4

CNWRA A center of excellence in earth sciences and engineeringTM Geosciences and Engineering Division 6220 Culebra Road San Antonio, Texas, U.S.A. 78238-5166 (210) 522-5160 .Fax (210) 522-5155

November 20,2007 Contract No. NRC-02-07-006 Project No. 14002.01.204 WM-00011

ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Mr. Eugene Peters Division of High-Level Waste Repository Safety U.S. Nuclear Regulatory Commission 1 1555 Rockville Pike

Rockville, MD 20852 EBB-2-BO2

SUBJECT: Updates to Total-system Performance Assessment (TPA) Version 5.1 Code and User Guide (AI 14002.01.204.801)

Dear Mr. Peters:

This letter transmits two items: (i) Revision 1 to the Total-system Performance Assessment (TPA) Version 5.1 User Guide and Module Descriptions and (ii) Sourice Code, Executable, and Data Files for TPA Version 5.1 b. Each of these items is provided in electronic format on separate compact discs. The changes reflected in TPA Version 5.1 b are updated parameter values for partition and retardation coefficients for niobium in the unsaturated and saturated zone flow and transport modules. This change affects model input data only; the source code is not changed from TPA Version 5.1 a. Revision 1 to the TPA Version 5.1 User Guide reflects these updated parameter values. For your convenience, a change summary for the user guide (Attachment A) and copies of the changed pages are attached to this letter. Because the pagination has not changes, the change pages can be used to replace the corresponding pages in the previous version of the user guide.

If you have any questions on this matter, please call me at 21 0-522-5249.

Sincerely,

*L&pw& James Winterle

Manager Performance Assessment

JW:bs E

Washington Office Twinbrook Metro Plaza #210 12300 Twinbrook Parkway Rockville, Maryland 20852-1606

Mr. Eugene Peters November 20,2007 Page 2

DHLWRS D. DeMarco S. Kim B. Meehan L. Kokajko J. Davis A. Mohseni J. Rubenstone K. Stablein J. Guttmann T. McCartin B. Hill M. Shah 6. Leslie M. Wong S. Whaley K. Compton C. Grossman T. Ghosh J. Cuadrado

CNWRNGED W. Patrick 8. Sagar S. Mohanty

Letter Only GED Directors GED Managers L. Gutierrez

L- SvvRl Records Copy B, IQS

Revision 1

TOTAL-SY STEM PERFORMANCE ASSESSMENT (TPA) VERSION 5.1

MODULE DESCRIPTIONS AND USER GUIDE

Prepared for

U.S. Nuclear Regulatory Commission Contract N RC-02-07-006

Prepared by

Center for Nuclear Waste Regulatory Analyses San Antonio, Texas

Coordina fed by

Bret Leslie Christopher Grossman

U.S. Nuclear Regulatory Commission

James Durham Center for Nuclear Waste Regulatory Analyses

September 2007 Revised November 2007

Attachment A

Title: TOTAL-SYSTEM PERFORMANCE ASSESSMENT (TPA) Revision 1 I I I November 2007 VERSION 5.1 MODULE DESCRIPTIONS AND USER GUIDE

Summary of Changes for Revision 1

Title Page Modified to reflect the new NRC contract number, revision number, and expand list of coordinators

Acknowledgements - Page xx Modified to reflect the new NRC contract number

Page 11 -28 Updated reference information in remarks column for MatrixKD_TSw._Nb[m3/kg] and MatrixKD_CHnv_Nb[m3/kg] parameters

Page 11 -29 Revised parameter values for MatrixKD_CHnz_Nb[m3/kgl, MatrixKD_-PPw_Nb[m3/kg], and MatrixKD_UCF_Nb[m3/kgl; updated reference information for these parameters in remarks column

Page 11-30 Revised parameter value for MatrixKD-BFw-Nb[m3/kg]; updated reference information for this parameter and for MatrixKD-UFZ-Nb[m3/kg] in remarks column

Page 12-22 Revised parameter value for ImmobileRd-STFF-Nb; updated reference information for this parameter in remarks column

ACKNOWLEDGMENTS

This User Guide for TPA Version 5.1 documents work performed by the Center for Nuclear Waste Regulatory Analyses (CNWRA) for the U.S. Nuclear Regulatory Commission (NRC) under Contract No. NRC-02-07-006. The activities reported here were performed on behalf of the NRC Office of Nuclear Material Safety and Safeguards, Division of High-Level Waste Repository Safety. This User Guide is an independent product of the CNWRA and does not necessarily reflect the view or regulatory position of the NRC. The NRC staff views expressed herein are preliminary and do not constitute a final judgment or deteirmination of the matters addressed or of the acceptability of a license application for a geologic repository at Yucca Mountain.

