[Federal Register: February 9, 2001 (Volume 66, Number 28)]
[Notices]
[Page 9729-9730]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09fe01-83]
[[Page 9729]]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-317 and 50-318]
Calvert Cliffs Nuclear Power Plant, Inc.; Calvert Cliffs Nuclear
Power Plant, Unit Nos. 1 and 2; Environmental Assessment and Finding of
No Significant Impact
The U.S. Nuclear Regulatory Commission (NRC) is considering
issuance of an exemption from certain requirements of Appendix G to
Part 50 of Title 10 of the Code of Federal Regulations (10 CFR Part 50)
for Renewed Facility Operating License Nos. DPR-53 and DPR-69, issued
to Calvert Cliffs Nuclear Power Plant, Inc. (CCNPPI or the licensee)
for operation of the Calvert Cliffs Nuclear Power Plant, Unit Nos. 1
and 2 (CCNPP), located in Calvert County, Maryland.
Environmental Assessment
Identification of the Proposed Action
Appendix G to Part 50 of Title 10 of the Code of Federal
Regulations (10 CFR Part 50) requires that pressure-temperature (P-T)
limits be established for reactor pressure vessels (RPVs) during normal
operating and hydrostatic or leak rate testing conditions.
Specifically, 10 CFR Part 50, Appendix G, states, ``The appropriate
requirements on both the pressure-temperature limits and the minimum
permissible temperature must be met for all conditions.'' Appendix G of
10 CFR Part 50 goes on to specify that the requirements for these
limits are the American Society of Mechanical Engineers Boiler and
Pressure Vessel Code (ASME Code), Section XI, Appendix G, limits.
The licensee requested in its submittal dated September 14, 2000,
that the staff exempt CCNPP from the specific requirement of Appendix G
to 10 CFR Part 50 that the P-T limits meet the safety margin
requirements specified in the ASME Code, Section XI, Appendix G and
instead use an alternate fracture toughness curve shown in the ASME
Code, Section XI, Appendix A as permitted by ASME Code Case N-640. Code
Case N-640 permits the use of an alternate reference fracture toughness
(KIC fracture toughness curve instead of K1a
fracture toughness curve) for reactor vessel materials in determining
the P-T limits. Since the KIC fracture toughness curve shown
in ASME Code, Section XI, Appendix A, Figure A-2200-1 (the
KIC fracture toughness curve) provides greater allowable
fracture toughness than the corresponding K1a fracture
toughness curve of ASME Code, Section XI, Appendix G, Figure G-2210-01,
using Code Case N-640 for establishing the P-T limits would be less
conservative than the methodology currently endorsed by 10 CFR Part 50,
Appendix G, and therefore, an exemption to apply the Code Case would be
required.
The proposed action is in accordance with the licensee's
application for exemption dated September 14, 2000.
The Need for the Proposed Action
Because the RCS P-T operating window is defined by the P-T
operating and test limit curves developed in accordance with the ASME
Code, Section XI, Appendix G, procedure, continued operation of CCNPP
with the present P-T curves without the relief provided by ASME Code
Case N-640 would unnecessarily require the RPVs to maintain a
temperature exceeding 212 deg.F in a limited operating window during
the pressure test. Consequently, steam vapor hazards would continue to
be one of the safety concerns for personnel conducting inspections in
primary containment. Implementation of the proposed P-T curves, as
allowed by ASME Code Case N-640, does not significantly reduce the
margin of safety and would eliminate steam vapor hazards by allowing
inspections in primary containment to be conducted at a lower coolant
temperature.
10 CFR 50.60(b) allows proposed alternatives to the requirements of
Appendix G to be used when an exemption is granted by the Commission
under 10 CFR 50.12.
In the request for exemption to use Code Case N-640, the staff has
determined that, pursuant to 10 CFR 50.12(a)(2)(ii), the underlying
purpose of the regulation will continue to be served by the
implementation of this Code Case.
Environmental Impacts of the Proposed Action
The NRC has completed its evaluation of the proposed action and
concludes that the exemption described above would provide an adequate
margin of safety against brittle failure of the CCNPP RPVs.
The proposed action will not significantly increase the probability
or consequences of accidents, no changes are being made in the types of
any effluents that may be released offsite, 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 nonradiological environmental impacts, the
proposed action does not involve any historic sites. It does not affect
nonradiological plant effluents and has no other environmental impact.
Therefore, there are no significant nonradiological 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
denial of the proposed action (i.e., the ``no-action'' alternative).
Denial of the application 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 for the
Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2, dated April
1984.
Agencies and Persons Consulted
In accordance with its stated policy, on January 31, 2001, the
staff consulted with the Maryland State official, R. McLean of the
Maryland Department of Natural Resources, regarding the environmental
impact of the proposed action. The State official had no comments.
Findings 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 September 14, 2000, which is available for
public inspection at the NRC Public Document Room, located at One White
Flint North, 11555 Rockville Pike (first floor), Rockville, Maryland.
Publicly available records will be accessible electronically from the
ADAMS Public Library component on the NRC Web site, http://www.nrc.gov
(the Electronic Reading Room).
Dated at Rockville, Maryland, this 2nd day of February 2001.
[[Page 9730]]
For the Nuclear Regulatory Commission.
Donna Skay,
Project Manager, Section 1, Project Directorate I, Division of
Licensing Project Management, Office of Nuclear Reactor Regulation.
[FR Doc. 01-3366 Filed 2-8-01; 8:45 am]
BILLING CODE 7590-01-U