWFP, which are shown in Table A

- 3

.A

- 3 Rev. 1 10/3/2002 Table A
- 1 Schedule for Panel Closure (After Westinghouse, 2002)

Panel # Closure time (years)

1 5.11
2 6.15 3 7.36
4 9.39
5 11.93 6 14.55
7 17.38 8 23.18 9 28.98 10 35.00

Table A
- 2 Maximum Headspace Concentrations for VOCs (After DOE, 1996, and WIPP Waste Information System Headspace Gas Concentration Report, 2002)

Compound Maximum Headspace

Concentration (milligrams per cubic meter) Carbon Te trachloride 3625.77 Chlorobenzene 63.99 Chloroform 76.79 1,1

- Dichloroethene 48.68 Methylene Chloride 3387.03 1,1,2,2

- Tetrachloroethane 69.65
Toluene 105.51 1,2

- Dichloroethane 1.24 1,1,1

- Trichloroethane 145.75A

- 4 Rev. 1 10/3/2002 Table A
- 3 VOC Concentrations of Concern (After Table IV.F.2.c of the HWFP. This list of VOCs is the same as the list of VOCs in the previous design (DOE, 1996a) except for 1,2
- dichloroethane and 1,1,1
- trichloroethane.)

Compound Drift E

- 300 Concentration Limit (m icrograms per cubic

meter)
Carbon Tetrachloride 1050 Chlorobenzene 1015 Chloroform 890 1,1

- Dichloroethene 410 Methylene Chloride 6700 1,1,2,2

- Tetrachloroethane 350
Toluene 715 1,2

- Dichloroethane 175 1,1,1

- Trichloroethane 3200A

- 5 Rev. 1 10/3/2002



### A.3.0 Model for Restricted Flow of VOCs The assumptions for the restricted air

- flow model are as follows:

• Gases (including VOCs) within the void space will obey the Ideal Gas Law. The gases will be generated at a rate of 0.1 moles per drum per year and will be stored by an increase in gas pressure. The rate of pressure buildup will be so gradual that it occurs at constant temperature.

• Volumetric reduction due to creep will reduce the void space at a rate of 31,430 ft 3 (890

m 3 ) per year (Appendix B) and will result in pre ssurization.

• Flow of gas out of the panel will obey Darcy's Law under quasi steady

- state conditions. Under quasi steady

- state conditions, the air pressure within the panel closure system will change so gradually that the compressive storage of the air wit hin the void space of the panel closure system could be neglected.

• Rates of gas generation, air outflow, and change in compressive storage will balance.

• Hydrodynamic dispersion through the barrier will be neglected.

• Analysis will consider the superposition of flow rates from individual panels according to the operating schedule for a nominal operational life of 35 years.
After panel closure, the volume, moles of gas, and pressure change as functions of time. The Ideal Gas Law (Hiller and Herber, 1960) is w ritten as:

V T R n p ⋅ ⋅ = (Equation A

- 3 )

where

p = Pressure in the panel

n = Moles of gas in the panel

R = Universal gas constant

T = Absolute temperature

V = Volume of the panel void spaceA

- 6 Rev. 1 10/3/2002

Differentiating Equation A

- 3 with respect to tim e t and using the chain rule results in:

2 V dt dV n V dt dn
T R dt dp ⋅

− ⋅

⋅ ⋅ = (Equation A

- 4 )

The rate at which gas enters the panel minus the rate that gas leaves the panel must equal the change in moles stored. Therefore, the mass

- balance relationship can be written as follows (DOE, 1996):

g atm s r p

p L A K T R p g dt dn

−

⋅ ⋅ ⋅

⋅ − = (Equation A

- 5 )

where

r

g = Panel gas generation rate

atm p = Atmospheric pressure
g = Air density

s K = Effective panel closure system conductivity

A = Cross

- sectional area

L = L ength of flow path
Conductance (C) can be defined as follows:

L A K C s ⋅ = (Equation A

- 6 )
Substituting into the ordinary differential equations, the following relations can be obtained:

2 ) (

V dt dV n V p p C T R p g T R dt dp atm

r ⋅ − ⋅ −

⋅ ⋅

⋅ −

⋅ ⋅ = g (Equation A

- 7 )

g atm r p

p C T R p g dt dn

−

⋅ ⋅

⋅ − = ( Equation A

- 8 )A

- 7 Rev. 1 10/3/2002

These two first

- order coupled ordinary differential equations can be solved by a simple explicit finite difference technique as follows:

t V dt

dV n V p p C T R p g T R p p j atm j j
r j j Δ

⋅ ⋅ − ⋅ −

⋅ ⋅

⋅ −

⋅ ⋅ + = − − −

− 2 1 1 1

1 ) ( g (Equation A

- 9 )



### t p p C T R p g n n atm j j
r j j 

### Δ

⋅ −

⋅ ⋅

⋅ − + = −

−

− 

### ) ( 1

1 1 

### g (Equation A

- 10 )

where

j p , j n = the pressure and moles of gas at the current time step

1

− j p , 1

− j n = the pressure and moles of gas at the previous time step

The initial conditions for the ordinary differential equations include: (1) the initial p ressure equals atmospheric pressure; and (2) the initial moles of gas can be determined by the Ideal Gas Law at initial volume and pressure. Further note that the volume can be approximated as a linear function of time:

b a + ⋅ = t t V ) ( (Equation A

- 11 )

where

a = Slope of the volume

- time relationship
b = Intercept of volume

- time relationship

t = Time
These expressions can be substituted into the above explicit finite difference relationships, and the pressure and molar air

- flow rates can be d etermined as functions of time. 

### A4.0 Effective Intrinsic Permeability of a Parallel System The effective flow conductance for a parallel system consisting of n flow components can be obtained in terms of the conductances of its flow components as follows (Freeze and Cherry, 1979):A

- 8 Rev. 1 10/3/2002 

## ∑

= = n

i i t C C 1 (Equation A

- 12 )

where

t

C = Total flow conductance of the system

i C = Flow conductance of the th i component
Based on the definition of flow conductance (Equation A

- 6), Equation A

- 12 can be rewritten as: 

## ∑

= = n

i i i t t L

A K L A K 1 (Equation A

- 13 )

or

t n

i i i

t A A K K 

## ∑

= = 1 (Equation A

- 14 )

where

t

K = Effective conductivity of the system

i A = Cross

- sectional area of the th i component

t A = Total cross

- sectional area of the system ( 

## ∑

= n

i i A 1 )

L = L ength of flow path


### A5.0 Effective Intrinsic Permeability of a Series System The effective flow conductance for a series system consisting of n flow components can be obtained in terms of the conductances of its flow components as fol lows (Freeze and Cherry, 1979): 

## ∑

= = n

i i t C C 1 1 1 (Equation A

- 15 )A

- 9 Rev. 1 10/3/2002

where

t

C = Total flow conductance of the system

i C = Flow conductance of the th i component
Based on the definition of flow conductance (Equation A

- 6), Equation A

- 15 can be rewritten as follows: 

## ∑

= = n

i i i

t t A K L A K L

1 (Equation A

- 16 )

or



## ∑

= = n

i i i t t
K L L K

1 (Equation A

- 17 )

where

t

K = Effective conductivity of the system

i L = Length of flow path for th i component

t L = Total length of flow path ( 

## ∑

= n

i i L 1 )

A = Cross

- s ectional area of the flow path



### A6.0 References Freeze, A., and J. Cherry, 1979, Groundwater, Prentice Hall, Inc., Englewood Cliffs, New Jersey.
Hiller, L., and R. Herber, 1960, Principles of Chemistry , McGraw

- Hill Book Company, New York.
U.S. Department o f Energy (DOE), 1996, "Detailed Design Report for an Operational Phase Panel Closure System," DOE/WIPP 96

- 2150 , U.S. Department of Energy, WIPP Project Office, Carlsbad, New Mexico.A

- 10 Rev. 1 10/3/2002

Westinghouse TRU Solutions, 2002, "Mining/Emplacement Schedule," June 1 st 2002 update.
WIPP Hazardous Waste Facility Permit, NM 4890139088

- TSDF, Aug. 31, 2001, Module IV

- Geologic Repository Disposal.
WIPP Waste Information System, 2002, "Headspace Gas Concentration Report", Report RP0430, 4/25/2002.

