ML25148A211

Supplemental Audit - Enclosure

ML25148A211
Person / Time
Site:	Saint Lucie
Issue date:	06/10/2025
From:	Lance Rakovan NRC/NMSS/DREFS/EPMB1
To:	Coffey R Florida Power & Light Co
Shared Package
ML25148A200	List: ML25148A211 ML25148A213
References
Download: ML25148A211 (1)

Text

Enclosure 2 ST. LUCIE NUCLEAR PLANT, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION SUPPLEMENTAL ENVIRONMENTAL REVIEW REQUESTS FOR CONFIRMATION OF INFORMATION Regulatory Basis Licensees are required by Title 10 of the Code of Federal Regulations (10 CFR) Part 51.53(c)(1) to submit with its application a separate document entitled Applicant's Environmental Report Operating License Renewal Stage. The U.S. Nuclear Regulatory Commissions (NRC) regulations at 10 CFR 51, which implement section 102(2) of the National Environmental Policy Act of 1969, as amended (NEPA), include requirements for applicants to provide information as may be useful in aiding the NRC staff in complying with NEPA. As part of its review, the NRC staff is required to prepare a Supplemental Environmental Impact Statement to NUREG-1437, Generic Environmental Impact Statement for License Renewal of Nuclear Plants. Review guidance for the staff is provided in NUREG-1555, Supplement 1, Revision 1, Standard Review Plans for Environmental Reviews for Nuclear Power Plants: Supplement 1 - Operating License Renewal.

Requests for Confirmation of Information The letter to Rod L. Penfield, Site Vice President, dated April 2, 2025 (Agencywide Documents Access and Management System [ADAMS] ML25078A071), contained an audit plan, which included a list of information needs with unique identifiers. During the environmental audit, the NRC staff reviewed documents that were made available on the applicants electronic information portal in response to the staff audit needs. The staff also participated in breakout sessions with applicant personnel for certain resource areas to gather information that will likely be used in the site-specific environmental impact statement. To the best of the staffs knowledge, this information on the applicants electronic information portal and discussed in breakout sessions is not currently on the docket or publicly accessible. The NRC staff requests that the applicant submits confirmation that the information gathered from the audit and listed below is correct or provides the associated corrected information.

1) Info Need AQN-1 As discussed during the environmental audit in response to information need AQN-1, please confirm the following, or provide a correction, if appropriate:

a) In accordance with St. Lucie Plant, Units 1 & 2 (St. Lucie) air operation permit (Permit No.1110071-016-AO), Florida Power and Light Company (FPL) is no longer required to retain emissions other than for nitrogen oxide.

b) Nitrogen oxide emissions for the 2020-2024 timeframe are as follows: 20.35 tons (year 2020), 24.89 tons (year 2021), 24.42 (year 2022), 13.09 (year 2023), and 31.98 tons (year 2024).

2) Info Need AQN-2 As discussed during the environmental audit in response to information need AQN-2, please confirm the following, or provide a correction, if appropriate: FPL has not received any notices of violation on non-compliances associated with St. Lucies air permit from 2019 to April 1, 2025.

2

3) Info Need AQN-3 As discussed during the environmental audit in response to information need AQN-3, please confirm the following, or provide a correction, if appropriate: there are no known field tests concerning ozone and nitrogen oxides emission generated by St. Lucies 230-kV in scope transmission lines.

4) Info Need AQN-4 As discussed during the environmental audit in response to information need AQN-4, please confirm the following, or provide a correction, if appropriate: FPL has not received any noise complains with respect to St. Lucies operations since June 14, 2022.

5) Info Need AQN-5 As discussed during the environmental audit in response to information need AQN-5, please confirm the following, or provide a correction, if appropriate: FPL has not conducted or commissioned noise surveys at or in the vicinity of St. Lucie since 2007.

6) Info Need FPE-2 As discussed during the environmental audit in response to information need FPE-2, please confirm the following, or provide a correction, if appropriate:

a) FPL is not aware of the presence of milkweed species (Asclepias spp.) at the St. Lucie site; b) Herbicides are applied in vicinity of the discharge canal, near the truck trap, near intake banks, and near the car wash area; and c)

There is no vegetation or herbicide management plan specific to the site.

