ML26014A267

NRC Staffs Answer to San Antonio Bay Estuarine Waterkeepers New Contention and Amended Contention 4

ML26014A267
Person / Time
Site:	05000614
Issue date:	01/14/2026
From:	Julie Ezell, Stephens S NRC/OGC
To:	Atomic Safety and Licensing Board Panel
SECY RAS
References
RAS 57574, ASLBP 25-991-01-CP-BD01, 50-614-CP
Download: ML26014A267 (0)

Text

January 14, 2026 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of LONG MOTT ENERGY, LLC (Long Mott Generating Station)

Docket No. 50-614-CP NRC STAFFS ANSWER TO SAN ANTONIO BAY ESTUARINE WATERKEEPERS NEW CONTENTION AND AMENDED CONTENTION 4 INTRODUCTION Pursuant to 10 C.F.R. § 2.309(i)(1) and the Atomic Safety and Licensing Boards December 17, 2025 Order,1 the staff (Staff) of the U.S. Nuclear Regulatory Commission (NRC) herein responds to the Motion to Add a New Contention and Amend Contention 4 (Motion) filed by San Antonio Bay Estuarine Waterkeeper (Waterkeeper) on December 31, 2025.2 In its Motion, Waterkeeper seeks to amend Contention 4, proffered originally on August 11, 2025,3 based on information submitted by Long Mott Energy, LLC (LME) in three supplemental submittals.4 Waterkeeper also seeks to add a new contention based on information submitted 1 Memorandum and Order (Establishing Schedule for Answers to Motion to Amend Contention 4)

(Dec. 17, 2025) (ADAMS Accession No. ML253351A186).

2 San Antonio Bay Estuarine Waterkeepers Motion to Add a New Contention and Amend Contention 4 Based on Long Motts Supplements to the [Preliminary Safety Analysis Report (PSAR)] (Dec. 31, 2025)

(ML25365B107) (Motion).

3 San Antonio Bay Estuarine Waterkeepers Petition to Intervene and Request for Adjudicatory Hearing (Aug. 11, 2025) (ML25223A335) (Petition).

4 Letter from Charles OConnor, LME, to Document Control Desk, NRC, Supplement #2 to the Preliminary Safety Analysis Report for the Long Mott Generating Station Construction Permit Application (Nov. 20, 2025) (ML25324A306 (package)) (Supplement 2); Letter from Charles OConnor, LME to Document Control Desk, NRC, Supplement #3 to the Preliminary Safety Analysis Report for the Long Mott Generating Station Construction Permit Application (Dec. 4, 2025) (ML25338A310 (package))

(Supplement 3); and Letter from Charles OConnor, LME to Document Control Desk, NRC, Supplement by LME in Supplement 2 to its preliminary safety analysis report (PSAR).5 For the reasons set forth below the Motion should be denied.

BACKGROUND On November 20, 2025, LME submitted Supplement 2 to its PSAR.6 LME states that Supplement 2, which contains five enclosures, includes redlined markups of certain Subsections to PSAR Chapter 2.4, Hydrology, based on additional site-specific information and analyses.7 More specifically, Enclosure 1 of Supplement 2 provides a revision to PSAR section 2.4.2, Floods. Enclosure 2 of Supplement 2 provides a revision to PSAR section 2.4.3, Probable Maximum Flood on Streams and Rivers. Enclosure 3 of Supplement 2 provides a revision to PSAR section 2.4.4, Potential Dam Failures. Enclosure 4 of Supplement 2 provides a revision to PSAR section 2.4.5, Probable Maximum Surge and Seiche Flooding, in which the design basis external flooding event analyzed is due to the maximum storm surge.8 Enclosure 5 of Supplement 2 provides a revision to PSAR section 2.4.10, Flood Protection Requirements.