## APPENDIX B

CAL CULATIONS OF PANEL VOLUME CLOSUREB

- 1 Rev. 1 10/3/2002 

### APPENDIX B CALCULATIONS OF PANEL VOLUME CLOSURE

B.1.0 Introduction This appendix presents the closure mechanisms and supporting calculations for panel volumetric closure for the analysis of gas pressurization within a c losed panel at the WIPP. The volume reduction is due to the panel volume change from viscoplastic creep closure of the walls, roof, and floor. As the walls, roof, and floor of the excavations converge, the total volume of the panel decreases. The volume tric closure of a panel is the result of several different mechanisms working simultaneously. These mechanisms include:

• Viscoplastic creep of the salt toward the excavation

• Fracturing in the roof and floor caused by the deviatoric stresses around the exca vation

• Bed separation at the clay seams in the roof and the floor.
The combination of these three mechanisms causes the observed convergence rates in Panels 1 and 2. Of these mechanisms, only creep of the salt reduces the total volume of the panel and por e space in the surrounding disturbed rock zone (DRZ). Fracturing in the roof and floor and bed separation transfer the void volume within the excavation to the DRZ. This void volume within the DRZ is assumed to be interconnected with the open excavation. Therefore the total reduction in volume within the panel, based simply on room closure, overestimates the effective reduction in void volume. However, quantifying the amount of interconnected void space within the DRZ would require a much more detailed analysis. Using the total volume change calculated from the room closure measurements is therefore considered conservative.
Other assumptions made in this calculation are:

• The volumetric closure rates are constant after panel closure.

• The waste in the pan el provides no significant resistance to creep closure during the initial 35 years.

• The air volume is the total volume of the excavations minus the solid volume of the waste in drums or other waste packages. The solid volume is estimated to be 3,908 m 3 (1 38,000 ft 3 ) (DOE, 1996).B

- 2 Rev. 1 10/3/2002

• The closure rate of each room in the panels equals the closure rate at the mid

- width and mid

- height of the room.

• The length of each room or drift is constant. To simplify the calculations, only the width and height change with cre ep closure. 

### B.2.0 Panel Volume Change Calculation The panel volume change calculation is performed in steps. First, the initial panel volume is calculated, then the room and drift closure rates are calculated, and finally the panel volumetric closure rat e is determined. Because the closure rates and the closure history in Panel 2 are different than Panel 1, the volume calculations for each panel are done separately. Following is a detailed description of each part of the calculation for Panel 1 and then for Panel 2.
B.2.1 Panel 1 Volume Change Calculation B.2.1.1 Initial Panel Volume The initial panel volume is determined immediately after completion of excavation. The total volume is calculated by summing the individual room and drift volumes within the panel. These volumes are based on the as

- built dimensions of the excavated rooms and drifts in Panel 1 (DOE, 1993). Table B

- 1 presents the room and drift dimensions and the calculated volume of each room and drift. The total initial volume of Panel 1 is 47,757 m 3 (1,686,500 ft 3 ).
The total solid volume of the waste in a filled panel is 3,908 m 3 (138,000 ft 3 ) (DOE, 1996). Subtracting the waste volume from the total panel volume gives the total initial void volume (43,850 m 3 [1,548,500 ft 3 ]) in the pa nel.

B.2.1.2 Closure Rates Using convergence data from Panel 1 the average closure rates of the rooms and drifts are determined. Closure rates within the rooms and drifts are higher in the first five years after excavation. When Panel 2 mining began, cl osure rates in Panel 1 increased about 30% on average. Therefore, three distinct time periods are considered: 0 to 5 years, 6 to 13 years, and beyond 13 years. The roof

- to

- floor and wall

- to

- wall closure rates for each of the rooms and drifts are present ed in Table B

- 2.
Because data from the east end of S1600 are not available for the Panel 2 mining period, the rates beyond five years for this area are assumed to be the same as in the west end of S1600 in the panel.B

- 3 Rev. 1 10/3/2002

Table B
- 1 Initial Room and Drift Dimensions and Volume of Panel 1

Room or Drift Initial Width (m) Initial Height (m) Initial Length (m) Initial Volume (m 3 ) Room 1 10.06 3.96 91.44 3644 Room 2 10.06 3.96 91.44 3644 Room 3 10.06 3.96 91.44 3644 Room 4 10.06 3.96 91.44 3644 Room 5 10.06 3.96 91.44 3644 Room 6 10.06 3.96 91.44 3644 Room 7 10.06 4.27 91.44 3925 S1950: Room 1 to Room 7 10.06 4.27 258.5 11094 S1950: Access to Room 1 6.10 3.96 12.18 294 S1600: Room 1 to Room 5 10.06 3.96 174.7 6961 S1600: Room 5 to Room 7 10.06 4.27 79.86 3428 S1600: Access to Room 1 4.27 3.66 12.18 190 Total Initial Panel Volume 47757

Table B
- 2 Panel 1 Room and Drift Closure Rates

Vertical Closure Rates Horizontal Closure Rates Room or Drift 0 t o 5 Years (cm/yr) 6 to 13

Years (cm/yr) > 13

Years (cm/yr) 0 to 5

Years (cm/yr) 6 to 13

Years (cm/yr) > 13

Years (cm/yr) Room 1 9.736 6.234 7.130 6.81 3.138 4.006 Room 2 9.736 6.303 6.057 6.81 3.688 4.446 Room 3 9.736 5.493 6.743 6.81 4.067 5.665 Room 4 9.736 5.441 6.496 6.81 3.831 4.496 Room 5 9.736 5.345 6.495 6.81 3.836 4.879 Room 6 9.736 5.305 6.933 6.81 2.913 3.976 Room 7 9.736 5.687 6.642 6.81 3.579 4.578 S1950: Room 1 to Room 7 9.736 5.513 11.594 6.81 3.370 5.612 S1950: Access to Room 1 5.87 8 4.436 6.490 5.09 2.674 4.079 S1600: Room 5 to Room 7 9.736 5.064 6.054 6.81 3.212 3.935 S1600: Room 1 to Room 5 9.736 5.064 6.054 6.81 3.212 3.935 S1600: Access to Room 1 3.478 1.753 1.938 4.01 1.954 2.157B

- 4 Rev. 1 10/3/2002

B.2.1.3 Volumetric Panel Closure Rate Usin g the closure rates from Table B

- 2 , the dimensions of the rooms and drifts in Panel 1 can be calculated at the end of each progressive year or for subsequent years using the following equations:

5

0 C D D t − = at five years 

## ( ) ssb t C

t C D D 5

5 0 − − − = for years six to thirteen



## ( ) ssa ssb t C

t C C D D 13

8 5 0 −

− − − = for years > thirteen

where:



### t = Number of years since excavation

t D = Magnitude of the dimension (height or width ) after year 

### t

0 D = Original magnitude of the dimension

5 C = Total convergence in the direction of the dimension after the first five years

ssb C = Steady

- state convergence r ate of the dimension before Panel 2 mining

ssa C = Steady

- state convergence rate of the dimension after Panel 2 mining
The dimension cannot go below zero. The length is assumed to remain constant. The volume is then calculated as:

L W H V t t t ⋅ ⋅ =
where:

t V = Volume of a section after year 

### t

t H = Height of a section after year 

### t

t W = Width of a section after year 

### t

L = Length of a section (constant)
The total volume for the panel is calculated by summing the volumes of the individual sections as follows:B

- 5 Rev. 1 10/3/2002 

## ∑

= − = n

i w i t Pt V V V 1 ) (

where:

Pt V = Volume of the entire panel, less the volume of the waste, after year 

### t

n = Number of sections

w V = Volume of the solids in the waste
The volume versus time for Panel 1 is shown graphically in Figure B

- 1 and in tabular form in Table B

- 3 . The average annual volume loss was found to be 790 cubic meters (27900 ft 3 ) per year. B.2.2 Panel 2 Volume Change Calculation The calculation of

volume change for Panel 2 differs slightly from that of Panel 1, primarily because only about two years’ data is available to date from Panel 2. Panel 2 was subdivided slightly differently than Panel 1 due to its different instrument layout.

B.2.2.1 Ini tial Panel 2 Volume Tabl e B

- 4 presents the room and drift initial dimensions and the calculated initial volume of each room and drift. The total initial volume of Panel 2 is 46,166 m 3 (1,630,300 ft 3 ). Subtracting the waste volume from the total panel volume gives the total initial void volume (42,258 m 3 [1,492,300 ft 3 ]) in the panel.

