Exelon Generation Company, LLC; Braidwood Station, Units 1 and 2, 35831-35837 [2021-14456]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 86, Number 127 (Wednesday, July 7, 2021)]
[Notices]
[Pages 35831-35837]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-14456]


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NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-456 and 50-457; NRC-2021-0128]


Exelon Generation Company, LLC; Braidwood Station, Units 1 and 2

AGENCY: Nuclear Regulatory Commission.

ACTION: Environmental assessment and finding of no significant impact; 
issuance.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is considering 
issuance of amendments to Renewed Facility Operating License Nos. NPF-
72 and NPF-77, that were issued to Exelon Generation Company, LLC, 
(licensee) for operation of the Braidwood Station, Units 1 and 2. The 
proposed amendments are contained in the licensee's letter dated May 
27, 2021, and would change technical specifications (TSs) surveillance 
requirement (SR) 3.7.9.2 to allow an ultimate heat sink (UHS) 
temperature of less than or equal to 102.8 degrees Fahrenheit ([deg]F) 
until September 30, 2021.

DATES: The environmental assessment and finding of no significant 
impact referenced in this document are available on July 7, 2021.

ADDRESSES: Please refer to Docket ID NRC-2021-0128 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publicly available information related to this document 
using any of the following methods:
     Federal Rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2021-0128. Address 
questions about Docket IDs in Regulations.gov to Stacy Schumann; 
telephone: 301-415-0624; email: [email protected]. For technical 
questions, contact the individuals listed in the FOR FURTHER 
INFORMATION CONTACT section of this document.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly available documents online in the 
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS 
Search.'' For problems with ADAMS, please contact the NRC's Public 
Document Room (PDR) reference staff at 1-800-397-4209, 301-415-4737, or 
by email to [email protected]. For the convenience of the reader, 
the ADAMS accession numbers are provided in a table in the 
``Availability of Documents'' section of this document.
     Attention: The PDR, where you may examine and order copies 
of public documents, is currently closed. You may submit your request 
to the PDR via email at [email protected] or call 1-800-397-4209 or 
301-415-4737, between 8:00 a.m. and 4:00 p.m. (ET), Monday through 
Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Briana Arlene, Office of Nuclear 
Material Safety and Safeguards, telephone: 301-415-1042; email: 
[email protected]; and Joel Wiebe, Office of Nuclear Reactor 
Regulation, telephone: 301-415-6606, email: [email protected]. Both 
are staff of the U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001.

SUPPLEMENTARY INFORMATION:

I. Introduction

    The NRC is considering issuance of amendments to Renewed Facility 
Operating License Nos. NPF-72 and NPF-77, that were issued to Exelon 
Generation Company, LLC, (Exelon) for operation of the Braidwood 
Station, Units 1 and 2, located in Will County, Illinois. Exelon 
submitted its license amendment request in accordance with Section 
50.90 of title 10 of the Code of Federal Regulation (10 CFR), by letter 
dated May 27, 2021. If approved, the license amendments would revise 
technical specification SR in TS 3.7.9.2 to allow a temporary increase 
in the allowable UHS average temperature of less than or equal to (<=) 
102.8 [deg]F (39.3 degrees Celsius ([deg]C)) through September 30, 
2021. Therefore, as required by 10

[[Page 35832]]

CFR 50.21, the NRC performed an environmental assessment (EA). Based on 
the results of the EA that follows, the NRC has determined not to 
prepare an environmental impact statement for the proposed amendments 
and is issuing a finding of no significant impact (FONSI).

