The U.S. Nuclear Regulatory Commission (NRC) is considering approval of the remediation (decommissioning) plan (DP) for the formerly licensed Union Carbide Corporation (UCC) facility in Lawrenceburg, Tennessee, 1988. This DP was submitted by UCAR Carbon Company, Inc. (UCAR) to NRC on August 19, 1998. UCAR is obligated to remediate the UCC site to meet the release criteria established in the Action Plan to Ensure Timely Remediation of Sites Listed in the Site Decommissioning Management Plan (NRC, 1992), and CFR Part 20 Subpart E.
On August 26, 1963, UCC was issued Special Nuclear Materials License No. SNM-724 (SNM-724), for testing equipment and nuclear fuels development. License No. SMB-720 (SMB-720), which authorized the possession of source material, was also held by the site. SNM-724 was terminated on June 4, 1974, and the U.S. Atomic Energy Commission (AEC) released the site for unrestricted use. SMB-720 was superceded by the State of Tennessee License No. S-5002-H8 and was terminated on August 28, 1975.
SNM-724 authorized possession of up to 500 grams (g) of fully-enriched (<94 percent ) uranium for testing of equipment and processes in the Lawrenceburg Fuel Development Facility located at Highway 43 South, Lawrenceburg, Tennessee. On May 22, 1964, the license was amended to authorize possession of 150 kilograms (kg) of U235 to make graphite-coated uranium-thorium carbide particles and graphite-matrix fuel elements. The possession limit was increased to 475 kg on June 12, 1964.
By letter dated February 4, 1974, the UCC submitted “closeout” survey information and requested that SNM-724 be terminated and the facility be released for unrestricted use. On April 5, 1974, Region II performed a closeout inspection which was documented in their Inspection Report 70-784/74-1. Region II recommended that the license be terminated, and the facility be released for unrestricted use. By AEC letter dated June 4, 1974, SNM-724 was terminated, and the UCC facility released for unrestricted use.
In 1991, Oak Ridge National Laboratory (ORNL) was contracted by NRC to review and evaluate all nuclear material licenses terminated by NRC or its predecessor agencies, since inception of material regulation in the late 1940s. One of the objectives of this review was to identify sites with potential for residual contamination, based on information in the license documentation. NRC evaluated the available survey data to determine if the information was sufficient to conclude that the site meets the existing guidelines for unrestricted use.
Radiological assessments performed at the UCC facility and immediate vicinity have identified the presence of enriched and depleted uranium on building surfaces in excess of current radiological release criteria. Sampling identified contamination in three buildings on the UCC site: (1) Building 10; (2) Building 5 Annex; and (3) the Metallurgy Laboratory. Surface contamination in Building 10, Building 5 Annex, and in the Metallurgy Laboratory was primarily present as fixed contamination.
Surface contamination for α and β/γ activity above the release guidelines was identified in 11 rooms in Building 10 (Rooms 106-2, 120, 121, 122, 124, 126, 128-1, 129, 132, 133, and 134) ranging from background to 106,469 dpm/100 square centimeter direct beta/gamma. For each sample containing significant contamination, results indicated the presence of enriched uranium. This is consistent with process knowledge of the operational history. For this reason, thorium is considered an insignificant indicator for evaluating surface activity data.
Uranium was also the primary contaminant in Building 5 Annex. Surface contamination was found in four rooms in Building 5 (Rooms 106, 107, 108, 110), ranging from background to 428,698 dpm/100 square centimeters direct beta/gamma.
Contamination in the Metallurgy Laboratory consists of localized surface contamination on the tops of the cabinets. There was no indication of radioactive material above the release criteria beyond the former restricted area boundary in the ground water, settling basins, or former sanitary sewer system.
UCAR will be conducting remediation activities without a license, because its license was terminated in 1974. However, remediation will be performed in accordance with current regulations and release limits (UCAR, 1998).
Planned Decommissioning Action
Decommissioning of the UCAR facility shall comply with the SDMP Action (NRC, 1992) Plan criteria. The conduct of decommissioning and decontamination in compliance with these criteria provides adequate protection of the public health and safety and of the environment. In implementing the decommissioning plan, UCAR shall reduce residual contamination on building surfaces to be below the NRC's unrestricted release criteria (NRC, April 1992) for uranium. Building surfaces will be decontaminated with pneumatic needle-scalers, floor scabblers, vacuums and/or similar equipment. Structures that cannot be cost-effectively decontaminated (e.g., counter tops, wooden drawers, duct work, and Room 134 penthouse) will be mechanically removed, reduced in volume/minimized, and packaged for disposal.