B.2.2.2 Panel 2 Closure Rates Using convergence data from Panel 2, the average closure rates of the rooms and drifts are determined. Due to the relatively short time since excavation in Panel 2, two rate periods were used: 0 to 1 years and beyond 1 year. This assumes that the rate calculated for the second year after excavation is the long

- term steady

- state rate. Because it usually takes about two years to reach steady

- state, the values used here are likely to overestimate the long

- term rates. The roof

- to

- floor and wall

- to

- wall closure rates for each of the rooms and drifts are presented in Table B

- 5

.B

- 6 Rev. 1 10/3/2002 0 5 10 15 20 25 30 35 40 45 50

0 5 10 15 20 25 30 35 40 45 50 Time (years)Panel Volume (1000xm3)

Figure B
- 1 Panel 1 Volume versus TimeB

- 7 Rev. 1 10/3/2002 Table B
- 3 Panel 1 Volume

Year Volume

(m 3 ) Year

(cont’d) Volume

(m 3 ) 0 43849.77 28 16599.56
5 36744.52 29 15724.08
6 35980.50 30 14857.13
7 3522 0.91 31 13998.73
8 34465.74 32 13148.86
9 33715.00 33 12307.53
10 32968.69 34 11474.74
11 32226.81 35 10650.49
12 31489.35 36 9834.775
13 30756.33 37 9027.598
14 29752.78 38 8228.958
15 28757.76 39 7438.857
16 27771.29 40 6657.294
17 26793.35 41 5884.269
18 25823.95 42 5166.191
19 24863.09 43 4642.604
20 23910.77 44 4124.191
21 22966.99 45 3610.953
22 22031.74 46 3102.889
23 21105.03 47 2599.999
24 20186.86 48 2102.285
25 19277.23 49 1609.744
26 18376.13 50 1122.378
27 17483.58B

- 8 Rev. 1 10/3/2002

Tabl e B
- 4 Initial Room and Drift Dimensions and Volume of Panel 2

Room or Drift Initial Width (m) Initial Height (m) Initial Length (m) Initial Volume (m3)
Room 1 10.06 3.96 91.44 3643 Room 2 10.06 3.96 91.44 3643 Room 3 10.06 3.9 6 91.44 3643 Room 4 10.06 3.96 91.44 3643 Room 5 10.06 3.96 91.44 3643 Room 6 10.06 3.96 91.44 3643 Room 7 10.06 3.96 91.44 3643 S2180: Room 1 to west rib Room 2 10.06 3.96 40.54 1615 S2520: Room 1 10.06 3.96 10.06 401 S2180: Room 2 to mid Room 3/4 pillar 10.06 3.96 65.84 2623 S2520: East rib of Room 1 to mid Room 2/3 pillar 10.06 3.96 55.78 2222 S2520: Mid Room 2/3 pillar to mid Room 3/4 pillar 10.06 3.96 40.54 1615 S2180: Mid Room 3/4 pillar to east rib Room 4 10.06 3.96 25.30 1008 S2520: Mid R oom 3/4 pillar mid Room 5/6 pillar 10.06 3.96 81.08 3230 S2180: East rib Room 4 to mid Room 5/6 pillar 10.06 3.96 55.78 2222 S2520: Mid Room 5/6 pillar to east rib Room 6 10.06 3.96 25.30 1008 S2180: Mid Room 5/6 pillar to Room 7 10.06 3.96 65.84 2623 S2520: East rib Room 6 to Room 7 10.06 3.96 40.54 1615 S2180: Access to west rib Room 1 4.27 3.66 12.18 190 S2520: Access to west rib Room 1 6.10 3.96 12.18 294 Total Initial Panel Volume 46,166B

- 9 Rev. 1 10/3/2002 Table B
- 5 Panel 2 Room and D rift Closure Rates

Vertical Closure Rates Horizontal Closure Rates Room or Drift 0 to 1 Years (cm/yr) > 1

Years (cm/yr) 0 to 1

Years (cm/yr) > 1

Years (cm/yr) Room 1 17.19 9.375 12.14 6.246 Room 2 10.14 9.375 14.85 6.113 Room 3 17.51 8.432 15.39 5.957 Room 4 20.19 8.923 16.74 6.341 Room 5 18.41 7.855 14.98 5.495 Room 6 12.21 7.672 14.08 5.488 Room 7 13.10 8.548 11.33 5.106 S2180: Room 1 to west rib Room 2 19.25 8.723 6.19 6.323 S2520: Room 1 11.66 7.633 15.78 5.562 S2180: Room 2 to mid

- Room 3/4 pillar 21.37 9.473 6.19 6.323 S2520: East rib of Room 1 to mid Room 2/3 pillar 25.26 9.458 15.78 5.562 S2520: Mid Room 2/3 pillar to Mid Room 3/4 pillar 22.13 8.806 15.68 5.797 S2180: Mid Room 3/4 pillar to east rib Room 4 24.30 10.756 13.91 6.323 S252 0: Mid Room 3/4 pillar mid Room 5/6 pillar 20.44 8.406 15.68 5.797 S2180: East rib Room 4 to mid Room 5/6 pillar 18.10 9.463 13.91 6.323 S2520: Mid Room 5/6 pillar to east rib Room 6 12.75 8.189 10.60 4.666 S2180: Mid Room 5/6 pillar to Room 7 12.08 7.0 65 12.20 4.832 S2520: East rib Room 6 to Room 7 11.36 6.624 10.60 4.666 S2180: Access to west rib Room 1 6.92 4.266 7.12 4.358 S2520: Access to west rib Room 1 7.39 5.102 11.06 5.804B

- 10 Rev. 1 10/3/2002

B.2.2.3 Volumetric Panel Closure Rate Using the closure rates from Tabl e B

- 4 , the dimensions of the rooms and drifts in Panel 2 can be calculated at the end of each progressive year or for subsequent years using the following equations:

1

0 C D D t − = after the first y ear

2 1 0 C C D D t − − = after the second year



## ( ) ss t C

t C C D D 2

2 1 0 −

− − − = for years > two

where:

t = Number of years since excavation

t D = Magnitude of the dimension (height or width) after year t

0 D = Original magnitude of the dimension

1 C = Total convergence in the direction of the dimension after the first year

2 C = Total convergence in the direction of the dimension during the second year

ss C = Steady

- state convergence rate of the dimension

The volume is then calculated as for Panel 1 (Section B.2.1.3). The volume versus time for Panel 2 is shown graphically in Figure B

- 2 and in tabular form in Table B

- 6 . The average annual volume loss was found to be 989 m 3 (34,930 ft 3 ) per year.
B.2.3 Average Volumetric Panel Closure Rate In the current analyses, the volume closure rate is taken as the average of the volume closure rates of Panels 1 and 2 that is 890 m 3 (31,430 ft 3 ) per year. Also, the void volume of Panel 2 (42,258 m 3 ) is taken as typical of all panels.


### B.3.0 References U.S. Department of Energy (DOE), 1996, "Detailed Design Report for an Operational Phase Panel Closure System," DOE/WIPP 96

- 2150 , U.S. Department of Energy, WIPP Project Office, Carlsbad, New Mexico.B

- 11 Rev. 1 10/3/2002

U.S. Department of Energy (DOE), 1993, “Geotechnical Analysis Report, July 1991 through June 1992,” DOE

- W

IPP 93

- 019 , U.S. Department of Energy, Washington D.C.B

- 12 Rev. 1 10/3/2002 0 5 10 15 20 25 30 35 40 45 50

0 5 10 15 20 25 30 35 40 45 50 Time (years)Panel Volume (1000xm3)

Figure B
- 2 Panel 2 Volume versus TimeB

- 13 Rev. 1 10/3/2002 Table B
- 6 Panel 2 Volume

Year Volume

(m 3 ) Year

(cont’d) Volume

(m 3 ) 0 42,258 21 17,232
1 39,706 22 1 6,229
2 38,487 23 15,237
3 37,264 24 14,257
4 36,053 25 13,289
5 34,853 26 12,332
6 33,665 27 11,387
7 32,489 28 10,453
8 31,324 29 9,531
9 30,170 30 8,620
10 29,029 31 7,721
11 27,898 32 6,834
12 26,780 33 5,958
13 25,672 34 5,094
14 24,577 3 5 4,241
15 23,493 36 3,409
16 22,420 37 2,600
17 21,360 38 1,803
18 20,310 39 1,016
19 19,272 40 241
20 18,246

## APPENDIX C

FLAC MODELING OF THE WIPP PANEL CLOSURE SYSTEMC

- 1 Rev. 1 10/3/2002 

### APPENDIX C FLAC MODELING OF THE WIPP PANEL CLOSURE SYSTEM

Numer ical modeling is considered here for quantifying the interaction of block wall with the surrounding rocksalt. A series of models were developed to evaluate the interaction of the panel closure system with the surrounding salt. This appendix discusses the code used and describes the material constitutive models used in the stress analysis.
All calculations were performed in accordance with the RockSol Consulting Group, Inc., Quality Assurance Program and comply with Westinghouse TRU Solutions requirements. These constitute quality records and are maintained in accordance with WIPP procedures. These records include verification and validation documents.