7) Info Need FPE-3 As discussed during the environmental audit in response to information need FPE-3, please confirm the following, or provide a correction, if appropriate:

a) Alligators have been observed on the canal banks and in the surrounding mangrove habitat; b) Within the last 10 years no alligators have been observed in the stormwater ponds; and c)

No alligators have been caught in the intake.

8) Info Need FPE-4 As discussed during the environmental audit in response to information need FPE-4, please confirm the following, or provide a correction, if appropriate: a total of 11 West Indian Manatees have been captured in the St. Lucie intake canal since operations began -

February 1991, August 1991, September 1996, December 1996, May 2003, June 2006, December 2006, January 2008, November 2008, January 2010, and June 2024.

9) Info Need GG-1 As discussed during the environmental audit in response to information need GG-1, please confirm the following, or provide a correction, if appropriate:

a) Fuel usage from onsite combustion units between 2020 and 2024 is consistent with the fuel usage from onsite combustion units between 2015 and 2019. Therefore, greenhouse gas (GHG) emissions from onsite combustion units between 2020 and 2024 are similar to those presented in Table 3.3-11 of the environmental report (ER)

(ML21215A319);

b) Sulfur hexafluoride is used in circuit breakers at St. Lucie and for leak detection in water boxes

3 c)

Circuit breakers are sent to a vender to be refilled and are not refilled onsite; d) FPL plans to replace circuit breakers that use sulfur hexafluoride to ones that do not use sulfur hexafluoride by 2027; e) As part of St. Lucies program to manage refrigeration appliances that use ozone depleting substances, FPL submits notifications to the Environmental Protection Agency (EPA) for leaks of ozone depleting substances from refrigeration appliances in accordance with 40 CFR 82; f)

St. Lucie is not subject to EPAs GHG reporting program.

10) Info Need GG-3 As discussed during the environmental audit in response to information need GG-3, please confirm the following, or provide a correction, if appropriate:

a) The statement Using a GWL [global warming level] 2°C scenario, the surface water temperature on the coastline of Florida is expected to increase by 3.6°F in Section 5.13.2.3 of the ER Supplement (ML25034A029) should be revised to state Using GWL 2° C scenario, the surface water temperature on the Atlantic Ocean coastline of Florida is expected to increase by 1.5 to 3 °F.

b) FPL has not conducted thermal discharge studies that account for increases in water temperature in the Atlantic Ocean due to climate change.

11) Info Need GW-1 As discussed during the environmental audit and in response to information needs GW-1 and SW-3, FPL provided 2017 and 2022 Site Conceptual Model Update reports. Please confirm the following information from these reports, or provide a correction, if appropriate:

a) From the 2022 Site Conceptual Model Update report, Hydrogeologic Conceptual Site Model Update for St. Lucie Power Station, prepared by Radiation Safety & Control Services, Inc., July 26, 2022.

i.

Depth of the sheet pile retaining wall structure along the intake canal at the intake structure (areal extent shown in 2024 Annual Radioactive Effluent Release Report

[ARERR] on page 11 or 57) extends to elevation -63 ft National Geodetic Vertical Datum (where NGVD as used in this report indicates National Geodetic Vertical Datum of 1929). (see page 13 of 38) ii.

Site characterization of the surficial aquifer demonstrates that salinity increases from 0.4 parts per thousand (ppt) near the water table surface (15-20 feet bgs) to values in excess of 30 ppt at depths 45 bgs. (see page 14 of 38) iii.

Water surface elevations of onsite water bodies were estimated during May 2022 to be the following (ft NGVD). (see page 17 of 38)

Discharge Canal Intake Canal East Basin West Basin 2022 9

-3 3

3 iv.

Depths of building foundations are elevation -23.75 ft NGVD for the reactor containment buildings and from elevation -20.35 to -6.85 ft NGVD for the reactor auxiliary buildings. (see page 21 of 38) v.

Hydraulic conductivity testing results were conducted in onsite wells in the 1990s to address fuel contamination. Results of testing in the diesel storage tanks area east of the reactor containment buildings indicated a hydraulic conductivity of 4.0 ft/day. These tests were conducted in wells finished in the Class I fill at the site.

Results of testing in the area of the site downgradient of the East and West

4 Basins indicated a hydraulic conductivity of 0.89 ft/day. These tests were conducted in wells finished in the Class II fill at the site. (see page 23 of 38) b) Confirm the following information from the 2017 Site Conceptual Model Update report discussed by FPL during the April 2025 Environmental Audit, Site Conceptual Model St.

