Commonwealth Edison Company, Byron Station, Units 1 and 2,
Braidwood Station, Units 1 and 2; Environmental Assessment and Finding
of no Significant Impact
[Federal Register: January 5, 2001 (Volume 66, Number 4)]
[Notices]
[Page 1158-1160]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05ja01-102]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. STN 50-454, STN 50-455, STN 50-456 and STN 50-457]
Commonwealth Edison Company, Byron Station, Units 1 and 2,
Braidwood Station, Units 1 and 2; Environmental Assessment and Finding
of no Significant Impact
The U.S. Nuclear Regulatory Commission (NRC) is considering
issuance of amendments to Facility Operating License Nos. NPF-37, NPF-
66, NPF-72 and NPF-77; issued to Commonwealth Edison Company (ComEd or
licensee), for operation of Byron Station, Units 1 and 2 (Byron),
located in Ogle County, Illinois, and Braidwood Station, Units 1 and 2
(Braidwood), located in Will County, Illinois.
Environmental Assessment
Identification of the Proposed Action
The proposed action would allow ComEd to increase the maximum
reactor core power level from 3411 megawatts thermal (MWt) to 3586.6
MWt, which is an increase of 5 percent of rated core thermal power for
each unit at Byron Station, Units 1 and 2, and for each unit at
Braidwood Station, Units 1 and 2. The proposed action is in accordance
with the licensee's application for amendment dated July 5, 2000, as
supplemented on November 27, 2000.
The Need for the Proposed Action
The proposed action permits an increase in the licensed core
thermal power from 3411 MWt to 3586.6 MWt and for each of the four
units and provides the flexibility to increase the potential electrical
output of Byron Station, Units 1 and 2, and Braidwood Station, Units 1
and 2.
Environmental Impacts of the Proposed Action
ComEd has submitted an environmental evaluation supporting the
proposed power uprate and provided a summary of its conclusions
concerning both the radiological and non-radiological environmental
impacts of the proposed action.
[[Page 1159]]
Radiological Environmental Assessment: Radwaste Systems
The reactor coolant contains activated corrosion products, which
are the result of metallic materials entering the water and being
activated in the reactor region. Under power uprate conditions, the
feedwater flow increases with power and the activation rate in the
reactor region increases with power. The net result may be an increase
in the activated corrosion product production. However, the evaluation
has shown that the power uprate will not cause a significant change in
the types or a significant increase in the amounts of any radiological
effluent that may be released offsite.
Non-condensible radioactive gas from the main condenser, along with
air in-leakage, normally contains activation gases (principally N-16,
O-19 and N-13) and fission product radioactive noble gases. This is the
major source of radioactive gas (greater than all other sources
combined). These non-condensible gases, along with non-radioactive air,
are continuously removed from the main condensers which discharge into
the offgas system. The changes in gaseous effluents are small and are
well within the uncertainty of the calculation of the original limits
following implementation of the power uprate.
ComEd has concluded that there will be no significant change in the
level of controls or methodology used for the processing of radioactive
effluents; or handling of solid radioactive waste at Byron and
Braidwood will not be impacted by operation at uprated power
conditions, and the slight increase in effluents discharged would
continue to meet the requirements of part 20 of Title 10 of the Code of
Federal Regulations (10 CFR) and 10 CFR part 50, appendix I. Therefore,
the power uprate will not appreciably affect the ability to process
liquid or gaseous radioactive effluents and there are no significant
environmental effects from radiological releases.
Dose Consideration
ComEd evaluated the potential effects of power uprate conditions on
the radiation sources within the plant and the radiation levels during
normal and post-accident conditions. The original calculations for
determining the normal operational doses and radiation shielding
requirements were very conservative and had additional margin assumed
in the calculations. It was determined that these margins are
sufficient to accommodate any increases attributed to the five percent
increase in rated thermal power. The power uprate has no significant
effect on plant normal operation radiation zones and shielding
requirements. In addition, the normal operation component of the total
integrated dose used for radiological equipment qualification (EQ) is
not affected by the power uprate.
The power uprate does not involve significant increases in the
offsite doses to the public from noble gases, airborne particulates,
iodine, tritium, or liquid effluents. An upper bound analysis for the
potential impact of the power uprate indicates that the increase in
radiological releases and resultant dose impact is bounded by the
percentage increase in the reactor core power. Therefore, the normal
offsite doses are not significantly affected by operation at the
uprated power level and remain below the limits of 10 CFR part 20 and
10 CFR part 50, appendix I.
The uprate program included a reanalysis or evaluation of all other
aspects of large-break loss-of-coolant accident (LBLOCA), small-break
loss-of-coolant accidents (SBLOCA), non-LOCA accidents, and Nuclear
Steam Supply System (NSSS) and balance-of-plant (BOP) structures,
systems, and components. Major NSSS components (e.g., reactor pressure
vessel, pressurizer, reactor coolant pumps, and steam generators); BOP
components (e.g., turbine, generator, and condensate and feedwater
pumps); and major systems and sub-systems (e.g., safety injection,
auxiliary feedwater, residual heat removal, electrical distribution,
emergency diesel generators, containment cooling, and the ultimate heat
sink) have been assessed with respect to the bounding conditions
expected for operation at the uprated power level. Control systems
(e.g., rod control, pressurizer pressure and level, turbine overspeed,
steam generator level, and steam dump) have been evaluated for
operation at uprated power conditions. Reactor trip and Engineered
Safety Feature (ESF) actuation setpoints have been assessed and no
needed changes were identified as a result of uprated power operations.
