[Federal Register Volume 70, Number 132 (Tuesday, July 12, 2005)]
[Pages 40065-40068]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E5-3679]



[Docket No. 40-09015]

Environmental Assessment and Finding of No Significant Impact 
Related to Incorporating the Decommissioning Plan for the Michigan 
Department of Natural Resources (Mdnr) Bay City, MI, Tobico Marsh Site 
Into the License

AGENCY: Nuclear Regulatory Commission.

ACTION: Environmental Assessment and Finding of No Significant Impact.


FOR FURTHER INFORMATION CONTACT: David Nelson, Project Manager, 
Materials Decommissioning Section, Decommissioning Directorate, 
Division of Waste Management and Environmental Protection, Office of 
Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory 
Commission, Mail Stop T7E18, Washington, DC 20555. Telephone: 301-415-
6626; fax number: 301-415-5397; e-mail: [email protected].


I. Introduction

    The Nuclear Regulatory Commission (NRC) is considering issuing a 
license amendment to Material License No. SUC-1581 issued to the 
Michigan Department of Natural Resources (MDNR), to incorporate the 
Tobico Marsh State Game Area Decommissioning Plan (DP) for the MDNR, 
Bay City, Michigan, Tobico Marsh site into the License. SUC-1581 was 
issued in 1999 authorizing MDNR to possess on-site radioactive 
materials related to the decommissioning of the MDNR Tobico Marsh site. 
In a letter dated April 2, 2003, MDNR requested that the Tobico Marsh 
State Game Area DP be incorporated into the licensee. On January 30, 
2004, MDNR submitted a revised DP (Revision 1) and in a letter dated 
December 20, 2004, MDNR proposed additional changes to Revision 1. The 
license will be amended to include all of the revisions and changes 
described in the January 30, 2004, and December 20, 2004, letters.
    If the NRC approves the amendment, the DP will be incorporated into 
the MDNR License. The NRC has prepared an Environmental Assessment (EA) 
in support of this proposed action in accordance with the requirements 
of Part 10 of the Code of Federal Regulations (10 CFR) Part 51. Based 
on the EA, the NRC has determined that a Finding of No Significant 
Impact (FONSI) is appropriate.

II. Environmental Assessment


    The site is a small part of the former (now closed) industrial 
waste disposal area locally known as the Hartley & Hartley Landfill. 
The industrial waste disposal facility, which opened in the mid-1950's, 
was originally operated by the Hartley family and is estimated to have 
received 18,000 barrels of spent solvents, oils, and other liquid and 
solid wastes for disposal during the 1960's and early 1970's. Foundry 
waste containing low levels of naturally occurring radioactivity in the 
form of magnesium-thorium slag was also disposed of at the site 
beginning in 1970. By 1973, disposal activities on site had ceased.
    Currently, the Hartley & Hartley Landfill industrial disposal site 
is treated as two separate sites (the MDNR site and the SC Holdings, 
Inc site) after having been subdivided. In a formal land exchange 
concluded in 1973, the Hartleys conveyed land to the State of Michigan 
that included approximately three acres where waste disposal had 
previously occurred in return for lands bordering their industrial 
waste site. The 3-acre portion, now known as the MDNR site, is part of 
the State of Michigan property which is known as the Tobico Marsh State 
Game Area.
    The 3-acre portion was an area where the Hartley's mined 
(excavated) a former beach-ridge sand deposit. The excavation resulted 
in surface depressions flooded with surface water and near-surface 
ground water. Industrial wastes, including drums, spent solvents, oils 
and other liquid and solid wastes were disposed of in the excavations. 
In addition to these materials, magnesium-thorium slag containing 
naturally occurring thorium (Th) was also disposed of in the 
excavations beginning in 1970. The slag, thought to have been generated 
by Wellman Dynamics at a site within Bay City, Michigan, was a 
byproduct of casting and foundry operations involving magnesium-thorium 
    In 1984, to contain the chemical wastes and preclude the potential 
migration of chemical (non-radioactive) contaminants beyond those areas 
already impacted by the disposal, a bentonite slurry wall was placed 
around the disposal area and covered with a 1.5 m (5 ft) thick clay 
cap. The slurry walls and cap formed a cell which contained the 
chemical wastes, as well as the slag containing magnesium-thorium 
    A small building and adjacent concrete pad, which are still in 
place, were constructed on-site after the slurry walls and clay cover 
were installed. A leachate collection and treatment system (LCTS) was 
installed within the cell and slurry walls. The small building was 
designed to house the LCTS controls. The building has been used to 
stage survey equipment and temporarily store potentially radiologically 
contaminated waste generated during previous on-site surveying 
activities. The LCTS was designed by the Michigan Department of 
Environmental Quality (MDEQ) to withdraw liquid non-radiological 
contaminants (leachate) from the waste cell to prevent hydrostatic 
pressure in the cell from building to a point that chemical 
contaminants would leak from the cell. In the past, there was no 
noticeable buildup of pressure within the cell. The LCTS was never 
operated and, MDNR believes that liquid levels within the cell will not 
build to the point where operation of the LCTS is needed.
    The primary radioactive source term within the cell is comprised of 
pockets of vitreous, thorium-bearing slag that lie in a lens that is 
approximately 5 to 6 feet below the ground surface. A clay cover 
(approximately 5 feet thick at the center of the cell) overlays the 
ground surface. On August 26, 1999, the NRC

