[Federal Register Volume 59, Number 55 (Tuesday, March 22, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-6641]
[[Page Unknown]]
[Federal Register: March 22, 1994]
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NUCLEAR REGULATORY COMMISSION
[Docket 70-925; License SNM-928]
Finding of No Significant Impact and Opportunity for a Hearing
Amendment of Special Nuclear Material; Cimarron Corp., Crescent, OK
The U. S. Nuclear Regulatory Commission is considering the
amendment of Special Nuclear Material License SNM-928 for the Cimarron
Corporation located near Crescent, Oklahoma.
Summary of the Environmental Assessment
Identification of the Proposed Action
The proposed action is an amendment of License SNM-928 to allow the
disposal of uranium-contaminated soil on the site of the Cimarron
Corporation's Uranium Plant near Crescent, Oklahoma. From 1965 to 1975,
Kerr-McGee Corporation, Cimarron Corporation's parent company, produced
uranium fuel for nuclear reactors at the Cimarron facility. The Uranium
Plant has been inactive since 1975, and Kerr-McGee is engaged in
decommissioning the Plant and neighboring facilities on the Cimarron
site. Approximately 11,000 cubic meters (400,000 cubic feet) of soil
around the Uranium Plant were contaminated with spilled uranium during
the years of operation.
As part of site decommissioning, Kerr-McGee has requested
authorization to collect the contaminated soil and dispose of it in a
burial cell on another part of the Cimarron site. The contaminated soil
that would be buried on the site contains low-enriched uranium in
concentrations between 30 and 250 picocuries of total uranium per gram
of soil (pCi/g). The soil to be buried does not contain long-lived
uranium daughters or any other radioactive isotopes at concentrations
significantly above background levels. The NRC regulation that applies
to this request is 10 CFR 20.2002 (formerly 10 CFR 20.302), Method for
Obtaining Approval of Proposed Disposal Procedures. NRC policy on
onsite disposal of uranium-contaminated soil pursuant to 10 CFR 20.302
is described in the ``Branch Technical Position on Disposal or Onsite
Storage of Thorium or Uranium Wastes from Past Operations'' (the BTP)
(46 FR 52061, October 23, 1981). The proposed disposal will conform to
Option 2 of the BTP and will constitute a principal step toward site
decommissioning and license termination.
Need for the Proposed Action
A large amount of soil around the Cimarron Uranium Plant has been
contaminated with low-enriched uranium. If the contamination is left
where it is, within 0.3 to 0.6 meters (1 to 2 feet) of the surface, it
is likely that 'people using the site in the future will be exposed to
unnecessary radiation.
While Kerr-McGee has not yet requested license termination, it is
the NRC staff's understanding that they will do so and that they plan
to request that the site be released without restrictions on its future
ownership or use. The overall condition of the Cimarron site, including
its suitability for unrestricted release, will be the subject of a
future licensing action and a separate Environmental Assessment. If
there is to be unrestricted release of the site, however, it would be
better for the present extent of uranium contamination not to be left
in the surface soil around the Uranium Plant. Whether or not the
Cimarron site is ultimately released for unrestricted use, removal of
the surface contamination will be an improvement in the condition of
the site.
Environmental Impacts of the Proposed Action
There will be minimal environmental impacts associated with the
actual moving of the contaminated soil. It will only be moved from one
part of the site to another, 400-500 meters away. The soil is mildly
radioactive and will be handled with routine health physics precautions
for the workers. Measures will be taken to minimize dust while handling
the soil, and measurements will be made to confirm that significant
quantities of uranium-bearing dust are not blown off the site. Site-
specific calculations done for the Environmental Assessment have shown
that the potential radiation dose to the nearest resident from the
earthmoving will be a cumulative committed effective dose equivalent of
no more than 0.67 mrem, which is much smaller than the annual dose due
to natural background radiation, and less than the 25 mrem per year
used by the U.S. Environmental Protection Agency as the dose limit for
maximally exposed individuals in unrestricted areas around uranium fuel
cycle facilities (40 CFR part 190).