The results of all of the above analyses and evaluations have yielded
acceptable results and demonstrate that all design basis acceptance
criteria will continue to be met during uprated power operations.
For post-accident conditions, the existing post-accident dose rate
maps are adequate for power uprate conditions, and variances from
existing calculated values are insignificant. The resulting radiation
levels were determined to be within current regulatory limits, and
there would be no effect on the plant equipment, access to vital areas,
or habitability of the control room envelope and the Technical Support
Center. The licensee has determined that access to areas requiring
post-accident occupancy will not be significantly affected by the power
uprate.
The calculated whole body and thyroid doses at the exclusion area
boundary that might result from a postulated design basis LOCA were
evaluated. All offsite doses evaluated at uprated power conditions
remain below established regulatory limits. Therefore, the results of
the radiological analyses remain below the 10 CFR part 100 guidelines
and all radiological safety margins are maintained.
Non-Radiological Environmental Assessment
The licensee reviewed the non-radiological environmental impacts of
the power uprate based on information submitted in the Environmental
Report, Operating License Stage, the NRC Final Environmental Statement
(FES), and the requirements of the Environmental Protection Plan. Based
on this review, the licensee concluded that the proposed power uprate
has no significant effect on the non-radiological elements of concern
and the plant will be operated in an environmentally acceptable manner
as established by the FES. In addition, the licensee states that
existing Federal, State, and local regulatory permits presently in
effect accommodate the power uprate without modification.
Byron Station Effluent Analysis and Evaluation
The Circulating Water (CW) System at Byron Station is a closed loop
cooling system designed to dissipate waste heat from the turbine cycle
to the atmosphere using natural draft cooling towers; one tower for
each unit. Tower blowdown is accomplished by diverting flow from the
circulating water system downstream of the CW pumps and upstream of the
condenser and tower and discharging it to the Rock River.
The increase in heat associated with the power uprate will
primarily affect the CW system and will be approximately 5 percent
higher than the heat at the present power level. This will result in a
1 deg.F CW temperature increase. The current CW temperature rise is
approximately 22 deg.F at 100 percent power. Although the National
Pollutant Discharge Elimination System (NPDES) Permit does not specify
a maximum cooling tower blowdown temperature, it controls temperature
at the edge of the mixing zone in the river.
[[Page 1160]]
It has been determined that under a worst-case scenario, the tower
blowdown temperature would be approximately 120 deg.F and has set this
value as the administrative limit. Assuming a nominal summer river
supply temperature of 70 deg.F-90 deg.F and a cooling tower blowdown
temperature of 96 deg.F, the proposed power uprate will not impact the
120 deg.F administrative limit.
Braidwood Station Effluent Analysis and Evaluation
The CW system at Braidwood Station is a closed loop cooling system
similar to that at the Byron Station, except that waste heat is
rejected from the turbine cycle to a cooling lake. Three CW pumps per
unit pump cooling water from the lake to the main condenser. Discharge
from the condenser is returned to the lake, where it is separated from
the intake supply by a dike. The heat duty increase associated with
power uprate is mainly associated with the CW System and will be
approximately 5 percent higher than at the present power level. This
will result in a 1 deg.F increase to the CW temperature rise, which is
now approximately 21.8 deg.F at 100 percent power. The increase will
nominally increase the lake temperature as the lake temperature is
primarily influenced by climatic conditions.
Byron and Braidwood operate in compliance with a NPDES Permit,
which requires all effluents to be closely monitored to assure
compliance with the permit levels. There is no significant change in
the types or a significant increase in the amounts of non-radiological
effluents that may be released offsite due to the power uprate of each
of the units at Byron Station, Units 1 and 2, and Braidwood Station,
Units 1 and 2.
Noise Evaluation
The noise effects due to operation of Byron Station and Braidwood
Station at uprated power conditions were reviewed. No increase in noise
from the turbine or reactor building will result due to uprated power
operations. In addition, the turbine and the reactor building supply
and exhaust fans will continue to operate at current speeds, and the
associated noise levels will also be unaffected by uprated power
operations. In summary, the overall noise levels at Byron Station and
Braidwood Station will not increase due to the power uprate.
The non-radiological environmental impacts related to the proposed
power uprate at Byron Station and Braidwood Station have been reviewed
and there are no adverse impacts or significant changes required to the
current NPDES Permits or other plant administrative limits. No changes
to land use would result and the proposed action does not involve any
historic sites. Therefore, no new or different types of non-
radiological environmental impacts are expected.
Summary
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 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
nonradiological 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 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
denial of the proposed action (i.e., the ``no-action'' alternative).
Denial of the application would result in no change in current
environmental impacts, but would reduce the operational flexibility
that would be afforded by the proposed change. 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
Byron Station, Units 1 and 2, and in the Final Environmental Statement
for Braidwood Station, Units 1 and 2.
Agencies and Persons Consulted
In accordance with its stated policy, on December 18, 2000, the
staff consulted with the Illinois State official, Frank Niziolek of the
Illinois Department of Nuclear Safety, 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 July 5, 2000, as supplemented on November 27,
2000. Documents may be examined, and/or copied for a fee, at the NRC's
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 22nd day of December 2000.
For the Nuclear Regulatory Commission.
Anthony J. Mendiola,
Chief Section 2, Project Directorate III, Division of Licensing Project
Management, Office of Nuclear Reactor Regulation.
[FR Doc. 01-360 Filed 1-4-01; 8:45 am]
BILLING CODE 7590-01-P
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