The contributions of Bret Leslie and James Durham, who served as ,the central coordinators for this entire document, and Christopher Grossman, who assisted in coordination, are greatly appreciated. Technical and programmatic reviews performed by Bret Leslie, Christopher Grossman, Andrew Campbell, Keith Compton, and Albert Wong contributed to the overall consistency and quality of this document. The administrative support provided by Beverly Street, Leona Selvey, and Nora Naukam, and the editorial reviews b y Lauren Mulverhill were essential to the timely completion of this document. Appreciation is also given to Bret Leslie, Christopher Grossman, James Durham, Patrick Laplante, Ron Janetzke, Femi Osidele, and Ali Simpkins for their service on the TPA User Guide Committee, which provided guidance to authors and reviews to ensure consistency in content and level of detail. The authors gratefully acknowledge benefitting from the foundation of the user guide previously developed for TPA Version 4.0 (Mohanty, et al., 2000).

QUALITY OF DATA, ANALYSES, AND CODE DIEVELOPMENT

DATA: No original CNWRA-generated data are contained in this report.

ANALYSES AND CODES: No original technical analyses are preseinted in this user guide. This report documents the technical basis for and use of TPA Version 5.1, which has been developed and fully validated in accordance with CNWRA Technical Operating Procedure TOP-018.

REFERENCE:

Mohanty, S., T.J. McCartin, and D.W. Esh. “Total-system Performance Assessment (TPA) Version 4.0 Code: Module Descriptions and User’s Guide.” San Antonio, Texas: CNWRA. 2000.

xx

Input Block In tpa. inp

UZFT

UZFT

UZFT

Table 11-1. Reference Data for Parameters of tpa.inp Used bv UZFT (continued) (Disclaimer: The listed input parameter distributions and values were provided for th

and are subject to change in subset

Parameter Name MatrixKD_TSw_Se[m3/kg] MatrixKD_CHnvSe[m3/kgl MatrixKD_CHnzSe[m3/kgl MatrixKD_PPw_Se[m3/kgl MatrixKD_UCF_Se[m3/kg] MatrixKD_BFw_Se[m3/kg] MatrixKD_UFZ_Se[m3/kg]

Description

Matrix sorption coefficient K,, of selenium (Se) for each of the hyd rost rat igraphic units

K D

[m3/kgl

K D Matrix sorption coefficient> K,, of niobium (Nb) for the Topopah Spring welded tuff [m3/kg]

KD Matrix sorption coefficient, K,, of niobium (Nb) for the Calico Hills vitric tuff [m3/kgl

snt versions or updates to the

Distribution Type and Parameter Value(s)

constant 0.0001

constant 0.4

consiani 0.4

elease of TPA Version 5.1 jut data.)

.

Remarks Bechtel SAC Company, LLC (2001 a) gives the same range for all rock types for selenium K$, from 0 to 0.001 m3/kg, beta distribution, expected value = 0,0001, stdev = 0.0001, COV = 1 .O. Expected value is used here (constant). The same value is assigned for each hydrostratigraphic layer.

Layer Names: TSw = Topopah Spring welded tuff CHnv = Calico Hills vitric tuff CHnz = Calico Hills zeolitic tuff PPw = Prow Pass tuff UCF = Upper Crater Flat tuffs BFw = Bullfrog welded tuff UFZ = Unsaturated Fault Zone (hypothetical unit) Using the trivalent chemical analogy, the DOE mediar expected K, value for americium is used in place of a K, for niobium. Tuffs in the Topopah Spring welded hydrostratigraphic unit are mostly vitric (Bechtel SAC Company, LLC, 2002). Data from Bechtel SAlC Company, LLC (2004a) for sorption onto vitric tuff list: americium K, values from 0.1 to 1 .O m3/kg in a piecewise distribution range, with 0.1 = 0 percent, 0.4 = 50 percent, and 1 .O = 100 percent. Only the mediar expected value is used here (constant value). Using the trivalent chemical analogy, K s for americium are used in place of K s for niobium. Tuffs in the Calico Hills nonwelded vitric hydrostratigraphic unit have vitric layer properties with respect to sorption (Bechtel SAC Company, LLC, 2002). Data from Bechtel SAlC Company, LLC (2004a) for sorption onto vitric tuff lists americium K, values from 0.1 to 1 .O m3/kg in a piecewise distribution range, with 0.1 = 0 percent, 0.4 = 50 percent, and 1 .O = 100 percent. Only the median expected value is used here (constant value).

