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OBattelle.

* Pacific Northwest Laboratoriesm.

P.O. Box 999Rkhland, Washington U.S.A. 99M2Telephone (509) 376-8410

Telex 15 2874

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July 14, 1988

Lynn Deering, Project ManagerGeotechnical BranchDivision of Waste ManagementOffice of Nuclear Material Safety

and SafeguardsU. S. Nuclear Regulatory Commission55111 Rockville PikeRockville, MD 20852

Dear Lynn:

SUBJECT: June Monthly Progress Report for HMSS Project B2485-7:Performance Assessment of Low-level Radioactive Waste Sites

Attached for your use and comment is the June monthly progress report. If

you have any questions or comments, please contact me at FTS 444-8410 at yourearliest convenience.

Sincerely,

r4 d P.F yMarcel P. BergeronSenior Research HydrogeologistHydrology SectionGEOSCIENCES DEPARTMENTENVIRONMENTAL AND EARTH SCIENCES CENTER

MPB/cac

Enclosuresi

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Lynn Deering - OmelleJuly 14, 1988Page 2

CC:

; Director Director,Division of Low-level Waste Management Office of NHSS

Attn: Planning Program andAnalysis Staff

ChiefTechnical BranchDivision of Low-level Waste Management Chiefand Decommissioning Operations Branch

Division of Low-level WasteChief, Management andWaste Management BranchOffice of Research Docket Control Center (NMSS/WM)

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MONTHLY _ PROGRESS' REPORT FOR JUNE'1988< -

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NMSS PROJECT B2485 7-

PERFORMANCE ASSESSMENT FOR LOW-LEVEL WASTE SITES

SUMARY OF- ACTIVITIES DURING THE REPORT PERIOD"

Task 1 - Project Management Activities

Project management activities have: continued as planned.

Task 2~- Preparation of Site Geoscience Information Reports

Project staff continue to focus efforts on the preparation of siteinformation reports.. A first draft of the Sheffield site information reportwas'sent to the NMSS-PM on June 23 for review and comment.

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Site literature reviews and compilation of geologic, hydrologic, geochemical,and geophysical infomation' have continued for the West Valley site.Preparation of the site infomation report has continued and is approximately50 percent complete.

Task 3 - Compilation of Geoscience Database System

One of the IBM-PS/2 computers and an HP Laserjet printer with the.Sheffield site geoscience database system, Lotus 1-2-3, the TECS0FT graphicspackage', Wordperfect Library software, and other system software installedwas shipped to the NHSS-PM in early June. Also included in the shipment wereuser's manuals for all installed software. A letter report which summarizesthe details and data structure of the Sheffield site database was also sentto the NMSS-PM for review and comment on June 7, 1988.

Task 4 - Selection and Supply of Graphics and Statistical Software

-Final testing of the data base system with the TECSOFT graphics packagewere completed prior to shipping the computer and data base system to the_NMSS-PM in early June. Because of other project activities, no work has beenin the evaluation of geostatistical software packages that could potentiallybe used in the database system. We anticipate continuing our evaluation inupcoming months.

Task 5 - Transfer of Performance Assessment Codes

No activities to report.

Task 6 - Evaluation of LLW Site Performance

Project staff continue to develop performance assessment models for theSheffield site. The focus of activities has been on development of a site

~(CFEST) computer code developed )y Gupta et al (gy, and Solute Transportground-water model using the Cou) led Fluid, Ener1987). The code is a finite

element code which is capable of simulating steady state or transient coupled

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fluid, heat and solute transport in two (areal by or along assymetricalcross-sections) or three dimensions. Only the fluid component of the code is

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being used in the Sheffield site model. I

The model contains three major layers. The uppermost layer represents silts,clays, and silty sands belonging to the Peoria Loess, the Roxana Silt, andupper parts of the Glasford Formation including the Berry Clay, the RadnorTill and the silty sand units of the Toulon Member. The middle layer of themodel represents the permeable pebbly sand unit of the Toulon Member. Thelower layer of the model represents silts, clays, and silty sands belong tothe less permeable lower units in the Glasford Formation: the Hulick Till andthe Duncan Mills Members.

A finite-element grid consistent with the mapped areal and vertical extent ofthe model units has been developed for use in the site ground-water flowmodel. The surface grid, designed to correspond to site boundaries, welllocations, and tranch boundaries, contains a total of 453 surface nodas. Thethree-dimensional grid contains a total of 1245 nodes. The top surface ofthe model coincides with the water table measured during July 1984 when itwas at its highest in recent years. This surface was chosen for modelcalibration because it presumably represents a condition of maximum areal andvertical saturation of the permeable pebbly sand unit of the Toulon Memberand a minimum ground-water travel-time from the site to the Strip Mine Lake.

The north and west model boundaries are alligned with topographic drainagedivides to represent areas where we have assumed that no ground-water entersthe study area (i.e no-flow boundaries). The east and south boundaries ofthe model are alligned with the edge of Strip Mine Lake and along LawsonCreek where we have )rescribed head boundaries corresponding to the lakelevel and the creek 3ed level. These boundaries are used to representground-water discharge out of the study area at these surface water bodies.

