[Federal Register Volume 60, Number 41 (Thursday, March 2, 1995)]
[Notices]
[Pages 11689-11692]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-5137]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-410]
Niagara Mohawk Power Corporation; 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-69, issued to Niagara Mohawk Power Corporation (the licensee), for
operation of the Nine Mile Point Nuclear Station, Unit 2 (NMP-2),
located in Oswego County, New York.
Environmental Assessment
Identification of the Proposed Action
This Environmental Assessment has been prepared to address
potential environmental issues related to the licensee's application to
amend the NMP-2 operating license dated July 22, 1993, as supplemented
January 9, 1995. The proposed amendment would increase the licensed
core thermal power from 3323 MWt to 3467 MWt, which represents an
approximate increase of 4.3% over the current licensed power level.
This request is in accordance with the generic boiling water reactor
(BWR) power uprate program established by the General Electric Company
(GE) and approved by the U.S. Nuclear Regulatory Commission (NRC) staff
in a letter from W. Russell, NRC, to P. Marriotte, GE, dated September
30, 1991. Implementation of the proposed power uprate at NMP-2 will
result in an increase of steam flow to approximately 105% of the
current operating limit, but will require no changes to the basic fuel
design. Core reload design and fuel parameters will be modified as
power uprate is implemented to support the current 18-month reload
cycle. The higher power level will be achieved by expanding the power/
flow map and by increasing, slightly, reactor vessel dome pressure. The
maximum recirculation flow limit will not be increased over the
preuprate value. Implementation of this proposed power uprate will
require minor modifications, such as, resetting of the low set safety
relief setpoints, as well as the calibration of plant instrumentation
to reflect the uprated power. Plant operating, emergency, and other
procedure changes will be made where necessary to support uprated
operation.
The proposed action involves NRC issuance of a license amendment to
uprate the authorized power level by changing the operating license,
including Appendix A of the license (Technical Specifications). No
change is needed to Appendix B of the license (Environmental Protection
Plan--Nonradiological).
The Need for the Proposed Action
The proposed action would authorize the licensee to increase the
potential electrical output of NMP2 by approximately 45 megawatts and
thus would provide additional electrical power to service domestic and
commercial areas of the licensee's grid.
Environmental Impacts of the Proposed Action
The ``Final Environmental Statement (FES) related to operation of
Nine Mile Point Nuclear Station, Unit No. 2'' was issued May 1985
(NUREG-1085). By letter of July 22, 1993, the licensee submitted the
proposed amendment to implement power uprate for NMP2, which is the
subject of this environmental assessment. Section 11.3 of the NMP2
power uprate licensing topical report (GE report NEDC-31994P, Revision
1) which was submitted as Enclosure 3 to NMPC's July 22, 1993,
submittal, provided an environmental assessment of the proposed power
uprate. Some environmental effects will remain the same, while power
uprate may nominally increase others. Actual effects are at worst
proportional to the approximately 5% increase in turbine steam flow.
Increased core flow has no discernable effect on the environmental
assessment.
The licensee provided information regarding the nonradiological and
radiological environmental effects of the proposed action in the July
22, 1993, application and in its supplemental information dated January
9, 1995. The NRC staff has reviewed the potential nonradiological and
radiological effects of the proposed action on the environment as
described below. [[Page 11690]]
Nonradiological Environmental Assessment
Power uprate will not change the method of generating electricity
nor the method of handling any influents from minor effluents to the
environment. Therefore, no new or different types of environmental
impacts are expected.
The NRC staff reviewed the nonradiological impact of operation at
uprated power levels on influents from and effluents to Lake Ontario.
NMP-2 utilizes a closed-loop circulating water system and a natural
draft cooling tower for dissipating heat from the main turbine
condenser. Other equipment is cooled by the service water system. The
cooling tower and service water system are operated in accordance with
the requirements of the State Pollutant Discharge Elimination System
(SPDES) Permit No. NY-000-1015, which was issued by the New York State
Department of Environmental Conservation (NYSDEC) on October 26, 1994,
and became effective on December 1, 1994. It expires on December 1,
1999. This new discharge permit was issued by New York State since the
previous permit had expired.