II. Environmental Assessment

Plant Site and Environs

    Braidwood is in Will County, Illinois approximately 50 miles (mi); 
80 kilometers (km) southwest of the Chicago Metropolitan Area and 20 mi 
(32 km) south-southwest of Joliet. The Kankakee River is approximately 
5 mi (8 km) east of the eastern site boundary. An onsite 2,540-acre 
(ac); 1,030-hectare (ha) cooling pond provides condenser cooling. 
Cooling water is withdrawn from the pond through the lake screen house, 
which is located at the north end of the pond. Heated water returns to 
the cooling pond through a discharge canal west of the lake screen 
house intake that is separated from the intake by a dike. The pond 
typically holds 22,300 acre-feet (27.5 million cubic meters) of water 
at any given time. The cooling pond includes both ``essential'' and 
``non-essential'' areas. The essential cooling pond is the portion of 
the cooling pond that serves as the UHS for emergency core cooling, and 
it consists of a 99-ac (40-ha) excavated area of the pond directly in 
front of the lake screen house. The essential cooling pond's principal 
functions are to dissipate residual heat after reactor shutdown and to 
dissipate heat after an accident. It is capable of supplying 
Braidwood's cooling system with water for 30 days of station operation 
without additional makeup water. For clarity, use of the term ``UHS'' 
in this EA refers to the 99-ac (40-ha) essential cooling pond, and use 
of the term ``cooling pond'' or ``pond'' describes the entire 2,540-ac 
(1,030-ha) area, which includes both the essential and non-essential 
areas.
    The cooling pond is part of the Mazonia-Braidwood State Fish and 
Wildlife Area, which encompasses the majority of the non-UHS area of 
the cooling pond as well as Illinois Department of Natural Resources 
(IDNR) owned lands adjacent to the Braidwood site to the south and 
southwest of the cooling pond. Exelon and the IDNR have jointly managed 
the cooling pond as part of the Mazonia-Braidwood State Fish and 
Wildlife Area since 1991 pursuant to a long-term lease agreement. Under 
the terms of the agreement, the public has access to the pond for 
fishing, waterfowl hunting, fossil collecting, and other recreational 
activities.
    The cooling pond is a wastewater treatment works as defined by 
Section 301.415 of Title 35 of the Illinois Administrative Code (35 IAC 
301.415). Under this definition, the cooling pond is not considered 
waters of the State under Illinois Administrative Code (35 IAC 301.440) 
or waters of the United States under the Federal Clean Water Act (40 
CFR 230.3(s)), and so the cooling pond is not subject to State water 
quality standards. The cooling pond can be characterized as a managed 
ecosystem where IDNR fish stocking and other human activities primarily 
influence the species composition and population dynamics.
    Since the beginning of the lease agreement between Exelon and IDNR, 
the IDNR has stocked the cooling pond with a variety of game fish, 
including largemouth bass (Micropterus salmoides), smallmouth bass (M. 
dolomieu), blue catfish (Ictalurus furcatus), striped bass (Morone 
saxatilis), crappie (Pomoxis spp.), walleye (Sander vitreum), and tiger 
muskellunge (Esox masquinongy x lucius). IDNR performs annual surveys 
to determine which fish to stock based on fishermen preferences, fish 
abundance, different species' tolerance to warm waters, predator and 
prey dynamics, and other factors. Because of the warm water 
temperatures experienced in the summer months, introductions of warm-
water species, such as largemouth bass and blue catfish, have been more 
successful than introductions of cool-water species, such as walleye 
and tiger muskellunge. Since annual surveys began in 1980, IDNR has 
collected 47 species in the cooling pond. In recent years, bluegill 
(Lepomis macrochirus), channel catfish (Ictalurus punctatus), threadfin 
shad (Dorosoma petenense), and common carp (Cyprinus carpio) have been 
among the most abundant species in the cooling pond. Gizzard shad 
(Dorosoma cepedianum), one of the most frequently affected species 
during periods of elevated pond temperatures, have decreased in 
abundance dramatically in recent years, while bluegills, which can 
tolerate high temperatures with relatively high survival rates, have 
noticeably increased in relative abundance. IDNR-stocked warm water 
game species, such as largemouth bass and blue catfish, continue to 
persist in small numbers, while cooler water stocked species, such as 
walleye and tiger muskellunge, no longer appear in IDNR survey 
collections. No federally listed species or designated critical 
habitats protected under the Endangered Species Act (ESA) occur within 
or near the cooling pond.
    The Kankakee River serves as the source of makeup water for the 
cooling pond. The river also receives continuous blowdown from the 
cooling pond. Water is withdrawn from a small river screen house 
located on the Kankakee River, and liquid effluents from Braidwood are 
discharged into the cooling pond blowdown line, which subsequently 
discharges into the Kankakee River.
    The plant site and environs are described in greater detail in 
Chapter 3 of the NRC's November 2015, Generic Environmental Impact 
Statement for License Renewal of Nuclear Plants: Regarding Braidwood 
Station, Units 1 and 2, Final Report (NUREG-1437, Supplement 55) 
(herein referred to as the ``Braidwood FSEIS'' (Final Supplemental 
Environment Impact Statement)). Figure 3-5 on page 3-7 of the Braidwood 
FSEIS depicts the Braidwood plant layout, and Figure 3-4 on page 3-6 
depicts the cooling pond, including the portion of the pond that 
constitutes the essential cooling pond (or UHS) and the blowdown line 
to the Kankakee River.

