ML20151X143
| ML20151X143 | |
| Person / Time | |
|---|---|
| Issue date: | 09/01/1998 |
| From: | Mearse S NRC OFFICE OF ADMINISTRATION (ADM) |
| To: | Kalmbach R, Patrick W CENTER FOR NUCLEAR WASTE REGULATORY ANALYSES |
| References | |
| CON-FIN-J-5220, CON-NRC-02-98-002, CON-NRC-2-98-2 NUDOCS 9809160282 | |
| Download: ML20151X143 (7) | |
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NUCLEAR REGULATORY COMMISSION 7
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e Center for Nuclear Waste Regulatory Analyses (CNWRA)
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Attn: Wesley C. Patrick, President 6220 Culebra Road PROJECT Un. _ _ _ _ __ __,,
PO Drawer 28510 San Antonio, TX 78228-0510
SUBJECT:
TASK ORDER NO. 004, Entitled " ATLAS - EVALUATION OF INFILTRATION, SEEPAGE AND GROUND-WATER CONTAMINATION" Under Contract No.
NRC-02-98-002 l
Dear Mr. Pet-Ls.
In accordance with the Section G.5, Ipsk Order Procedures, of the subject contract, this letter definitizes Task Order No. 4. This effort shall be performed in accordance with the enclosed Statement of Work and the Contractor's technical proposal dated July 15,1998, with revision 1 dated August 4,1998, which are incorporated by reference and made a part of this task order.
Task Order number 4 shall be in effect from August 21,1998, through December 21,1998 with a cost ceiling of $65,694. The amount of $59,111 represents reimbursable costs, the amount of j
51,854 represents the cost of facilities capital, and the sum of $4,729 represents the fixed fee.
The obligated amount shall, at no time, exceed the task order ceiling. When and if the amount (s) paid and payable to the Contractor hereunder shall equal the obligated amount, the Contractor shall not be obligated to continue performance of the work unless and until the Contracting Officer shall increase the amount obligated with respect to this task order. Any work undertaken by the Contractor in excess of the obligated amount specified above is done so at the Contractor's sole risk.
1 This task order obligates funds in the amount of $48,116, of which $42,387 represents reimbursable costs, $1,000 represents the cost of facilities capital, and $4,729 represents the fixed fee. Accounting data for this task order is as follows:
B&R NO.:
85-015-123-030 JOB CODE:
J5220 BOC:
252A APPN. NO.:
31X0200.860 OBLIGATED AMOUNT:
$48,116 The following individual is considered to be essential to the successful performance of the work hereunder Mr. Amit Armstrong. The Contractor agrees that such personnel shall not be removed from the effort under the task order without compliance with the Contract Clause H.1 Key Personnel.
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y g p.g g 9809160282 980901 PDR CONTR NRC-02-98-002 PDR
Task Order No. 4 Page 2 Your contacts during the course of this task are:
Technical Matters:
Jayne Halvorsen Project Officer
-(301) 415 4001 Myron Fliefel Technical Monitor (301)415-6629 Contractual Matters: Donald A. King i
Senior Contract Specialist i
(301) 415-6731 The issuance of this task order does not amend any terms or conditions of the subject contract.
Please indicate your acceptance of this task order by having an official, who is authorized to bind your organization, execute three (3) copies of this document in the spaces provided and return two copies to the U.S. Nuclear Regulatory Commission, Attn: Mr. Donald King, ADM/DCPM/CMB3, Mail Stop T-712, Washington, DC 20555. You should retain the third copy i
for your records.
If you have any questions regarding this matter, please contact Mr. Donald A. King (301) 415-6731.
Sincerely, e
Sharon D. Mearse, Contracting Officer Contract Management Branch No.3 Division of Contracts and Property Management Office of Administration Encicture:
As stated ACCEPTED:
A NAME R. B. Kalmbach j
Director, Contracts TITLE l
September 1, 1998
~DATE
l Attachment TASK ORDER NO. 4:
ATLAS - EVALUATION OF INFILTRATION, SEEPAGE AND GROUND-WATER CONTAMINATION JOB CODE J5220 NRC ISSUING OFFICE NMSS NRC PROJECT MANAGER JAYNE HALVORSEN, 301-415-6001 NRC TECHNICAL MONITOR MYRON FLIEGEL, 301-415-6629 DOCKET NUMBER:
40-3453 TAC NUMBER:
FEE RECOVERABLE:
YES 1.0 Backa_ round T he Nuclear Regulatory Commission (NRC) is currently reviewing Atlas Corporation's proposed reclamation plan for its uranium mill tailings pile near Moab, Utah. The tailings pile is near the Colorado River and has contaminated the alluvial ground water, which is seeping into the river.