The withdrawal of cooling water from Lake Ontario is expected to
increase slightly due to the increased heat loads. Emergency system
flows are expected to remain generally unchanged. Increased heat loads
are expected for nonsafety related loads such as the main generator
stator coolers, hydrogen coolers, and exciter coolers. These systems,
as well as other systems (e.g., RHR heat exchangers, emergency diesel
generator coolers, and spent fuel pool heat exchangers) noted in
Section 6 of the July 22, 1993, submittal are expected to require
additional cooling and an increase in flowrate. The increase in water
intake to the cooling tower is due to increased evaporation in the
cooling tower. The increase in flowrate is expected to be small and
within a nominal 5 percent increase. Conservatively assuming a 5
percent increase in the withdrawal rate, the intake approach flowrate
velocity is expected to increase from 0.5 fps to 0.53 fps. Observations
by the licensee have shown fish impingement to be very low and in most
cases nonexistent. The NYSDEC has evaluated the potential effects of
the current intake flowrate and has concluded that no special aquatic
studies are required to assess the biological impact. No aquatic
studies were included in the licensee's new SPDES discharge permit
which was effective December 1, 1994. The licensee has stated that
because the current intake flowrates are low and the aquatic impacts of
withdrawal are minimal, an increase of 5 percent is not expected to
result in a significant impact, if any impact at all. The NRC staff
agrees with the licensee's assessment and does not expect any
significant impact due to the 5 percent increase in withdrawal
flowrate.
The licensee does not expect an increase in the cooling tower
blowdown. The cooling tower blowdown rate is controlled by total copper
concentration in the circulating water system and the economic use of
water treatment chemicals. The current blowdown rate is approximately
40 percent of the designed rate and is restricted to ensure compliance
with the total copper concentration limitation imposed by the SPDES
permit and by economic use of water treatment chemicals. The licensee
has stated that if the blowdown rate was increased by 5-10 percent in
order to evaluate cooling tower efficiency and to reduce the cycles of
concentration of natural salts in the circulating water system, the
copper limitation could still be met and the flowrate impact would be
less than design. In addition, the NYSDEC has evaluated the service
water and cooling tower blowdown based on the original design
flowrates, as well as the state of the art technology of the discharge
diffuser. The NYSDEC has concluded that no thermal measurements or
thermal plume studies are necessary because of the low flowrates and
the design of the discharge structure. Therefore, the licensee
concluded that because the withdrawal rate is currently low and the
cooling tower blowdown rate is currently below original design, the 5
percent increase in water withdrawal or an increase in blowdown is not
expected to result in any additional environmental impact since any
increase in flowrate is expected to be no more than the original system
design. The NRC staff has reviewed the licensee's assessment and
concludes the increased flowrates will not result in a significant
increase in environmental impact.
The licensee has conservatively estimated that the power uprate
will result in an annual increase in dissolved solids from water
passing through the soil in the area of the Energy Center of
approximately 0.012 ppm. Since even the most sensitive species are not
affected by soil salinization of less than 1,280 ppm, it is highly
unlikely that even salt-sensitive species would be measurably affected
by this additional deposition rate during operation of the NMP-2
cooling tower at power uprate conditions. Therefore, the NRC staff has
concluded that the increase in cooling tower drift due to the proposed
power uprate will have no significant increase in environment impact
and would still be well below the levels of concern to local soil and
vegetation.
Nonradiological effluent discharges from other systems were also
considered. Nonradiological effluent limits for such systems as floor
and equipment drains are established in the SPDES permit. Discharges
from these systems are not expected to change significantly, if at all,
because operation at uprated power levels are governed by the limits in
the SPDES permit. Thus, the impact on the environment from these
systems as a result of operation at uprated power levels is not
significant.
With the exception of the cooling tower, all other significant
noise producing equipment associated with the service water and
circulating water systems are located inside buildings and/or well
below grade where the noise level would have little, if any,
environmental impact. There is no expected increase in cooling tower
noise levels associated with the proposed power uprate since there are
no plans to increase its flow rate as part of the proposed power
uprate. The main turbine and generator will operate at the same speed
and thus will not contribute to increased offsite noise. Although the
main station transformers will operate at a slightly (approximately 4.3
percent) increased kilovolt-ampere level, the slight increase will
cause an insignificant increase in the overall noise level. Therefore,
the NRC staff has concluded that the outside noise level increase will
be insignificant.