Lucie Station, prepared by GHD/BHI Energy, May 2017.

i.

The concrete liner of the discharge canal contains two, 2-inch diameter pipes per 12-foot panel. (see page 11 of 74) ii.

Local groundwater flow patterns are altered by subsurface structures. For example, flow from monitoring well MW-6 is forced to move around Unit 1 reactor and between Unit 1 reactor and the auxiliary building. The flow patterns will also be influenced by the sheet piling reported to exist at the headwall where the intake canal enters the facility. To assess the influence of subsurface structures on groundwater flow, a preliminary assessment was conducted using a groundwater flow model implemented in Visual MODFLOW Pro v.4.2 (using MODFLOW 2000) that incorporated site subsurface structures and boundary conditions. The model confirmed the flow pattern observed from field measurements. (see page 14 of 74) iii.

Figures 4 and 5 (groundwater contour maps for September 14, 2007) show groundwater elevations and flow vectors derived from the MODFLOW model results. (see pages 30 and 31 of 74) iv.

Operation of the Stations cooling water system, by use of the intake and discharge canals significantly influences groundwater flow. Groundwater generally flows from northeast to the west and south in response to the hydraulic heads in the discharge and intake canals. The typical hydraulic head difference between the discharge and intake canals is approximately 12 feet. The overwhelming majority of the groundwater beneath the Site discharges to the intake canal, where it is captured and subsequently used as cooling water prior to discharge to the Atlantic Ocean. A minor component of groundwater moves from the northern discharge canal and discharges to the Big Mud Creek. This water does not pass through areas where elevated tritium levels occur. (see page 20 of 74; labeled Page 16) v.

Average water surface elevations of onsite water bodies during August 24, 2007 and September 14, 2007 were the following (ft NGVD). (see page 47 of 74; Table 3)

Discharge Canal Intake Canal East Basin West Basin August 24, 2007 7.84

- 4.34 5.30 4.70 September 14, 2007 8.79

- 3.02 6.12 4.79 vi.

Figures 14 and 16 (W-E and NE-SW cross sections for November 2016, pages 39 and 40 of 74) show cross-sections for the A-A and B-B transects shown on Figure 2, Site Plan, of the 2023 ARERR (Enclosure 1 of ML24060A179, page 12 in the pdf document).

5

12) Info Need GW-2 As discussed during the environmental audit and in response to information need GW-2, FPL provided tritium results for groundwater samples from the ten border monitoring wells during 2024. Results of the monitoring were as shown in the table below. Please confirm that the table is correct. (LLD = lower limit of detection)

Tritium (pCi/L) in border wells during 2024 Date Well 1/26/2024 4/24/2024 8/2/2024 10/2/2024 H70

<LLD

<LLD

<LLD

<LLD H71 414 530 350 394 H72

<LLD

<LLD

<LLD

<LLD H73

<LLD

<LLD

<LLD

<LLD H74

<LLD

<LLD

<LLD

<LLD H75

<LLD

<LLD

<LLD

<LLD H76

<LLD

<LLD

<LLD

<LLD H77

<LLD

<LLD

<LLD

<LLD H78

<LLD

<LLD

<LLD

<LLD H79 135

<LLD

<LLD

<LLD 133 LLD 143

13) Info Need HH-1 As discussed during the virtual audit session in response to information need HH-1, FPL conducted a Light Detection and Ranging survey of the in-scope transmission lines and the survey confirmed compliance with National Electrical Safety Code (NESC) clearance standards in 2011. Please confirm the following, or provide a correction, if appropriate:

a) As shown in the selected images from this survey made available for NRC staff review--

the in-scope transmission lines that span from the plan to the onsite switchyard have adequate clearance; b) The nearest point for public approach is from a publicly accessible internal plant road and parking spaces on the southeast corner of the switchyard; c)

The clearance for the conductor to the ground near this point is approximately 41 ft (13.41 m); and d) The required clearance for 230KV lines is 22.5 ft (6.858 m) per the 2023 NESC that the Florida Public Service Commission adopted on September 16, 2024.