### C.1.0 FLAC Code FLAC software has been used for numerical modeling of the underground excavations at th e Waste Isolation Pilot Plant (WIPP) since 1991. FLAC (Itasca, 2000) is a finite difference code that simulates the behavior of rock and soil

- like structures. The WIPP Reference Creep Law is built into FLAC. The version of FLAC (Version 4.00) used for t he panel closure system modeling has been verified against the WIPP Second Benchmark Problem (Krieg, 1984).


### C.2.0 Material Constitutive Models The material properties associated with the material constitutive models are given in Tables C

- 1 through C

- 3. T hese are standard properties used in a wide variety of previous WIPP geotechnical FLAC modeling. The halite properties are based on Krieg (1984). The Mohr

Coulomb model was used for block wall and its properties were calculated using Atkinson et al. (198 9) and Ahmed and Drysdale (1988) and ACI 530.1

- 95. The block wall has a minimum compressive strength of 5000 psi (34.5 MPa) (Appendix D).


### C.3.0 References Ahmed, H. and R. G. Drysdale, 1988, “Flexural Tensile Strength of Concrete Block Masonry,” ASCE Jou rnal of Structural Engineering, pp 50

- 66.
Atkinson, R. H., B. P. Amadei, S. Saeb, and S. Sture, 1989, “Response to Masonry Bed Joints in Direct Shear,” ASCE Journal of Structural Engineering, pp 2276

- 2296.C

- 2 Rev. 1 10/3/2002

Itasca Consulting Group, Inc. (Itasca), 2000, “FLA C User’s Guide,” Itasca Consulting Group, Inc., Minneapolis, Minnesota.
Krieg, R. D., 1984, “Reference Stratigraphy and Rock Properties for the Waste Isolation Pilot Plant,” SAND83

- 1908, Sandia National Laboratories, Albuquerque, New Mexico.

Table C
- 1 Halite Material Properties
Property Value Bulk modulus (GPa) 20.7 Shear modulus (GPa) 12.4 Density (km/m 3 ) 2,300 Activation energy (cal/mol) 12,000
A 4.56
B 127 D (Pa - n /s) 5.79x10 - 36

n 4.9 Universal Gas constant (cal/(mol . K)) 1.987 Critical strain rate (1/s) 5.39x10 - 08

Table C
- 2 Concrete Material Properties

Property Value Bulk modulus (GPa) 11.6 Shear modulus (GPa) 9.0 Density (kg/m3) 2,300 Friction angle (degrees) 35 Cohesion (MPa) 9.1 Tension cut

- off (MPa) 1.2C

- 3 Rev. 1 10/3/2002 Table C
- 3 Clay Seam, Rock/Concrete Contact, and Construction Joint Material Properties

Property Value Normal stiffness (Pa/m) 1.0x10 12 Shear stiffness (Pa/m) 5.0x10 10 Cohesion (Pa) 0.0 Friction (degrees) 30

## APPENDIX D TECHNICAL SPECIFICATIONS01010

- 1 Rev. 1 10/3/2002 

### SECTION 01010 

## SUMMARY OF WORK PART 1

- GENERAL

1.1 Scope This section includes:

• Scope of Work

• Definitions and Abbreviations

• List of Drawings

• Work by Others

• Contractor’s Use of Site

• Contractor’s Use of Facilities

• Wor k Sequence

• Work Plan

• Health and Safety Plan (HASP)

• Contractor Quality Control Plan (CQCP)

• Submittals
1.2 Scope of Work The Contractor shall furnish all labor, materials, equipment and tools to construct two (2) panel closure systems. The closure system co nsists of an explosion isolation wall and run of mine salt backfill, one of each to be installed in the air

- intake drift and the air

- exhaust drift of a waste disposal panel, as shown on the Drawings and described in these Specifications. Unless otherwise agreed by Westinghouse, the Contractor shall use Westinghouse supplied equipment underground. Such use shall be coordinated with Westinghouse and may include the use of Westinghouse qualified operators.
The scope of work shall include but not necessarily be limited to the following units of work:

• Develop work plan, health and safety plan (HASP) and contractors quality control plan (CQCP)

• Prepare and submit all plans requiring approval

• Mobilize to site

• Coordinate construction with WIPP operations01010

- 2 Rev. 1 10/3/2002

• Perform th e following for the air

- intake entry and the air

- exhaust entry:

- Prepare the surfaces for the explosion isolation wall

- Construct the explosion isolation wall

- Place run of mine salt material

• Clean up construction areas in underground and above ground

• S ubmit all required record documents

• Demobilize from site

1.3 Definitions and Abbreviations Definitions Concrete masonry units

— Concrete blocks used for construction of the explosion isolation wall.
Creep

— Viscoplastic deformation of salt under deviatoric str ess. Explosion isolation wall

— A mortared concrete block wall adjacent to the panel waste disposal area that can sustain the pressure and temperature transients of a methane explosion.
Methane explosion

— A postulated deflagration caused by methane gas at an explosive level.

Partial closure

— The process of rendering a part of the hazardous waste management unit in the underground repository inactive and closed according to approved facility closure plans.
Volatile Organic Compound (VOC)

— Any VOC with Hazardous Waste Facility Permit emission limits.
Westinghouse

— Westinghouse TRU Solutions, LLC as the construction management authority.01010

- 3 Rev. 1 10/3/2002

Abbreviations/Acronyms ACI American Concrete Institute
ANSI American National Standards Institute
ASTM American Society for T esting and Materials
CFR Code of Federal Regulations CQCP Contractor Quality Control Plan
DOE U.S. Department of Energy
DWG Drawing
EPA U.S. Environmental Protection Agency
HASP Health And Safety Plan
JHA Job Hazard Analysis
LHD Load Haul Dump
LLC Limited Liability Corporation
MSHA U.S. Mine Safety and Health Administration
RCRA Resource Conservation and Recovery Act
USACE U.S. Army Corps of Engineers
VOC Volatile Organic Compound
WIPP Waste Isolation Pilot Plant
1.4 List of Drawings The foll owing Drawings are made apart of this Specification:
DWG 110

- CD001 Panel closure system, title sheet
DWG 110

- CD002 Panel closure system, underground waste disposal panel configuration
DWG 110

- CD003 Panel closure system, construction details01010

- 4 Rev. 1 10/3/2002

1.5 Work by Others Survey All survey work to locate, control, confirm, and complete the work will be performed by Westinghouse. All survey work for record purposes will be performed by Westinghouse. The Contractor shall be responsible for developing the concrete blo ck wall to fit the excavation.

Other Westinghouse may elect to perform certain portions, or all, of the work. The work performed by the Westinghouse will be defined prior to the contract. Unless otherwise agreed by Westinghouse, the Contractor shall use underground equipment furnished by Westinghouse for construction of the explosion isolation walls and placement of the run of mine salt. Underground mining personnel who are qualified for the operation of such underground construction equipment may be mad e available to the Contractor. The use of Westinghouse equipment shall be coordinated with Westinghouse.

1.6 Contractor's Use of Site Site Conditions The site is located near Carlsbad, New Mexico, as shown on the Drawings. The underground arrangements and location of the WIPP waste disposal panels are shown on the Drawings. The work is to construct the explosion isolation walls and place run of mine salt in the air

- intake and air

- exhaust drifts of one of the panels upon completion of the disposal phase of that panel. The waste disposal panels are located approximately 2,150 ft (655 m) below the ground surface. The Contractor shall visit the site and become familiar with the site and site conditions prior to preparing his bid proposal.