PSAR section 2.4.10, as updated by Supplement 2, Enclosure 5, states that requirements for systems, structures, and components (SSCs) at the facility ensure that water ingress from the design basis hazard level external flood does not adversely impact the capability of safety-related SSCs to carry out their safety functions.9 The PSAR also states that [d]etailed flooding mitigation plans will be developed as plant design progresses and will be provided with the plant final design in the Operating License Application.10 LME submitted two additional supplements

1. 4 to the Preliminary Safety Analysis Report for the Long Mott Generating Station Construction Permit Application (Dec. 12, 2025) (ML25346A256 (package)) (Supplement 4).

5 Supplement 2.

6 Id.

7 Id. at 1.

8 See Supplement 2, Encl. 5 at 2.4.10-2.

9 Id. at 2.4.10-2.

10 Id. at 2.4.10-2; see also Construction Permit Application Part II Preliminary Safety Analysis Report, section 2.4.10, Flooding Protection Requirements, at 2.4-315. (ML25090A061) (PSAR).

in December 2025.11 The NRC Staffs review of the LMEs construction permit application and its PSAR supplements is ongoing and the Staff has not reached any conclusions about the acceptability of the application.

DISCUSSION I.

Standing The NRC Staff incorporates here its discussion of standing in its September 5, 2025, Answer, in which the NRC Staff states its position that Waterkeeper has demonstrated representational standing in this matter.12 II.

Contention Admissibility The NRC Staffs September 5, 2025, Answer discusses the Commissions requirements for proffering an admissible contention.13 Portions of that discussion are particularly relevant here. A petitioner must fulfill each one of the requirements in 10 C.F.R. § 2.309(f)(1) for a particular contention to be admissible.14 Under 10 C.F.R. § 2.309(f)(1)(vi), a proposed contention must demonstrate a genuine dispute exists with the applicant on a material issue of law or fact. A dispute at issue is material if its resolution would make a difference in the outcome of the licensing proceeding.15 Further, [n]either mere speculation nor bare or conclusory assertions, even by an expert, alleging that a matter should be considered will suffice to allow the admission of a proffered contention.16 Additionally, NRC guidance does not 11 See Supplement 3 (updating Table 2.0-1 to reflect changes LME made in Supplement 2); Supplement 4 (adding site-specific information and analyses in PSAR section 2.5, Geology).

12 NRC Staffs Answer to San Antonio Bay Estuarine Waterkeeper Petition to Intervene and Request for Hearing, at 4-7 (Sep. 5, 2025) (ML25249A000).

13 See id. at 8-11.

14 See, e.g., Entergy Nuclear Operations, Inc. (Indian Point, Unit 2), CLI-16-5, 83 NRC 131, 136 (2016).

15 Holtec International (Hi-STORE Consolidated Interim Storage Facility), CLI-20-4, 91 NRC 167, 190 (2020) (citing Duke Energy Corp. (Oconee Nuclear Station, Units 1,2, and 3), CLI-99-11, 49 NRC 328, 333-34 (1999)).

16 System Energy Resources, Inc. (Early Site Permit for Grand Gulf ESP Site), LBP-04-19, 50 NRC 277, 289 (2004); see also, Entergy Nuclear Generation Co. (Pilgrim Nuclear Power Station), CLI-12-15, 75 NRC 704, 714 (2012) (Bare assertions and speculation even by an expert, are insufficient to trigger a full adjudicatory proceeding.); Amergen Energy Co. (Oyster Creek Nuclear Generating Station), CLI create legal requirements.17 Although NRC guidance documents are not legally binding, and compliance with them is not required, they describe an approach to compliance with [NRC] rules that is acceptable to the NRC.18 Amended Contention 4 is inadmissible because Waterkeeper does not identify any requirement to address climate change in a PSAR and requests more than the NRCs rules require.

