[Federal Register Volume 75, Number 123 (Monday, June 28, 2010)]
[Notices]
[Pages 36700-36701]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-15626]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-289; NRC-2010-0221]
Exelon Generation Company, LLC; Three Mile Island Nuclear
Station, Unit 1; Environmental Assessment and Finding of No Significant
Impact
The U.S. Nuclear Regulatory Commission (NRC) is considering
issuance of an exemption from Title 10 of the Code of Federal
Regulations (10 CFR) part 50, Appendix R, Section III.G, ``Fire
Protection of Safe Shutdown Capability,'' for the use of an operator
manual action in lieu of the requirements specified in Appendix R,
Section III.G.2, for Renewed Facility Operating License No. DPR-50,
issued to Exelon Generation Company, LLC (the licensee), for operation
of Three Mile Island Nuclear Station, Unit 1 (TMI-1), located in
Dauphin County, Pennsylvania. Therefore, as required by 10 CFR 51.21,
the NRC performed an environmental assessment. Based on the results of
the environmental assessment, the NRC is issuing a finding of no
significant impact.
Environmental Assessment
Identification of the Proposed Action
The proposed action would grant an exemption to the requirements of
10 CFR part 50, appendix R, section III.G.2, based on an operator
manual action contained in the licensee's Fire Hazards Analysis Report
(FHAR), which is part of the TMI-1 Updated Final Safety Analysis
Report. The licensee's FHAR requires that the identified operator
manual action be performed outside of the control room to achieve safe
shutdown following a fire in Fire Zone AB-FZ-6 (Demineralizer and ``A''
Motor Control Center Area). The licensee states that the manual action
was subjected to a manual action feasibility review for TMI-1 that
determined that the manual action is feasible and can be reliably
performed.
The proposed action is in accordance with the licensee's
application dated March 3, 2009, as supplemented by letter dated March
15, 2010 (Agencywide Documents Access and Management System (ADAMS)
Accession Nos. ML090630134 and ML100750093, respectively).
The Need for the Proposed Action
The proposed exemption modifies an existing exemption which was
granted by letter dated December 30, 1986 (ADAMS Accession No.
8701090216). The proposed modified exemption involves an operator
manual action to open the supply breaker for the motor control center
which powers valve MU-V-36, and then locally ensure that MU-V-36 is
open. The proposed exemption specifies a reduced (40 minute) time frame
to perform these actions as compared to one hour in the original
exemption. The reduced timeframe is being specified because recent
plant testing has shown that the backup air supply to seal injection
valve MU-V-20 would only allow the valve to stay open for approximately
75 minutes under the postulated conditions. With MU-V-20 closed,
ensuring that valve MU-V-36 is open provides a minimum recirculation
flow path for the makeup pumps. By maintaining a minimum recirculation
flow path, the makeup pumps will not be susceptible to pump damage from
operation in a ``deadheaded'' condition. The recent test results on MU-
V-20 necessitate a time reduction for the specified operator manual
action to maintain sufficient time margin in order to prevent potential
operation of the makeup pumps in a ``deadheaded'' condition.
The proposed exemption is necessary because the crediting of
operator manual actions to achieve and maintain hot shutdown is not
addressed in 10 CFR part 50 appendix R, section III.G.2, and an
exemption is therefore required in accordance with 10 CFR 50.12.
Environmental Impacts of the Proposed Action
The NRC has completed its evaluation for the proposed action and
concludes that the operator manual action addressed in the application
is feasible and can be reliably performed. Further, the NRC concludes
that there is sufficient defense-in-depth within the fire protection
program to ensure that a redundant train necessary to achieve and
maintain safe shutdown of the plant will remain free of fire damage in
the event of a fire in the postulated area.
The details of the staff's safety evaluation will be provided in
the exemption that will be issued as part of the letter to the licensee
approving the exemption to 10 CFR part 50, appendix R, section III.G.2.
As described in the staff's safety evaluation that will be provided
to the licensee with the exemption, the proposed action will not
significantly increase the probability or consequences of accidents.
