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Finding of No Significant Impact and Notice of Availability of the Environmental Assessment Addressing A License Amendment Request To Approve Rio Algom Mining Llc's Application for Alternate Concentration Limits At Its Lisbon Uranium Mill Tailings Impoundment Located in San Juan County, UT

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Nuclear Regulatory Commission.


Notice of availability of an environmental assessment and finding of no significant impact.

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Jill Caverly, Fuel Cycle Facilities Branch, Division of Fuel Cycle Safety and Safeguards, Office of Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, Mail Stop T8-A33, Washington, DC 20555-0001, telephone (301) 415-6699 and e-mail

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I. Introduction

The U.S. Nuclear Regulatory Commission (NRC) is considering the issuance of an amendment to Rio Algom Mining LLC's (Rio Algom) Source Materials License SUA-1119. The proposed action would revise groundwater protection standards from background to alternate concentration limits (ACL) at its Lisbon Uranium Mill Tailings Impoundment located in San Juan County, Utah. The licensee's application for ACLs was made pursuant to 10 CFR part 40, Appendix A, Criterion 5 B(6), by letter dated May 22, 2002, as revised by additional information sent, at the staffs request, on January 7, 2004, January 12, 2004, and February 19, 2004. This request was previously noticed in the Federal Register on July 24, 2002 (67FR48495), with an opportunity to provide written comments or to request a hearing.

Pursuant to the requirements of 10 CFR Part 51, Environmental Protection Regulations for Domestic Licensing and Related Regulatory Functions, the NRC has prepared an environmental assessment (EA) to evaluate the environmental impacts associated with this request. Based on this evaluation, the NRC has concluded that a Finding of No Significant Impact (FONSI) is appropriate for the proposed licensing action.

II. EA Summary

The EA was prepared to evaluate the environmental impacts associated with Rio Algom's application for ACLs for groundwater at its Lisbon uranium mill facility. Approving this action will result in the cessation of active groundwater remediation (pump and treat), allowing groundwater contamination at the site to migrate and naturally degrade over time and distance. ACLs for this groundwater will be protective at the site boundary. In addition, a post-remediation groundwater monitoring program will assure that protection of human health and the environment is maintained.

As indicated in the ACL application and the response to the staff's request for additional information (RAI), Rio Algom proposes the following revised standards (ACL) at the Point of Compliance (monitoring location):

AquiferArsenic (mg/L)Molybdenum (mg/L)Selenium (mg/L)Uranium (mg/L)

Rio Algom asserts that it has met the Federal requirements under 10 CFR part 40, Appendix A, Criterion 5 for ACLs. It has included fate and transport modeling to demonstrate that groundwater contaminant levels will degrade to acceptable levels prior to migrating to the point of exposure (POE), i.e., property boundary. At this point, an exposure assessment indicates that the human dose from all viable pathways will not exceed the criteria in subpart E of 10 CFR part 20 (25 mrem/year). Additionally, a corrective action assessment indicates that the ACL approach is the only economical alternative that will be protective of human health and the environment.

The NRC staff has reviewed this request in accordance with the requirements under 10 CFR part 40, Start Printed Page 22101Appendix A, Criterion 5 and NRC guidance NUREG-1620 Rev 1, “Standard Review Plan for Review of a Reclamation Plan for Mill Tailings Sites Under Title II of the Uranium Mill Tailings Radiation Control Act of 1978.”

Groundwater flow and transport modeling from Rio Algom estimates that only uranium will migrate past the property boundary above background levels for the above stated constitutents during the 1,000 year compliance period. The maximum estimated uranium concentration in the groundwater will be 0.32 mg/L at the property boundary. Rio Algom has included flow and transport modeling to demonstrate that groundwater contaminant levels will degrade to acceptable levels prior to migrating to the POE, i.e, the property boundary.