The Motion does not provide any amended text to be used as an amended Contention 4, but rather states, in part that it seeks to amend Contention 4 to make clear that the climate change critique raised in its August 11, 2025, Petition extends to Supplement 2, Supplement 3, and Enclosure 6 to Supplement 4 because those supplements do not include an analysis of the effects of climate change.19 Pursuant to 10 C.F.R. § 2.309(f)(1)(iv) and (vi) a petition must demonstrate that the issue raised in the contention is material to the findings the NRC must make to support the action that is involved in the proceeding and show that a genuine dispute exists with the applicant on a material issue of law or fact. In its August 11, 2025 Petition, Waterkeepers declarant states to my knowledge, the NRC has no regulatory requirement to consider the safety and environmental effects of climate change in its licensing decisions for nuclear reactors.20 In its Motion, Waterkeeper cites no regulation or requirement to address 28, 68 NRC 658, 674 (2008) (Bare assertions and speculation, such as Citizens experts speculation that [i]t is... likely that an analysis that complies with the ASME Code would predict that the [cumulative usage factor] would become greater than one during the proposed period of extended operation, and that the environmental factors in the [license renewal application] and the [request for additional information]

are probably non-conservative, do not supply the requisite support.); Interim Storage Partners LLC (WCS Consol. Interim Storage Facility), LBP-19-7, 90 NRC 31, 90 (2019) (A contention cannot be admitted on bare assertions and speculation alone.).

17 See, e.g., Entergy Nuclear Operations, Inc. (Indian Point, Units 2 & 3), CLI-15-6, 81 NRC 340, 358 (2015) (To be sure, Staff guidance documents do not have the force of law and we are not bound to follow them.); Int'l Uranium (USA) Corp., CLI-00-1, 51 NRC 9, 19 (2000) (stating guidance does not have the force of regulation and does not impose any additional legal requirements upon licensees. Licensees remain free to use other means to accomplish the same regulatory objectives.); Nextera Energy Seabrook, LLC (Seabrook Station, Unit 1), LBP-20-12, 92 NRC 431, 453 (2020) (Indeed, an agency violates the Administrative Procedure Act if it treats a guidance document as binding, either on itself or on the regulated community.).

18 Areva Enrichment Servs., LLC (Eagle Rock Enrichment Facility), CLI-11-4, 74 NRC 1, 8 n.35 (2011).

19 Motion at 9.

20 Petition, Ex. F at ¶ 12.

climate change in the PSAR or any requirement for the NRC to consider climate change as part of its review of a construction permit application, and through its declarant, acknowledges that the NRC does not require the applicant to provide such an analysis.21 Through its Amended Contention 4, Waterkeeper seeks more than the regulations require, and, as such, it must be rejected as a collateral attack on the NRCs rules.22 Moreover, Waterkeeper fails to show a genuine dispute with the information the applicant included in its supplements to its construction permit application on a material issue of law or fact because Waterkeeper has shown no requirement for the applicant to address climate change. Therefore, Amended Contention 4 is inadmissible.

Waterkeepers new proposed contention challenging the safety of the current plant design due to asserted deficiencies in LMEs analyses in Supplement 2 to its PSAR are not adequately supported.

Waterkeepers new proposed contention states that [u]nder 10 C.F.R. § 50.34 and the National Environmental Policy Act (NEPA), LMEs Supplement 2 to the PSAR fails to support a conclusion that the plant is adequately safe as currently designed, nor does it demonstrate acceptable environmental impacts.23 Specifically, Waterkeeper challenges LMEs analysis of 21 See Motion at 9; Petition, Ex. F at ¶ 12. The NRC Staff notes that Principal Design Criterion 2 in LMEs PSAR requires, in part, [a]ppropriate consideration of the severity of the natural phenomena that have been historically reported for the site and surrounding area with sufficient margin for the limited accuracy, quantity, and period of time in which the historical data have been accumulated. LME Application, Part II, PSAR at 5.3-2-5.3-3; cf. 10 C.F.R. part 50, app. A, General Design Criterion 2 (the NRC Staff notes that this regulation does not specifically apply to this application). Waterkeeper also does not acknowledge the NRCs Process for the Ongoing Assessment of Natural Hazards Information (POANHI), which uses a graded approach to proactively seek, evaluate, and respond to new information on natural hazards (e.g.,

seismic, flooding, and extreme weather). See Proposed Resolution of Remaining Tier 2 and 3 Recommendations Resulting from the Fukushima Dai-ichi Accident, Commission Paper SECY-16-0144 (Dec. 29, 2016) (ML16286A586 (package)); Staff RequirementsSECY-16-0144Proposed Resolution of Remaining Tier 2 and 3 Recommendations Resulting from the Fukushima Dai-ichi Accident (May 3, 2017) (ML17123A453); see also Process for the Ongoing Assessment of Natural Hazards Information, NRC Office Instruction LIC-208 (Nov. 20, 2019) (ML19210C288).