Contractor's Use of Site Areas at the ground surface will be designated for the Contractor's use in assembling and storing his equipment and materials. The Contractor shall utilize only those areas designated.
Limited space within the underground area will be designated for the Contractor's use for storage of material and setup of equipment.01010

- 5 Rev. 1 10/3/2002

Coordination of Contractor's Work

The Contractor is advised that on

- going waste emplacement and excavation operations will be conducted throughout the period of construction of the p anel closure system. These operations have priority over the Contractor's work. The Contractor shall coordinate his construction operations with that of the waste emplacement and mining operations. All coordination shall be through Westinghouse.

1.7 Con tractor's Use of Facilities Existing facilities at the site available for use by the Contractor are:

• Waste shaft conveyance

• Salt skip hoist

• 460 volt AC , 3 phase power

• Water (underground, at waste shaft only) (above ground, at location designated by Westing house) Additional information on these facilities is presented in Section 02010.
1.8 Work Sequence Work Sequence shall be as shown on the Drawings and as directed by Westinghouse.

1.9 Work Plan The Contractor shall prepare a Work Plan fully describing his proposed construction operation. The work plan shall define all proposed equipment and methods. Westinghouse shall approve the Work Plan and no work shall be performed prior to approval of the Work Plan.
1.10 Health and Safety Plan (HASP) The Contractor s hall obtain, review, and agree to applicable portions of the existing WIPP Safety Manual, WP 12

- 1. The Contractor shall prepare a project

- specific HASP taking into account all applicable sections of the WIPP Safety Manual. All personnel shall be qualifie d to work underground. All personnel operating heavy construction equipment shall be qualified to operate such equipment. The Contractor shall also perform a Job Hazard Analysis (JHA) in accordance with WP 12

- 111. Westinghouse shall approve the HASP and JHA and no work shall be performed prior to approval of the HASP and JHA.01010

- 6 Rev. 1 10/3/2002

1.11 Contractor Quality Control Plan (CQCP) The Contractor shall prepare a CQCP identifying all personnel and procedures necessary to produce an end product, which complies with t he contract requirements. The CQCP shall comply with all Westinghouse requirements, including operator training and qualification; and Section 01400, Contractor Quality Control, of this Specification. Westinghouse shall approve the CQCP and no work shall be performed prior to approval of the CQCP.

1.12 Submittals Submittals shall be in accordance with Westinghouse Submittal Procedures and as required by the individual Specifications.



### PART 2

- PRODUCTS Not used



### PART 3

- EXECUTION

Not used

End of section01090

- 1 Rev. 1 10/3/2002 

### SE CTION 01090 

## REFERENCE STANDARDS PART 1

- GENERAL

1.1 Scope This section includes:

• Provision of Reference Standards at Site

• Acronyms used in Contract Documents for Reference Standards 1.2 Quality Assurance For products or workmanship specified by associati on, trade, or Federal Standards, the Contractor shall comply with requirements of the standard, except when more rigid requirements are specified or are required by applicable codes.
Conform to reference by date of issue current on the date of the owner

- contractor agreement.
The Contractor shall obtain, at his own expense, a copy of the standards referenced in the individual Specification sections and shall maintain that copy at the jobsite until completion and acceptance of the work.
Should specified R eference Standards conflict with the contract documents, the Contractor shall request clarification from Westinghouse before proceeding.

1.3 Schedule of References Various publications referenced in other sections of the Specifications establish requiremen ts for the work. These references are identified by document number and title. The addresses of the organizations responsible for these publications are listed below.

ACI ACI International

P.O. Box 9094 Farmington Hills, MI 48333 Ph: 248

- 848

- 370001090

- 2 Rev. 1 10/3/2002

A NSI American National Standards Institute

25 West 43rd St. New York NY 10036 Ph: 212

- 642

- 4900 Fax: 212

- 398

- 0023

ASTM ASTM International

100 Barr Harbor Drive P.O. Box C700, West Conshohocken, Pennsylvania, USA 19428

- 2959 Ph: 610

- 832

- 9585 Fax: 610

- 832

- 9555

CFR Code of Federal Regulations

Government Printing Office P.O. Box 371954, Pittsburgh, PA 15250

- 7954 Ph: 202

- 512

- 1800 Fax: 202

- 512

- 2250

EPA Environmental Protection Agency

Public Information Center 401 M St., SW Washington, DC 20460 Ph: 202

- 26 0

- 2080 Fax: 202

- 260

- 6257

FTM

- STD Federal Test Method Standards

Standardization Documents Order Desk Bldg. 4D 700 Robbins Ave. Philadelphia, PA 19111

- 5094 Ph: 215

- 697

- 2179 Fax : 215

- 697

- 297801090

- 3 Rev. 1 10/3/2002

NIST National Institute of Standards and Technology

100 Bureau Drive, Stop 3460 Gaithersburg, MD 20899

- 3460 Ph: 301

- 975

- 6478 Fax: 301

- 975

- 8295

NRMCA National Ready

- Mixed Concrete Association

900 Spring St Silver Spring, MD 20910 Ph: 301

- 587

- 1400 Fax: 301

- 585

- 4219

NTIS National Technical Information Service

U.S. De partment of Commerce Springfield, VA 22161 Ph: 703

- 605

- 6000 Fax: 703

- 321

- 8547

PCA Portland Cement Association

5420 Old Orchard Road Skokie, IL 60077 Ph: 847

- 966

- 6200 Fax: 847

- 966

- 8389

End of section01400

- 1 Rev. 1 10/3/2002 

### SECTION 01400 

## CONTRACTOR QUALITY CONTROL

PART 1

- GENERAL

1.1 Scope This section includes:

• Contractor Quality Control Plan (CQCP)

• Reference Standards

• Quality Assurance

• Tolerances

• Testing Services

• Inspection Services

• Submittals
1.2 Related Sections

• 01090

- Reference Standards

• 01600

- Material and Equipme nt

• 02222

- Excavation

• 03100

- Mortar

• 03300

- Unit Masonry System

• 03400

- Masonry Explosion Isolation Structure

• 04100

- Salt Backfill 1.3 Contractor Quality Control Plan (CQCP) The Contractor shall prepare a Contractor Quality Control Plan (CQCP), as descri bed in Part 3. No work shall be performed prior to Westinghouse approval of the CQCP.

1.4 Reference Standards Refer to individual Specification sections for standards referenced therein, and to Section 01090, Reference Standards, for general listing.

Stan dards referenced in this section are as follows:

ASTM C 1077

- 02 Standard Practice for Laboratories Testing Concrete and Concrete

Aggregates for Use in Construction and Criteria for Laboratory Evaluation01400

- 2 Rev. 1 10/3/2002

ASTM C 1093

- 95 Standard Practice for Accreditation o f Testing Agencies for Unit Masonry

ASTM E 329

- 01a Standard Specification for Agencies Engaged in the Testing and/or

Inspection of Materials Used in Construction

ASTM E 543

- 02 Standard Practice for Agencies Performing Nondestructive Testing

ASTM E 548

- 9 4 Standard Guide for General Criteria Used for Evaluating Laboratory

Competence

1.5 Quality Assurance The Contractor shall:

• Monitor suppliers, manufacturers, products, services, site conditions, and workmanship to produce work of specified quality

• Comply with specified standards as minimum quality for the work except where more stringent tolerances, codes, or specified requirements indicate higher standards or more precise workmanship

• Perform work with qualified persons to produce required and specified qu ality

1.6 Tolerances The Contractor shall:

• Monitor excavation, fabrication, and tolerances in order to produce acceptable work. The Contractor shall not permit tolerances to accumulate.
1.7 Testing Services Unless otherwise agreed by Westinghouse, the Cont ractor shall employ an independent firm qualified to perform the testing services and other services specified in the individual Specification sections, and as may otherwise be required by Westinghouse. Testing and source quality control may occur on or o ff the project site.
The testing laboratory shall comply with applicable sections of the Reference Standards and shall be authorized to operate in the State of New Mexico.
Testing equipment shall be calibrated at reasonable intervals traceable to either th e National Institute of Standards and Technology or accepted values of natural physical constants.01400

- 3 Rev. 1 10/3/2002

1.8 Inspection Services The Contractor may employ an independent firm to perform inspection services as a supplement to the Contractor's quality control as s pecified in the individual Specification sections, and as may be required by Westinghouse. Inspection may occur on or off the project site.
The inspection firm shall comply with applicable sections of the Reference Standards.

