Constellation Energy Generation, LLC; Braidwood Station, Units 1 and 2; Environmental Assessment and Finding of No Significant Impact, 61500-61506 [2024-16895]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 89, Number 147 (Wednesday, July 31, 2024)]
[Notices]
[Pages 61500-61506]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-16895]


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NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-456 and 50-457; NRC-2024-0112]


Constellation Energy Generation, LLC; Braidwood Station, Units 1 
and 2; Environmental Assessment and Finding of No Significant Impact

AGENCY: Nuclear Regulatory Commission.

ACTION: Notice; issuance.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is considering 
amending Renewed Facility Operating License Nos. NPF-72 and NPF-77, 
which authorize Constellation Energy Generation, LLC, (Constellation, 
the licensee) to operate Braidwood Station

[[Page 61501]]

(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) through September 30, 2024. The NRC 
staff is issuing an environmental assessment (EA) and finding of no 
significant impact (FONSI) associated with the proposed amendments.

DATES: The EA and FONSI referenced in this document are available on 
July 31. 2024.

ADDRESSES: Please refer to Docket ID NRC-2024-0112 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-2024-0112. 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, at 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: The PDR, where you may examine and order copies 
of publicly available documents, is open by appointment. 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 amending Renewed Facility Operating License 
Nos. NPF-72 and NPF-77, which authorize Constellation to operate 
Braidwood, 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), ``Application for amendment of license, construction permit, or 
early site permit,'' by letter dated June 4, 2024. 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)) through September 
30, 2024. In accordance with 10 CFR 51.21, the NRC has determined that 
an EA is the appropriate form of environmental review for the requested 
action. 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 allow Constellation to operate Braidwood, 
Units 1 and 2, at UHS temperatures up to 102.8 [deg]F (39.3 [deg]C) 
until September 30, 2024. The proposed action is in response to the 
licensee's license amendment request application dated June 4, 2024. 
The proposed action would amend the Braidwood, Units 1 and 2, renewed 
operating licenses 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) through September 30, 2024. 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, 
2023. After September 30, 2023, 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, 2024. After September 30, 2024, 
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) through September 30, 2024. 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, 
2024. 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, September 30, 
2021, September 30, 2022, and September 30, 2023. The NRC issued EAs 
for the 2020, 2021, 2022, and 2023, UHS amendments in the Federal 
Register on September 10, 2020 (85 FR 55863), July 7, 2021 (86 FR 
35831), July 20, 2022 (87 FR 43301), and June 16, 2023 (88 FR 39487), 
respectively. The NRC issued the license amendments on September 24, 
2020, July 13, 2021, August 10, 2022, and July 13, 2023, respectively. 
The only difference between the previously approved amendments to TS SR 
3.7.9.2 and the proposed action is that the proposed action would 
replace the year ``2023'' with ``2024.'' It should also be noted that 
during the past 4 years the temperature of the UHS has not exceeded 102 
[deg]F, so no cumulative effects need be considered.

Need for the Proposed Action

    The proposed action would allow Constellation to operate Braidwood, 
Units 1 and 2, during the hot summer months by allowing an UHS 
temperature of <=102.8 [deg]F (39.3 [deg]C) until September 30, 2024. 
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 letter dated July 15, 2020, as supplemented by letter 
dated August 14, 2020. The NRC subsequently granted the licensee's 
request by letter dated September 24, 2020. The NRC approved similar 
requests for subsequent years by letters dated July 13, 2021, August 
10, 2022, and July 13, 2023. Constellation projects that similar 
conditions are likely this year. The proposed action

[[Page 61502]]

would provide the licensee with operational flexibility until September 
30, 2024, so that the plant shutdown criteria specified in the TS are 
not triggered unless UHS temperature exceeds 102.8 [deg]F (39.3 
[deg]C).

Plant Site and Environs

    Braidwood Station, in Will County, Illinois, is located 
approximately 50 miles (mi) or 80 kilometers (km) southwest of the 
Chicago Metropolitan Area and 20 mi (32 km) south-southwest of Joliet. 
The Kankakee River is approximately five 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 without additional makeup water. The term 
``UHS'' in this EA refers to the 99-ac (40-ha) essential cooling pond, 
and 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 also 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. Constellation 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 also 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. In addition, the cooling pond is a managed ecosystem 
where IDNR fish stocking and other human activities primarily influence 
species composition and population dynamics.
    Since the beginning of the lease agreement, 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) or 
``Braidwood FSEIS'' (Final Supplemental Environment Impact Statement). 
Figure 3-5 on pages 3-7 in the Braidwood FSEIS depicts the Braidwood 
Station layout, and Figure 3-4 on pages 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.