22 NextEra Energy Seabrook, LLC (Seabrook Station, Unit 1), CLI-12-5, 75 NRC 301, 315 (2012)

(citations omitted); see Philadelphia Electric Co. (Peach Bottom Atomic Power Station, Units 2 and 3),

ALAB-216, 8 AEC 13, 20-21 (1974) (explaining that a contention that seeks to raise an issue that is not proper for adjudication in the proceeding or that does not apply to the facility in question, or seeks to raise an issue that is not concrete or litigable must also be rejected).

23 Motion at 3, citing 10 C.F.R. § 50.34(a)(2), 10 C.F.R. § 50.34(a)(3), and 10 C.F.R. § 50.34(a)(4). The Motion states that LME characterizes Supplement 2 as confirmatory in nature and states that the new probable maximum precipitation (PMP) and probable maximum flood (PMF) in Enclosure 2 of Supplement 2, LMEs dam analysis in Enclosure 3 of Supplement 2, and LMEs discussion of flood protection analysis in Enclosure 5 of Supplement 2.24 Waterkeeper does not explain how LME fails to meet 10 C.F.R. § 50.34, other than stating, generally, that the PSAR fails to support a conclusion that the plant is adequately safe as currently designed.25 Waterkeeper raises several issues with LMEs PMF and PMP analysis and dam failure analysis, but does not assert that any SSCs are not properly protected based on LMEs analyses or that the storm surge event is not the bounding event (i.e., the maximum external flooding event). In its proposed new contention, Waterkeeper challenges LMEs PMP and PMF analyses and dam failure analyses, neither of which are the bounding design basis external flooding event analyzed in the LME PSAR. LMEs design basis external flooding event analyzed in the LME PSAR is due to the maximum storm surge.26 The PSAR states that the still water level as a result of the probable maximum storm surge is predicted to be at elevation 36.38 ft (11.1 m) NAVD 88.27 When including wave water runup, the PSAR states that the flood water level at the wall of the buildings on the site is predicted to be at elevation 46.49 ft (14.17 m) NAVD 88.28 LMEs PSAR states that requirements for SSCs at the facility ensure that water ingress from the design basis hazard level external flood does not adversely impact the capability of safety-related SSCs to carry out their safety functions.29 As discussed below, while Waterkeeper raises several issues with LMEs PMF and PMP analysis and dam failure analysis, analyses offered in Supplement 2 do not confirm the representations in the initial [construction permit application]-PSAR. Motion at 2-3. The NRC Staff notes that Supplement 2 states that [t]he NRC, as described in Reference 2, noted that LME expected this additional site-specific information to be confirmatory in nature. Supplement 2 at 1.

24 See Motion at 4-9.

25 Id. at 2.

26 See Supplement 2, Encl. 5 at 2.4.10-2.

27 Supplement 2, Encl. 4 at 2.4.5-13; see also Supplement 2, Encl. 5 at 2.4.10-2.

28 Id.

29 See Supplement 2, Encl. 5 at 2.4.10-2.

it does not explain how the asserted deficiencies result in the plant not being adequately safe as currently designed or how any regulatory requirement is not met.

Waterkeeper argues that LMEs PMF and PMP analysis in Enclosure 2 of Supplement 2, contains a gap or omission because a specific lake was not included in LMEs modeling,30 but the lake in question was, in fact, included. Pursuant to 10 C.F.R. § 2.309(f)(1)(vi), a petition must provide sufficient information to show that a genuine dispute exists with the applicant on a material issue of law or fact. In asserting that Green Lake is not included in LMEs PMF and PMP modeling, Waterkeeper cites Figures 2.4.3-39, 2.4.3-47, and 2.4.3-48.31 But Waterkeepers declarant does not mention Figure 2.4.3-26, which shows that Green Lake is included in the model for the Guadalupe River postulated PMF.32 Waterkeepers assertions regarding Green Lake do not, therefore, support admission of its new proposed contention.

