Joseph J. Holonich, Chief and Daniel M. Gillen, Assistant
Chief
Uranium Recovery Branch
Office of Nuclear Material Safety and
Safeguards
ABSTRACT
This paper provides insight into the U.S. Nuclear Regulatory Commission's uranium recovery program. It specifically focuses on the reclamation and cleanup of abandoned uranium mills and uranium mills currently undergoing reclamation. In this paper I discuss issues facing NRC regarding the ultimate cleanup of byproduct material as defined in Section 11e.(2) of the Atomic Energy Act. This is essentially the byproduct material produced from the processing of ore primarily for its uranium or thorium content.
INTRODUCTION
The U.S. Nuclear Regulatory Commission's regulation of uranium recovery activities is a multifaceted endeavor. Essentially, three types of facilities are involved in the uranium recovery program: 1) operating solution mines called in situ leach facilities; 2) uranium mills in operation or standby status; and 3) uranium mills currently undergoing reclamation. The priorities and licensing needs for each type of facility are very different. Because this conference focuses on waste management, this paper will be on uranium mills undergoing reclamation. To provide a logical context for the information presented here, I would like to start by providing some information on the legislative framework within which NRC's uranium recovery program must operate. Then I would like to discuss some experience from surface reclamation work at uranium mills undergoing reclamation and to provide insight into some groundwater cleanup activities. Finally, this paper will provide a quick view of what uranium recovery facilities can do to dispose of 11e.(2) material and material other than 11e.(2) byproduct material in tailing impoundments.
LEGISLATIVE FRAMEWORK FOR THE URANIUM RECOVERY PROGRAM
NRC efforts regarding the stabilization of mill tailings and the cleanup of groundwater are governed by the Uranium Mill Tailings Radiation Control Act of 1978. I will simply call this the "Act" for the rest of this paper. Congress passed this Act because historically, under the Atomic Energy Act, both the Atomic Energy Commission and then its successor, NRC, had regulatory jurisdiction over the production of source material. However, neither agency had the authority to regulate byproduct material generated from the milling process. To address this lack of regulatory authority, Congress passed the Act to ensure: 1) the long-term stabilization and control of sites; and 2) the cleanup of groundwater. In addition, the Act established responsibilities for the U.S. Department of Energy (DOE), the U.S. Environmental Protection Agency (EPA), NRC, and States where uranium mill tailings are located. Basically, there are two main Titles to this Act. Title I deals with DOE's remediation of abandoned mill sites, and Title II provides NRC with the authority to regulate byproduct material at commercial sites it licenses.
Under Title I, DOE is responsible for the cleanup of 22 uranium mill sites designated by the Act as well as any additional sites added by the Secretary of Energy. Title I also requires that: 1) EPA promulgate the standards to be used to determine if DOE has acceptably remediated a site: 2) NRC concur that the DOE reclamation work is in compliance with the EPA standards; and 3) States in which the abandoned mill sites are located pay 10 percent of the cost of site reclamation. In addition, the Act requires that DOE be licensed by NRC as the long-term custodian of the site.
Title II of the Act provides a definition of 11e.(2) byproduct material, which is the waste produced by the processing of ore mainly for its uranium or thorium content. Title II also gives NRC the authority to regulate 11e.(2) byproduct material. As with Title I, EPA is assigned the responsibility for establishing the standards that NRC is to use in determining the release limits and design criteria for stabilization of 11e.(2) byproduct material. In addition, Title II requires long-term custodial care of the sites. The State in which the site is located has the first "right of refusal" to become the long-term custodian and NRC licensee for the site. If the State decides not to take the site, DOE then becomes the custodian.
NRC reviews surface reclamation and groundwater cleanup in both the Title I and Title II programs. For each aspect, EPA has promulgated requirements that NRC must use to determine the acceptability of proposed actions. The basic areas covered by the surface cleanup requirements include: 1) limitation of radon emission from the tailings impoundment to 20 pci/gm; 2) stabilization of the impoundment for 1000 years but not less than 200; and 3) soil cleanup of radium contamination to 5pci/gm in the top 15 cms (6 inches) and 15 pci/gm in every 15 cms (6 inches) thereafter. For groundwater, the standards are either: 1) background at the site; 2) maximum concentration limits established by EPA; or 3) alternate concentration limits established by NRC on a site-specific risk basis.