14) Info Need LU-1 As discussed during the environmental audit in response to information need LU-1, please confirm the following, or provide a correction, if appropriate:

a) The West Test Facility and Quality Control Building removal was completed; b) The second switchyard was completed; and c)

Dune renourishment is performed after hurricanes based on severity of erosion and was last completed in 2023.

6

15) Info Need MC-1 As discussed during the environmental audit in response to information need MC-1, please confirm the following meteorological measurements from St. Lucies meteorological monitoring program for the 2013-2024 period of record and confirm that the period of record is 11.5 years since the data for the 2013 year was only available for half the year or provide a correction, if appropriate.

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN Mean Wind Speed (miles per hour) 6.9 7.8 7.1 7.2 6.7 5.8 5.3 6.3 5.8 7.1 7.2 6.6 6.6 Prevailing Wind Direction (degrees from) 320 160 160 140 80 160 160 160 70 70 70 320 70 Monthly Average Temperatures

(°F) 65.7 69.1 71.4 74.7 77.6 80.3 82.1 82.5 81.4 78.7 73.6 69.7 75.7 Monthly Precipitation (inches) 1.6 1.4 1.0 2.1 2.2 3

2.1 3.2 2.9 3.1 1.8 1.5 26

16) Info Need SNF-1 The St. Lucie ER states that the Independent Spent Fuel Storage Installation (ISFSI) is sized to accommodate all the spent nuclear fuel generated for the current operating term and the existing spent fuel pools could presumably accommodate the proposed term subsequent license term of 20 years. Please confirm the following, or provide a correction, if appropriate:

a) That if an onsite ISFSI expansion was pursued during the subsequent license renewal period, FPL would use existing procedures such as those discussed in the 2021 ER Section 3.7.6 to site the expansion within St. Lucie's NRC-licensed site (the host area required by 10 CFR 72.106, for an ISFSI general license under 10 CFR 72.210);

b) The review process would consider regulations for, and commitments to, the protection of endangered species, wetlands and coastal areas, and archeological findings; and c)

The preferable candidate site would be located on developed/disturbed land.

17) Info Need SW-1 As discussed during the environmental audit in response to information need SW-1, please confirm the following, or provide a correction, if appropriate:

a) In October 2022, nutrient and oil and grease sampling associated with Outfall I-008 was incomplete due to the wrong preservative used in the sample container.

b) The contract laboratory was contacted and asked to re-sample the outfall; however, the laboratory did not have an appropriate unpreserved sample container for reanalysis.

c)

FPL notified the Florida Department of Environmental Protection (FDEP) via email and noted the missed sampling in the discharge monitoring report for October 2022.

d) There were no corrective actions required by FDEP.

e) There were no notices of violation or additional non-compliances associated with wastewater discharges to receiving surface waters since the St. Lucie subsequent license renewal (SLR) ER was written.

7

18) Info Need SW-3 As discussed during the environmental audit in response to information need SW-3, please confirm the following, or provide a correction, if appropriate:

a) The below salinity data have been collected from Big Mud Creek as part of FPLs program to test the Ultimate Heat Sink valves at the St. Lucie Plant.

Date Pre-test salinity (ppt)

Post-test salinity (ppt) 2/14/2023 32.77 32.28 5/11/2023 32.4 32.7 8/29/2023 30.35 30.45 11/16/2023 30.62 30.41 2/1/2024 30.42 30.38 4/30/2024 35.03 35.29 4/30/2024 35.39 35.21 7/24-25/24 35.03 35.29 7/24-25/24 35.39 35.21 10/29/2024 27.27 27.32 2/5/2025 33.21 33.36 ppt = parts per thousand b) The below salinity data have been collected from the discharge canal as part of FPLs program to test the Ultimate Heat Sink valves at the St. Lucie Plant.

Date Time Salinity (ppt) 8-29-24 08:33 36.11 8-29-24 12:16 36.06 11-16-24 08:18 36.21 11-16-24 12:11 36.07 ppt = parts per thousand c)

The below salinity in groundwater data from Table 4 of the St. Lucie Station 2017 Conceptual Model document, which was provided on the portal as part of the response to information need SW-3. Also, please confirm the reference for the depth provided in the table (e.g., top of casing, ground surface) and the vertical reference datum (e.g.,

mean low water, NGVD).