1.9 Submittals The Contractor

shall submit a CQCP as described herein.
Prior to start of work, the Contractor shall submit for approval, the testing laboratory name, address, telephone number and name of responsible officer of the firm as well as a copy of the testing laboratory compl iance with the reference ASTM standards and a copy of report of laboratory facilities inspection made by Materials Reference Laboratory of National Institute of Standards and Technology with memorandum of remedies of any deficiencies reported by the inspec tion.
The Contractor shall submit the names and qualifications of personnel proposed to perform the required inspections, along with their individual qualifications and certifications. Once approved by Westinghouse these personnel shall be available as ma y be required to promptly and efficiently complete the work.



### PART 2

- PRODUCTS

Not used


### PART 3

- EXECUTION 3.1 General The Contractor is responsible for quality control and shall establish and maintain an effective quality control system. The quality contr ol system shall consist of plans, procedures, and organization necessary to produce an end product which complies with the contract requirements. The system shall cover all construction operations, both on site and off site, and shall be keyed to the propo sed construction sequence. The project superintendent will be held responsible for the quality of work on the job. The project superintendent in this context is the individual with the responsibility for the overall management of the project including qual ity and production.01400

- 4 Rev. 1 10/3/2002

3.2 Contractor Quality Control Plan 3.2.1 General The Contractor shall supply, not later than 30 days after receipt of notice to proceed, the Contractor Quality Control Plan (CQCP) which implements the requirements of the Contract. The CQCP shall identify personnel, procedures, control, instructions, tests, records, and forms to be used. Construction shall not begin until the CQCP is approved by Westinghouse.
3.2.2 Content of the CQCP The CQCP shall cover all construction operations, bot h on site and off site, including work by subcontractors, fabricators, suppliers, and purchasing agents and shall include, as a minimum, the following items:

• A description of the quality control organization, including a chart showing lines of authority an d acknowledgment that the Contractor Quality Control (CQC) staff shall implement the control system for all aspects of the work specified.

• The name, qualifications (in resume format), duties, responsibilities, and authorities of each person assigned a CQC function.

• A description of CQCP responsibilities and a delegation of authority to adequately perform the functions described in the CQCP, including authority to stop work.

• Procedures for scheduling, reviewing, certifying, and managing submittals, including those of subcontractors, off site fabricators, suppliers, and purchasing agents. These procedures shall be in accordance with Westinghouse Submittal Procedures.

• Control, verification, and acceptance testing procedures as may be necessary to ensure that th e work is completed to the requirements of the Drawings and Specifications.

• Procedures for tracking deficiencies from identification, through acceptable corrective action, to verification that identified deficiencies have been corrected.

• Reporting procedur es, including proposed reporting formulas.
3.2.3 Acceptance of Plan Acceptance of the Contractor's plan is conditional. Westinghouse reserves the right to require the Contractor to make changes in his CQCP and operations, including removal of personnel, i f necessary, to obtain the quality specified.
3.2.4 Notification of Changes After acceptance of the CQCP, the Contractor shall notify Westinghouse in writing of any proposed change. Proposed changes are subject to acceptance by Westinghouse.01400

- 5 Rev. 1 10/3/2002

3.3. Tests 3. 3.1 Testing Procedure The Contractor shall perform specified or required tests to verify that control measures are adequate to complete the work to contract requirements. Upon request, the Contractor shall furnish, at his own expense, duplicate samples of test specimens for testing by Westinghouse. The Contractor shall perform, as necessary, the following activities and permanently record the results:

• Verify that testing procedures comply with contract requirements.

• Verify that facilities and testing equi pment are available and comply with testing standards.

• Check test instrument calibration data against certified standards.

• Verify that recording forms and test identification control number system, including all of the test documentation requirements, have been prepared.

• Record the results of all tests taken, both passing and failing. Specification paragraph reference, location where tests were taken, and the sequential control number identifying the test will be given. If approved by Westinghouse, actual test reports may be submitted later with a reference to the test number and date taken. An information copy of tests performed by an off site or commercial test facility will be provided directly to Westinghouse.
3.4 Testing Laboratory The testing labora tory shall provide qualified personnel to perform specified sampling and testing of products in accordance with specified standards, and the requirements of Contract Documents.
Reports indicating results of tests, and compliance or noncompliance with the c ontract documents will be submitted in accordance with Westinghouse submittal procedures. Testing by an independent firm does not relieve the Contractor of the responsibility to perform the work to the contract requirements.
3.5 Inspection Services The in spection firm shall provide qualified personnel to perform specified inspection of products in accordance with specified standards.01400

- 6 Rev. 1 10/3/2002

Reports indicating results of the inspection and compliance or noncompliance with the contract documents will be submitted in accordance with Westinghouse submittal procedures.
Inspection by the independent firm does not relieve the Contractor of the responsibility to perform the work to the contract requirements.
3.6 Completion Inspection 3.6.1 Pre

- Final Inspection At appropr iate times and at the completion of all work, the Contractor shall conduct an inspection of the work and develop a punch list of items which do not conform to the Drawings and Specifications. The Contractor shall then notify Westinghouse that the work is ready for inspection. Westinghouse will perform this inspection to verify that the work is satisfactory and appropriately complete. A final punch list will be developed as a result of this inspection. The Contractor shall ensure that all items on this l ist are corrected and notify Westinghouse so that a final inspection can be scheduled. Any items noted on the final inspection shall be corrected in a timely manner. These inspections and any deficiency corrections required by this paragraph will be acco mplished within the time slated for completion of the entire work
. 3.6.2 Final Acceptance Inspection The final acceptance inspection will be formally scheduled by Westinghouse based upon notice from the Contractor. This notice will be given to Westinghou se at least 14 days prior to the final acceptance inspection. The Contractor shall assure that all specific items previously identified as unacceptable, along with all remaining work performed under the contract, will be complete and acceptable by the dat e scheduled for the final acceptance inspection.

3.7 Documentation The Contractor shall maintain current records providing factual evidence that required quality control activities and/or tests have been performed. These records shall include the work of subcontractors and suppliers and shall be on an acceptable form approved by Westinghouse.
3.8 Notification of Noncompliance Westinghouse will notify the Contractor of any noncompliance with the foregoing requirements. The Contractor shall take immediate co rrective action after receipt of such notice. Such notice, when delivered to the Contractor at the worksite, shall be deemed sufficient for the purpose of notification. If the Contractor fails or refuses to comply promptly, Westinghouse may issue an orde r stopping all or part of the work until satisfactory corrective action has been taken. No part01400

- 7 Rev. 1 10/3/2002

of the time lost due to such stop orders shall be made the subject of claim for extension of time or for excess costs or damages by the Contractor.

End of sect ion01600

- 1 Rev. 1 10/3/2002 

### SECTION 01600 

## MATERIAL AND EQUIPMENT PART 1

- GENERAL

1.1 Scope This section includes:

• Equipment

• Products

• Transportation and Handling

• Storage and Protection

• Substitutions
1.2 Related Sections

• 01010

- Summary of Work

• 01400

- Contractor Quality Control

• 02010

- Mobilization and Demobilization

• 02222

- Excavation

• 03100

- Mortar

• 03300

- Unit Masonry System

• 03400

- Masonry Explosion Isolation Structure

• 04100

- Salt Backfill 1.3 Equipment The Contractor shall specify his proposed equipment in the Work Plan. P ower equipment for use underground shall be either electrical or diesel engine driven. All diesel engine equipment shall be certified for use underground at the WIPP site.

1.4 Products The Contractor shall specify in the Work Plan, or in subsequently re quired submittals, the proposed products including, but not limited to, the mortar mix and its components, masonry blocks, and run of mine salt. The proposed products shall be supported by laboratory test results as required by the Specifications. All pr oducts shall be subject to approval by Westinghouse.01600

- 2 Rev. 1 10/3/2002

1.5 Transportation and Handling
The Contractor shall:

• Transport and handle products in accordance with manufacturer's instructions.

• Promptly inspect shipments to ensure that products comply with require ments, quantities are correct, and products are undamaged.

• Provide equipment and personnel to handle products by methods to prevent soiling, disfigurement, or damage.
1.6 Storage and Protection The Contractor shall:

• Store and protect products in accordance with manufacturers' instructions.

• Store with seals and labels intact and legible.

• Store sensitive products in weather tight, climate controlled, enclosures in an environment favorable to product.

• Provide ventilation to prevent condensation and degradation of products.

• Store loose granular materials on solid flat surfaces in a well

- drained area and prevent mixing with foreign matter.

• Provide equipment and personnel to store products by methods to prevent soiling, disfigurement, or damage.