Description of the Proposed Action

    The proposed action would revise the Braidwood TS to allow a 
temporary increase in the allowable average temperature of water 
withdrawn from the UHS and supplied to the plant for cooling from <=102 
[deg]F (38.9 [deg]C) to <=102.8 [deg]F (39.3 [deg]C) until September 
30, 2021. Specifically, the proposed action would revise TS SR 3.7.9.2, 
which currently states, ``Verify average water temperature of UHS is 
<=102.8 [deg]F until September 30, 2020. After September 30, 2020, 
verify average water temperature of UHS is <=102 [deg]F'' to state 
``Verify average water temperature of UHS is <=102.8 [deg]F until 
September 30, 2021. After September 30, 2021, verify average water 
temperature of UHS is <=102 [deg]F.''
    Under the current TS, if the average UHS temperature as measured at 
the discharge of the operating essential service water system pumps is 
greater than 102 [deg]F (38.9 [deg]C), TS 3.7.9 Required Actions A.1 
and A.2 would be entered concurrently and would require the licensee to 
place Braidwood in hot standby (Mode 3) within 12 hours and cold 
shutdown (Mode 5) within 36 hours. The proposed action would allow 
Braidwood to continue to operate during times when the UHS indicated 
average water temperature exceeds 102 [deg]F (38.9 [deg]C) but is less 
than or equal to 102.8 [deg]F (39.3 [deg]C) until September 30, 2021. 
The current TS's UHS average

[[Page 35833]]

water temperature limit of 102 [deg]F (38.9 [deg]C) would remain 
applicable to all other time periods beyond September 30, 2021.
    The proposed action is nearly identical to previously approved 
license amendments that allowed for the average water temperature of 
the UHS to be <=102.8 [deg]F until September 30, 2020. The NRC issued 
an EA for the 2020 UHS amendments in the Federal Register on September 
10, 2020, (85 FR 55863) and the NRC issued the amendments on September 
24, 2020. The only difference between the previously approved 
amendments to SR 3.7.9.2 and the proposed action is that the proposed 
action would replace ``2020'' with ``2021.'' The proposed action is in 
accordance with the licensee's application dated May 27, 2021.

Need for the Proposed Action

    The licensee has requested the proposed amendments in connection 
with historical meteorological and atmospheric conditions that have 
resulted in the TS UHS temperature being challenged. These conditions 
included elevated air temperatures, high humidity, and low wind speed. 
Specifically, from July 4, 2020, through July 9, 2020, northern 
Illinois experienced high air temperatures and drought conditions, 
which caused sustained elevated UHS temperatures. In response to these 
conditions in 2020, the licensee submitted license amendment requests 
contained in the licensee's letter dated July 15, 2020, as supplemented 
by letter dated August 14, 2020. The NRC subsequently granted Exelon's 
request in September 2020. The licensee projects that similar 
conditions are likely this year.
    The proposed action would provide the licensee with operational 
flexibility until September 30, 2021, during which continued high UHS 
temperatures are likely so that the plant shutdown criteria specified 
in the TS are not triggered.