Environmental Impacts of the Proposed Action

    The proposed action consists of changing the year ``2023'' to 
``2024'' in TS SR 3.7.9.2, allowing a temporary increase in the 
allowable UHS average temperature of <=102.8 [deg]F (39.3 [deg]C) until 
September 30, 2024.
    The proposed changes would not increase the probability or 
consequences of radiological accidents. There would be no change to the 
types or amounts of radioactive effluents released into the environment 
and, therefore, no change in occupational or public radiation exposure 
from the proposed changes. Therefore, there would be no significant 
radiological environmental impacts associated with the proposed action.
    In addition, the proposed action would have no direct impacts on 
land use or terrestrial biota, as the proposed action involves no new 
construction or modification of plant operational systems. There would 
be no changes to the quality or quantity of nonradiological effluents 
and no changes to the plant's National Pollutant Discharge Elimination 
System permits would be needed. Overall staffing levels would not 
increase; therefore, worker vehicle air emissions are not expected to 
increase. In addition, there would be no noticeable effect on 
socioeconomic conditions in the region, no environment justice impacts, 
and no impacts to historic and cultural resources from the proposed 
action.
    Temporarily raising the maximum allowable UHS temperature could 
increase cooling pond water temperatures until September 30, 2024. 
Because the proposed action would not affect Braidwood's licensed 
thermal

[[Page 61503]]

power level, the temperature rise across the condensers as cooling 
water travels through the cooling system would remain unchanged. 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, could also experience a 
corresponding increase. The additional heat load is expected to 
dissipate across some thermal gradient as discharged water travels down 
the discharge canal and through the 99-ac (40-ha) UHS.
    Fish kills often 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 Braidwood operation and high cooling pond temperatures. Appendix B, 
section 4.1, of the Braidwood renewed facility operating licenses, 
requires Constellation to report unusual or important environmental 
events, including fish kills, related to plant operation to the NRC. 
Since November 2015 (issuance of the Braidwood FSEIS), Constellation 
has not reported any additional fish kill events to the NRC. Although 
not related to plant operation, several fish kills have occurred since 
this time, the most recent of which happened in August 2018 and July 
2020.
    In section 4.7.1.3 of the Braidwood FSEIS, 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, 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). The NRC staff concluded 
in its environmental review that increasing the TS limit to <=102.0 
[deg]F (38.9 [deg]C) would have no significant environmental effect, 
and the NRC issued a FONSI with the EA.
    In 2020, 2021, 2022, and 2023 the NRC granted additional 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, 
September 30, 2022, and September 30, 2023, respectively. The NRC staff 
concluded in their reviews that temporarily increasing the TS limit to 
<=102.8 [deg]F (39.3 [deg]C) would have no significant environmental 
effect, and the NRC issued FONSIs with the EAs.
    The NRC staff has also determined that this proposed action would 
result in no significant impact to aquatic resources in the cooling 
pond for the same reasons reached in the 2020, 2021, 2022, and 2023, 
license amendments. The NRC 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 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 fish species can be 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 in the cooling 
pond. Additionally, the proposed action would only increase the 
allowable UHS average water temperature until September 30, 2024. Thus, 
any impacts to the aquatic communities in the managed cooling pond, if 
experienced, would be temporary in nature, and fish populations could 
recover 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 previously discussed, these fish could 
have already experienced thermal stress and possibly died, and the 
additional temperature increase would not measurably affect the 
mortality rate. For fish with thermal tolerances above 95 [deg]F (35 
[deg]C), such as bluegill, increased mortality is possible, as 
previously explained.
    In addition, 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 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 present inconsistent information on thermal 
tolerance limits, data from past fish kill events indicate that Cairns' 
study results more closely describe the cooling pond's bluegill 
population because the licensee has not reported bluegill as one of the 
species having been affected by past high temperature events. Thus, 
bluegills are likely acclimating to temperature rises at rates that 
allow individuals to remain in high temperature areas until 
temperatures