[[Page 40066]]

issued Source Material License No. SUC-1581 to MDNR authorizing 
possession of the thorium-bearing slag and decommissioning of the site. 
Prior to 1999, the site had never been licensed.
    On April 2, 2003, MDNR submitted a DP for the site. The DP outlined 
decommissioning activities including the removal of the building, the 
adjacent concrete pad and the above-grade components of the LCTS. 
Following those activities, the site would be released for unrestricted 
use as specified in 10 CFR 20.1402 and the radioactive materials 
license would be terminated. The NRC staff determined that the 
submittal was incomplete, and on January 30, 2004, MDNR submitted a 
revised and updated DP (Revision 1). On August 27, 2004, the NRC staff 
transmitted a letter to MDNR requesting additional information (RAI) 
related to Revision 1. In a December 20, 2004, letter, MDNR responded 
to the RAIs and provided supplemental information to the Revision 1 DP 
that indicated the on-site building, concrete pad and above-grade 
components of the LCTS would not be removed but would remain intact.

The Proposed Action

    The proposed action is to amend Source Materials License No. SUC-
1581 to incorporate the revised DP into the license. The revised DP 
proposes that the on-site building, adjacent concrete pad and LCTS 
remain in place and intact and all residual radioactivity be contained 
within the on-site engineered cell. With regard to the radiological 
materials, the site will be released for unrestricted use.

Need for the Proposed Action

    The proposed action is to amend Source Materials License No. SUC-
1581 to conduct activities on-site that would lead to the release of 
the MDNR Tobico Marsh State Game Area site located at 2301 Two Mile 
Road, Bay County, Michigan, for unrestricted use. The licensee's action 
of leaving the radiological material (the thorium-bearing slag) in 
place within the cell conforms with the NRC regulation that the dose to 
the average member of the critical group is below the requirements in 
10 CFR 20 Subpart E for unrestricted release before license 
termination. The licensee needs the license amendment to incorporate 
the revised DP into the license. NRC is fulfilling its responsibilities 
under the Atomic Energy Act to make a decision on a proposed license 
amendment for incorporation of a revised DP into the license and to 
ensure the protection of public health and safety and the environment.

