02-30098. Environmental Assessment and Finding of No Significant Impact; Materials License No. 49-09955-10, University of Wyoming, Laramie, WY

The U.S. Nuclear Regulatory Commission (NRC) is considering the approval of the University of Wyoming's revised decommissioning plan for two former burial sites located near Laramie, Wyoming, and amending NRC Materials License 49-09955-10 to remove the two sites from the license.

Environmental Assessment

Background

The University of Wyoming (licensee) submitted a decommissioning plan to the NRC by letter dated October 21, 1998. The licensee subsequently submitted a revised decommissioning plan to the NRC by letter dated May 30, 2001. The licensee requested that two former radioactive material burial sites located near Laramie, Wyoming, be released for unrestricted use. The NRC is considering the issuance of an amendment to Materials License 49-09955-10 to release these two burial sites for unrestricted use. The purpose of this Environmental Assessment (EA) is to assess the environmental consequences of this license amendment request.

Proposed Action

The proposed action is to amend NRC Materials License 49-09955-10 to release for unrestricted use the two former burial sites located near Laramie, Wyoming. The licensee would not be required to remediate the two sites if the NRC approves the license amendment request.

Purpose and Need for Proposed Action

NRC regulation 10 CFR 30.36 (the Timeliness Rule) requires licensees to decommission their facilities when licensed activities cease, and to request termination of their radioactive materials licenses. The purpose of the Timeliness Rule is to reduce the potential risk to the public and environment that may result from delayed decommissioning of inactive facilities and sites. The purpose of the proposed action is to remove the two former burial sites from the University of Wyoming's radioactive materials license because the licensee no longer uses the two burial sites. The licensee would continue to possess radioactive material under its NRC license at other locations specifically listed in the license. If removed from the license, the two burial sites would no longer be subject to NRC regulatory oversight, and the licensee would be in compliance with Timeliness Rule requirements.

History/Facility Description

The University of Wyoming has used radioactive material since about 1950. The licensee disposed of radioactive waste material at two separate burials sites from about 1952 until 1985. The licensee was authorized to dispose of radioactive material by burial in accordance with 10 CFR 20.304 between 1959-1981. Prior to 1959, burial of radioactive material was not authorized by § 20.304 but may have been conducted under a specific U.S. Atomic Energy Commission authorization or license condition at that time. During 1981, § 20.304 was rescinded by the NRC. The licensee then conducted burials in accordance with § 20.302 until 1985. During 1985, the NRC rejected the licensee's request to continue to dispose of radioactive material by burial in accordance with § 20.302. As a result, burial of radioactive material was permanently discontinued during March 1985.

The first burial site was known as the Quarry site. This disposal site was a dry borehole located at a University-owned sandstone quarry. The quarry is situated approximately 7.5 miles (12 kilometers) to the northeast of Laramie. The University believes that the Quarry site was used during 1952-1957. The licensee cannot pinpoint the exact location of the 100-foot (30.48 meters) borehole but is aware of the general location of the borehole.

The airport site is located on University-owned land situated approximately 2 miles (3.2 kilometers) west of Laramie. This site is located near the Laramie Municipal Airport and consists of approximately 40,000 square feet (3716 square meters) of land. This second site was used from 1959 until 1985.

Radiological Status

Based on a records review, the licensee determined that it most likely disposed of only microcurie or millicurie quantities of short-lived radioisotopes in the Quarry site borehole, including phosphorus-32, sulfur-35, iron-59, zinc-65, and iodine-131. Carbon-14, a long-lived beta-emitting radionuclide, apparently was also buried at this site. The licensee's request to release the two former burial sites for unrestricted use is based on dose modeling calculations using the NRC-approved DandD computer code. The licensee chose the drinking water scenario from DandD Version 1.0 for the Quarry site because this site cannot be farmed. The licensee calculated a resident dose of up to 2.74 millirems per year using DandD, a value well below the 25-millirem limit specified in 10 CFR 20.1402.