Environmental Impacts of the Proposed Action

    Regarding radiological impacts, the proposed action would not 
result in any changes in the types of radioactive effluents that may be 
released from the plant offsite. No significant increase in the amount 
of any radioactive effluent released offsite or significant increase in 
occupational or public radiation exposure is expected from the proposed 
action. Separate from this EA, the NRC staff is evaluating the 
licensee's safety analyses of the potential radiological consequences 
of an accident that may result from the proposed action. The results of 
the NRC staff's safety analysis will be documented in a safety 
evaluation (SE). If the NRC staff concludes in the SE that all 
pertinent regulatory requirements related to radiological effluents are 
met by the proposed UHS temperature limit increase, then the proposed 
action would result in no significant radiological impact to the 
environment. The NRC staff's SE will be issued with the license 
amendments, if approved by the NRC. If the NRC staff concludes that all 
pertinent regulatory requirements are not met by the proposed UHS 
temperature limit increase, the requested amendment would not be 
issued.
    Regarding potential non-radiological impacts, temporarily raising 
the maximum allowable UHS temperature from <=102 [deg]F (38.9 [deg]C) 
to <=102.8 [deg]F (39.3 [deg]C) could cause increased cooling pond 
water temperatures until September 30, 2021. Because the proposed 
action would not affect Braidwood's licensed thermal power level, the 
temperature rise across the condensers as cooling water travels through 
the cooling system would remain constant. Thus, if water in the UHS 
were to rise to 102.8 [deg]F (39.3 [deg]C), heated water returning to 
the cooling pond through the discharge canal, which lies west of the 
river screen house, would also experience a corresponding 0.8 [deg]F 
(0.4 [deg]C) increase. That additional heat load would dissipate across 
some thermal gradient as discharged water travels down the discharge 
canal and through the 99-ac (40-ha) UHS.
    Fish kills are likely to occur when cooling pond temperatures rise 
above 95 [deg]F (35 [deg]C), the temperature at which most fish in the 
cooling pond are thermally stressed. For example, Section 3.7.4 of the 
Braidwood FSEIS describes six fish kill events for the period of 2001 
through 2015. The fish kill events, which occurred in July 2001, August 
2001, June 2005, August 2007, June 2009, and July 2012, primarily 
affected threadfin shad and gizzard shad, although bass, catfish, carp, 
and other game fish were also affected. Reported peak temperatures in 
the cooling pond during these events ranged from 98.4 [deg]F (36.9 
[deg]C) to over 100 [deg]F (37.8 [deg]C), and each event resulted in 
the death of between 700 to as many as 10,000 fish. During the July 
2012 event, cooling pond temperatures exceeded 100 [deg]F (37.8 
[deg]C), which resulted in the death of approximately 3,000 gizzard 
shad and 100 bass, catfish, and carp. This event coincided with the 
NRC's granting of Enforcement Discretion to allow Braidwood to continue 
to operate above the TS limit of <=100 [deg]F (37.8 [deg]C). The IDNR 
attributed this event, as well as four of the other fish kill events, 
to high cooling pond temperatures resulting from Braidwood operation. 
Appendix B, Section 4.1 of the Braidwood renewed facility operating 
licenses, requires Exelon to report to the NRC the occurrence of 
unusual or important environmental events, including fish kills, 
causally related to plant operation. Since the issuance of the 
Braidwood FSEIS in November 2015, Exelon has not reported any 
additional fish kill events to the NRC. Although not causally related 
to plant operation, fish kills have occurred since this time, the most 
recent of which occurred in August 2018 and July 2020.
    In Section 4.7.1.3 of the Braidwood FSEIS, the NRC staff concluded 
that thermal impacts associated with continued operation of Braidwood 
during the license renewal term would result in SMALL to MODERATE 
impacts to aquatic resources in the cooling pond. MODERATE impacts 
would primarily be experienced by gizzard shad and other non-stocked 
and low-heat tolerant species. As part of its conclusion, the NRC staff 
also noted that because the cooling pond is a highly managed system, 
any cascading effects that result from the loss of gizzard shad (such 
as reduction in prey for stocked species, which in turn could affect 
those stocked species' populations) could be mitigated through IDNR's 
annual stocking and continual management of the pond. At that time, the 
UHS TS limit was <=100 [deg]F (37.8 [deg]C).
    In 2016, the NRC granted license amendments that increased the 
allowable UHS average water temperature TS limit from <=100 [deg]F 
(37.8 [deg]C) to <=102.0 [deg]F (38.9 [deg]C). In the EA associated 
with these amendments, the NRC staff concluded that increasing the TS 
limit to <=102.0 [deg]F (38.9 [deg]C) would have no significant 
environmental impacts, and the NRC issued a FONSI with the EA.
    In 2020, the NRC granted license amendments that temporarily 
increased the allowable UHS average water temperature TS limit from 
<=102.0 [deg]F (38.9 [deg]C) to <=102.8 [deg]F (39.3 [deg]C) until 
September 30, 2020. In the EA associated with these amendments, the NRC 
staff concluded that temporarily increasing the TS limit to <=102.8 
[deg]F (39.3 [deg]C) would have no significant environmental impacts, 
and the NRC issued a FONSI with the EA.
    The NRC staff finds that the proposed action would not result in 
significant impacts to aquatic resources in the cooling pond for the 
same reasons that the NRC staff made this conclusion regarding the 2020 
amendments. The

[[Page 35834]]