Once the soil is buried, potential environmental impacts could
result from leaching of the uranium from the disposal cell, erosion of
the burial site cover, or human activities on the site that disturb the
burial. Each of these possibilities is considered in detail in the
Environmental Assessment that supports this Finding.
The buried contaminated soil will be covered with at least 1.2
meters (4 feet) of clean soil. The cover will protect site users from
direct exposure to radiation and will prevent direct inhalation of
resuspended contaminated soil and the uptake of uranium by crops or
other vegetation. The susceptibility of the burial site cover to
erosion has been closely evaluated. The cover will not be prone to
gullying or sheetwash erosion because of its location on a ridge top
and because the contaminated soil will be placed in a trench excavated
from relatively solid rock.
The prospect that uranium will leach into the local groundwater has
also been carefully reviewed. The Environmental Assessment contains
details on the conceptual model used to analyze the proposed burial
cell and its surroundings, and a computer simulation of the movement of
water from the burial cell to the nearest drinking water aquifer. The
top of the nearest aquifer is 9 meters (30 feet) below ground, about 6
meters (20 feet) below the bottom of the buried uranium. Much of the
uranium that will be buried is not soluble and will not be transported
away from the burial cell by groundwater in any case. The soluble
portion of the uranium will move slowly down toward the aquifer as
rainwater infiltrates the burial cell. Due to interactions with the
soil, the dissolved uranium will move much more slowly than the
groundwater itself. After 1,000 years, a commonly used cutoff time, the
uranium concentration in the groundwater would still be at natural
background levels. (Background uranium concentrations in the local
shallow groundwater are mostly between 1 and 2 pCi/L.)
The possibility of future human intrusion into the buried soil
cannot be totally excluded. If a future site owner were to remove the
1.2 meters (4 feet) of soil cover or regrade the site generally or dig
into the buried soil in the course of construction activities, the
value of the cover would be at least partly eliminated. Calculations
done by the NRC staff to support contaminated soil burials such as this
one have shown that a physical intrusion into buried contaminated soil
would not result in an excessively high dose to the intruder as long as
the concentration of uranium in the soil is kept below the limits
discussed in the Environmental Assessment. Based upon the average
concentration of uranium that the licensee expects to dispose of in the
burial cell, the total effective dose equivalent to an intruder is
expected to be under 7 millirem. In order to have the potential for
exposures as low as reasonably achievable and to reduce the likelihood
of intrusion, the NRC staff will require that notice be placed in the
land title recording the exact location and amount of buried
contaminated soil, and that cairns be placed to mark the corners of the
burial area. This notification is not to be considered a restriction on
the sale or future use of the site.
Conclusion
There will be no significant environmental impact or adverse effect
on human health or safety from the permanent disposal of between 11,000
and 14,000 cubic meters (400,000 and 500,000 cubic feet) of uranium-
contaminated soil on the Crescent, Oklahoma, site. The NRC staff
recommends that Kerr-McGee Corporation be authorized to conduct this
burial under the conditions and restrictions described in the
Environmental Assessment and summarized below. The major conditions and
restrictions are: 1. That Kerr-McGee determines that all buried soil
conforms to the uranium concentration and lung-fluid solubility limits
defined in the Environmental Assessment (in abridged form, that the
concentration of uranium be between 30 and 100 pCi/g if the uranium is
soluble in lung-fluid, with a concentration as high as 250 pCi/g
allowed if the uranium can be shown to be completely insoluble in lung-
fluid using a method approved by the NRC); and
2. That Kerr-McGee takes the steps described in the Environmental
Assessment (such as placing a water-impermeable barrier across the
vehicle access trench entering the disposal cell) to improve the
drainage characteristics of the burial cell.
It will also be required that the title to the Cimarron property be
amended to explain that low-level radioactive waste is buried on the
site, to show exactly where the burial cell is located, and to document
the quantity and identity of the buried waste.
Alternatives to the Proposed Action
Leaving the soil where it is would increase the risk of unnecessary
radiation exposure to future users of the site if the site is
eventually released for unrestricted use. Kerr-McGee has not yet
applied for termination of the license, but they have expressed their
intention of doing so and have declared that unrestricted release of
the site is their objective. The majority of the contamination under
consideration is in the top 0.3 to 0.6 meters (1 to 2 feet) of soil
around the Uranium Plant.