• Arrange storage of

products to permit access for inspection and periodically inspect to verify products are undamaged and are maintained in acceptable condition.

1.7 Substitutions 1.7.1 Equipment Substitutions The Contractor may substitute equipment for that proposed in the Work Plan subject to Westinghouse approval.

1.7.2 Product Substitutions The Contractor may not substitute products after the proposed products have been approved by Westinghouse unless he can demonstrate that the supplier/source of that product no longe r exists in which case he shall submit alternate products with lab test results to Westinghouse for approval. In the case that product is a component in a mix, the Contractor shall perform mix testing using that component and submit laboratory test result s.01600

- 3 Rev. 1 10/3/2002 

### PART 2

– PRODUCTS

Not used


### PART 3

- EXECUTION

Not used

End of section02010

- 1 Rev. 1 10/3/2002 

### SECTION 02010 

## MOBILIZATION AND DEMOBILIZATION

PART 1

- GENERAL

1.1 Scope This section includes:

• Mobilization of Equipment and Facilities to Site

• Contractor Use of Site

• Use of Existi ng Facilities

• Demobilization of Equipment and Facilities

• Site Cleanup
1.2 Related Sections

• 01010

- Summary of Work

• 01600

- Material and Equipment



### PART 2

- PRODUCTS Not used


### PART 3

- EXECUTION 3.1 Mobilization of Equipment and Facilities to Site Upon author ization to proceed, the Contractor shall mobilize his equipment and facilities to the jobsite. Equipment and facilities shall be as specified and as defined in the Contractor's Work Plan.
Westinghouse will provide utilities at designated locations. The C ontractor shall be responsible for all hookups and tie

- ins required for his operations.
The Contractor shall be responsible for providing his own office, storage, and sanitary facilities.
Areas will be designated for the Contractor's use in the underground area in the vicinity of the panel closure system installation. These areas are limited.02010

- 2 Rev. 1 10/3/2002

3.2 Contractor Use of Site The Contractor shall use only those areas specifically designated for his use by Westinghouse. The Contractor shall limit his on

- site trav el to the specific routes required for performance of his work, and designated by Westinghouse.
3.3 Use of Existing Facilities Existing facilities available for use by the Contractor are:

• Waste shaft conveyance

• Salt skip hoist

• 460 Volt AC, 3 phase power

• Wa ter underground at waste shaft only

• Water on surface at location designated by Westinghouse The Contractor shall arrange for use of the facilities with Westinghouse and coordinate his actions and requirements with ongoing Westinghouse operations.

Use of w ater in the underground will be restricted. No washout or cleanup will be permitted in the underground except as designated by Westinghouse. Above ground washout or cleanup of equipment will be allowed in the areas designated by Westinghouse.

The Contrac tor is cautioned to be aware of the physical dimensions of the waste conveyance and the air lock.
The Contractor shall be responsible for any damage incurred by the existing site facilities as a result of his operations. Any damage shall be reported immed iately to Westinghouse and repaired at the Contractor's cost.
3.4 Demobilization of Equipment and Facilities At completion of this work, the Contractor shall demobilize his equipment and facilities from the job site. All Contractor's equipment and materia ls shall be removed and all disturbed areas restored. Utilities shall be removed to their connection points unless otherwise directed by Westinghouse.
3.5 Site Cleanup At conclusion of the work, the Contractor shall remove all trash, waste, debris, excess construction materials, and restore the affected areas to their prior condition, to the satisfaction of02010

- 3 Rev. 1 10/3/2002

Westinghouse. A final inspection will be conducted by Westinghouse and the Contractor before final payment is approved.

End of section02222

- 1 Rev. 1 10/3/2002 

### SECTION 02222 

## EXCAVATION PART 1

- GENERAL

1.1 Scope This section includes:

• Excavation for surface preparation and leveling of surrounding areas for explosion isolation wall

• Disposition of excavated materials

• Field measurement and survey
1.2 Related Sections

• 01010

- Sum mary of Work

• 01600

- Material and Equipment

• 03400

- Masonry Explosion Isolation Structure
1.3 Reference Documents Krieg, R. D., 1984, “Reference Stratigraphy and Rock Properties for the Waste Isolation Pilot Plant,” SAND83

- 1908, Sandia National Laboratorie s, Albuquerque, New Mexico.
1.4 Field Measurements and Survey All survey required for performance of the work will be provided by Westinghouse.



### PART 2

- PRODUCTS Not used


### PART 3

- EXECUTION 3.1 Excavation for Surface Preparation and Leveling of Surroundin g Areas for Explosion Isolation Wall The Contractor shall excavate and prepare the surface around the entire perimeter of the explosion isolation walls by removing all loose material, generally squaring the excavation

cross

- section, and cleaning all rock s urfaces. The surface preparation of the floor shall produce a surface suitable for placing the first course of block in the explosion isolation walls. Excavation may be performed by either mechanical or manual means. Use of explosives is prohibited.02222

- 2 Rev. 1 10/3/2002

3 .2 Disposition of Excavated Materials The Contractor shall dispose of all excavated materials as directed by Westinghouse.
3.3 Field Measurements and Survey All survey required for performance of the work will be provided by Westinghouse. The Contractor s hall protect all survey control points, benchmarks, etc., from damage by his operations. Westinghouse will verify that the Contractor has excavated to the required lines and grades. No block work is to be erected until approved by Westinghouse.

End of se ction03100

- 1 Rev. 1 10/3/2002 

### SECTION 03100 

## MORTAR PART 1

- GENERAL

1.1 Scope This section includes:

• Mortar for Explosion Isolation Wall.

1.2 Related Sections

• 01010

- Summary of Work

• 01400

- Contractor Quality Control

• 01600

- Material and Equipment

• 03300

- Unit Masonry System

• 03 400

- Masonry Explosion Isolation Structure
1.3 References
ASTM C 91

- 01 Standard Specification for Masonry Cement
ASTM C 144

- 02 Standard Specification for Aggregate for Masonry Mortar
ASTM C 150

- 02 Standard Specification for Portland Cement
ASTM C 207

- 9 1 Standard Specification for Hydrated Lime for Masonry Purposes
ASTM C 270

- 01a Standard Specification for Mortar for Unit Masonry
ASTM C 780

- 02 Standard Test Method for Preconstruction and Construction Evaluation of

Mortars for Plain and Reinforced Unit Masonry
ASTM C 1142

- 95 Standard Specification for Extended Life Mortar for Unit Masonry
ASTM C 94

- 00 Standard Specification for Ready

- Mixed Concrete
1.4 Submittals for Review and Approval The Contractor shall submit the followings 30 days prior to the i nitiation of work at the site:

• Design mix.

• Certified laboratory tests for the proposed design mix, indicating conformance of mortar to property requirements of ASTM C 270, and test and evaluation reports to ASTM C 780.03100

- 2 Rev. 1 10/3/2002

The mix shall not be used until appro ved by Westinghouse.
1.5 Submittals at Completion The Contractor shall submit certified laboratory test results for the construction testing of mortar mix.
1.6 Quality Assurance The Contractor shall:

• Perform work in accordance with the Contractor's Quality Control Plan and referenced ASTM standards.

• Acquire cement, aggregate, and component materials from the same source throughout the work.
1.7 Delivery Storage Handling The Contractor shall maintain packaged materials clean, dry and protected against dampne ss, freezing and foreign matter.



### PART 2

- PRODUCTS 2.1 Mortar Mix The Contractor shall provide mortar for explosion isolation walls, which shall conform with ASTM C 270 type M, using the property specification 3,000 psi at 28 days as the minimum requiremen t. The Contractor shall provide the mortar design mix to achieve the minimum compressive strength requirement for masonry structure as specified in Section 03400. Aggregate for mortar shall conform to ASTM C 144.

2.2 Water Water used in mixing concrete shall be of potable quality, free of injurious amounts of oil, acid, alkali, organic matter, or other deleterious substances. Water shall conform to the provisions in ASTM C 94, and in addition, shall conform to the following:

• PH not less than 6.0 or grea ter than 8.0

• Carbonates and/or bicarbonates of sodium and potassium: 1000 ppm maximum

• Chloride ions (Cl): 250 ppm maximum

• Sulfate ions (SO 4 ): 1000 ppm maximum

• Iron content: 0.3 ppm maximum

• Total solids: 2000 ppm maximum03100

- 3 Rev. 1 10/3/2002

The source of water is to be indicat ed and certified copies of test data from an approved laboratory confirming that the water to be used meets the above requirements shall be submitted for approval with the trial mix data.
The supply of materials as defined in the design mix shall remain th e same throughout the job.


