[Federal Register Volume 70, Number 118 (Tuesday, June 21, 2005)]
[Pages 35744-35745]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E5-3199]



Draft Report for Comment: ``Consideration of Geochemical Issues 
in Groundwater Restoration at Uranium In-Situ Leach Mining 
Facilities,'' NUREG/CR-6870

AGENCY: Nuclear Regulatory Commission.

ACTION: Notice of availability and request for comments.



    Some mining processes use fluids to dissolve (or leach) a mineral 
without the need to remove physically the ore containing the mineral 
from an ore deposit in the ground. In general, these ``in-situ'' leach 
mining operations at uranium mines are considerably more 
environmentally benign than traditional mining and milling of uranium 
ore. Nonetheless, the use of leaching fluids to mine uranium may 
contaminate the groundwater aquifer in and around the region from which 
the uranium is extracted. The U.S. Nuclear Regulatory Commission (NRC) 
requires licensees to restore the aquifer to established water-quality 
standards following the cessation of in-situ leach mining operations.
    The NRC also requires licensees to ensure that sufficient funds 
will be available to cover the cost of decommissioning their 
facilities. For these uranium mines, restoration generally consists of 
pumping specially treated water into the affected aquifer and removing 
the displaced water--and thereby the undesirable contaminants--from the 
system. Because groundwater restoration can represent approximately 40 
percent of the cost of decommissioning a uranium leach mining facility, 
a good estimate of the necessary volume of treatment water is important 
to estimate the cost of decommissioning accurately.
    The subject report, prepared for the NRC by the U.S. Geological 
Survey, summarizes the application of a geochemical model to the 
restoration process to estimate the degree to which a licensee has 
decontaminated a site where a leach mining process has been used. 
Toward that end, this report analyzes the respective amounts of water 
and chemical additives pumped into the mined regions to remove and 
neutralize the residual contamination using 10 different restoration 
strategies. The analyses show that strategies that used hydrogen 
sulfide in systems with low natural oxygen content provided the best 
results. On the basis of those findings, this report also summarizes

[[Page 35745]]

the conditions under which various restoration strategies will prove 
successful. This, in turn, will allow more accurate estimates of 
restoration and decommissioning costs.
    The subject report will be useful for licensees and State 
regulators overseeing uranium leach mining facilities, who need to 
estimate the volume of treatment water needed to decontaminate those 
    Solicitation of Comments: The NRC seeks comments on the report and 
is especially interested in comments on the utility and feasibility of 
the modeling techniques described in the report.

DATES: The NRC will consider all written comments received before 
August 31, 2005. Comments received after August 31, 2005, will be 
considered if it is practical to do so, but the NRC staff is able to 
ensure consideration only for comments received on or before this date. 
Comments should be addressed to the contact listed below.
    Availability: An electronic version of the report is available in 
Adobe Portable Document Format at http://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr6870/cr6870.pdf and can be read with 
Adobe Acrobat Reader software, available at no cost from http://www.adobe.com. Hard and electronic copies are available from the 
contact listed below.

U.S. Nuclear Regulatory Commission, 11545 Rockville Pike, Rockville, MD 
20852, telephone (301) 415-6192, e-mail [email protected].

    Dated at Rockville, Maryland, this 10th day of June, 2005.
    For the Nuclear Regulatory Commission.
Cheryl A. Trottier,
Chief, Radiation Protection, Environmental Risk & Waste Management 
Branch, Division of Systems Analysis and Regulatory Effectiveness, 
Office of Nuclear Regulatory Research.
[FR Doc. E5-3199 Filed 6-20-05; 8:45 am]