NRC estimated past seepage rates from the pile to the ground water that resulted in the present level of ground-water contamination and future seepage rates after reclamation of the pile. Based on the significant difference between the seepage rates, NRC concluded that Atlas' proposal would result in significantly lower concentrations of contaminants in the ground water and subsequently in the river, in the future. Recently, an analysis was performed by another organization which concluded that the past and present seepage rates from the pile to the ground water are much lower than NRC's estimates, and are much closer to the estimated future seepage rate. If that analysis is correct, then Atlas' proposed reclamation plan will not significantly improve the level of contamination in the ground water and the river. NRC has reviewed the analysis and found, what it concluded were significant deficiencies, that if corrected, would result in much higher past seepage rates from the pile to the ground water.
Nevertheless, NRC desires an independent, in-depth, analysis of the issue.
2.0 Ob.iective The objective of this task is to determine past, present, and future rates of infiltration into, and seepage out of the bottom of, the Atlas uranium mill tailings pile, by means of numerical modeling; and to estimate steady-state ground-water contamination after pile stabilization and the time to reach steady-state.
3.0 Technical Qualifications Reauired The CNWRA shall provide the services of a ground-water modeler. Familiarity with the Nuclear Regulatory Commission regulatory process is required.
4.0 Level of Effort i
The estimated effort for this task is outlined in the Contractor's Proposal dated July 15,1998.
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l 5.0 C.pmoletion Date Four months from the effective date of the Task Order.
6.0 Scope of Work l
l a.
CNWRA staff shall review background information and visit the Atlas site to develop an understanding of the site, the tailings pile, the ground-and surface-water systems, the observed levels of contamination, and the issues related to infiltration, seepage and future levels of contamination.
b.
CNWRA staff shall coordinate and discuss work with an independent NRC consultant (INC) to be identified by NRC. Discussion with the INC should be initiated by CNWRA at major decision points (such as, but not limited to, domain development, parameter selection, and sensitivity analysis) during the task and also on a regular schedule, agreed to by CNWRA and the INC.
CNWRA shall develop a three-dimensional numerical model of the Atlas tailings pile and c.
ground-water system. A documented, referenced code, such as PORFLOW, should be used, with site-specific characteristics and dats to represent the tailings and ground water.
For the tailings pile, the model should incorporate the growth of the pile over the operationallife of the mill, the characteristics of the tailings, including porosity and permeability, as determined by measurements and comparisons with other tailings piles, and the chemical characteristics of the tailings fluids.
For the ground-water system, the model should include aquifer characteristics, as determined by Atlas and other investigators, it should incorporate periodic inundation of the floodplain by the river, resulting in recharge, bank storage and drainage.
d.
CNWRA should use historical data to calibrate the model. There is a significant amount of hydraulic and chemical data that should be used in the calibration:
pile coeration and saturation - During the operation of the mill, large amounts of tailings solution was being added to the pile. Information is available on rates of water added to the pile. Almost the entire pile was covered by a permanent pool of water. The pile was presumably completely saturated during this time. In the mid 1980s, the mill stopped operating and the only water level changes were the result of precipitation, evaporation, and seepage from the bottom. In 1990, Atlas started pumping water from the pile, spraying it to the air, where most of it evaporated. Information is available on the amount pumped. In addition, Atlas monitored water level in the pile, as the saturation level went down. During this time, the area of the permanent pool of water on the pile continually diminished and eventually disappeared and Atlas placed an interim cover over the tailings. Currently, because the interim surface of the pile is a bowl, intermittent 2 of 5
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l pools develop and disappear due to the effects of precipitation, evaporation, and seepage.
orecioitation and evaporati r)- In the analysis for the DEIS, the ORNL hydrologist t
estimated, based on regional precipitation and evaporation and the permeability of tailings material, that the net infiltration into the pile averages 16 gpm. Historical precipdation data can be used to refine the contribution of precipitation / evaporation to the water balance. Currently and in the past, very little precipitation runs off the pile; f
rather it collects in the center. Regrading proposed in the reclamation plan will convey most precipitation away from the pile.
ground water historical data - Atlas has collected data from several wells showing changes in ground-water levels and concentration over time. Some of the data appear to show a discrete plume front arriving and passing some wells.
oround-water data collected in November 1997 - this data provides good areal representation of current ground-water contamination.
c.
