[Federal Register Volume 88, Number 116 (Friday, June 16, 2023)]
[Notices]
[Pages 39487-39492]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-12853]


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NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-456 and 50-457; NRC-2023-0105]


Constellation Energy Generation, 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, which authorize Constellation Energy Generation, LLC, 
(Constellation, licensee) to operate Braidwood Station (Braidwood), 
Units 1 and 2. The proposed amendments would change Technical 
Specification (TS) 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) from the date of issuance of the amendments 
through September 30, 2023.

DATES: The environmental assessment (EA) and finding of no significant 
impact (FONSI) referenced in this document are available on June 16, 
2023.

ADDRESSES: Please refer to Docket ID NRC-2023-0105 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-2023-0105. Address 
questions about Docket IDs in Regulations.gov to Stacy Schumann; 
telephone: 301-415-0624; email: [email protected]. For technical 
questions, contact the individual 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, 
instructions about obtaining materials referenced in this document are 
provided in the ``Availability of Documents'' section.
     NRC's PDR: You may examine and purchase copies of public 
documents, by appointment, at the NRC's PDR, Room P1 B35, One White 
Flint North, 11555 Rockville Pike, Rockville, Maryland 20852. To make 
an appointment to visit the PDR, please send an email to 
[email protected] or call 1-800-397-4209 or 301-415-4737, between 8 
a.m. and 4 p.m. eastern time (ET), Monday through Friday, except 
Federal holidays.

FOR FURTHER INFORMATION CONTACT: Joel S. Wiebe, Office of Nuclear 
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001, telephone: 301-415-6606; email: [email protected].

SUPPLEMENTARY INFORMATION:

I. Introduction

    The NRC is considering issuance of amendments to Renewed Facility 
Operating License Nos. NPF-72 and NPF-77, which authorize Constellation 
Energy Generation, LLC, to operate Braidwood Station, Units 1 and 2, 
located in Will County, Illinois. Constellation 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 March 24, 2023. If 
approved, the license amendments would revise TS SR 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)) from 
the date of issuance of the amendments through September 30, 2023. 
Therefore, as required by 10 CFR 51.21, 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 FONSI.

II. Environmental Assessment

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) from the date of 
issuance of the amendments through September 30, 2023. 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, 2022. After September 30, 2022, 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, 2023. After 
September 30, 2023, 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) from 
the date of issuance of the amendments through September 30, 2023. The 
current TS's UHS average water temperature limit of 102 [deg]F (38.9 
[deg]C) would remain applicable to all other time periods beyond 
September 30, 2023. 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 for specified periods 
until September 30, 2020, September 30, 2021, and September 30, 2022. 
The NRC issued EAs for the 2020, 2021, and 2022, UHS amendments in the 
Federal Register on September 10, 2020 (85 FR 55863), July 7, 2021 (86 
FR 35831), and July 20, 2022 (87 FR 43301), respectively. The NRC 
issued the amendments on September 24, 2020, July 13, 2021, and August 
10, 2022, respectively. The only difference

[[Page 39488]]

between the previously approved amendments to SR 3.7.9.2 and the 
proposed action is that the proposed action would replace the year with 
``2023.'' It should also be noted that during the past 3 years, the 
temperature of the UHS has not exceeded 102 [deg]F, so no cumulative 
effects of the previously authorized amendments need be considered. The 
proposed action is in accordance with the licensee's application dated 
March 24, 2023.

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 the 
licensee's request in September 2020. A similar request for subsequent 
years was granted by NRC letters dated July 13, 2021, and August 10, 
2022. Constellation projects that have similar conditions are likely 
this year. The proposed action would provide the licensee with 
operational flexibility until September 30, 2023, during which period 
continued high UHS temperatures are likely, so that the plant shutdown 
criteria specified in the TS are not triggered.

Plant Site and Environs

    Braidwood is in Will County, Illinois, approximately 50 miles (mi) 
or 80 kilometers (km) southwest of the Chicago Metropolitan Area and 20 
mi (32 km) south-southwest of Joliet, IL. The Kankakee River is 
approximately 5 mi (8 km) east of the eastern site boundary. An onsite 
2,540-acre (ac) or 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. The licensee 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 the 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 the licensee 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.