If left there, it would be more prone to disturbance by future
users of the site than if it were buried under 1.2 meters (4 feet) of
clean cover. In areas cleaned to 30 pCi/g or less, it is estimated
using the BTP scenario that the average radiation exposure from the
enriched uranium will be reduced by more than half.
Transporting the contaminated soil away from the Cimarron site is a
possible alternative, but would be very expensive in light of the large
volume of soil. As explained in detail in the Environmental Assessment,
shipment of the soil to a commercial low-level waste burial ground
would cost approximately one hundred times as much as onsite disposal
(around $10,000,000 versus $100,000). As stated by NRC's ``Action Plan
to Ensure Timely Cleanup of Site Decommissioning Management Plan
Sites'' (57 FR 13389; April 16, 1992), soil contaminated with low
concentrations of uranium can be disposed of by onsite burial and that
such burial does not preclude ultimate release of the site for
unrestricted use. The licensee is required to show that the uranium
concentration in the soil falls into a specific range and that onsite
disposal is preferable to other options. A cost differential of one
hundred times is a strong basis for the licensee to consider onsite
burial preferable to shipment to a commercial burial ground.
Agencies and Persons Consulted
The NRC staff has consulted with the Oklahoma State Department of
Health, the agency responsible for radiological safety issues in the
state of Oklahoma. The Oklahoma State Department of Health wrote the
portion of the Environmental Assessment dealing with the potential
nonradiological hazards of the proposed disposal.
Oak Ridge Associated Universities has provided support to the NRC
on topics related to the validation of Kerr-McGee's radiological survey
methods.
Finding of No Significant Impact
The NRC staff has prepared an Environmental Assessment for the
proposed amendment of Special Nuclear Material License SNM-928. On the
basis of this assessment, the NRC staff has concluded that the
environmental impacts that could 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 Environmental Assessment and other documents related to this
proposed action are available for public inspection and copying at the
NRC Public Document Room located at the Gelman Building, 2120 L Street,
NW., Washington, DC.
Opportunity for a Hearing
Any person whose interest may be affected by the issuance of this
amendment may file a request for a hearing. Any request for hearing
must be filed with the Office of the Secretary, U.S. Nuclear Regulatory
Commission, Washington, DC 20555, within 30 days of the publication of
this notice in the Federal Register; be served on the NRC staff
(Executive Director for Operations, One White Flint North, 11555
Rockville Pike, Rockville, MD 20852); on the licensee (Cimarron
Corporation, P.O. Box 25861, Kerr-McGee Center, Oklahoma City, OK
73124); and must comply with the requirements for requesting a hearing
set forth in the Commission's regulation, 10 CFR part 2, subpart L,
``Informal Hearing Procedures for Adjudications in Materials Licensing
Proceedings.''
These requirements, which the requestor must address in detail,
are:
1. The interest of the requestor in the proceeding;
2. How that interest may be affected by the results of the
proceeding, including the reasons why the requestor should be permitted
a hearing;
3. The requestor's areas of concern about the licensing activity
that is the subject matter of the proceeding; and
4. The circumstances establishing that the request for hearing is
timely, that is, filed within 30 days of the date of this notice.
In addressing how the requestor's interest may be affected by the
proceeding, the request should describe the nature of the requestor's
right under the Atomic Energy Act of 1954, as amended, to be made a
party to the proceeding; the nature and extent of the requestor's
property, financial, or other (i.e., health, safety) interest in the
proceeding; and the possible effect of any order that may be entered in
the proceeding upon the requestor's interest.
Dated at Rockville, Maryland, this 15th day of March 1994.
For the Nuclear Regulatory Commission.
Robert C. Pierson,
Chief, Licensing Branch, Division of Fuel Cycle Safety and Safeguards,
Office of Nuclear Material Safety and Safeguards.
[FR Doc. 94-6641 Filed 3-21-94; 8:45 am]
BILLING CODE 7590-01-M