Since the change being evaluated in this assessment involves only a
change to the time allotted to accomplish a previously approved
operator manual action, no changes are being made in the types of
effluents that may be released off-site. Likewise, there is no
significant increase in the amount of any effluent released off-site
because the time change has no impact on any effluent release path or
duration. There is no significant increase in occupational radiation
exposure because, as described in the staff's safety evaluation, the
areas of consideration for the operator manual action are expected to
have dose rates of less than 10 millirem per hour. Since there is no
impact to any radiological effluents or in-plant dose rates from the
operator manual action time change, there is no impact to public
radiation exposure. Therefore, there are no significant radiological
environmental impacts associated with the proposed action.
[[Page 36701]]
The operator manual action described in the proposed exemption
involves ensuring recirculation flow within the plant makeup system
such that it continues to operate as designed. It does not have any
impact to water usage or impact plant systems that contribute to non-
radiological effluent releases from the plant. Therefore, the proposed
action does not result in changes to land use or water use, or result
in changes to the quality or quantity of non-radiological effluents.
Likewise, no changes to the National Pollution Discharge Elimination
System permit are needed and no effects on the aquatic or terrestrial
habitat in the vicinity or the plant, or to threatened, endangered, or
protected species under the Endangered Species Act, or impacts to
essential fish habitat covered by the Magnuson-Stevens Act are
expected. For the same reasons, there are no impacts to the air or
ambient air quality, nor are there impacts to historical and cultural
resources. With no impact of the proposed exemption beyond the site
boundary, there would be no noticeable effect on socioeconomic
conditions in the region. Therefore, no changes or different types of
non-radiological environmental impacts are expected as a result of the
proposed action.
Accordingly, the NRC concludes that there are no significant
environmental impacts associated with the proposed action.
Environmental Impacts of the Alternatives to the Proposed Action
As an alternative to the proposed action, the NRC staff considered
denial of the proposed action (i.e., the ``no-action'' alternative).
Denial of the application would not result in a decrease in current
environmental impacts. If the proposed action was denied, the licensee
would have to perform plant modifications and/or reroute or wrap cables
to achieve compliance. The environmental impacts of the proposed action
and the alternative action are similar.
Alternative Use of Resources
The action does not involve the use of any different resources than
those previously considered in the Final Environmental Statement
Related to the Operation of Three Mile Island Nuclear Station, Units 1
and 2, NUREG-0552, dated December 1972, and Generic Environmental
Impact Statement for License Renewal of Nuclear Plants (NUREG-1437,
Supplement 37), dated June 2009.
Agencies and Persons Consulted
In accordance with its stated policy, on March 29, 2010, the NRC
staff consulted with the Pennsylvania State official, Dennis Dyckman,
of the Pennsylvania State Department of Environmental Protection,
regarding the environmental impact of the proposed action. The State
official had no comments.
Finding of No Significant Impact
On the basis of the environmental assessment, the NRC concludes
that the proposed action will not have a significant effect on the
quality of the human environment. Accordingly, the NRC has determined
not to prepare an environmental impact statement for the proposed
action.
For further details with respect to the proposed action, see the
licensee's letter dated March 3, 2009, as supplemented on March 15,
2010 (ADAMS Accession Nos. ML090630134 and ML100750093, respectively).
Documents may be examined, and/or copied for a fee, at the NRC's Public
Document Room (PDR), located at One White Flint North, Room O1 F21,
11555 Rockville Pike (first floor), Rockville, Maryland. Publicly
available records will be accessible electronically from the ADAMS
Public Electronic Reading Room on the Internet at the NRC Web site,
http://www.nrc.gov/reading-rm/adams.html. Persons who do not have
access to ADAMS or who encounter problems in accessing the documents
located in ADAMS should contact the NRC PDR Reference staff by
telephone at 1-800-397-4209 or 301-415-4737, or send an e-mail to
[email protected].
Dated at Rockville, Maryland, this 15th day of June 2010.
For the Nuclear Regulatory Commission.
Peter Bamford,
Project Manager, Plant Licensing Branch I-2, Division of Operating
Reactor Licensing, Office of Nuclear Reactor Regulation.
[FR Doc. 2010-15626 Filed 6-25-10; 8:45 am]
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