[[Page 39489]]

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 and no 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 doses 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 nonradiological 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, 2023. 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 by 0.8 [deg]F (0.4 [deg]C) 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 Constellation 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, the licensee 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, 2021, and 2022, 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, September 30, 2021, and September 30, 2022, 
respectively. In the EAs 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 
and 2021 amendments. The staff's justification for this conclusion is 
as 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, 2023. 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

[[Page 39490]]

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 EA.
    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 1 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 
the licensee 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 allowed 
under the current TS limit, for at least one hour would result in 
observable deaths. However, as stated previously, the licensee 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, the flow path between the 
discharge canal and the UHS, and the UHS itself constitute a small area 
as compared to the cooling pond. Thus, while the incremental increase 
would likely increase the area over which cooling pond temperatures 
would rise above currently allowed temperatures, 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 as compared to current operations, for those species 
with thermal tolerances at or near 95 [deg]F (35 [deg]C), and would 
result in an insignificant increase in the number of individuals 
affected for species with thermal tolerances above 95 [deg]F (35 
[deg]C), such as bluegill.
    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 Constellation and IDNR. Continued stocking would mitigate any 
effects resulting from the proposed action. Also, as stated previously, 
although the plants have been authorized to operate up to 102.8 [deg]F 
temporarily, at no time in the past 3 years did the UHS temperature 
exceed 102 [deg]F. 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 action 
would result in a significant difference in the number or intensity of 
fish kill events or otherwise result in significant impacts to 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 
(IEPA) 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.
    Under the proposed action, Constellation would remain subject to

[[Page 39491]]

the federal and State regulatory controls described in this notice. The 
NRC staff finds that Constellation'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 amounts 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 as a result of 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 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 regarding the proposed action is not 
necessary because the NRC staff has determined that the requested 
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 to 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 from the date of issuance of the amendments through 
September 2023. The no-action alternative would result in no change in 
environmental conditions or impacts at Braidwood beyond those 
considered in the Braidwood FSEIS.

Alternative Use of Resources

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

Agencies and Persons Consulted

    In accordance with the Commission's regulations, the Illinois State 
official was notified of the proposed issuance of the amendment on 
April 25, 2023. The State official had no comments.

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 Constellation for 
operation of Braidwood that would revise the TS for the plant to 
temporarily increase the allowable average temperature of the UHS from 
the date of issuance of the amendments to September 30, 2023.
    On the basis of the EA included in section II and incorporated by 
reference 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 one or more of the following methods, as 
indicated.

[[Page 39492]]



------------------------------------------------------------------------
                  Document                       ADAMS accession No.
------------------------------------------------------------------------
                        License Amendment Request
------------------------------------------------------------------------
Constellation Energy Generation, LLC.        ML23083B941.
 License Amendment to Braidwood Station,
 Units 1 and 2, Technical Specification
 3.7.9, ``Ultimate Heat Sink,'' dated March
 23, 2023.
------------------------------------------------------------------------
                       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. Final Report:   ML15274A093 (Package).
 Five Year Post-Construction Monitoring of
 the Unionid Community Near the Braidwood
 Station Kankakee River Discharge, dated
 September 29, 2015.
Exelon Generation Company, LLC. Byron and    ML14339A044.
 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. Concurrence  ML15299A013.
 Letter Concluding Informal Consultation
 with the NRC for Braidwood License
 Renewal, dated October 20, 2015.
Exelon Generation Company, LLC. License      ML21147A543.
 Amendment to Braidwood Station, Units 1
 and 2, Technical Specification 3.7.9,
 ``Ultimate Heat Sink,'' dated May 27, 2021.
Exelon Generation Company, LLC. License      ML20197A434.
 Amendment to Braidwood Station, Units 1
 and 2, Technical Specification 3.7.9,
 ``Ultimate Heat Sink,'' dated July 15,
 2020.
Exelon Generation Company, LLC. Supplement   ML20227A375.
 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. Generic  ML15314A814.
 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. Exelon   ML053040362.
 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. Exelon   ML053040366.
 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. Record   ML15322A317.
 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.
Braidwood Station, Units 1 and 2--Issuance   ML22173A214.
 of Amendments Re: Ultimate Heat Sink
 Temperature Increase, dated August 10,
 2022.
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.
U.S. Nuclear Regulatory Commission.          ML21165A041.
 Environmental Assessment and Finding of No
 Significant Impact Related to Temporary
 Revision of Technical Specifications for
 the Ultimate Heat Sink, dated June 30,
 2021.
U.S. Nuclear Regulatory Commission.          ML21154A046.
 Braidwood Station, Units 1 and 2--Issuance
 of Amendments Re: Temporary Revision of
 Technical Specifications for the Ultimate
 Heat Sink, dated July 13, 2021.
------------------------------------------------------------------------
(\1\) These references are subject to copyright laws and are, therefore,
  not reproduced in ADAMS.


    Dated: June 12, 2023.

    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. 2023-12853 Filed 6-15-23; 8:45 am]
BILLING CODE 7590-01-P