ML26048A028
| ML26048A028 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 02/16/2026 |
| From: | Wilber P US Dept of Commerce, National Marine Fisheries Service, US Dept of Commerce, National Oceanographic and Atmospheric Administration |
| To: | Healy S Office of Nuclear Material Safety and Safeguards |
| References | |
| F/SER47:LW/pw | |
| Download: ML26048A028 (0) | |
Text
UNITED STATES DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration NATIONAL MARINE FISHERIES SERVICE Southeast Regional Office 263 13th Avenue South St. Petersburg, Florida 33701-5505 https://www.fisheries.noaa.gov/region/southeast February 16, 2026 F/SER47:LW/pw (Sent via Electronic Mail)
Shannon Healy, Environmental Scientist, Ecological Resources U.S. Nuclear Regulatory Commission Office of Nuclear Material Safety and Safeguards Washington, DC 20555-0001
Dear Ms. Healy:
NOAAs National Marine Fisheries Service (NMFS) reviewed Generic Environmental Impact Statement for License Renewal of Nuclear Plants, Supplement 11, Second Renewal, Regarding Subsequent License Renewal for St. Lucie Plant, Units 1 and 2 (Docket Numbers: 50-335 and 50-389), dated December 2025 (EIS). Renewal of these licenses would authorize Florida Power
& Light Company (FPL) to continue to operate Units 1 and 2 until March 1, 2056, and April 6, 2063, respectively. As described in the letter dated December 23, 2025, from the Nuclear Regulatory Commission (NRC), the EIS includes an Essential Fish Habitat (EFH) Assessment.
The NRC staff has concluded the continued operation of St. Lucie Plant may adversely affect EFH designated by the South Atlantic Fishery Management Council (SAFMC), Mid-Atlantic Fishery Management Council (MAFMC), or NMFS, although the NRC believes the adverse effects would be no more than minimal. As the nations federal trustee for the conservation and management of marine, estuarine, and anadromous fishery resources, NMFS provides the following comments and recommendations pursuant to authorities of the Fish and Wildlife Coordination Act and the Magnuson-Stevens Fishery Conservation and Management Act (Magnuson-Stevens Act).
Project Description The St. Lucie Plant is located on Hutchinson Island, St. Lucie County, between Ft. Pierce and St.
Lucie Inlets. The St. Lucie Plant is separated from the mainland on its western side by the Indian River Lagoon and on the eastern side by the Atlantic Ocean. The St. Lucie Plant discharges its once-through cooling water to the Atlantic Ocean via two discharge pipes with either a Y-port diffuser or a multi-port diffuser. The northern outfall pipe is 1,500 feet offshore, while the southern outfall is 1,900 feet offshore. Both outfalls lie in approximately 23 feet of water with no hardbottom present in the immediate vicinity. The plants emergency cooling water intake system withdraws water from the Indian River Lagoon at Big Mud Creek.
Essential Fish Habitat in the Project Area Hutchinson Island is a barrier island with salt marsh, intertidal flats, and unconsolidated soft bottom habitats. The SAFMC designates these habitats as EFH in the Fishery Management Plans (FMPs) for penaeid shrimp, the snapper-grouper complex, and coastal migratory pelagic species. SAFMC identifies these areas as EFH because shrimp and fish concentrate in these shallow productive habitats for feeding and refuge and experience high growth and survival rates
2 when occupying these habitats (i.e., sub-tidal shallow bottom and nearshore coastal waters).
SAFMC also identifies coastal inlets, mangroves, submerged aquatic vegetation (SAV),
nearshore hardbottom (e.g., octocorals), and Phragmatopoma (i.e., worm reefs) as Habitat Areas of Particular Concern (HAPCs) in one more of these FMPs. HAPCs are subsets of EFH that are rare, particularly susceptible to human-induced degradation, especially important ecologically, or located in an environmentally stressed area. The SAFMC provides detailed information on the EFH requirements of managed species and HAPCs in a comprehensive amendment to its fishery management plans, Fishery Ecosystem Plan of the South Atlantic Region, and Users Guide to Essential Fish Habitat Designations by the South Atlantic Fishery Management Council.
The MAFMC designates estuarine waters and tidal creeks as EFH for summer flounder and bluefish. Detailed information about the EFH requirements of species managed by MAFMC are included in separate amendments to individual FMPs and in technical reports prepared by the NMFS Northeast Fishery Science Center.
NMFS manages highly migratory species (HMS), such as sharks, under the Atlantic HMS FMP.
EFH designated by that FMP in the project area includes coastal inlets and estuaries for bull sharks, blacknose sharks, blacktip sharks, sandbar sharks, Caribbean reef sharks, spinner sharks, scalloped hammerhead sharks, bonnethead sharks, great hammerhead sharks, lemon sharks, tiger sharks, nurse sharks and Atlantic sharpnose sharks. Florida estuaries are nursery habitat for a multitude of coastal sharks with pregnant females entering estuaries to pup during spring through early summer and then neonates and juveniles using these areas as nursery habitats until exiting in the fall (McCallister et al. 2013).
Other species of commercial or recreational importance found in the project area include red drum, Atlantic croaker, spot, cobia, spotted seatrout, Atlantic menhaden, bay anchovy, striped mullet, and weakfish. Several of these species were captured during baseline fish sampling at inshore and offshore locations, as well as the intake canals (EIS Appendix C).