Based on groundwater fate and transport modeling, water quality and use will not be impacted by the proposed action because the State of Utah has determined that the aquifer can be classified as a Class III, Limited Use Groundwater Aquifer under Utah Administrative Code R317-6-3.6, due to the background concentrations found in License Conditions 53B and 53C. This characterization was confirmed in a letter from the State of Utah to the U.S. NRC dated January 12, 2004. Modeling indicates that of the hazardous constituents in the groundwater contaminant plume (arsenic, selenium, molybdenum, and uranium) only uranium will migrate past the long-term care boundary. It is estimated that the uranium plume will intersect the boundary in approximately 500 to 1000 years but will be at levels consistent with the class of use and will not present a significant risk to human health or the environment. The long-term groundwater monitoring program will monitor levels within the plume and downgradient of the plume to assure protection of human health and the environment to confirm that model predictions are correct.

The State of Utah also indicated in an e-mail dated January 13, 2004, that the proposed ACL approach satisfies Utah State Rule R317-6-15 and will meet the requirements of a Class III-limited Use Aquifer. The ACL will be an acceptable corrective action if the uranium groundwater concentrations at the POE do not exceed a human dose of 25 mrem/year (10 CFR part 20, subpart E). Therefore, performing an exposure assessment at the POE conforms with guidance in NUREG-1620, section which states that “exposure pathways should be identified and evaluated using water classification and water use standards, along with existing and anticipated water uses.”

The results of Rio Algom's exposure assessment (including its bounding analyses) and the NRC staff's confirmatory analysis indicate that the dose to the critical group, i.e., the offsite rancher, at the POE from site-generated uranium should not exceed 25 mrem/year, which conforms to the NRC criteria for unrestricted release of sites with residual radioactivity in 10 CFR part 20.1402.

Rio Algom conducted a corrective action assessment to identify potential remedial alternatives for the restoration of site groundwater, and to determine the costs and benefits associated with various remedial actions. Rio Algom believes that the only economically viable alternative is natural attenuation because the cost benefit ratios associated with active remedial alternatives are far too great to justify their implementation. Additionally, Rio Algom believes that the proposed action is necessary because it is technically impracticable and economically infeasible to remediate the groundwater to the background levels required by its License Condition 53. The NRC staff has reviewed and agrees with these conclusions.

III. Finding of No Significant Impact

Pursuant to 10 CFR part 51, the NRC has prepared the EA, summarized above. The staff has determined that no significant environmental impacts are expected when groundwater pump and treat programs are terminated. There will be no significant impacts to the surface features and therefore, no effect on wildlife.

Constituents in the groundwater will migrate off site but will not pose any significant impact to the environment because attenuation of the constituents will be at levels that are consistent with the aquifer class of use as designated by the State of Utah. A dose model verified that the constituents in the groundwater will not cause additional risk to human health or the environment.

The proposed NRC approval of the action when combined with known effects on resource areas at the site, including further site remediation, is not anticipated to result in any cumulative impacts at the sites. Therefore, the NRC staff has concluded that there will be no significant environmental impacts on the quality of the human environment and, accordingly, the staff has determined that preparation of an Environmental Impact Statement is not warranted.

IV. Further Information

The EA for this proposed action, as well as the licensee's request, as supplemented and revised, are available electronically for public inspection and copying from the Publicly Available Records (PARS) component of NRC's document system (ADAMS). ADAMS is accessible from the NRC Web site at​reading-rm/​adams.html. The ADAMS Accession Numbers for the licensee's request, as supplemented and revised, are: ML021710023, ML021710056, ML021710083, ML021710139, ML021710181, ML021710189, ML021710450, ML021710605, and ML021750010. The ADAMS Accession number for the EA is ML040990712. Most of the documents referenced in the EA are also available through ADAMS. Documents can also be viewed electronically on the public computers located at the NRC's Public Document Room, O1 F21, One White Flint North, 11555 Rockville Pike, Rockville, MD 20852. The PDR reproduction contractor will copy documents for a fee. Persons who do not have access to ADAMS, should contact the NRC PDR Reference staff by telephone at l-800-397-4209, or 301-415-4737, or by e-mail to

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Dated in Rockville, Maryland, this 12th day of April, 2004.

For the Nuclear Regulatory Commission.

Jill Caverly,

Project Manager, Fuel Cycle Facilities Branch, Division of Fuel Cycle Safety and Safeguards, Office of Nuclear Material Safety and Safeguards.

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[FR Doc. E4-910 Filed 4-22-04; 8:45 am]