Calibration of the model has begun and will continue into July. Thecalibration approach will make use of an inhouse inverse procedure developedfor the CFEST code. The procedure begins with the use of a kriging programwhich is used to krige water levels measered in July 1984 to the model node

| locations. This step will provide the model with an initial starting head| distribution and associated estimation errors. The objective of the

procedure will then be to match the predicted water levels at each node withkriged at water levels each node within some tolerable error. The kriged

! heads at each node will be weighted by the kriging error so that more weightwill be placed on values at nodes close to measured heads. An inverse methodwill then be used to adjust the hydraulic conductivity and recharge values ofthe model. In initial attempts, the recharge will be held at a constantvalue consistent with those calculated from previous hydrologic budget andunsaturated flow analysis and horizontal and vertical hydraulic conductivityof each layer will be allowed to vary in zones representing each model layerwithin the range of values measured at the site. Once the best possiblecalibration is achieved with this method, the surface of the model will bedivided into three recharge zones, corresponding to areas where each of themodel layers outcro). Previously derived bydraulic conductivities will beheld constant and tie recharge values will be varied until the best match tothe measured data is achieved. At this point, the model will be divided intosmaller zonation patterns in each model layer representing expected areas of

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different hydraulic properties and recharge and the inverse procedure will beused again to refine the model until an acceptable match is achieved.

Task 7 - Evaluation of Source-tem Release

Project staff are awaiting initial model results from Task 6 beforecontinuing work on this task. No work was performed on this task during thereport period.

Task 8-Short-tArmTechnicalAssistance

No activities to report.

STATUS OF MILESTONES FOR FY 1988

Task 2: Preparation of Site Information Reports

Site Information Report - Sheffield Ill Site (May 19,1988): First draftsent to NMSS-PM on June 23, 1988 for review and coment.

Site Information Report - West Valley NY Site (September 19,1988):.

First draft in preparation. Work is continuing on schedule. Noproblems to repcrt.

Task 3: Compilation of Geoscience Database System

Letter Report of Sheffield Ill Site Database (May 5, 1988): Work iscompleted. Letter report sent to the NMSS-PM on June 7, 1988 forcoment.

Letter Report of West Valley, NY Site Database ( Oct. 3, 1989): Workcontinuing on schedule. No problems to report.

Task 4: Selection of Statistical and Graphics Software

Letter Report Describing Software Recomendations (December 31, 1987):Work is completed. Letter report was sent to the NMSS-PM on January 12,1988 for coment.

Task 8: Short-tenn Technical Assistance

Letter Report Sumarizino Technical Assistance Activities (September30, 1988): No activities to report to date.

Other Deliverables:

Annual Project Sumary (September 30,1988): Work is continuing onschedule. No problems to report.

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MEETINGS / TRAVEL

None to report.

POTENTIAL PROBLEM AREAS

None to report.

LISTING 0F ABSTRACTS AND PAPERS PREPARED BY PROJECT STAFF'0VRING REPORT PERIOD

None to report.

REFERENCES CITED IN MONTHLY PROGRESS REPORT

Gupta, S.K., C.R. Cole, C.T. Kincaid, and A.M. Moni.1987. Coupled. Fluid, Energy, and Solute Transport (CFEST) Model: Formulation andUser's Manual. Office of Nuclear Waste Isolation Report BMI/0NWI-660,Battelle Memoria! Institute, Columbus, Ohio.

PLANNED ACTIVITIES F0Q SUBSEQUENT MONTHS.

Task 1 - Preparation of Project Work Plan:

o Continue project management activities.

Task 2 - Preparation of Site Geoscience Information Reports

e Incor) orate NRC staff comments and finalize site information report forthe Sleffield, Ill site for publication.

e Continue with site literature reviews and data compilation fromavailable sources for West Valley, New York site.

e Continue preparation of the West Valley site infomation report.

e Visit to the West Valley, New York site has been postponed indefinitely.

Task 3 - Compilation of Geoscience Database System

o Continue transfer of geologic, hydrologic, geochemical, and geophysicalinformation from the West Valley site from available information.

Task 4 - Selection and Supply of Graphics and Statistical Software

e Continue evaluation of geostatistical software for use in the databasesystem.

Task 5 - Transfer of Perfomance Assessment Codes;

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s e Begin the selection and collation of documentation for appropriate|' computer codes that will be used in the site performance assessment task

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(task 6)-for transfer to the NRC. Activities on this task will beginduring the last quarter of FY 1988.

Task 6 - Evaluation of LLW Site Performance

Continuedevelopmentofperformanceassessmentmodels(ground-wateroflow and solute transport models) for the Sheffield site.

Task 7 - Evaluation of Source-term Release

o Continue formulation of an appropriate source-term release model to beused in the Sheffield site performance assessment task (task 6).

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