SURFACE RECLAMATION ACTIVITIES
Surface reclamation at uranium mill sites involves the cleanup of contaminated soil, and the long-term stabilization of the tailings impoundment. In the review of surface reclamation activities, NRC uses a multidisciplinary effort. The technical areas most involved in surface reclamation are: 1) surface-water hydrology to evaluate the erosion potential; 2) geotechnical engineering to address embankment stability and construction activities; and 3) health physics to evaluate soil cleanup and radon barrier design. In conducting its review, NRC will determine if DOE (for Title I mills) or the mill licensee (for Title II mills) has acceptably demonstrated that the design meets the applicable requirements. The process involves, first, determining what threats can affect the long-term stabilization of the tailings impoundment. These threats include such phenomena as earthquakes or flooding events. Once these design parameters are quantified, licensees are, then, required to demonstrate that the proposed design can withstand the threat. The overall approach for conducting these reviews has been well-established through the development of a Standard Review Plan and other staff guidance as well as nearly a decade of review experience.
After staff has completed the NRC review, NRC requires licensees to implement the accepted design or soil cleanup program through license conditions. In addition, NRC will ensure continued oversight of the surface reclamation work by inspecting ongoing activities. These inspections are usually led by staff from NRC's regional office in Arlington, Texas, but also include inspection team members from NRC Headquarters. The regional staff focuses on the health physics program, whereas Headquarters staff look at ongoing construction and soil cleanup work. In either case, the staff inspecting ongoing activities will be checking them to ensure continued compliance with commitments made by licensees and incorporated into license conditions. Also, the staff looks at ongoing work to ensure that it is being done in an acceptable manner.
One area where NRC policy has just recently developed regards the cleanup of contaminated soils at mill sites. NRC's effort on soil cleanup emphasizes relying on the licensee's program to ensure that cleanup is done properly. Currently, NRC is trying to ensure that the licensee's previously approved program for soil cleanup is being properly implemented. To achieve its objective, NRC will try to determine that: 1) cleanup is being done consistent with procedures; 2) procedures implement the commitments made in accepted soil cleanup plans; 3) licensee records provide objective evidence to show that cleanup is being done in an acceptable manner and the applicable cleanup standard is being met; and 4) the results of some side-by-side sampling demonstrate acceptable cleanup. Unless, through its inspections, the staff finds major problems, related to health and safety, with an approved plan, NRC will not be reexamining previously accepted plans. NRC only will need to conduct its own independent surveys for what are expected to be a small number of sites. This new streamlined approach allows NRC to use its resources efficiently, and eliminates the need for costly confirmatory surveys, except for sites where the surveys are actually needed.
In the Title I program, DOE is continuing to progress on completing its surface reclamation program. In the Act, DOE is required to complete the surface work and have the sites licensed for long-term care by September 1998. To date, NRC has licensed seven sites, and plans to license seven more in Fiscal Year 1997 and four in Fiscal Year 1998. The only Title I site that would not be licensed by the statutorily mandated completion date is the Cheney disposal cell located outside of Grand Junction, Colorado. DOE has the authority to keep this cell open to accept additional cleanup material, the majority of which is expected to come from the Grand Junction area. At one time, the city of Grand Junction used mill tailings in road and utility construction. As these are repaired, the tailings will need to be disposed of-- hence the reason for leaving the Cheney open. For unlicensed sites, DOE is continuing work on completing construction activities, and NRC is performing the necessary reviews. Both DOE and NRC plan to complete their efforts on the timetable needed to meet the Congressional date.
Work in the Title II program is progressing, but is not as far along as the Title I program. At present, 16 sites are currently undergoing reclamation. One site, the Tennessee Valley Authority cell in Edgemont, South Dakota, has been licensed for long-term care. A second site, the Atlantic Richfield Company site in Bluewater, New Mexico, is completed and nearing long-term licensing. The remaining 14 sites are undergoing active surface reclamation. Presently many have accepted reclamation plans, and are continuing with ongoing construction work. Others are changing designs to accommodate more robust designs. Soil cleanup has been completed for a few mill sites, whereas others are in the process of completing this work.
For some mills, surface reclamation is tied to the completion of groundwater cleanup activities. In their groundwater cleanup programs, many mill sites placed the evaporation ponds on the top of tailings impoundments. Because of this, NRC must allow licensees to stop their groundwater cleanup programs before surface reclamation work can be completed. Hence, for many sites, groundwater cleanup becomes a critical path item in meeting surface reclamation schedules.
GROUNDWATER CLEANUP ACTIVITIES
Nearly all uranium mill sites have groundwater contamination. These include both the DOE Title I sites, and the Title II commercial sites. There are two fundamental issues surrounding the groundwater cleanup at mills. One is a determination of how successful cleanup programs have been, and the other is a determination of what are acceptable limits for groundwater cleanup. For Title I sites, DOE is just beginning to develop its strategies and program for groundwater cleanup. Because of this, there is little to report on what types of experience NRC has acquired from the Title I sites. On the other hand, NRC has had many years of experience regarding both groundwater cleanup and monitoring of Title II sites. This experience has been helpful in understanding what needs to be done to ensure acceptable implementation of a groundwater program. Presently, NRC has identified two major issues involving groundwater cleanup.