staff's justification for this conclusion follows.
    The proposed increase in the allowable UHS average water 
temperature limit by 0.8 [deg]F (0.4 [deg]C) would not increase the 
likelihood of a fish kill event attributable to high cooling pond 
temperatures because the current TS limit for the UHS of 102.0 [deg]F 
(38.9 [deg]C) already allows cooling pond temperatures above those at 
which most fish species are thermally stressed (95 [deg]F (35 [deg]C)). 
In effect, if the UHS temperature rises to the current TS limit, fish 
within or near the discharge canal, within the flow path between the 
discharge canal and UHS, or within the UHS itself would have already 
experienced thermal stress and possibly died. Thus, an incremental 
increase in the allowable UHS water temperature by 0.8 [deg]F (0.4 
[deg]C) and the corresponding temperature increases within and near the 
discharge canal and within the flow path between the discharge canal 
and UHS would not significantly affect the number of fish kill events 
experienced in the cooling pond. Additionally, the proposed action 
would only increase the allowable UHS average water temperature until 
September 30, 2021. Thus, any impacts to the aquatic community of the 
cooling pond, if experienced, would be temporary in nature, and fish 
populations would likely recover relatively quickly.
    While the proposed action would not affect the likelihood of a fish 
kill event occurring during periods when the average UHS water 
temperature approaches the TS limit, the proposed action could increase 
the number of fish killed per high temperature event. For fish with 
thermal tolerances at or near 95 [deg]F (35 [deg]C), there would likely 
be no significant difference in the number of affected fish per high 
temperature event because, as already stated, these fish would have 
already experienced thermal stress and possibly died and the additional 
temperature increase would not measurably affect the mortality rate of 
these individuals. For fish with thermal tolerances above 95 [deg]F (35 
[deg]C), such as bluegill, increased mortality is possible, as 
described in this notice.
    The available scientific literature provides conflicting 
information as to whether incremental temperature increases would cause 
a subsequent increase in mortality rates of bluegill or other high-
temperature-tolerant fish when temperatures exceed 100 [deg]F (37.8 
[deg]C). For instance, in laboratory studies, Banner and Van Arman 
(1973) demonstrated 85 percent survival of juvenile bluegill after 24 
hours of exposure to 98.6 [deg]F (37.0 [deg]C) water for stock 
acclimated to 91.2 [deg]F (32.9 [deg]C). At 100.0 [deg]F (37.8 [deg]C), 
survival decreased to 25 percent, and at 100.4 [deg]F (38.0 [deg]C) and 
102.0 [deg]F (38.9 [deg]C), no individuals survived. Even at one hour 
of exposure to 102.0 [deg]F (38.9 [deg]C) water, average survival was 
relatively low at between 40 to 67.5 percent per replicate. However, in 
another laboratory study, Cairns (1956 in Banner and Van Arman 1973) 
demonstrated that if juvenile bluegill were acclimated to higher 
temperatures at a 3.6 [deg]F (2.0 [deg]C) increase per day, individuals 
could tolerate water temperatures up to 102.6 [deg]F (39.2 [deg]C) with 
80 percent survival after 24 hours of exposure.
    Although these studies provide inconsistent thermal tolerance 
limits, information from past fish kill events indicates that Cairns' 
results better describe the cooling pond's bluegill population because 
Exelon has not reported bluegill as one of the species that has been 
affected by past high temperature events. Thus, bluegills are likely 
acclimating to temperature rises at a rate that allows those 
individuals to remain in high temperature areas until temperatures 
decrease or that allows individuals time to seek refuge in cooler areas 
of the pond. Alternately, if Banner and Van Arman's results were more 
predictive, 75 percent or more of bluegill individuals in high 
temperature areas of the cooling pond could be expected to die at 
temperatures approaching or exceeding 100 [deg]F (37.8 [deg]C) for 24 
hours, and shorter exposure time would likely result in the death of 
some reduced percentage of bluegill individuals.
    Under the proposed action, fish exposure to temperatures 
approaching the proposed UHS TS average water temperature limit of 
102.8 [deg]F (39.3 [deg]C) and those exposed to the associated 
discharge, which would be 0.8 [deg]F (0.4 [deg]C) higher than under the 
current TS limit, for at least one hour would result in observable 
deaths. However, as stated previously, Exelon has not reported bluegill 
as one of the species that has been affected during past fish kills. 
Consequently, the NRC staff assumes that bluegill and other high-
temperature-tolerant species in the cooling pond would experience 
effects similar to those observed in Cairn's study. Based on Cairn's 
results, the proposed action's incremental and short-term increase of 
0.8 [deg]F (0.4 [deg]C) could result in the death of some additional 
high-temperature-tolerant individuals, especially in cases where 
cooling pond temperatures rise dramatically over a short period of time 
(more than 3.6 [deg]F (2.0 [deg]C) in a 24-hour period).
    Nonetheless, the discharge canal, flow path between the discharge 
canal and the UHS, and the UHS itself is a small portion of the cooling 
pond. Thus, while the incremental increase would likely increase the 
area over which cooling pond temperatures would rise, most of the 
cooling pond would remain at tolerable temperatures, and fish would be 
able to seek refuge in those cooler areas. Therefore, only fish within 
or near the discharge canal, within the flow path between the discharge 
canal and UHS, or within the UHS itself at the time of elevated 
temperatures would likely be affected, and fish would experience such 
effects to lessening degrees over the thermal gradient that extends 
from the discharge canal. This would not result in a significant 
difference in the number of fish killed per high temperature event 
resulting from the proposed action when compared to current operations 
for those species with thermal tolerances at or near 95 [deg]F (35 
[deg]C) and an insignificant increase in the number of individuals 
affected for species with thermal tolerances above 95 [deg]F (35 
[deg]C), such as bluegill. Additionally, the cooling pond is a managed 
ecosystem in which fish stocking, fishing pressure, and predator-prey 
relationships constitute the primary population pressures.
    Fish populations affected by fish kills generally recover quickly, 
and thus, fish kills do not appear to significantly influence the fish 
community structure. This is demonstrated by the fact that the species 
that are most often affected by high temperature events (threadfin shad 
and gizzard shad) are also among the most abundant species in the 
cooling pond. Managed species would continue to be assessed and stocked 
by the IDNR on an annual basis in accordance with the lease agreement 
between Exelon and IDNR. Continued stocking would mitigate any minor 
effects resulting from the proposed action.
    Based on the foregoing analysis, the NRC staff concludes that the 
proposed action would not result in significant impacts to aquatic 
resources in the cooling pond.
    Some terrestrial species, such as birds or other wildlife, rely on 
fish or other aquatic resources from the cooling pond as a source of 
food. The NRC staff does not expect any significant impacts to birds or 
other wildlife because, if a fish kill occurs, the number of dead fish 
would be a small proportion of the total population of fish in the 
cooling pond. Furthermore, during fish kills, birds and other wildlife 
could consume many of the floating, dead fish. Additionally, and as 
described previously, the NRC staff does not expect that the proposed