Sample location Date Sample Depth (ft)

Salinity (ppt)

DT-MW-6 9/14/2007 16 0.4 DT-MW-6 9/14/2007 18 0.4 DT-MW-6 9/14/2007 20 0.4 DT-MW-6 9/14/2007 22 0.5 average 0.425 DT-MW-11 8/17/2007 14 1.7 DT-MW-11 8/17/2007 16 1.8 DT-MW-11 8/17/2007 18 1.8 DT-MW-11 8/17/2007 20 1.8 average 1.78 DT-MW-18D 8/17/2007 40 26.6

8 DT-MW-18D 8/17/2007 45 24.8 average 25.7 DT-MW-22D 8/17/2007 35 26.3 DT-MW-22D 8/17/2007 40 30.55 average 28.43 MP-MW-7A 9/14/2007 14.5 2.4 MP-MW-7A 9/14/2007 16.5 2.5 average 2.45 MP-MW-13D 8/17/2007 40 24.4 MP-MW-13D 8/17/2007 45 24.3 average 24.35 NB-PSLED-1 9/14/2007 17 0.4 NB-PSLED-1 9/14/2007 19 0.4 NB-PSLED-1 9/14/2007 21 0.4 NB-PSLED-1 9/14/2007 23 0.4 average 0.4 TLO1-MW-002 9/14/2007 16 1

TLO1-MW-002 9/14/2007 17 1

TLO1-MW-002 9/14/2007 19 1.1 TLO1-MW-002 9/14/2007 21 1.1 TLO1-MW-002 9/14/2007 23 1.1 average 1.06 ppt = parts per thousand

19) Info Need SW-5 As discussed during the environmental audit in response to information need SW-5, please confirm the following, or provide a correction, if appropriate:

a) The FDEP issued the final NPDES (National Pollutant Discharge Elimination System) and IWW (Industrial Wastewater) permit on March 24, 2025. Some key changes to the NPDES permit include:

I.

monthly copper monitoring of the intake and discharge, monthly chlorine dioxide analysis instead of continuous to all residual oxidants monitoring II.

decreased sampling frequencies for certain analyses such as total suspended solids for the waste monitoring tank, and III.

the implementation of an enhanced Best Management Practices Plan.

b) The basis for permit limitations and monitoring requirements is provided in Section 3 of the permit fact sheet, which is included as Attachment 2 of the final permit.

9

20) Info Need SW-6 In FDEP's intent to issue letter for the NPDES/IWW permit dated February 6, 2025, the FDEP considered potential impairments to receiving waters from PSL effluent in Section 4 of the permit fact sheet. The FDEP concluded that effluent from St. Lucie discharges do not contribute to impairments in the Atlantic Ocean and issued a final NPDES/IWW permit.

Please confirm the following, or provide a correction, if appropriate: discharges from St.

Lucie do not contribute to impairments in the Atlantic Ocean.

21) Info Need SW-7 As discussed during the environmental audit in response to information need SW-7, please confirm the plant surface water withdrawals from 2021-2024 as presented below.

2021 2022 2023 2024 Monthly Maximum (MGM) 46,096 46,096 46,097 46,095 Monthly Average (MGM) 41,541 43,426 43,697 40,451 Monthly Minimum (MGM) 24,485 27,117 33,842 23,050 Yearly Total (MGY) 498,496 521,109 524,361 485,414 Yearly Total (MGD) 1,366 1,428 1,437 1,326 MGM = millions of gallons per month MGY = millions of gallons per year MGD = millions of gallons per day

22) Info Need SW-9 As discussed during the environmental audit in response to information need SW-9, please confirm the following, or provide a correction, if appropriate:

a) A conduit exists between the mangrove impoundment and the intake canal that allows for flushing water pumped from the intake canal to flow through the mangrove impoundment and passively discharge back to the intake canal.

b) No other connection exists between the mangrove impoundment and any other surface water.

c)

The primary purpose of flushing the mangrove impoundment is for mosquito control and to enhance the growth of mangroves.

23) Info Need SW-11 As discussed during the environmental audit in response to information need SW-11, please confirm the following, or provide a correction, if appropriate: St Lucie has not reduced power to meet thermal discharge limits in the last 5 years.

24) Info Need SW-15 As discussed during the environmental audit in response to information need SW-15, please confirm the following, or provide a correction, if appropriate: a) Receiving Environment Monitoring Program (REMP) locations H13 and H36 are supplemental locations; and b) H13 is located on the north side of the plant in Big Mud Creek and H36 is in the discharge canal.