After calibration of the model, CNWRA should run it to determine future contamination in the alluvial ground water after steady state (or near steady state)is achieved. The 4
model should incorporate: precipitation / evaporation and runoff with both a 10 cm/sec permeability cover and a 10* cm/sec permeability cover, seepage, ground-water flow, and river influence.
CNWRA should prepare maps showing estimated levels of contaminants in the ground water at steady state.
f.
CNWRA should model pile drainage and ground-water effects as the pile dewaters. The model should incorporate pumping by Atlas with the present system of wells and with improvements to enhance pile dewatering, such as an expanded well field and wick drains. CNWRA should prepare graphs of pile seepage and ground-water contamination versus time.
g.
CNWRA should perform a sensitivity analysis, by varying key parameters within reasonable ranges and within the constraints imposed by historical data and the calibration of the model to determine which parameters produce the greatest influence on the predictive results.
h.
CNWRA should prepare a draft report that shall be sent to the INC for review, but not to NRC staff. The draft report shallinclude: (1) a description of the numerical model used, (2) values or ranges of values used in the modeling for the various input parameters, (3) a description of the model calibration and the results, including comparisons with historical data, in numerical and graphical form, (4) a discussion of the results of the modeling of future contamination in the ground water after steady state is reached, l
including presentation of results in numerical and graphical form, (5) a discussion and l
graphical presentation of the results of the modeling of projected pile drainage over l
time, and (6) a discussion of the sensitivity analysis performed.
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After receipt of comments from the INC. CNWRA should prepare a final report, taking into consideration the INC's comments.
7.0 Meeting and Travel NRC records, which cannot be readily provided, may have to be researched. A trip to search NRC records and to consult with NRC staff may be necessary. It is estimated that a one person t.*ip of three day duration to Washington D.C. may be required.
CNWRA staff will visit the Atlas site near Moab, Utah to obtain first-hand knowledge of the tailings pile, the floodplain, and the Colorado River. A two-person trip of three days duration will be required.
8.0 Indeoendent NRC Consultant i
NRC willidentify an independent NRC consultant to function as an advisor and to perform a quality assurance role. CNWRA shall coordinate and discuss conceptual models, assumptions, modeling approaches, results, and interpretations with the independent NRC concultant.
9.0 NRC-Furnished Materials Reports written by Oak Ridge National Laboratory, Grand Junction Colorado:
" Limited Groundwater Investigation of the Atlas Corporation Moab Mill, Moab, Utah" January 9,1998.
" Tailings Pile Seepage Model, The Atlas Corporation Moab Mill, Moab, Utah,"
January 9,1998.
" Supplemental Modeling and Analysis Report, Atlas Corporation Moab Mill, Moab, Utah," February 5,1998.
" Final Technical Evaluation Report for the Proposed Revised Reclamation Plan for the Atlas Corporation Moab Mill," NUREG-1532, March 1997.
" Preliminary Final Environmental Impact Statement Related to Reclamation of the Uranium Mill Tailings at the Atlas Site, Moab, Utah," NUREG-1531, March 1997. (Predecisional) 9.0 Schedule The following schedule of the staff time required is based on estimates of time intervals to accomplish this task.
Calendar Time To Accomplish Task Elaosed Time l
Review background information and visit site 2 weeks 2 weeks Preliminary discussion with NRC independent consultant 1 week 3 weeks 4 of 5
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1 Develoo three-dimensional numerical model 2 weeks 5 weeks Calibr ate model using historical data 1 week 6 weeks Use model to estimate steady-state ground-water contamination 1 week 7 weeks Model transient pile drainage 1 week 8 weeks Perform sensitivity analysis 2 weeks 10 weeks Prepare draft report 3 weeks 13 weeks Receive comments from the INC
[2 weeks]
15 weeks Prepare final report 1 week 16 weeks j
10.0 Reoorts The final report shall be submitted to NRC in hard copy and in electronic form. Periodic progress reports shall be made to NRC verbally, by telephone, several times during the course of the task, as needed or as requested by NRC.
1 11.0 Technical Direction Technical instructions may be issued from time to time during the duration of this task.
Technical instructions shall not constitute new assignments of work or changes of such nature as to justify an adjustment in cost or period of performance. Directions for changes in the scope of work, cost, or period of performance shall be coordinated through the NMSS Project Manager.
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