Alternatives to the Proposed Action

    The NRC staff and MDNR considered four alternatives for the 
decommissioning plan: (1) Complete removal of the waste cell contents 
(both radiological and chemical materials); (2) removal of only the 
radiological material from the waste cell; (3) leaving the radiological 
material in the waste cell, leaving the on-site building, adjacent 
concrete pad and LCTS on site, terminating the license, and releasing 
the site for unrestricted use; and (4) taking no remedial action and 
retaining the site license (``No Action Alternative''). The preferred 
alternative, No. 3, is described, in detail, in Revision 1 the DP as 
supplemented by the December 20, 2004, letter from MDNR.
    The MDNR site contains radiological as well as chemical materials. 
The chemical materials are regulated by the MDEQ under Part 201 of 
Michigan regulations. The radiological and chemical materials are all 
contained within an on-site engineered waste cell that has slurry walls 
and a clay cap.
    Alternatives 1 and 2 would cause the contents of the waste cell to 
be disturbed, leading to a potential release of the materials to the 
surrounding environment. Specifically, excavation of the waste cell 
would expose workers and visitors to hazardous materials within the 
cell. Hazardous materials could be released via effluents or 
transmission in the air potentially contaminating the surrounding 
environs. Shipping the materials off-site for disposal could also 
expose workers and others to the materials before, during, and after 
shipment to the disposal site. The environmental impact presented by 
these two alternatives could potentially put workers and the 
surrounding environment at risk and are, therefore, not environmentally 
sound options.
    Alternative 3 is the preferred alternative, because the alternative 
has little, if any, impact on the environment. Based on an independent 
dose assessment, the NRC staff concluded that, if the radiological 
material in the cell, the building, the concrete pad, and the LCTS are 
left in place, no additional actions are needed at the MDNR site for it 
to be released for unrestricted use per 10 CFR 20.1402.
    The ``No Action Alternative'' (Alternative 4) is not acceptable 
because retaining a license would impose an unnecessary regulatory 
burden on MDNR. Since no additional actions are needed at the MDNR site 
for it to be released for unrestricted use per 10 CFR 20.1402, there is 
no longer any need for requiring that the licensee maintain security at 
the site and/or maintain the site's materials license.

Environmental Impacts of the Proposed Action

    The Affected Environment at the MDNR site includes the above grade 
components of the LCTS; the 3-acre landfill encapsulated with slurry 
walls and a clay cover; the shallow groundwater below the site; and, 
the potentially impacted offsite groundwater and surface water.
    The residual radioactivity at this site consists of two components. 
The primary source term consists of the magnesium-thorium slag 
materials buried within the waste cell and secondary source term 
consists of contamination on surfaces. Site characterization surveys 
found no evidence that the clay cap, the building or the concrete pad 
surfaces were contaminated. However, the clay cap could have been 
contaminated if magnesium-thorium slag materials have been brought to 
the surface of the cap during site characterization and the 
contamination could have spread to the building and pad surfaces. 
Boreholes were drilled through the clay cap during site 
characterization and samples were collected from within the cell. The 
concrete pad was also used to process the samples and may have been 
contaminated during processing. Waste generated during the sampling 
activities was placed in a 55 gallon drum and stored in the building. 
The 55 gallon drum could have leaked and contaminated the interior 
surfaces of the building. The clay cap and all of the building and pad 
surfaces will be surveyed during the final status surveys.
    The radionuclide composition of the primary and secondary source 
terms are assumed to be the same, because the secondary source terms 
are essentially derived from the primary source term in the waste cell. 
The isotopic composition for Th-230 and Th-232 and their progeny is: 
(1) Pb-210--0.5%, (2) Ra-226--1.1%, (3) Ra-228--16.1%, (4) Th-228--
16.1%, (5) Th-230--50.0%, and (6) Th-232--16.1%.
    The non-radiological contamination at this site is contained within 
the encapsulated waste cell. The non-radiological contamination 
includes organic chemicals which are regulated by the MDEQ, not by the 
NRC. The non-radiological contamination will be present after NRC 
license termination. Approval of the proposed action does not absolve 
the licensee of any other responsibilities it may have under Federal, 
State, or local statutes or

[[Page 40067]]