25) Info Need SW-16 As discussed during the environmental audit in response to information need SW-16, please confirm the following, or provide a correction, if appropriate:

a) That the surface water sample collected at supplemental monitoring location H36 on January 4, 2023, was collected during a waste monitor tank (WMT) release. The WMT

10 release occurred from January 4, 2023, at 1 :52 p.m. to January 5, 2023, at 4:15 a.m.

The concentration of tritium released from the WMT was 1.49E+08 pCi/L.

b) A similar event occurred in 2021. The surface water sample collected at H36 on April 14, 2021, was collected during a WMT release, which occurred that day from 4:55 a.m. to 4:55 p.m. The concentration of tritium released from the WMT was 1.18E+08 pCi/L.

c)

Supplemental monitoring location H36 is in the discharge canal.

26) Info Need TR-4 As discussed during the environmental audit in response to information need TR-4, please confirm the following, or provide a correction, if appropriate on the least term, a Florida State designated threatened species:

a) The Inwater Research Group (IRG) survey in 2024 found one least tern colony on the rooftops of buildings C1 and C2 with approximately 42 nests; b) This is the largest and most productive least tern nesting in St. Lucie County; c)

Two incidents occurred where downy chicks fell from the roof but both were returned to the roof by FPL; and d) IRG recommended covers be placed over water drainage pipes and chick fencing around the buildings to contain chicks.

27) Info Need WM-1 (-2, -3, and -4)

Please confirm the following regarding unplanned/inadvertent releases, or provide a correction, if appropriate:

a) There have been no reportable unplanned releases of radioactive materials (unplanned/inadvertent radioactive liquid or gaseous releases) which would trigger a notification requirement since the previous audit took place in February 2022 (besides what are documented in the effluent release reports).

b) There have been no reportable inadvertent nonradioactive releases that would be classified as an incidental spill which would trigger a notification requirement since the previous audit took place in February 2022.

c)

There have been no reportable spills/releases that triggered the notification requirement according to the reporting provisions of Title 40 of the Code of Federal Regulations Part 110 as it relates to the discharge of oil in such quantities as may be harmful pursuant to Section 311(b)(4) of the Federal Water Pollution Control Act since June 14, 2022.

d) There have been no reportable spills that triggered notification in accordance with the reporting provision under Florida Administrative Code 62-780 and under the site conditions of certification since June 14, 2022.

28) Info Need WM-5 (and -6)

Please confirm the following, or provide a correction, if appropriate: that there are no proposed changes or upgrades to the hazardous and mixed waste management program or the low-level waste program being considered during the license renewal term.

29) Info Need VR-1 As discussed during the environmental audit in response to information need VR-1, please confirm the following, or provide a correction, if appropriate: there have been no new and significant changes, such as major lighting changes, since ER submission that would have significantly changed plant aesthetics.

11 ST. LUCIE NUCLEAR PLANT, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION SUPPLEMENTAL ENVIRONMENTAL REVIEW REQUESTS FOR ADDITIONAL INFORMATION

1) Info Need GG-2 REQUIREMENT: Title 10 of the Code of Federal Regulations (10 CFR) Section 51.53(c)(3)(ii)(Q) states that applicants shall include an assessment of the effects of any observed and projected changes in climate on environmental resource areas that are affected by license renewal.

ISSUE: Section 5.13.2.3 of the Environmental Report (ER) Supplement (Agencywide Documents Access and Management System [ADAMS] ML25034A029) discussed climate change impacts on water resources. Section 3.6.1.2.6 of the ER (ML21215A319) states that cooling water intake water temperatures for each unit are measured and averaged for each month. Figure 3.6-4 of the ER (ML21215A319) provides water intake temperatures for the 2015-2020 period. The ER, however, did not discuss observed trends of intake cooling water temperatures.

REQUEST: Please provide a time series figure of the monthly intake and monthly seasonal average intake cooling water temperatures for the 2013-2024 period of record. Additionally, provide a discussion and any relevant information as to whether a warming trend has been observed.