In the technical arena, the issue that is currently starting to become significant is the inability of groundwater cleanup programs to meet established limits such as background or maximum concentration limits. Because of this, uranium recovery licensees are beginning to apply for approval of alternate concentration limits. Alternate concentration limits are site-specific limits that NRC sets for individual constituents, on a risk basis.
To help licensees develop alternate concentration limit applications, the staff has issued regulatory guidance. This guidance lays out the types of information licensees need to provide in an alternate concentration limit application, and provides guidance on what methods licensees can use to demonstrate that the use of alternate concentration limits at their sites can be acceptable. To date, NRC has accepted one application for alternate concentration limits. This was from the Atlantic Richfield, Bluewater, New Mexico, site. In its application, Atlantic Richfield requested alternate concentration limits for three constituents. Using the guidance it had developed, NRC reviewed the Atlantic Richfield submittal, and found the alternate concentration limits proposed for uranium, selenium, and molybdenum acceptable. Once the alternate concentration limits were accepted, Atlantic Richfield was able to show that its groundwater cleanup program could be stopped because the groundwater was in compliance with applicable standards. Several other licensees have applications in place requesting alternate concentration limits for their sites; however, because of the need for additional information, none is under active review.
The second issue in the groundwater area involves the presence of NRC/State concurrent jurisdiction over groundwater cleanup. Because the Act does not expressly preempt the regulation of mill tailings to the Federal Government, individual States have jurisdiction over the nonradiological constituents in groundwater. Although NRC will continue to conduct the regulatory program for groundwater protection it believes is acceptable for the protection of public health and safety, States may require that licensees adhere to more stringent State standards. This creates a problem in terms of what should be done if an NRC licensee meets all applicable Federal standards and is ready to terminate its license, but has not met the more restrictive State standards. If NRC were to terminate the license, it could be saddling DOE with the responsibility and cost for additional cleanup to meet State standards. On the other hand, if NRC did not terminate the license, it would not be able to identify to licensees what additional work needed to be done. Presently there is no easy way to resolve this issue. NRC is attempting to work with States to address the problem, with some mixed success.
DISPOSAL OF MATERIAL IN TAILINGS PONDS
The last topic I want to touch on deals with the ability of mills to dispose of material in their tailings ponds. There are several mills that have the authority to take other 11e.(2)byproduct material, and dispose of it in their existing tailings impoundments. Mostly, this material is the 11e.(2) byproduct material generated from the operation of in situ leach facilities. This effort is especially important because of the Commission's desire to avoid the proliferation of numerous, small disposal cells. Some mill sites also have the authority to take other 11e.(2) byproduct material, with prior NRC approval, on a case-by-case basis. An example could be 11e.(2) byproduct material cleaned up by DOE at various sites throughout the country. One mill site is currently looking into obtaining authorization to take any type of 11e.(2) byproduct material without NRC approval on a case-by-case basis. Review of this application is currently ongoing, with NRC waiting for additional information from the applicant.
Although the placement of 11e.(2) byproduct material from in situ leach facilities into existing tailings impoundments is a policy codified by the Commission in 10 CFR Part 40, Appendix A, Criterion 2, it has not necessarily been an easy policy to implement. Individual States are concerned with the transportation of waste across their boundaries. This concern is of such importance to some States that at least one petitioned NRC to modify a license authorizing the disposal of 11e.(2) byproduct material. Overall, however, the process is working well, and the mill acceptance of in situ-generated 11e.(2) byproduct material is a policy that is being successfully implemented.
A second category of material that mills can dispose of in their tailings impoundments is material other than 11e.(2) byproduct material. In September 1995, NRC finalized its guidance on one acceptable approach that mills could use to demonstrate that material other than 11e.(2) byproduct material could be disposed of in tailings ponds. Essentially, this material would be source-material-contaminated soil. The staff position was published in the Federal Register on September 22, 1995. The position lays out 10 different criteria that licensees can apply to demonstrate that material other than 11e.(2) byproduct material can be disposed of in the tailings impoundment. Demonstrating compliance with some of the 10 criteria is a difficult task that requires licensee coordination with EPA and DOE, as well as with low-level-waste compact States. However, as in any guidance, the approach outlined in the Federal Register notice is only one recommended path. To date, there have been no applications requesting the authority to dispose of material other than 11e.(2) byproduct material in tailings impoundments.
SUMMARY
It is evident that NRC has a diverse and complex uranium recovery program that is influenced by many factors. To address the issues within the program, NRC has had to maintain a flexible approach in implementing its regulatory responsibilities. Work continues in both the technical and policy aspects to address issues related to operation, reclamation, and disposal in the program. Overall, the program continues to move forward in meeting statutorily mandated requirements for abandoned uranium mills, in supporting the completion of surface reclamation, and in cleaning up groundwater at commercial mill sites.