[[Page 61504]]

decrease or allow 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 for at least 1 hour could 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 temperature 
increase 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 events 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 Constellation and IDNR. Continued stocking would mitigate any 
minor effects resulting from the proposed action. As previously stated 
in this notice, although authorized to operate up to 102.8 [deg]F (39.3 
[deg]C), at no time in the past 3 years did the UHS temperature exceed 
102 [deg]F (38.9 [deg]C).
    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 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 or 
ecological resources along or within the Kankakee River. Occasionally, 
the licensee has applied for a provisional variance to allow higher-
than-permitted temperatures at the edge of the discharge mixing zone. 
For instance, Exelon, the license holder at the time, applied for and 
the Illinois Environmental Protection Agency (IEPA) granted one 
provisional variance in 2012 during a period of extremely warm weather 
and little to no precipitation. Constellation reported no fish kills or 
other events to the IEPA and 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, Constellation would remain subject to 
the regulatory controls described in this notice. The NRC staff finds 
it reasonable to assume 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 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 the FWS. The survey documented the

[[Page 61505]]

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 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, the impacts of the proposed action would 
be confined to the UHS cooling pond and would not affect water 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 consultation was 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 proposed 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 discussion and findings previously described in this 
EA, the NRC concludes that the proposed action would not significantly 
affect plant safety and would not have a significant adverse effect on 
the probability of an accident occurring. In addition, there would be 
no significant nonradiological environmental impacts associated with 
the proposed action. Accordingly, the NRC concludes that the proposed 
action would have no significant environmental effect on the quality of 
the human environment.

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. Therefore, 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). The no-action 
alternative would result in no change in current 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

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

III. Finding of No Significant Impact

    Constellation submitted a license amendment request in accordance 
with 10 CFR 50.90. The request seeks to amend Renewed Facility 
Operating License Nos. NPF-72 and NPF-77, issued to Constellation for 
operation of Braidwood. The amendments would revise TS 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, 2024. The NRC is considering the 
requested amendments.
    In addition, the NRC staff conducted an environmental review of the 
proposed action, and prepared an EA, which is provided in Section II of 
this notice and is incorporated by reference in this FONSI. The NRC 
determined the proposed action would not significantly affect plant 
safety, would not have a significant adverse effect on the probability 
of an accident occurring, and would not have any significant 
radiological or nonradiological impacts. Based on the EA, the NRC staff 
has concluded that the proposed action will not have a significant 
impact on the quality of the human environment. Based on its finding, 
the NRC has decided not to prepare an environmental impact statement 
for the proposed action.
    As required by 10 CFR 51.32(a)(5), the related environmental 
document is the ``Generic Environmental Impact Statement for License 
Renewal of Nuclear Plants: Regarding Braidwood Station, Units 1 and 2, 
Final Report,'' NUREG-1437, Supplement 55, which provides the latest 
environmental review of current operations and description of 
environmental conditions at Braidwood.
    Section IV lists the environmental documents related to the 
proposed action and includes information on the availability of these 
documents.
    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.

----------------------------------------------------------------------------------------------------------------
                    Document description                                     ADAMS accession No.
----------------------------------------------------------------------------------------------------------------
                                                Amendment Request
----------------------------------------------------------------------------------------------------------------
Constellation Energy Generation, LLC. License Amendment to   ML24156A245.
 Braidwood Station, Units 1 and 2, Technical Specification
 3.7.9, ``Ultimate Heat Sink,'' dated June 4, 2024.
----------------------------------------------------------------------------------------------------------------

[[Page 61506]]

