[Federal Register Volume 64, Number 208 (Thursday, October 28, 1999)]
[Notices]
[Pages 58106-58107]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-28228]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-423]
Northeast Nuclear Energy Company, et al.; Millstone Nuclear Power
Station, Unit No. 3, Environmental Assessment and Finding of No
Significant Impact
The U.S. Nuclear Regulatory Commission (the Commission) is
considering issuance of an amendment to Facility Operating License No.
NPF-49, issued to Northeast Nuclear Energy Company (NNECO or the
licensee), for operation of the Millstone Nuclear Power Station, Unit
No. 3 (MP3), located in New London County, Connecticut.
Environmental Assessment
Identification of the Proposed Action
The proposed action would revise the analysis for the design basis
loss-of-coolant accident (LOCA) to include the dose contribution from a
previously unevaluated radioactivity release pathway to the
environment. The licensee identified a potential pathway for post
accident back-leakage of highly radioactive containment sump water from
the Recirculation Spray System (RSS) to the Refueling Water Storage
Tank (RWST). Since the RWST is
[[Page 58107]]
vented to the atmosphere, this pathway could contribute to an
inadvertent release of radioactivity not previously accounted for in
offsite dose calculations. Previously, the licensee had assumed no
radiological consequences due to back-leakage. This revision adds the
dose from RWST back-leakage to the LOCA analysis, as documented in the
Final Safety Analysis Report (FSAR).
The proposed action is in accordance with the licensee's
application for amendment dated May 7, 1998, as supplemented by letter
dated January 22, 1999.
The Need for the Proposed Action
Pursuant to 10 CFR 50.59 licensees are required to obtain prior NRC
approval of changes to the facility that involve an unreviewed safety
question. The licensee determined that the back-leakage from RSS to the
RWST involves an unreviewed safety question. Therefore, the licensee
was required to obtain prior NRC approval for changes to the LOCA
analysis and the FSAR to incorporate the dose consequences of the
potential for back-leakage from the RSS to the RWST that had not been
previously accounted for in offsite dose calculations.
Environmental Impacts of the Proposed Action
The NRC has completed its evaluation of the proposed action and
concluded that the contribution to the LOCA dose to the thyroid (most
limiting organ) from the RWST back-leakage as calculated by the
licensee is small (2.1 rem at the Low Population Zone (LPZ) and 0.9 rem
at the Control Room). When added to the licensee's previously
calculated doses, the affected LOCA doses to the thyroid are 11 rem at
the LPZ and 12 rem at the Control Room. The increase are small when
compared to, and these results continue to meet the acceptance criteria
in, 10 CFR Part 100 for the offsite dose consequences and in 10 CFR
Part 50, Appendix A, General Design Criterion (GDC) 19 for the control
room. All other offsite and control room doses were unchanged. On this
basis the staff determined there is no significant radiological
environmental impact.
The proposed action will not increase the probability or
consequences of accidents, no changes are being made in the types of
any effluents that may be released off site, and there is no
significant increase in occupational or public radiation exposure.
Therefore, there are no significant radiological environmental impacts
associated with the proposed action.
With regard to potential non-radiological impacts, the proposed
action does not involve any historic sites. It does not affect non-
radiological plant effluents and has no other environmental impact.
Therefore, there are no significant non-radiological environmental
impacts associated with the proposed action.
Accordingly, the NRC concludes that there are no significant
environmental impacts associated with the proposed action.
Alternatives to the Proposed Action
As an alternative to the proposed action the staff considered
requiring the licensee to maintain zero back-leakage from the RSS to
the RWST. Since this is the original analysis condition, this
alternative is the same as the staff denying the proposed action (i.e.,
the ``no-action'' alternative). Zero back-leakage cannot be ensured for
the valves between the RSS and the RWST; therefore, this alternative is
impractical. Denial of the proposed action would result in no change in
current environmental impacts. The environmental impacts of the
proposed action and the alternative action are similar.
Alternative Use of Resources
This action does not involve the use of any resources not
previously considered in the ``Final Environmental Statement Related to
the Operation of Millstone Nuclear Power Station, Unit No. 3,'' dated
December 1984 (NUREG-1064).
Agencies and Persons Consulted
In accordance with its stated policy, on September 23, 1999, the
staff consulted with the Connecticut State official, Mr. Fred
Scheuritzel of the 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 May 7, 1998, as supplemented by letter dated
January 22, 1999, which are available for public inspection at the
Commission's Public Document Room, The Gelman Building, 2120 L Street,
NW., Washington, DC, and at the local public document rooms located at
the Learning Resources Center, Three Rivers Community-Technical
College, 574 New London Turnpike, Norwich, Connecticut, and the
Waterford Library, 49 Rope Ferry Road, Waterford, Connecticut.
Dated at Rockville, Maryland, this 22nd day of October 1999.
For the Nuclear Regulatory Commission.
John A. Nakoski, Sr.,
Project Manager, Section 2, Project Directorate I, Division of
Licensing Project Management, Office of Nuclear Reactor Regulation.
[FR Doc. 99-28228 Filed 10-27-99; 8:45 am]
BILLING CODE 7590-01-P