The licensee disposed of a number of radionuclides at the airport site. The radionuclides of concern at the airport site are hydrogen-3 and carbon-14. At this site, the licensee chose the resident farmer scenario using DandD Version 2.1.0. Using several NRC-approved variations to the DandD default parameters (the default parameters that were adjusted for the airport site were the diet-fruit, number of unsaturated layers, unsaturated zone thickness, and crop yield parameters), the licensee calculated that the resident farmer dose would be less than or equal to 22.5 millirems per year. This calculated value is also below the 25-millirem limit specified in 10 CFR 20.1402.

Alternatives

The licensee asks that the NRC approve the license amendment request as submitted. The alternatives available to the NRC to the proposed action are:

1. Deny the amendment request by taking no action; or

2. Approve the license amendment request but require the licensee to take some additional action not specified in the revised decommissioning plan such as remediation of the two sites.

The Timeliness Rule requirements do not allow the NRC to implement the no action alternative; therefore, Alternative 1 is not a viable option and will be eliminated from further study and consideration in this EA.

Affected Environment

The Quarry site is situated approximately 8 miles (13 kilometers) to the northeast of Laramie. The exact location of the borehole is not known by the licensee. According to the documentation provided by the licensee, the Quarry site is unoccupied and is occasionally used for livestock grazing. There are no ponds on the property. The area is sparsely covered by vegetation that consists mostly of prairie grasses with some interspersed shrubs and sagebrush. The site is roughly 750 square feet (70 square meters) in size and is located in NW1/4 of NW1/4 of Section 5, Range 72 West, Township 16 North. The licensee installed a monitoring well down-gradient of the borehole during 1994 in order to obtain groundwater samples for analyses. During well installation, a continuous flow of groundwater was established at about 236 feet (72 meters) below the surface. Previously licensed radioactive material was not detected in the water samples that were collected during late-1994.

The airport site consists of approximately 40,000 square feet (3716 square meters) of land. This burial site is located in an 861-acre (348 hectares) tract of University-owned land bounded by Highway 130 to the north, near Highway 230 to the south, the airport to the west, and West Laramie to the east. This site is located in NE1/4 of NW1/4 of Section 35, Range 74 West, Township 16 North. The site is in a “steppe” climate zone, typical of semi-arid grassland prairies. The vegetation is well suited for livestock grazing and consists of grasses, sedges, some forbs, and a few scattered shrubs. According to information provided by the licensee, the nearest aquifer is located at least 700 feet (213 meters) below the surface. Further, the shallow groundwater is unfit for human and livestock consumption. As such, city water is the predominate water source and is piped to residents and businesses near the airport.

Environmental Impacts of the Proposed Action on Occupational and Public Health

The licensee's request to release the two burial sites for unrestricted use is based, in part, on dose modeling calculations conducted using the NRC-approved DandD computer code. The licensee concluded that the annual dose to members of the public for the Quarry site would be no more than 2.74 millirems per year, while the annual dose for the airport site would be no more than 22.5 millirems per year. Both calculated doses are below the 25 millirem per year dose limit specified in 10 CFR 20.1402.

The NRC conducted a technical review of the licensee's DandD calculations. This review is documented in an internal NRC Memorandum dated December 31, 2001. In summary, the staff concluded that the doses from exposure to residual radioactive material currently situated at both locations are sufficiently low to allow for the unrestricted release of the sites in accordance with 10 CFR 20.1402.

Environmental Impacts of Alternative 2 on Occupational and Public Health

If the licensee were required to remediate the two burial sites, the individuals conducting reclamation would be subjected to exposure to radioactive material. The radionuclides of concern are hydrogen-3 and carbon-14. Both of these radionuclides emit low energy beta particles. From an occupational health and safety standpoint, the worst case scenario is the intentional exhumation of the buried wastes without any radiological controls in place. This scenario is unlikely because the licensee would be expected to have a radiation protection program in place during remediation. Even without any radiological controls, it is highly unlikely that any worker would receive a dose during reclamation that would exceed the occupational dose limits specified in 10 CFR 20.1201 because of the quantities and types of radionuclides present in the waste material. Therefore, if reclamation were to occur, it is probable that occupational exposures would be within the dose limits specified in the NRC's regulations.