Waterkeeper also challenges the change in the left bank elevation (also referred to as the barge canal or riverbank canal elevation), but does not explain how the left bank elevation affects LMEs conclusion that the probable maximum storm surge is the bounding event, and thus does not explain how or if any SSCs are adversely affected here. For a contention to be admissible, 10 C.F.R. § 2.309(f)(1)(vi) requires a petitioner to show that a genuine dispute exists with the applicant on a material issue of law or fact, including references to specific portions of the application (including the applicants environmental report and safety report) that the petitioner disputes and the supporting reasons for each dispute, or, if the petitioner believes that the application fails to contain information on a relevant matter as required by law, the identification of each failure and the supporting reasons for the petitioners belief. The 30 Motion at 5; see also Motion, Encl. A at ¶ 16.

31 Figure 2.4.3-39 shows the flood routing model developed for the LMGS site and its direct watershed.

Figure 2.4.3-47 depicts the Guadalupe River Basin and USGS Gage Stations. Figure 2.4.3-48 depicts the San Antonio River Basin and USGS Gage Stations. Waterkeeper mistakenly relies on these figures to indicate that Green Lake is excluded from the PMF and PMP analysis in LMEs application.

32 Supplement 2, Encl. 2 at 2.4.3-9, 2.4.3-47; see also Supplement 2, Encl. 3 at 2.4.4-29, which shows Green Lake included in the Guadalupe River Cross Sections for the HEC-RAS Study Limit.

Commission has explained that [a] dispute at issue is material if its resolution would make a difference in the outcome of the licensing proceeding.33 Waterkeeper states that the change in the left bank elevation from 33.91 ft to 41.72 ft NAVD 88 has a significant effect on what flood waters would reach the LME site and inundate it.34 Waterkeeper further states that the source of the bank elevation is not supplied, the location for the elevation is not provided, and its location relative to the LME site is not provided.35 Waterkeeper states that because the left riverbank canal elevation relies on a single point ground elevation at a single point location as justification for not routing the dam failure analysis across the land between the Guadalupe River models eastern extremity the dam failure analysis is inadequate and deficient.36 However, Waterkeeper does not attempt to explain or address whether or how these issues would render the probable maximum storm surge, which is the design basis external flooding event for which the plant must be designed, incorrect. Nor does Waterkeeper provide facts or information to assert that the left bank elevation change would result in a maximum external flooding event greater than the probable maximum storm surge or otherwise demonstrate that the probable maximum storm surge does not bound the PMP or PMF. In addition, and contrary to its assertion that the plant is not adequately safe as designed, Waterkeeper does not argue that any SSCs are not properly protected. Waterkeepers assertions regarding the elevation of the left bank elevation do not, therefore, support admission of its new proposed contention.

Waterkeeper, through its declarant, states that the PSAR discussion gives no justification for not considering a hydrologic or seismic failure of the Canyon Dam,37 and states 33 HI-STORE Consolidated Interim Storage Facility, CLI-20-4, 91 NRC at 190 (citing Oconee Nuclear Station, CLI-99-11, 49 NRC at 333-34).

34 Motion at 4.

35 Id. at 5.

36 See Motion at 8-9. The Staff notes that Revision 0 of the PSAR stated that due to the presence of high bluff areas on the west side of the plant, the site is not flooded during the dam failure event. LME Application, Part II, PSAR at 2.4-50; see also Supplement 2, Encl. 1 at 2.4.2-4.