General exposure rate levels will be reduced to levels below 5 microroentgen per hour (uR/hr) above background, measured at 1 meter (m) above the surface.
UCAR is proposing to conduct a final survey to demonstrate: (1) That surface contamination levels meet the guideline levels for uranium established in “Guidelines for Decontamination of Facilities and Equipment Prior to Release for Unrestricted Use or Start Printed Page 46186Termination of Licenses for Byproduct, Source or Special Nuclear Material;” and (2) that exposure rate measurements are less than 5 uR/hr measured 1 meter above the surface. UCAR has committed to conducting the final survey in accordance with the NRC approved site survey plan, as well as any applicable regulatory requirements.
The Need for the Planned Action
The former UCAR facility is currently being used to manufacture non-radiological carbon products. The planned action is necessary to reduce residual contamination at the site to meet NRC's unrestricted release criteria.
Alternative to the Planned Action
The alternative to the proposed action is to take no action. A no-action alternative would mean the site would not be remediated now. Although there is no immediate threat to the public health and safety from this site, not undertaking remediation, at this time, does not solve the regulatory and potential long-term health and safety problems associated with having residual contamination on site. In addition, pursuing no action would delay remediation until some time in the future, when remediation costs could be much higher than they are today. Therefore, the no-action alternative is not acceptable.
Environmental Impacts of the Planned Action
Radiological impacts that could result from the remediation of the former UCC site are direct exposure, inhalation, and ingestion hazards to workers. These hazards could occur during decontamination of building surfaces and excavation and packaging of contaminated soil.
The radioactive material of concern at this site is enriched uranium. Surface contamination in Buildings 10 and 5 Annex, and the Metallurgy Laboratory is primarily fixed. Gamma exposure rate measurements taken at locations throughout the site do not exceed background levels, with the exception of five locations near the incinerator pad. The highest radiation exposure rate detected near the incinerator pad is 26 uR/hr above background. Because the gamma exposure rate measurements are low, direct exposure to workers is not a significant radiological hazard.
Building surfaces, such as concrete floors, walls, and ceilings, will be decontaminated with equipment, such as pneumatic needle-scalers, floor scabblers, vacuums, and/or similar equipment. This equipment will be equipped with the appropriate health and safety devices, such as high-efficiency particulate air filters. If determined necessary by the Radiation Safety Officer (RSO), containment enclosures will be constructed for contamination control. UCAR will implement an occupational exposure monitoring program to ensure that internal and external exposures of workers are well below the regulatory limits. Respiratory protection will be required for workers when airborne radioactivity could result in exposures above the administrative action levels set in the health and safety plan.
Although the potential for external exposure to workers is low, UCAR will survey work areas for direct radiation whenever remediation is being performed. If dose rates exceed 5 mrem/hr, or if the RSO determines that worker exposure could exceed 10 percent of the regulatory limits found in Part 20, Subpart C “Occupational Dose Limits,” worker exposure will be monitored with thermoluminescent dosimeters.
UCAR has committed to implement a contamination monitoring and control program to detect and minimize the spread of contamination. Contamination monitoring will be accomplished by: (1) Conducting routine surveys; (2) use of access controls to prevent inadvertent personnel access to contaminated areas; (3) use of radiation work permits in areas where there is potential for workers to exceed 10 percent of the regulatory limits; (4) use of personal protection equipment; and (5) employee training.
UCAR has committed to implementing a contaminant monitoring and control program to detect and minimize off-site effluent releases (UCAR, in its DP Section 3.3.4, 1998). The primary pathway for off-site release of radioactive material is airborne effluent. Inhalation and ingestion impacts will be minimized to the workers and public by controlling airborne material levels. Routine and special environmental monitoring will be conducted to detect, assess, and limit potential airborne releases. Air monitoring will be performed in work areas using Breathing Zone Air (BZA) samplers or high-volume air samplers. Administrative action levels at 10 percent of the regulatory limits for airborne effluents have been established. Investigations will be performed if administrative action levels are exceeded. No liquid wastes have been identified and none are expected.