If remediation were to occur, the potential harm to the public from exposure to radioactive material would be bounded by the DandD calculations. The DandD scenario used by the licensee assumed that the waste material volume was evenly distributed in the top 6 inches (15 centimeters) of soil. Therefore, the remediation of the two sites would most likely have a minimal radiological impact on members of the public.

Remediation of the sites may have short-term health and safety consequences caused by the excavation, packaging, and shipping of the residual radioactive material. These non-radiological impacts would include the normal risks of exhuming the wastes with earth-moving equipment and transportation of the material to an out-of-state disposal facility. The risks include death or injury from a construction or transportation accident.

There would be minimal risk to members of the public from exposure to radioactive wastes during transport because the radionuclides of concern are low energy beta emitters. The beta particles would not be able to penetrate the walls of the shipping container. The only radiological risks associated with the transport of the wastes would involve the cleanup of any spilled material. In the unlikely event that a spill were to occur during transport, radiological controls would most likely be implemented during the cleanup of the spilled waste material. Therefore, the risks associated with the transport of the waste material is minimal.

If remediated, the material would be transported to an out-of-state disposal facility.

Environmental Impacts of Proposed Action on Effluent Releases, Environmental Monitoring, Water Resources, Noise, Geology, Soils, Air Quality, Demography, Biota, Cultural and Historic Resources, and Visual/Scenic Quality

The NRC staff considered the potential impacts of the leaching of radioactive and non-radioactive material into the groundwater. The shallow surface groundwater in the vicinity of the two sites is not used as a drinking water supply and is unfit for human consumption. Local members of the public obtain water from the city. The impacts that potentially contaminated groundwater would have on members of the public was considered as part of the DandD modeling scenarios. In summary, the NRC believes that, if left undisturbed, the two sites would have a minimal impact on the environs of the sites, including groundwater.

The NRC contacted both the U.S. Fish and Wildlife Service and the Wyoming State Historic Preservation Office for their respective assessments. The Fish and Wildlife Service concluded that it was unlikely that the Proposed Action would adversely affect any threatened or endangered species. The Wyoming State Historic Preservation Officer determined that no historic properties would be affected by the Proposed Action.

Environmental Impacts of Alternative 2 on Effluent Releases, Environmental Monitoring, Water Resources, Noise, Geology, Soils, Air Quality, Demography, Biota, Cultural and Historic Resources, and Visual/Scenic Quality

The remediation of the two former burial sites would cause some environmental harm. The waste material would have to be excavated, packaged, and transported to an out-of-state disposal facility. The excavation process would be accomplished by heavy equipment and trucks that would disturb the general area. The prevailing winds will most likely disperse some of the excavated material offsite. The resulting surface void would have to be refilled with clean soil and contoured or fenced to prevent inadvertent intrusion. Vegetation in the vicinity of the reclaimed site would be temporarily disturbed.

Mitigation measures that could reduce the adverse impacts or enhance beneficial impacts were considered by the NRC. The licensee conducted an As Low As Reasonably Achievable (ALARA) analysis to compare the benefit from averted dose achieved by remediation with the costs of cleanup and waste disposal. The licensee calculated the benefit from the collective averted dose using the guidance provided in (draft) Regulatory Guide DG-4006, Demonstrating Compliance with the Radiological Criteria for License Termination, dated August 1998. The licensee calculated a total benefit of $8398 from the averted dose for the airport burial site, assuming a monetary value of $2,000 per rem.

The licensee also calculated the remediation costs for decommissioning the airport burial site. The estimated cost of excavating, transporting and disposing of the material at an offsite low-level waste disposal facility was about $7.6 million. The majority of the cost involves waste disposal at an offsite location. The licensee also points out that the public would be economically harmed since the University is a publicly funded school and the $7.6 million would have to come from the state general fund or diverted from the University's budget.