[[Page 35835]]

action would result in a significant difference in the number or 
intensity of fish kill events or otherwise result in significant 
impacts on aquatic resources in the cooling pond.
    With respect to water resources and ecological resources along and 
within the Kankakee River, the Illinois Environmental Protection Agency 
imposes regulatory controls on Braidwood's thermal effluent through 
Title 35, Environmental Protection, Section 302, ``Water Quality 
Standards,'' of the Illinois Administrative Code (35 IAC 302) and 
through the National Pollutant Discharge Elimination System (NPDES) 
permitting process pursuant to the Clean Water Act. Section 302 of the 
Illinois Administrative Code stipulates that ``[t]he maximum 
temperature rise shall not exceed 2.8 [deg]C (5 [deg]F) above natural 
receiving water body temperatures,'' (35 IAC 302.211(d)) and that 
``[w]ater temperature at representative locations in the main river 
shall at no time exceed 33.7 [deg]C (93 [deg]F) from April through 
November and 17.7 [deg]C (63 [deg]F) in other months'' (35 IAC 
302.211(e)). Additional stipulations pertaining to the mixing zone 
further protect water resources and biota from thermal effluents. The 
Braidwood NPDES permit contains special conditions that mirror these 
temperature requirements and that stipulate more detailed temperature 
requirements at the edge of the mixing zone. Under the proposed action, 
Braidwood thermal effluent would continue to be limited by the Illinois 
Administrative Code and the Braidwood NPDES permit to ensure that 
Braidwood operations do not create adverse effects on water resources 
or ecological resources along or within the Kankakee River. 
Occasionally, Exelon has applied for a provisional variance to allow 
higher-than-permitted temperatures at the edge of the discharge mixing 
zone. For instance, Exelon applied for and the IEPA granted one 
provisional variance in 2012 during a period of extremely warm weather 
and little to no precipitation. Exelon reported no fish kills or other 
events to the IEPA or the NRC that would indicate adverse environmental 
effects resulting from the provisional variance. The details of this 
provisional variance are described in Section 4.7.1.3 of the Braidwood 
FSEIS.
    Under the proposed action, Exelon would remain subject to the 
regulatory controls described in this notice. The NRC staff finds it 
reasonable to assume that Exelon's continued compliance with, and the 
State's continued enforcement of, the Illinois Administrative Code and 
the Braidwood NPDES permit would ensure that Kankakee River water and 
ecological resources are protected. Further, the proposed action would 
not alter the types or amount of effluents being discharged to the 
river as blowdown. Therefore, the NRC staff does not expect any 
significant impacts to water resources or ecological resources within 
and along the Kankakee River from temporarily increasing the allowable 
UHS average water temperature TS limit.
    With respect to federally listed species, the NRC staff consulted 
with the U.S. Fish and Wildlife Service (FWS) pursuant to section 7 of 
the ESA during its license renewal environmental review for Braidwood. 
During that consultation, the NRC staff found that the sheepnose 
(Plethobasus cyphyus) and snuffbox (Epioblasma triquetra) mussels had 
the potential to occur in the areas that would be directly or 
indirectly affected by license renewal (i.e., the action area). In 
September 2015, Exelon transmitted the results of a mussel survey to 
the NRC and FWS. The survey documented the absence of federally listed 
mussels near the Braidwood discharge site in the Kankakee River. Based 
on this survey and other information described in the Braidwood FSEIS, 
the NRC concluded that the license renewal may affect, but is not 
likely to adversely affect the sheepnose mussel, and the NRC determined 
that license renewal would have no effect on the snuffbox mussel. The 
FWS concurred with the NRC's ``not likely to adversely affect'' 
determination in a letter dated October 20, 2015. The results of the 
consultation are further summarized in the Record of Decision for 
Braidwood license renewal.
    As previously described, impacts of the proposed action would be 
confined to the cooling pond and would not affect water resources or 
ecological resources along and within the Kankakee River. The NRC's 
previous ESA section 7 consultation confirmed that no federally listed 
aquatic species occur within or near the cooling pond. The NRC has not 
identified any information indicating the presence of federally listed 
species in the area since that consultation concluded, and the FWS has 
not listed any new aquatic species that may occur in the area since 
that time. The proposed action would not result in any disturbance or 
other impacts to terrestrial habitats, and thus, no federally listed 
terrestrial species would be affected. Accordingly, the NRC staff 
concludes that the proposed action would have no effect on federally 
listed species or designated critical habitat. Consultation with the 
FWS for the proposed action is not necessary because Federal agencies 
are not required to consult with the FWS if the agency determines that 
an action will have no effect on listed species or critical habitat.
    The NRC staff has identified no foreseeable land use, visual 
resource, noise, or waste management impacts given that the proposed 
action would not result in any physical changes to Braidwood facilities 
or equipment or changes any land uses on or off site. The NRC staff has 
identified no air quality impacts given that the proposed action would 
not result in air emissions beyond what would be experienced during 
current operations. Additionally, there would be no socioeconomic, 
environmental justice, or historic and cultural resource impacts 
associated with the proposed action since no physical changes would 
occur beyond the site boundaries and any impacts would be limited to 
the cooling pond.
    Based on the foregoing analysis, the NRC staff concludes that the 
proposed action would have no significant environmental impacts.