The licensee has stated that the proposed power uprate will not
require any changes to the SPDES discharge permit nor to the NMP-2
Environmental Protection Plan. The NRC staff agrees with this
assessment and, therefore, we have concluded that the proposed power
uprate will have an insignificant impact on the nonradiological
elements of concern.
Radiological Environmental Assessment
The licensee evaluated the impact of the proposed power uprate
amendment to show that the applicable regulatory acceptance criteria
relative to radiological environmental impacts will continue to be
satisfied for the uprated power conditions. In conducting this
evaluation, the licensee considered the effect of the higher power
level on liquid radioactive wastes, gaseous radioactive wastes, and
radiation levels both in the plant and offsite during both normal
operation and post-accident.
The floor drain collector subsystem waste collector subsystem both
receive [[Page 11691]] inputs from a variety of sources (e.g., leakage
from component cooling water system, reactor coolant system, condensate
and feedwater system, turbine plant cooling water system, and auxiliary
steam system). However, leakages from these systems are not expected to
increase significantly since the operating pressures of these systems
are either being maintained constant or are being increased only
slightly due to the proposed power uprate.
The largest single source of liquid radioactive waste is from the
ultrasonic cleaning of the condensate demineralizers. These
demineralizers remove activated corrosion products which are expected
to increase proportionally to the proposed power uprate. However, the
total volume of processed waste is not expected to increase
significantly, since the only appreciable increase in processed waste
will be due to the slightly more frequent cleaning of these
demineralizers. Based on a review of plant effluent reports and the
slight increase expected due to the proposed power uprate, the NRC
staff has concluded that the slight increase in the processing of
liquid radioactive wastes will not have a significant increase in
environment impact and that requirements of 10 CFR part 20 and 10 CFR
part 50, appendix I, will continue to be met.
Gaseous radioactive effluents are produced during both normal
operation and abnormal operation occurrences. These effluents are
collected, controlled, processed, stored, and disposed of by the
gaseous radioactive waste management systems which include the various
building ventilation systems, the offgas system, and the standby gas
treatment system (SGTS). The concentration of radioactive gaseous
effluents released through the building ventilation systems during
normal operation is not expected to increase significantly due to the
proposed power uprate since the amount of fission products released
into the reactor coolant (and subsequently into the building
atmosphere) depends on the number and nature of fuel rod defects and is
not dependent on reactor power level. The concentration of activation
products contained in the reactor coolant is expected to remain
unchanged, since the linear increase in the production of these
activation products will be offset by the linear increase in steaming
rate. Therefore, based on its review of the various building
ventilation systems, the NRC staff has concluded that there will not be
a significant adverse effect on airborne radioactive effluents as a
result of the proposed power uprate.
Radiolysis of the reactor coolant causes the formation of hydrogen
and oxygen, the quantities of which increase linearly with core power.
These additional quantities of hydrogen and oxygen would increase the
flow to the recombiners by 4.3 percent during uprated power conditions.
The offgas system was originally designed for 105 percent of warranted
steam flow which would not be exceeded during operation at the proposed
uprated power level. Therefore, no changes will be required in the
offgas system and since the offgas system will be operated within the
originally evaluated design conditions, there will be no environmental
impact that was not previously evaluated.
The SGTS is designed to minimize offsite radiation dose rates
during venting and purging of both the primary and secondary
containment atmosphere under accident or abnormal conditions. This is
accomplished by maintaining the secondary containment at a slightly
negative pressure (more negative than or equal to -0.25 inch water
gauge) with respect to the outside atmosphere and discharging the
secondary containment atmosphere through high-efficiency particulate
air (HEPA) filters and charcoal absorbers. As noted in the Updated
Safety Analysis Report (USAR), the SGTS charcoal absorbers are designed
for a charcoal loading capacity of 10 mgI/gC and get the design
requirements for 30-day and 100-day loss-of-coolant accident (LOCA)
scenarios. The proposed power uprate would increase the post-LOCA
iodine loading by 4.3 percent but the charcoal loading would still
remain within the 10 mgI/gC loading and therefore, there would be no
significant increase in environmental impact.