In summary, the NRC agrees that the cost of remediation would exceed the financial benefit from the averted dose that would be saved if the airport site were to be remediated.

The licensee did not conduct an ALARA analysis of the Quarry site, in part, because the exact location of the former borehole is not known.

The NRC has found no other activities in the areas that could result in cumulative impacts.

Agencies and Persons Contacted

The NRC contacted both the U.S. Department of Interior, Fish and Wildlife Service, and the Wyoming State Historic Preservation Office during the development of this EA. The Fish and Wildlife Services concluded that it was unlikely that the Proposed Action would adversely affect any threatened or endangered species. Also, according to the Wyoming State Historic Preservation Office, the Proposed Action would not affect any historic properties. The Wyoming Emergency Management Agency has reviewed the proposed action and had no additional comments.

Conclusion

Based on its review, the NRC staff has concluded that the environmental impacts associated with the proposed action are not significant; and therefore, do not warrant denial of the license amendment request. The NRC staff believes that the proposed action will result in minimal environmental impacts. The staff has determined that the proposed action, approval of the license amendment request to release the two former burial sites for unrestricted use, is the appropriate alternative for selection.

List of Preparers

This EA was prepared by Robert Evans, Senior Health Physicist, Fuel Cycle & Decommissioning Branch, Division of Nuclear Materials Safety, Region IV, and reviewed by Dr. D. Blair Spitzberg, Chief, Fuel Cycle & Decommissioning Branch.

List of References

Documents pertaining to this EA are available for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of NRC's document system (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/​reading-rm/​adams.html (the Public Electronic Reading Room). ADAMS accession numbers are located in parentheses following the reference.

1. NRC Inspection Report 030-01176/95-01 dated May 9, 1995 (not available in ADAMS).

2. University of Wyoming letter to NRC dated October 21, 1998 (not available in ADAMS).

3. University of Wyoming letter to NRC dated May 30, 2001 (ML011580440).

4. NRC Memorandum, “Review of Dose Modeling Supporting the Revised Decommissioning Plan for the Quarry and Airport Burial Sites,” dated December 31, 2001 (ML013540074).

5. NRC Letter to U.S. Fish and Wildlife Service dated April 24, 2002 (ML021140673).

6. NRC Letter to Wyoming State Historic Preservation Office dated April 24, 2002 (ML021140684).

7. U.S. Fish and Wildlife Service letter to NRC dated May 20, 2002 (ML021500264).

8. Wyoming State Historic Preservation Office letter to NRC dated June 17, 2002 (ML 021830731).

9. Wyoming Emergency Management Agency letter to NRC dated September 10, 2002 (ML022690527).

Finding of No Significant Impact

Pursuant to the National Environmental Policy Act of 1969 (NEPA) and the Commission's regulations in 10 CFR part 51, the Commission has determined that there will not be a significant effect on the quality of the environment resulting from the approval of the revised decommissioning plan and release of the two former burial sites for unrestricted use. Accordingly, the preparation of an Environmental Impact Statement is not required for the proposed amendment to Materials License 49-09955-10, which will remove the Quarry and airport sites from the license. This determination is based on the foregoing EA performed in accordance with the procedures and criteria in 10 CFR part 51.

This EA and other documents related to this proposed action are available for public inspection and copying at the NRC Public Document Room in NRC's One White Flint North Headquarters building, located at 11555 Rockville Pike (first floor), Rockville, Maryland. The documents may also be viewed in the Agency-wide Documents Access and Management System (ADAMS) Public Electronic Reading Room at Web address http://www.nrc.gov/​reading-rm/​adams.html.

Dated in Arlington, Texas, this 19th day of November, 2002.

For the Nuclear Regulatory Commission.

D. Blair Spitzberg,

Chief, Fuel Cycle Decommissioning Branch, Division of Nuclear Materials Safety, Region IV.