37 Motion at 7.

that an overtopping event will almost certainly lead to higher flood levels near the LME site than the failure mode analyzed in Supplement 2.38 Neither Waterkeeper nor its declarant provide any support for its ipse dixit assertion that an overtopping event will almost certainly lead to higher flood levels near the LME site.39 Speculationeven when proffered by an expertis insufficient to support an admissible contention.40 In addition, Waterkeeper does not assert that any SSCs would not be properly protected or that the maximum storm surge event is not the bounding event (i.e., the design basis external flooding event against which the plant must be designed). In fact, the maximum storm surge event is described in Enclosure 4 of Supplement 2, which Waterkeeper does not challenge in its Motion.41 Because Waterkeepers assertions regarding the Canyon Dam failure analysis amount to speculation, these assertions do not support the admissibility of its new contention.

Finally, Waterkeeper states that the analyses in Supplement 2 do not demonstrate acceptable environmental impacts.42 Pursuant to 10 C.F.R. § 2.309(f)(1)(vi), a petition for hearing must provide sufficient information to show that a genuine dispute exists with the applicant on a material issue of law or fact. Waterkeeper does not describe what aspects of the environmental impacts are unacceptable or reference any section of the LMEs environmental report.43 Waterkeepers failure to challenge LMEs supplement to its environmental report with specificity renders its proposed new contention inadmissible.

38 Id. at 8 (emphasis added).

39 Id. at 8. Waterkeeper points to no regulation and instead, points to an NRC guidance document, JLD-ISG-2013-01, stating that LME invokes its use for the first time in Enclosure 3 of Supplement 2. See Motion at 6. The ISG document is guidance, and thus LME is not required to meet it. See, e.g., Eagle Rock Enrichment Facility, CLI-11-4, 74 NRC at 8 n.35 (2011). NRC guidance does not create legal requirements. See supra n.17.

40 See Grand Gulf ESP Site, LBP-04-19, 50 NRC at 289; see also supra n.16.

41 See Supplement 2, Encl. 4.

42 Motion at 2.

43 Moreover, NRC regulations do not require a showing that the environmental impacts of a particular action are acceptable. See 10 C.F.R. § 51.45 (stating the applicant must submit an environmental report CONCLUSION For the reasons discussed above, Waterkeepers Motion to add a new contention and amend Contention 4 should be denied. In its Amended Contention 4, Waterkeeper identifies no regulatory requirement for climate change per se to be addressed in a PSAR or any requirement for the NRC to consider climate change as part of its review of a construction permit application, contrary to 10 C.F.R. § 2.309(f)(1)(iv) and (vi). In its proposed new contention, Waterkeeper does not explain how LME fails to meet 10 C.F.R. § 50.34 or how the plant is not safe as currently designed. In addition, and while the NRC Staffs review of LMEs construction permit application and supplemental information submitted is ongoing and the NRC Staff has reached no conclusions regarding the application, Waterkeeper has also failed to challenge LMEs recent supplements to its PSAR with specificity or with supporting facts or expert opinion that is more than speculative in nature. Waterkeepers Motion should therefore be denied.

Respectfully submitted,

/Signed (electronically) by/

Samuel K. Stephens Counsel for NRC Staff Mail Stop: O-15-B04 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Telephone: (301) 415-1581 E-mail: samuel.stephens@nrc.gov Executed in Accord with 10 CFR 2.304(d)

Julie G. Ezell Counsel for NRC Staff Mail Stop: O-15-B04 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Telephone: (301) 287-9157 E-mail: julie.ezell@nrc.gov containing certain information, including a description of the proposed action, a statement of its purposes, a description of the environment affected, and discuss the following considerations).

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of LONG MOTT ENERGY, LLC (Long Mott Generating Station)

Docket No. 50-614-CP Certificate of Service Pursuant to 10 C.F.R. § 2.305, I hereby certify that the NRC STAFFS ANSWER TO SAN ANTONIO BAY ESTUARINE WATERKEEPERS NEW CONTENTION AND AMENDED CONTENTION 4, has been filed through the NRCs E-Filing System this 14th day of January 2026.

/Signed (electronically) by/

Samuel K. Stephens Counsel for NRC Staff Mail Stop: O-15-B04 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Telephone: (301) 415-1581 E-mail: samuel.stephens@nrc.gov