regulations regarding the non-radiological contamination.
    The site and much of the immediate area, except for the adjacent 
former Hartley & Hartley landfill, is marsh land. The site itself is a 
small portion of the Tobico Marsh State Game Area. The shallow 
groundwater on-site is non-potable and there is no surface water.
    The environmental impacts of the licensee's requested action were 
evaluated by reviewing the results of MDNR's dose assessments. Those 
assessments assume that the radiological contaminants remain within the 
waste cell and the surfaces of the building and the concrete pad do not 
exceed the derived concentration guideline levels (DCGLs). The licensee 
used computer codes RESRAD and DandD to demonstrate that doses from 
residual radioactivity did not exceed the regulatory limit (25 mrem/
yr). RESRAD and DandD used both probabilistic and deterministic 
procedures for each source term. Since the site will remain a 
controlled landfill, the most realistic use for the land is infrequent 
hunting and/or fishing.
    Therefore, composite recreational scenario parameters were used by 
RESRAD to calculate potential on-site doses. The DandD code used all 
but one default parameters to calculate on-site dose. The ``time in the 
building'' parameter was adjusted, however, to more realistically 
describe the potential exposure from the surface radioactivity on the 
building and the concrete pad. The NRC staff performed independent 
analyses of the licensee's dose assessments and was in agreement with 
MDNR's methods and results.
    For the residual radioactivity in the waste cell, the licensee 
assumed that the activity of thorium in the slag was its specific 
activity and used that activity to generate a dose for the composite 
recreational use scenario. Even with this very conservative estimate of 
thorium activity, the estimated potential dose was much less than 25 
mrem/yr and no DCGLs were reported for the waste cell.
    For the residual radioactivity on the clay cap, the licensee 
calculated the dose to a recreational user to be much less than 25 
mrem/yr. Although there is no evidence that the clay cap is 
contaminated, the licensee developed gross DCGLs for the clay cap. The 
gross DCGLs are directly related to the activity of Th-232, a surrogate 
for the mixture of radionuclides present in the surface contamination. 
MDNR used the composite recreational scenario to calculate gross DCGLs, 
even though, MDNR believes that the likelihood of the presence of 
thorium contaminated materials on the clay cover is extremely low.
    For contamination on the surfaces of the building and the concrete 
pad, the licensee calculated the dose to the average member of the 
critical group to be much less than 25 mrem/yr. Although there is no 
evidence that the surfaces of the building and the concrete pad are 
contaminated, the licensee developed a gross DCGLs for those surfaces. 
The licensee developed the gross DCGL based upon a light-industrial 
building use scenario assuming a person spent limited time in the 
building. Again, NRC staffs' independent analyses of the licensee's 
dose assessments was in agreement with MDNR's.
    The NRC staff evaluated the potential radiological exposure to an 
offsite receptor resulting from groundwater seepage through the slurry 
walls. This potential radiological exposure is very low due to the 
following reasons:
    1. Any seepage of radiological contaminated groundwater through the 
slurry walls will be dispersed and diluted as the groundwater slowly 
travels to Saginaw Bay of Lake Huron.
    2. The travel time for groundwater to reach Saginaw Bay from the 
site is long (several thousand years) because of the distance (2.24 
kilometers) between the two locations and because of the low hydraulic 
gradient (0.0002 ft/ft) of the water table.
    3. Thorium's solubility in groundwater is very low (Appendix I, 
MDNR, 2004).
    4. The concentration of the radiological contaminated groundwater 
will become highly diluted if it is discharged into the much larger 
surface water volume of Saginaw Bay.
    5. There are no receptors along the groundwater pathway between the 
site and Saginaw Bay.
    The NRC staff also evaluated whether there would be any adverse 
radiological consequences from the operation of the LCTS and a 
hypothetical leak from the LCTS. Based on the following consideration, 
the staff concluded that there would be no adverse consequences. MDNR 
collected samples of leachate to determine if thorium in the slag had 
migrated into the leachate. The sampling results provided evidence that 
the slag was highly insoluble and would not readily migrate within the 
cell. In addition, there is no evidence that the liquid level within 
the cell would rise to the point that the LCTS would need to be 
operated to reduce it. Additionally, to receive any measurable dose, an 
individual would have to be directly exposed to leachate that had 
leaked from the LCTS during operation. The probability of a 
hypothetical leak of contaminated liquid from the operation of the LCTS 
in sufficient quantities to result in measurable dose to an average 
member of the critical group is very low. Thus, consideration of 
possible adverse radiological consequences from leaving the LCTS in 
place were determined not to be necessary.
    The revised DP provides that the radiological contaminants within 
the waste cell would remain in place and the building and the concrete 
pad would be decontaminated, if necessary, to meet the DCGLs. The total 
dose for the site from the radiological material in the waste cell and 
the surface contamination on the clay cap and the surfaces of the 
building and concrete pad will not exceed 25mrem/yr.
    The NRC staff reviewed the Environmental Impacts of the licensee's 
requested action to leaving the site ``as is'' and release it for 
unrestricted use (Alternative 3). Based on the staff's review of the 
DP, the staff determined that the radiological environmental impacts 
associated with the licensee's proposed action are bounded by the 
impacts evaluated in NUREG-1496, ``Generic Environmental Impact 
Statement of Rulemaking on Radiological Criteria for License 
Termination of NRC-Licensed Nuclear Facilities.''