Input Block In tpa.inp

UZFT

-~

UZFT

UZFT

-

Table 11-1. Reference Data for Parameters of fpa.inp Used by UZFT (continued) (Disclaimer: The li

ai

Parameter Name MatrixKD_CHnzNb[m3/kg]

id input parameter distributions and values were DRWided for the release of TPA ierslon 5.1 are subject to change in subseq

Description

Matrix sorption coefficient, K,, of niobium (Nb) for the Calico Hills zeolitic tuff

KD

[m3/kgl

K D Matrix sorption coefficient, K,, of niobium (Nb) for the Prow Pass welded tuff [m3/kgl

KD Matrix sorption coefficient, K,, of niobium (Nb) for the Upper Crater Flat tuff [m3/kgl

Int versions or updates to the

Distribution Type and Parameter Value@)

constant 5.5

constant 5.5

constant 5.5

#ut data.)

Remarks Using the trivalent chemical analogy, K$ for americium are used in place of K s for niobium. Tuff: in the Calico Hills nonwelded zeolitic hydrostratigraphic unit have zeolitic layer properties with respect to sorption (Bechtel SAIC Company, LLC, 2002). Data from Bechtel SAlC Company, LLC (2004a) for sorption onto zeolitic tuff lists americium K, values from 1 .O to 10.0 m3/kg in a uniform distribution. The mean expected value of 5.5 is used here (constant value). Using the trivalent chemical analogy, K$ for americium are used in place of Ks for niobium. The Prow Pass tuffs have both zeolitic and devitrified characteristics (Bechtel SAlC Company, LLC, 2002). Bechtel SAlC Company, LLC (2004a) lists zeolitic an( devitrified K s for americium ranging from 1 .O to 10.0 m3/kg (uniform distribution). The mean expected K, value of 5.5 for the zeolitic layers is used here (constant value). Using the trivalent chemical analogy, K s for americium are used in place of K s or niobium. The Upper Crater Flat hydrostratigraphic unit represents the non- to partially welded, devitrified, and zeolitized Crater Flat tuffs that occur above the water table in each potential repository subarea. Bechtel SAC Company, LLC (2004a) lists zeolitic and devitrified K s for americium ranging from 1 .O to 10.0 m3/kg (uniform distribution). The mean expected KD value o 5.5 is used here (constant value).

Input Block In tpa. inp

UZFT

UZFT

UZFT

Table 11-1. Reference Data for Parameters of tpainp Used by UZFT (continued) (Disclaimer: The listed input parameter distributions and values were arovided for the release of TPA Version 5.1

and are subject to change in subseq

Parameter Name KD Description MatrixKD-BFw-Nb[ m3/kgJ

Matrix sorption coefficient$ K,, of niobium (Nb) for the Bullfrog welded tuff [m3/kgI

~~

KD Matrix sorption coefficient K,, of niobium (Nb) for the optional Unsaturated Faul Zone tuff (m3/kg]

FractureRD-TSw-l FractureRD-CHnvl FractureRD-CHnzl

Fracture R D-U C F-I FractureRD-BFw-1 Fracture R D-U FZ-I

F:addieR E-r"P.W-i

RD Fracture retardation factor, R,,, for iodine (I) in each of the hydrostratigraphic units [unitless]

nt versions or updates to the I

Distribution Type and Parameter Value(s)

constant 5.5

constant 0.4

constant 1 .o

)ut data.)

Remarks Using the trivalent chemical analogy, K s for americium are used in place of K$ for niobium. The tuffs that comprise the Bullfrog welded tuff have vitric, zeolitic, and devitrified characteristics. The unit as a whole appears to have significant devitrified zones (Bechtel SAlC Company, LLC, 2002). Bechtel SAC Company, LLC (2004a) lists devitrified K s for americium ranging from 1 .O to 10.0 m3/kg (uniform distribution). The mean expected KD value of 5.5 is used here (constant value). Using the trivalent chemical analogy, K# for americium are used in place of K# for niobium. There is no direct information for the hypothetical Unsaturated Fault Zone in Bechtel SAIC Company, LLC (2002). Vitric sorption properties are assumed for this unit because they are conservative compared to zeolitic or devitrified K+. Data from Bechtel S A G Company, LLC (2004a) for sorption onto vitric tuff lists americium KD values from 0.1 to 1 .O m3/kg in a piecewise distribution range, with 0.1 = 0 percent, 0.4 = 50 percent, and 1 .O = 100 percent. Only the media! expected value is used here (constant value). Value assumes no fracture retardation (K, = 0, R, = 7). All layers, all nuclides. Also a bounding assumption for fracture transport. The s a m \c8!ue is assigned for each hydrostratigraphic layer.