### PART 3

- EXECUTION 3.1 General The Contractor shall furnish all labor, materials, equipment, and tools to perform all operations in connection with supplying and mixing mortar for constructing the explosion isolation walls. The C ontractor shall fully describe his proposed mortar mixing operation, including proposed equipment and materials in the Work Plan.
3.2 Mortar Mixing Mortar shall be machine

- mixed with sufficient water for a period of time not less than three minutes or more than ten minutes to achieve satisfactory workability. Maintain sand uniformly damp immediately before the mixing process. If water is lost by evaporation, retemper only within one and one half hours of mixing. Use mortar within two hours of mixing. Mo rtar which has hardened or stiffened due to hydration of the cement shall not be used.

3.3 Installation The Contractor shall install mortar to the requirements of Section 03300 Unit Masonry System.
3.4 Field Quality Control The Contractor shall provide a Quality Control Inspector to perform all sampling and testing to confirm that the mortar mix conforms to the proposed mix properties developed in the design mix.
Construction testing of mortar mix shall be in accordance with ASTM C 780 for compression
stre ngth. Four prism specimens shall be taken for each 50 ft 3 of mortar or fraction thereof placed each day.

End of section03300

- 1 Rev. 1 10/3/2002 

### SECTION 03300 

## UNIT MASONRY SYSTEM PART 1

– GENERAL

1.1 Scope This section includes:

• Concrete Masonry Units

1.2 Related Sections

• 01010 Summary of Work

• 01400 Contractor Quality Control

• 01600 Material and Equipment

• 03100 Mortar

• 03400 Masonry Explosion Isolation Structure
1.3 References ASTM C 55

- 01a Standard Specification for Concrete Brick
ASTM C 140

- 02 Standard Test Methods for Sampling and Testing Concrete Masonry Units and Related Units 1.4 Submittals for Revision and Approval The Contractor shall submit for approval the following 30 days prior to initiation of the work at the site.

• Certified laboratory test results for the pr oposed solid masonry units.
1.5 Quality Assurance The Contractor shall perform the work in accordance with the CQCP.



### PART 2

- PRODUCTS 2.1 Concrete Masonry Units Concrete masonry units shall be solid (no cavities or cores), load

- bearing, high

- strength indi vidual units having a minimum compressive strength of 5000 psi. Concrete masonry units shall be tested in accordance with ASTM C 140. All other aspects of the concrete masonry units shall comply with ASTM C 55, Type I Moisture Controlled.03300

- 2 Rev. 1 10/3/2002

Nominal modular

size shall be 8x8x16 inches, or as otherwise approved by Westinghouse
. Concrete brick shall comply with ASTM C 55, Grade N, Type I (moisture controlled) but having a minimum compressive strength of 5500 psi (Avg. 3 units) or 5000 psi for individual unit.

2.2 Mortar Mortar shall be as specified in Section 03100 Mortar.


### PART 3

- EXECUTION

Not used

End of section03400

- 1 Rev. 1 10/3/2002 

### SECTION 03400 

## MASONRY EXPLOSION ISOLATION STRUCTURE

PART 1

- GENERAL

1.1 Scope This section includes:

• Masonry Explosion Isolation Structure

1.2 Rel ated Sections

• 01010 Summary of Work

• 01400 Contractor Quality Control

• 01600 Material and Equipment

• 03100 Mortar

• 03300 Unit Masonry Structure
1.3 References ASTM C 1314

- 02a Standard Test Method for Compressive Strength of Masonry Prism

ACI 530.1

- 02 Specifica tion for Masonry Structures
1.4 Submittals for Revision and Approval The Contractor shall submit for approval the following 30 days prior to initiation of the work at the site.

• Certified laboratory test results for compressive strength of masonry by the pr ism method for a set of five masonry prisms. Materials used for the construction of the prisms shall be taken from those to be used in the construction of the explosion isolation wall. The minimum compressive strengths of the tests shall exceed f’ m as re quired in 1.6.
1.5 Quality Assurance The Contractor shall perform the work in accordance with the CQCP.03400

- 2 Rev. 1 10/3/2002

1.6 Compressive Strength of Masonry Compressive strength of masonry in each masonry wythe shall exceed 5000 psi (f’ m =5000 psi). The unconfined compres sive strength shall be determined by prism test method in accordance with ASTM C 1314 and ACI 530.1.



### PART 2

- PRODUCTS 2.1 Concrete Masonry Units Concrete masonry units shall be as specified in Section 03300 Unit Masonry System. Concrete masonry units s hall not be wetted unless otherwise approved by Westinghouse.

2.2 Mortar Mortar shall be as specified in Section 03100 Mortar.


### PART 3

- EXECUTION 3.1 General The Contractor shall furnish all labor, material, equipment and tools to perform all operations o f installing Unit Masonry Explosion Isolation Walls as shown on the Drawings.
The Contractor shall request that Westinghouse inspect and approve all surfaces before beginning any masonry work.

3.2 Installation The Contractor shall install the explosion iso lation walls using concrete masonry units as specified above. Masonry units shall be installed with 3/8

- inch mortar joints with full mortar bedding and full head joints. The mortar shall be sufficiently plastic and units shall be placed with sufficient p ressure to extrude mortar from the joint and produce a tight joint. Deep furrowing which produces voids shall not be used. The initial bed joint thickness shall not be less than 1/4 inch or more than 1 inch, subsequent bed joints shall be not less than 1 /4 inch or more than 5/8 inch in thickness.
Masonry units shall be installed in running bond with headers every third course. Masonry units shall be mortared tight to the ribs and the back wall to provide a seal all around the explosion isolation wall. All surfaces shall be clean and free of deleterious materials.
Cut concrete blocks may be used as required to minimize the dimensional fit

- up at the top or sides of the isolation walls. All interfaces between the explosion isolation wall and the rock03400

- 3 Rev. 1 10/3/2002

surfa ces shall be completely mortared to provide full contact between the rock surfaces and the block wall.
Construction joints shall be left as shown on the Drawings. Construction joints shall be left open and unfilled.
3.3 Field Quality Control The Contracto r shall provide a Quality Control Inspector to inspect the installation of the Unit Masonry Explosion Isolation Walls. Inspection and testing of the mortar shall be in accordance with Section 03100 Mortar. Inspection and testing of masonry units are in a ccordance with Section 03300. A prism test in accordance with Part 1.6 of Section 03400 shall be performed for each 2000 ft 3 of block wall.

End of section04100

- 1 Rev. 1 10/3/2002 

### SECTION 04100 

## SALT BACKFILL PART 1

- GENERAL

1.1 Scope This section includes:

• Salt Backfill Placem ent
1.2 Related Sections

• 01010 Summary of Work

• 01400 Contractor Quality Control

• 01600 Material and Equipment 1.3 Submittals for Revision and Approval The backfill emplacement method, dust control plan and other safety related material shall be approved by Westinghouse.
1.4 Quality Assurance The Contractor shall perform the work in accordance with the CQCP.



### PART 2

- PRODUCTS 2.1 Salt Backfill Material The salt backfill is run of mine salt and requires no grading or compaction. The salt backfill shall be free of organic material.


### PART 3

- EXECUTION 3.1 General The Contractor shall furnish all labor, material, equipment and tools to handle and place the salt backfill.
The Contractor shall use underground equipment and underground mine personnel as required in Part 1.5 Work by Others in Section 01010 Summary of Work. Westinghouse will supply run of mine salt. The Contractor shall make suitable arrangements for transporting and placing the run of mine salt.04100

- 2 Rev. 1 10/3/2002

3.2 Installation Run of mine salt shall be transporte d to the panel closure area after the construction of explosion isolation wall has been completed. Salt will be pushed against the explosion isolation wall until the entire opening is filled over the length and angle of layback as shown on Drawings. The s alt may be left at the angle of repose or some lower slope, but shall not be less than 1 (rise) to 2 (run). There should be no gap left between backfill and roof or sidewalls. Hand placement can be used to fill all the voids if necessary. Backfill may b e emplaced in layers to facilitate the construction.
3.3 Field Quality Control The Contractor shall provide a Quality Control Inspector to inspect the emplacement of backfill.

## APPENDIX E DESIGN DRAWINGS