Environmental Impacts of the Alternatives to the Proposed Action

    As an alternative to the proposed action, the NRC staff considered 
the denial of the proposed action (i.e., the ``no-action'' 
alternative). Denial of the proposed action would result in no changes 
to the current TS. Thus, under the proposed action, the licensee would 
continue to be required to place Braidwood in hot standby (Mode 3) if 
average UHS water temperatures exceed 102 [deg]F (38.9 [deg]C) for the 
temporary period of July 2021 through September 2021. The no-action 
alternative would result in no change in current environmental 
conditions or impacts at Braidwood.

Alternative Use of Resources

    There are no unresolved conflicts concerning alternative uses of 
available resources under the proposed action.

Agencies and Persons Consulted

    No additional agencies or persons were consulted regarding the 
environmental impact of the proposed action.

III. Finding of No Significant Impact

    The NRC is considering issuing amendments for Renewed Facility 
Operating License Nos. NPF-72 and NPF-77, issued to Exelon for 
operation of Braidwood that would revise the TS for the plant to 
temporarily increase the allowable average temperature of the UHS.
    On the basis of the EA included in Section II and incorporated by 
reference

[[Page 35836]]

in this finding, the NRC concludes that the proposed action would not 
have significant effects on the quality of the human environment. The 
NRC's evaluation considered information provided in the licensee's 
application as well as the NRC's independent review of other relevant 
environmental documents. Section IV lists the environmental documents 
related to the proposed action and includes information on the 
availability of these documents. Based on its finding, the NRC has 
decided not to prepare an environmental impact statement for the 
proposed action.
    This FONSI and other related environmental documents are available 
for public inspection and are accessible online in the ADAMS Public 
Documents collection at https://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's PDR 
reference staff by telephone at 1-800-397-4209 or 301-415-4737, or by 
email to [email protected].

IV. Availability of Documents

    The documents identified in the following table are available to 
interested persons through the methods indicated.