Potential Impacts to EFH Potential routes of effect for the St. Lucie Plant that the NRC identified include removal of habitat through withdrawals, physical alternation of habitat through discharges, chemical alteration of habitat (i.e., tritium introduction via the air/sea interface), and reduction in prey base (EIS Table 3.7). Chemical alterations from tritium are considered highly unlikely in Big Mud Creek, and are monitored in the discharge areas, with consistent limits below detection in recent operational history.
The St. Lucie cooling water intake system impinges and entrains aquatic organisms as it continuously withdraws water from the Atlantic Ocean. The intake system includes three velocity cap structures, three ocean intake pipelines, two headwall structures, and an intake canal. The velocity caps change the incoming current direction from vertical to horizontal, a design that reduces fish entrainment and complies with impingement mortality standards per 40 CFR 125.94(c)(4). FPL has examined the habitat impacts from the intake system several time since 1976, with the most recent studies in 2006, 2007, 2017, and 2018. After considering the results of these studies and weighing the costs and benefits of certain entrainment reduction technologies (e.g., close-cycling cooling), the Florida Department of Environmental Protection
3 (FDEP) agreed on March 24, 2025, that the existing design and operational measures (i.e.,
velocity cap structures) at St. Lucie are adequate.
St. Lucie discharges heated effluent in cooling ponds and offshore to the Atlantic Ocean using diffusers, which increase the discharge area and effectively increases rapid mixing with ambient waters. Acute, sublethal, and community-level effects of thermal effluents can occur to finfish and shellfish from once-through cooling systems and cooling ponds. In 2012, the NRC approved, and FPL implemented, an increase in thermal power levels from 2,700 MWt to 3,020 MWt for St Lucie Unit 1 and Unit 2 (an increase of 11.85 percent above the previously licensed level), which increase by two degrees (i.e., from 113 to 115 degrees) the temperature of the discharge to the Atlantic Ocean. Accordingly, FPL sought a revision to its National Pollutant Discharge Elimination System (NPDES) permit to allow for the additional heat load. On March 24, 2025, the FDEP issued a revised NPDES permit to comply with updated standards, along with an Administrative Order requiring FPL to conduct thermal and additional biological studies.
EIS Section 3.4.3.4 discusses models used to examine the thermal plume and to conclude that thermal limitations would be met at the edge of the mixing zone with the additional heat load.
Baseline and post-uprate thermal monitoring was used to validate model predictions and showed the largest plumes occurred during maximum southerly currents, and were approximately 180 acres in size. Researchers concluded heated water exiting the diffusers at 115 degrees, the maximum allowable discharge temperature under the NPDES permit, would be cooled down to 96 degrees within about 12.5 seconds, and the potential decrease in dissolved oxygen concentration is on the order of about 0.01 mg/L. Further, an analysis of potential incursions of the thermal plume into coastal waters found that the isotherm infrequently crosses into coastal waters, and when it did so, it occurred between the two discharge diffusers in southbound surface currents. All plume models revealed heated water quickly mixes with ambient ocean water, where mobile organisms can swim away from the plume to avoid the small area of heated surface water.
Monitoring of fish and shellfish from 2011 through 2015 wad done to determine if increased discharge temperatures would cause adverse effects on fish and shellfish in the vicinity of the discharge. No measureable impacts to the fish and shellfish were found in the vicinity of the St.
Lucie Plant and the NRC concluded that the additional uptake did not have a measurable effect on surf zone fish. To address effects to the prey base, EIS Section 3.4.3.4 and Appendix C describe studies of plankton in the vicinity of the St. Lucie Plant. Plankton sampling yielded numerous taxa of fish and crustacean eggs and larvae, showing the diverse and abundant fish and shellfish community.
Conclusion In conclusion, the St. Lucie Plant is in compliance with its NPDES permit from the Florida Department of Environmental Protection and an Industrial Wastewater Facility Permit from St.
Lucie County. Cooling water discharges are not expected to exceed thresholds identified in those permits for water temperature at the edge of the allowed mixing zone. The thermal and biological studies and validation show the heat at the point source dissipates quickly leading to no long-term adverse biological effects and possible minimum short-term impacts to EFH.
Monitoring studies show no major adverse effects to fisheries or their prey base related to plan
4 operation. While entrainment and impingement are concerns for the intake system, the design and operational measures (i.e., three velocity cap structures) in place are sufficient to reduce entrainment. Accordingly, NMFS has no EFH Conservation Recommendations for the proposed operating license extensions.
Thank you for the opportunity to provide these comments. Please direct related questions or comments to the attention of Dr. Lisa Wickliffe at Lisa.Wickliffe@noaa.gov.
Sincerely, Pace Wilber, Ph.D.
Acting Assistant Regional Administrator Habitat Conservation Division cc:
NRC, Shannon.Healy@nrc.gov, Lance.Rakovan@nrc.gov USFWS, FW4FLESRegs@fws.gov FWC, Lisa.Gregg@MyFWC.com EPA, Sable.Kacy@epa.gov SAFMC, Kathleen.Howington@safmc.net SER/47, Lisa.Wickliffe@noaa.gov Literature Cited:
McCallister, M., Ford R. and J. Gelsleichter. 2013. Abundance and Distribution of Sharks in Northeast Florida Waters and Identification of Potential Nursery Habitat, Marine and Coastal Fisheries, 5:1, 200-210, DOI: 10.1080/19425120.2013.786002 WILBER.THOMAS.P AYSON.1365820186 Digitally signed by WILBER.THOMAS.PAYSON.13658 20186 Date: 2026.02.15 18:07:29 -05'00'