2) Info Need FPE-6 REQUIREMENT: 10 CFR 51.53(c)(3)(ii)(E) requires that all license renewal applicants shall assess the impact of refurbishment, continued operations, and other license-renewal-related construction activities on important plant and animal habitats. Additionally, the applicant shall assess the impact of the proposed action on federally protected ecological resources in accordance with Federal laws protecting such resources, including but not limited to, the Endangered Species Act, the Magnuson-Stevens Fishery Conservation and Management Act, and the National Marine Sanctuaries Act. 10 CFR 51.41 requires that licensees submit information that may be useful in aiding the Commission in complying with section 102(2) of National Environmental Policy Act (NEPA) with information in an environmental report that should contain sufficient data to aid the Commission in its development of an independent analysis

[10 CFR 51.41(c)].

ISSUE: On May 13, 2024, NRC staff conducted an onsite audit of the St. Lucie site. The NRC staff and Florida Power & Light Co. (FPL) staff observed and discussed the emergency intake cooling system and as a result, the U.S. Nuclear Regulatory Commission (NRC) staff require additional information on the operation of this structure.

REQUEST: Please provide a description of the emergency intake cooling system operations located on Big Mud Creek and include the following information: a) the frequency and duration of operation of the emergency intake cooling system to include testing and average volume of water withdrawn during operation; b) if dredging is anticipated to occur in Big Mud Creek during the subsequent license renewal term to support operation of the emergency cooling system; c) if there are observers during operation of the emergency cooling system to watch for biota entering the intake canal; d) a description of any grating, screens, or other methods of preventing or mitigating entrainment or entrapment of biota in the intake canal; e) details of any communications with local, state, or Federal agencies regarding the operation of the intake with regard to ecological resources.

12

3) Info Need GW-1 REQUIREMENT: The requirements in 10 CFR 51.45(b) and 51.53(c)(2) state that the ER shall include a description of the affected environment. In addition, 10 CFR 51.53(c)(3)(ii)(P) requiresthat the ER contain an assessment of the impact of any documented inadvertent releases of radionuclides into groundwater, which includes descriptions of the applicants groundwater protection program, past inadvertent releases, and projected impacts to the environment (aquifers and connected surface water bodies) during the license renewal term.

ISSUE: The NRC staff is preparing an environmental impact statement (EIS) that considers the impacts of subsequent license renewal for St. Lucie on affected groundwater resources. The ER and ER supplement did not fully provide information regarding groundwater flow paths for radionuclides inadvertently released to groundwater, as affected by site hydrogeology and site infrastructure. Further, the ER, as supplemented, did not fully provide information on the salinity of groundwater and the Indian River Lagoon near the St. Lucie site. During the virtual audit, FPL discussed its 2022 Site Conceptual Model Update, as well as its 2017 Site Conceptual Model Update, both prepared under the groundwater protection program. These reports provided additional information describing groundwater flow paths at the St. Lucie site.

REQUEST: Please provide the following information.

a.

A description of past inadvertent releases of radionuclides into groundwater at St. Lucie Nuclear Plant.

b.

The following figures from the 2017 Site Conceptual Model Update report discussed by FPL during the April 2025 Environmental Audit, Site Conceptual Model St. Lucie Station, prepared by GHD/BHI Energy, May 2017.

i.

Figure 4. Groundwater Contour Map (High Tide) - September 14, 2007 (page 30 of 74) ii.

Figure 5. Groundwater Contour Map (Low Tide) - September 14, 2007 (page 31 of 74) iii.

Figure 16. NE-SW Cross Section - November 2016 (page 39 of 74) iv.

Figure 14. W-E Cross Section - November 2016 (page 40 of 74))

4) Info Need TR-3 REQUIREMENT: 10 CFR 51.53c(3)(ii)(E) states all license renewal applicants shall assess the impact of refurbishment, continued operations, and other license renewal-related construction activities on important plant and animal habitats.

ISSUE: The NRC staff is preparing an EIS that considers the environmental impacts of subsequent license renewal for St. Lucie. As part of the preparing the EIS, the staff must consider whether the has been any new information related to terrestrial resources. During the 2025 environmental audit, FPL provided its yearly Special Purpose Utility permit (SPUT) reports submitted to the U.S. Fish and Wildlife Service (FWS) on dead or injured birds in the last 10 years.

REQUEST: Please provide the yearly SPUT reports submitted to FWS on dead or injured birds for the last 10 years.