Radioactive waste will be segregated from non-radioactive waste and stored in a controlled, fenced area. Radioactive waste will be stored inside, if possible. Otherwise, it will be stored outside and covered to protect against the weather. Radioactive waste will be packaged, labeled, manifested, and shipped in accordance with NRC and U.S. Department of Transportation requirements.
This site is being remediated to the criteria listed in the SDMP Action Plan (NRC, 1992). The exposure to the public from the remediated site is expected to be within the limits stipulated in Part 20, Subpart D.
Agencies and Individuals Consulted
This environmental assessment (EA) was prepared by NRC staff. No other sources were used beyond those referenced in this EA. NRC staff provided a draft of the EA to the Tennessee Department of Environment and Conservation, Division of Radiological Health for review. By e-mail dated May 1, 2000, the Tennessee Department of Environment and Conservation Division of Radiological Health agreed with NRC's conclusion that the proposed action will not have any significant affect on the quality of the human environment.
NRC contacted the U.S. Fish and Wildlife Service (FWS) to determine the potential impacts of the proposed action on threatened and endangered species near the UCAR facility. By letter dated September 10, 1999, the FWS informed NRC that the proposed action would have no impact on threatened and endangered species.
NRC staff provided a draft of the EA to the U.S. Environmental Protection Agency (EPA) Region IV for review. By e-mail dated June 27, 2000, EPA did not have any comments on the proposed action. However, the EPA has noted the disagreement between the EPA and the NRC about the appropriate dose criteria to be used in decommissioning.
NRC also contacted the Tennessee State Historical Preservation Office to determine if any historical properties would be impacted by the proposed action. The Tennessee State Historical Preservation Office informed the NRC, by letter dated May 2, 2000, that there is no national register of historic places listed or eligible properties affected by the project.
During the decommissioning operation, radiological exposure to workers and annual average concentrations of radioactive materials released off-site will be in accordance with Part 20 limits. UCAR has committed to perform remediation in accordance with an acceptable Health and Safety Plan. The Health and Safety Start Printed Page 46187Plan shall provide adequate controls to keep potential doses to workers and the public from direct exposure, airborne material, and released effluents as low as is reasonably achievable.
NRC also believes that remediation of the facility according to the SDMP Action Plan criteria (NRC, 1992) adequately protects workers, members of the public, and the environment. The potential environmental impacts from the proposed action are not significant.
1. NRC, “Action Plan to Ensure Timely Remediation of Sites Listed in the Site Decommissioning Management Plan,” 57 FR 13389, April 16, 1992.
3. NRC, “Multi-Agency Radiation Survey and Site Investigation Manual, (MARSSIM),” NUREG-1575, December 1997.
4. NRC, “Draft Manual for Conducting Radiological Surveys in Support of License Termination,” NUREG/CR-5849, June 1992.
5. Union Carbide Company Inc., “Remediation (Decommissioning) Plan for the Formerly Licensed Union Carbide Corporation Facility (UCC), Lawrenceburg, TN,” August 19, 1998.
Finding of No Significant Impact
NRC has prepared an EA related to the approval of UCAR's Remediation (Decommissioning) Plan, Terminated License No. SNM-724 and SMB-720. On the basis of this EA, NRC has concluded that the environmental impacts that would be created by the proposed action would not be significant and do not warrant the preparation of an Environmental Impact Statement. Accordingly, it has been determined that a Finding of No Significant Impact is appropriate.
The EA and the documents related to this proposed action are available for public inspection and copying at NRC's Electronic Reading Room at http://www.nrc.gov/NRC/ADAMS/index.html.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Rebecca Tadesse, Project Manager, Decommissioning Branch, Division of Waste Management, Office of Nuclear Material Safety and Safeguards. Telephone: (301) 415-6221.Start Signature
Dated at Rockville, Maryland, this 20th day of July 2000.
For the Nuclear Regulatory Commission.
Larry W. Camper,
Chief, Decommissioning Branch, Division of Waste Management, Office of Nuclear Material Safety and Safeguards.
[FR Doc. 00-19005 Filed 7-26-00; 8:45 am]
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