------------------------------------------------------------------------
                 Document                       ADAMS Accession No.
------------------------------------------------------------------------
                        License Amendment Request
------------------------------------------------------------------------
Exelon Generation Company, LLC...........  ML21147A543
License Amendment to Braidwood Station,
 Units 1 and 2, Technical Specification
 3.7.9, ``Ultimate Heat Sink.''
Dated May 27, 2021.
------------------------------------------------------------------------
                       Other Referenced Documents
------------------------------------------------------------------------
Cairns J. 1956. Effects of heat on fish.   n/a (1)
 Industrial Wastes, 1 :180-183.
Banner A, Van Arman JA. 1973. Thermal      n/a (1)
 effects on eggs, larvae and juveniles of
 bluegill sunfish. Washington, DC: U.S.
 Environmental Protection Agency. EPA-R3-
 73-041.
Ecological Specialists, Inc..............  ML15274A093 (Package)
Final Report: Five Year Post-Construction
 Monitoring of the Unionid Community Near
 the Braidwood Station Kankakee River
 Discharge.
Dated September 29, 2015.
Exelon Generation Company, LLC...........  ML14339A044
Byron and Braidwood Stations, Units 1 and
 2, License Renewal Application,
 Braidwood Station Applicant's
 Environmental Report, Responses to
 Requests for Additional Information,
 Environmental RAIs AQ-11 to AQ-15.
Dated April 30, 2014.
U.S. Fish and Wildlife Service...........  ML15299A013
Concurrence Letter Concluding Informal
 Consultation with the NRC for Braidwood
 License Renewal.
Dated October 20, 2015.
Exelon Generation Company, LLC...........  ML20197A434
License Amendment to Braidwood Station,
 Units 1 and 2, Technical Specification
 3.7.9, ``Ultimate Heat Sink.''
Dated July 15, 2020.
Exelon Generation Company, LLC...........  ML20227A375
Supplement to License Amendment to
 Braidwood Station, Unit 1 and 2,
 Technical Specification 3.7.9,
 ``Ultimate Heat Sink.''
Dated August 14, 2020.
U.S. Nuclear Regulatory Commission.......  ML15314A814
Generic Environmental Impact Statement
 for License Renewal of Nuclear Plants:
 Regarding Braidwood Station, Units 1 and
 Final Report (NUREG-1437, Supplement
 55).
Dated November 30, 2015.
U.S. Nuclear Regulatory Commission.......  ML053040362
Exelon Generation Company, LLC; Docket
 No. STN 50-456; Braidwood Station, Unit
 1 Renewed Facility Operating License.
Issued on January 27, 2016.
U.S. Nuclear Regulatory Commission.......  ML053040366
Exelon Generation Company, LLC; Docket
 No. STN 50-457; Braidwood Station, Unit
 2 Renewed Facility Operating License.
Issued on January 27, 2016.
U.S. Nuclear Regulatory Commission.......  ML15322A317
Record of Decision; U.S. Nuclear
 Regulatory Commission; Docket Nos. 50-
 456 and 560-457; License Renewal
 Application for Braidwood Station, Units
 1 and 2.
Dated January 27, 2016.
U.S. Nuclear Regulatory Commission.......  ML16181A007
Environmental Assessment and Finding of
 No Significant Impact Related to
 Ultimate Heat Sink Modification.
Dated July 18, 2016.
U.S. Nuclear Regulatory Commission.......  ML16133A438
Braidwood Station, Units 1 and 2--
 Issuance of Amendments Re: Ultimate Heat
 Sink Temperature Increase.
Dated July 26, 2016.
U.S. Nuclear Regulatory Commission.......  ML20231A469
Environmental Assessment and Finding of
 No Significant Impact Related to
 Temporary Revision of Technical
 Specifications for the Ultimate Heat
 Sink.
Dated September 3, 2020.
U.S. Nuclear Regulatory Commission.......  ML20245E419
Braidwood Station, Units 1 and 2--
 Issuance of Amendments Re: Temporary
 Revision of Technical Specifications for
 the Ultimate Heat Sink.
Dated September 24, 2020.
------------------------------------------------------------------------
(1) These references are subject to copyright laws and are, therefore,
  not reproduced in ADAMS.



[[Page 35837]]

    Dated: June 30, 2021.

    For the Nuclear Regulatory Commission.
Joel S. Wiebe,
Senior Project Manager, Plant Licensing Branch III, Division of 
Operating Reactor Licensing, Office of Nuclear Reactor Regulation.
[FR Doc. 2021-14456 Filed 7-6-21; 8:45 am]
BILLING CODE 7590-01-P