The licensee has evaluated the effects of the power uprate on in-
plant radiation levels in the NMP-2 facility during both normal
operation and post-accident. The licensee has concluded that radiation
levels during both normal operation and post-accident may increase
slightly (at most, proportional to the increase in power level). The
slight increases in in-plant radiation levels expected due to the
proposed power uprate are not expected to affect radiation zoning or
shielding requirements. Individual worker occupational exposures will
be maintained with acceptable limits by the existing as low as is
reasonably achievable (ALARA) program which the licensee uses to
control access to radiation areas. Therefore, the NRC staff has
concluded that the slightly increased in-plant radiation levels will
not have a significant environmental impact.
The offsite doses associated with normal operation are not
significantly affected by operation at the proposed uprated power level
and are expected to remain well within the limits of 10 CFR part 20 and
10 CFR part 50, appendix I. These limits are imposed by Technical
Specifications 3/4.11.1, 3/4.11.2, 3/4.11.3, and 3/4.11.4, which will
not be changed by the proposed power uprate. Therefore, the NRC staff
has concluded that the offsite doses due to normal operation at the
proposed power uprate conditions will not result in a significant
environmental impact.
The dose evaluations for design basis accidents were performed for
issuance of the current operating license based on 105 percent of the
current rated power level. The proposed power uprate would be within
the assumptions used during original licensing of the plant and,
therefore, there will be no increase in environmental impacts over
those evaluated in the NRC staff's Final Environmental Statement
related to the operation of Nine Mile Point Nuclear Station, Unit No. 2
(NUREG-1085), May 1985.
The NRC staff has concluded that the NRC's FES (NUREG-1085) is
valid for operation at the proposed uprated power conditions. The NRC
staff also concluded that the plant operating parameters impacted by
the proposed uprate would remain within the bounding conditions on
which the conclusions of the FES are based.
The NRC staff has reviewed the licensee's reevaluation of the
potential radiological and nonradiological environmental impacts for
the proposed action. On the basis of this review, the NRC staff finds
that the radiological and nonradiological environmental impacts
associated with the proposed small increase in power are essentially
immeasurable and do not change the conclusion in the FES that the
operation of NMP-2 would cause no significant adverse impact upon the
quality of the human environment.
Accordingly, the Commission concludes that this proposed action
would result in no significant radiological or nonradiological
environmental impact.
Alternative to the Proposed Action
Since the Commission has concluded there is no measurable
environmental impact associated with the proposed action, any
alternative with equal or greater impact need not be evaluated. The
principal alternative would be to deny the requested amendment. Denial
would not significantly reduce the environmental impact of plant
operations, but would restrict operation [[Page 11692]] of NMP-2 to the
currently licensed power level. Denial of the amendment would prevent
the facility from generating the approximately additional 45 MWe that
is obtainable from the existing plant.
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 Nine Mile Point Nuclear Station, Unit No. 2,'' dated
May 1985.
Agencies and Persons Consulted
The Commission's staff reviewed the licensee's request and
consulted with the New York State official regarding the environmental
impact of the proposed action. The State official had no comment
regarding the NRC's proposed action.
Finding of No Significant Impact
Based upon the foregoing environmental assessment, the Commission
concludes that the proposed action will not have a significant effect
on the quality of the human environment.
Accordingly, the Commission has determined not to prepare an
environmental impact statement for the proposed license amendment.
For further details with respect to this action, see the
application for amendment dated July 22, 1993, as supplemented January
9, 1995. These documents are available for public inspection at the
Commission's Public Document Room, The Gelman Building, 2120 L Street,
NW, Washington, DC 20555 and at the Reference and Documents Department,
Penfield Library, State University of New York, Oswego, New York 13126.
Dated at Rockville, Maryland, this 24th day of February 1995.
For the Nuclear Regulatory Commission.
Ledyard B. Marsh,
Director, Project Directorate I-1, Division of Reactor Projects--I/II,
Office of Nuclear Reactor Regulation.
[FR Doc. 95-5137 Filed 3-01-95; 8:45 am]
BILLING CODE 7590-01-M