 
                                               Similar Amendments
----------------------------------------------------------------------------------------------------------------
Braidwood Station, Units 1 and 2--Issuance of Amendments     ML20245E419.
 Nos. 218 and 218 Re: Revision of Technical Specifications
 for the Ultimate Heat Sink (EPID L-2020-LLA-0159), dated
 September 24, 2020.
Braidwood Station, Units 1 and 2--Issuance of Amendments     ML21154A046.
 Nos. 222 and 222 Re: Revision of Technical Specifications
 for the Ultimate Heat Sink (EPID L-2020-LLA-0095), dated
 July 13, 2021.
Braidwood Station, Units 1 and 2--Issuance of Amendments     ML22173A214.
 Nos. 228 and 228 Re: Revision of Technical Specifications
 for the Ultimate Heat Sink (EPID L-2022-LLA-0082), dated
 August 10, 2022.
Braidwood Station, Units 1 and 2--Issuance of Amendment      ML23087A076.
 Nos. 232 and 232 Re: Revision of Technical Specifications
 for the Ultimate Heat Sink (EPID L-2022-LLA-0042), dated
 July 13, 2023.
----------------------------------------------------------------------------------------------------------------
                                           Other Referenced Documents
----------------------------------------------------------------------------------------------------------------
Cairns J. 1956. Effects of heat on fish. Industrial Wastes,  n/a.\1\
 1:180-183.
Banner A, Van Arman JA. 1973. Thermal effects on eggs,       n/a.\1\
 larvae and juveniles of bluegill sunfish. Washington, DC:
 U.S. Environmental Protection Agency. EPA-R3-73-041.
Ecological Specialists, Inc. Final Report: Five Year Post-   ML15274A093 (Package).
 Construction Monitoring of the Unionid Community Near the
 Braidwood Station Kankakee River Discharge, dated
 September 29, 2015.
Exelon Generation Company, LLC. Byron and Braidwood          ML14339A044.
 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,
 as modified by letter dated October 8, 2014 (ML14281A019).
U.S. Fish and Wildlife Service. Concurrence Letter           ML15299A013.
 Concluding Informal Consultation with the NRC for
 Braidwood License Renewal, dated October 20, 2015.
Exelon Generation Company, LLC. License Amendment to         ML20197A434.
 Braidwood Station, Units 1 and 2, Technical Specification
 3.7.9, ``Ultimate Heat Sink,'' dated July 15, 2020.
Exelon Generation Company, LLC Supplement to License         ML20227A375.
 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 Environmental    ML15314A814.
 Impact Statement for License Renewal of Nuclear Plants:
 Regarding Braidwood Station, Units 1 and 2, Final Report
 (NUREG-1437, Supplement 55), dated November 30, 2015.
U.S. Nuclear Regulatory Commission. Constellation Energy     ML053040362.
 Generation, LLC; Docket No. STN 50-456; Braidwood Station,
 Unit 1 Renewed Facility Operating License, issued on
 January 27, 2016, as amended through amendment number 234.
U.S. Nuclear Regulatory Commission. Constellation Energy     ML053040366.
 Generation, LLC; Docket No. STN 50-457; Braidwood Station,
 Unit 2 Renewed Facility Operating License, issued on
 January 27, 2016, as amended through amendment number 234.
U.S. Nuclear Regulatory Commission. Record of Decision;      ML15322A317.
 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. Environmental            ML16181A007.
 Assessment and Finding of No Significant Impact Related to
 Ultimate Heat Sink Modification, dated July 18, 2016.
U.S. Nuclear Regulatory Commission. Braidwood Station,       ML16133A438.
 Units 1 and 2--Issuance of Amendments Re: Ultimate Heat
 Sink Temperature Increase, dated July 26, 2016.
U.S. Nuclear Regulatory Commission. Environmental            ML20231A469.
 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. Environmental            ML21165A041.
 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. Federal Register         ML22159A176.
 Notice, Environmental Assessment and Finding of No
 Significant Impact Related to Temporary Revision of
 Technical Specifications for the Ultimate Heat Sink, dated
 July 15, 2022.
U.S. Nuclear Regulatory Commission. Federal Register         ML23110A122.
 Notice, Environmental Assessment and Finding of No
 Significant Impact Related to Temporary Revision of
 Technical Specifications for the Ultimate Heat Sink, dated
 June 12, 2023.
----------------------------------------------------------------------------------------------------------------
\1\ These references are subject to copyright laws and are, therefore, not reproduced in ADAMS.


    Dated: July 26, 2024.

    For the Nuclear Regulatory Commission.
Joel S. Wiebe,
Senior Project Manager, Licensing Projects Branch III, Division of 
Operating Reactors, Office of Nuclear Reactor Regulation.
[FR Doc. 2024-16895 Filed 7-30-24; 8:45 am]
BILLING CODE 7590-01-P