Layer Names: TSw = Topopah Spring welded tuff CHnv = Calico Hills vitric tuff CHnz = Calico Hills zeolitic tuff PPw = Prow Pass tuff UCF = Upper Crater Flat tuffs BFw = Bullfrog welded tuff UFZ = Unsaturated Fault Zone (hvpothetical unit)

Table 12-1. Reference Data for Parameters of tpainp Used by SZFT (continued) (Disclaimer: The listed input parameter distributions and values were provided for the release of TPA Version 5.1

and are subject to change in subseauent versions or UDdates to the inmt data.)

Input Block in tpa. inp

SZFT

SZFT

SZFT

SZFT

SZFT

Parameter Name ImmobileRd-STFF-Ni

I m mobile Rd-STFF-Se

ImmobileRd-STFF-Nb

ImmobileGrainDensiW- STFF[kg/m3]

ImrnobilePorosity-STFF

Description

Retardation factor for nickel in saturated tuff matrix during matrix diffusion [unitless]

RO

R O

Retardation factor for selenium in saturated tuff matrix during matrix diffusion [unitless]

RO

Retardation factor for niobium in saturated tuff matrix during matrix diffusion [unitless]

Po

@In

Matrix grain density of saturated tuff [kg/m3]

Matrix porosity in saturated tuff lunitlessl

Distribution Type and Parameter Value@)

:onstant 390.0

:onstant 2.0

:onstant 34300.0

:onstant !470.0

:onstant 1.2

Remarks Nickel sorption value taken from Bechtel SAlC Company, LLC (2001), which indicates nickel K,s in the saturated zone ranging from 0 to 0.2 m3/kg with a uniform distribution (an assumption that devitrified tuff is an adequate analog tc STFF and alluvium is also made). The mean or “expected value of 0.1 m3/kg is used and has been converted to an Ro of 990 using an STFF porosity of 0.20 and bulk density of 1,976 kg/m3. Selenium sorption value taken from Bechtel SAC Company, LLC (2001), which indicates selenium K,s in the saturated zone ranging from 0 to 0.001 m3/kg with a beta distribution (an assumption that devitrified tuff is an adequate analog to STFF and alluvium is also made). The mean or “expected value of 0.0001 m3/kg is used and has been converted to an R, of 1.98 (rounded to 2) using an STFF Dorositv of 0.20 and bulk densitv of 1.976 ka/m3. Using an analogy between expected trivalent species Nb” and Am3+, the Am retardation factor is substituted for Nb. Values in Saturated Zone Flow and Transport Analysis/Model Report (Bechtel SAC Company, LLC, 2003a) for Am sorption in STFF are 1 .O to 10.0 m3/kg with 3 truncated normal distribution (mean = 5.5, standard jeviation = 1.5). The mean (“expected”) K, value of 5.5 n3/kg for the devitrified layers is used and has been :onvetted to a retardation factor of 54300.0 assuming a Juik u’ensiiy of i ,976 kg/m’ and porosity of 0.20 for the STFF. DOE data (Bechtel SAC Company, LLC, 2003a) indicate that average grain density of layers that would make up STFF are not significantly different from 2,470 kg/m3. 4verage matrix porosity used by DOE in Bechtel SAlC Zompany, LLC (2003a) is 0.22. A small range is evident 3ut not likely to have sipnificant effects.

TOTAL-SYSTEM PERFORMANCE ASSESSMENT (TPA) VERSION 5.1

MODULE DESCRIPTIONS AND USER GUIDE

Revision 1

Cmrdina ted 13y:

Bret Leslie Christopher Gro., csman

US. Nuclear Regulatory

and

Center for Nuclear Waste Regulatov Analyses

Center for Nuclear Waste Regulatory Commlssion

San Antonio, Texas James Duhi3m

Prepared For: US. Nuclear Regulatow

Commission

/'

4, September 2007 ', \.

Revised November 2007 ,b , \ e,

/

4