Agencies and Persons Consulted

    This Environmental Assessment was prepared entirely by the NRC 
staff. The Michigan State Historic Preservation Office and the U. S. 
Fish and Wildlife Service were contacted regarding this action and 
neither had concerns regarding this licensing action. No remedial 
actions are planned for the site, therefore, the release of the MDNR 
site for unrestricted use would not affect historical or cultural 
resources, nor will it affect threatened or endangered species. No 
other sources of information were used beyond those referenced in this 
    NRC provided a draft of its Environmental Assessment to the State 
of Michigan Department of Environmental Quality (MDEQ) for its review. 
MDEQ agreed with the conclusions in the EA.

Conclusions and Finding of No Significant Impact

    Based on its review, the NRC staff concludes that the proposed 
action complies with 10 CFR Part 20 Subpart E. NRC has prepared this EA 
in support of the proposed license amendment to approve the DP. On the 
basis of the EA, NRC has concluded that the environmental impacts from 

[[Page 40068]]

proposed action are expected to be insignificant and has determined 
that preparation of an Environmental Impact Statement is not needed for 
the proposed action.

Sources Used

    1. NRC License No. 06-03754-01 inspection and licensing records.
    2. MDNR, Package dated January 30, 2004, ``License Amendment for 
the Tobico Marsh State Game Site and Submission of a Revised 
Decommissioning Plan.'' [ADAMS Accession No. ML040790356]
    3. NRC, Letter dated August 27, 2004, ``NRC Request for 
Additional Information (RAI) with Regard to the Decommissioning 
Plan, Revision 1, for the Michigan Department of Natural Resources' 
Tobico Marsh State Game Area Site, Kawkawlin, Michigan.'' [ADAMS 
Accession No. ML042290619]
    4. MDNR, Letter dated December 20, 2004, Response to RAI--August 
27, 2004, Tobico Marsh State Game Area Site and Submission of 
Additional Information Relative to the Decommissioning Plan Docket 
No. 40-9015, License SUC-1581. [ADAMS Accession No. ML050100126]
    5. NUREG-1748, Environmental Review Guidance for Licensing 
Actions Associated with NMSS Programs, August 2003.
    6. NUREG-1757, Volume 1, Rev 1, Consolidated NMSS 
Decommissioning Guidance, Decommissioning Process for Materials 
Licensees, Final Report, September 2003.
    7. Title 10 Code of Federal Regulations, Part 20, Subpart E, 
``Radiological Criteria for License Termination.''
    8. Title 10, Code of Federal Regulations, Part 51, 
``Environmental Protection Regulations for Domestic Licensing and 
Related Regulatory Functions.''
    9. MDEQ, E-Mail, ``MDNR Draft EA dated 3/24/05.''
    10. NUREG-1496, Generic Environmental Impact Statement of 
Rulemaking on Radiological Criteria for License Termination of NRC-
Licensed Nuclear Facilities, July 1997.

III. Further Information

    Documents related to this action, including the application for 
amendment and supporting documentation, are available electronically at 
the NRC's Electronic Reading Room at http://www.nrc.gov/reading-rm/adams.html. From this site, you can access the NRC's Agencywide 
Document Access and Management System (ADAMS), which provides text and 
image files of NRC's public documents. The ADAMS accession numbers for 
the document related to this notice are: ML042320524 for the August 26, 
1999, letter issuing the license, ML032790494 for the April 2, 2003, 
letter requesting license amendment to incorporate the DP into the 
license, ML040790356 for the January 30, 2004, letter revising the DP 
(Revision 1), and ML050100126 for the letter dated December 20, 2004, 
response to the NRC request for additional information. If you do not 
have access to ADAMS or if there are problems accessing the documents 
located in ADAMS, contact the NRC's Public Document Room (PDR) 
Reference staff at 1-800-397-4209, 301-415-4737, or by e-mail to 
[email protected].
    These documents may also be viewed electronically on the public 
computers located at the NRC's PDR, O 1 F21, One White Flint North, 
11555 Rockville Pike, Rockville, MD 20852. The PDR reproduction 
contractor will copy documents for a fee.

    Dated in Rockville, Maryland this 30th day of June, 2005.

    For the Nuclear Regulatory Commission.
Daniel M. Gillen,
Deputy Director, Office of Nuclear Material Safety and Safeguards, 
Division of Waste Management and Environmental Protection, 
Decommissioning Directorate.
[FR Doc. E5-3679 Filed 7-11-05; 8:45 am]