ML25365B107
| ML25365B107 | |
| Person / Time | |
|---|---|
| Site: | 05000614 |
| Issue date: | 12/31/2025 |
| From: | Perales M Perales, Allmon & Ice, P.C., San Antonio Bay Estuarine Waterkeeper |
| To: | Atomic Safety and Licensing Board Panel |
| SECY RAS | |
| References | |
| RAS 57569, ASLBP 25-991-01-CP-BD01, 50-614-CP | |
| Download: ML25365B107 (0) | |
Text
1 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)
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§ Docket No. 50-614-CP ASLBP No. 25-991-01-CP-BD01 December 31, 2025 SAN ANTONIO BAY ESTUARINE WATERKEEPERS MOTION TO ADD A NEW CONTENTION AND AMEND CONTENTION 4 BASED ON LONG MOTTS SUPPLEMENTS TO THE PSAR Pursuant to 10 C.F.R. § 2.309(c), San Antonio Bay Estuarine Waterkeeper (Waterkeeper or Petitioner) submits this Motion, by which it seeks leave to add a new contention and amend Contention 4 in its August 11, 2025 Petition to Intervene and Request for Hearing, based on Long Mott Energy, LLCs (LME) Supplements to its Preliminary Safety Analysis Report (PSAR)specifically, Supplements 2 and 3 and to Supplement 4.
I.
Introduction By this Motion, Waterkeeper seeks to add a new contention and to amend a portion of its Contention 4, based on LMEs PSAR Supplements 2 and 3 and Enclosure 6 to Supplement 4.1 As explained below, Waterkeeper maintains that Supplement 2 to the PSAR presents deficiencies regarding LMEs (1) Probable Maximum Precipitation (PMP) and Probable Maximum Flood (PMF) analyses; (2) dam failure analysis; and (3) flood 1 Supplement 2 to the PSAR for the LMGS CPA (released Dec. 1, 2025) (ML25324A306); Supplement 3 to the PSAR for the LMGS CPA (released Dec. 5, 2025) (ML25338A310); Supplement 4 to the PSAR for the LMGS CPA (released Dec. 17, 2025) (ML25346A256).
2 protection analysis. For these reasons, the PSAR does not support a conclusion that the plant is adequately safe as currently designed, nor does it demonstrate acceptable environmental impacts.
Further, Supplements 2 and 3 and Enclosure 6 to Supplement 4 to the PSAR fail to consider the effects of climate change. For this reason, Waterkeeper seeks to amend its Contention 4 to make clear that the noted deficienciesregarding failure to consider effects of climate changeremain unaddressed in these Supplements to the PSAR.
II.
Waterkeepers proposed new contention Under 10 C.F.R. § 50.342 and the National Environmental Policy Act (NEPA),3 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.
A.
LMEs Supplement 2 to the PSAR LME characterizes Supplement 2 to the PSAR as providing additional site-specific information... to support the descriptions of the LMGS hydrological characteristics and associated data collection, testing, analysis, and modeling that are contained in Section 2.4 2 E.g., 10 C.F.R. § 50.34(a)(2) (requiring [a] summary description and discussion of the facility, with special attention to design and operating characteristics, unusual or novel design features, and principal safety considerations); 10 C.F.R. § 50.34 (a)(3); 10 C.F.R. § 50.34(a)(4) (requiring [a] preliminary analysis and evaluation of the design and performance of structures, systems, and components of the facility with the objective of assessing the risk to public health and safety resulting from operation of the facility and including determination of the margins of safety during normal operations and transient conditions anticipated during the life of the facility, and the adequacy of structures, systems, and components provided for the prevention of accidents and the mitigation of the consequences of accidents).
3 42 U.S.C. § 4336(b)(1). As Waterkeeper maintained in its Petition, there is a reasonably foreseeable and potentially significant effect on the quality of the human environment at least due to the risk of accidents.
As drafted, the PSAR obscures the actual risk of accidents because of erroneous assumptions and omissions in the document.
3 of the LMGS PSAR,4 and that it is confirmatory in nature.5 But the new analyses offered in Supplement 2 do not confirm the representations in the initial CPA-PSAR; nor do they provide adequate site-specific analyses.6 Accordingly, Waterkeeper maintains that Supplement 2 presents a new basis for submitting a new contention.
As explained more fully below, Waterkeeper maintains that Supplement 2 to the PSAR provides a basis for a new contention challenging LMEs (1) Probable Maximum Precipitation (PMP) and Probable Maximum Flood (PMF) analyses; (2) dam failure analysis; and (3) flood protection analysis. An attached Declaration by Mr. Jeffrey T.
Mitman offers support for Waterkeepers proposed new contention.7 In it, Mr. Mitman explains why the analyses in Supplement 2 to the PSAR are deficient and do not support a conclusion that the plant is adequately safe as currently designed, nor does it demonstrate acceptable environmental impacts.
B.
Basis Statement Waterkeepers proposed new contention is based on the information contained in LMEs PMP and PMF analyses (PSAR Supplement 2, Enclosure 2, Subsection 2.4.3, Probable Maximum Flood on Streams and Rivers);8 dam failure analysis (PSAR Supplement 2, Enclosure 3, Subsection 2.4.4, Potential Dam Failures);9 and flood 4 LME PSAR Supplement 2 (Nov. 20, 2025) (ML25324A307), at pdf p. 1.
5 Id.
6 As an example, in the initial CPA-PSAR, the Guadalupe Rivers left bank elevation is represented as 33.91 ft NAVD 88. PSAR Section 2.4.3.1, p. 2.4-77. In Supplement 2, this elevation has changed to 41.72 NAVD 88. PSAR Supplement 2, Enclosure 2 at Section 2.4.3.1, p. 2.4.3-4, and Supplement 2, Enclosure 2 at Section 2.4.3.2.7, p. 2.4.3-17.
7 See Mitman Declaration, Enclosure A.
8 Enclosure 2 to LME PSAR Supplement 2 (Nov. 20, 2025) (ML25324A309) (hereinafter Enclosure 2).
9 Enclosure 3 to LME PSAR Supplement 2 (Nov. 20, 2025) (ML25324A310) (hereinafter Enclosure 3).
4 protection analysis (PSAR Supplement 2, Enclosure 5, Subsection 2.4.10, Flood Protection Requirements).10 Waterkeeper addresses each in turn below.
- 1.
LMEs analysis of PMP and PMF on streams and rivers First, Waterkeeper addresses Enclosure 2, which amends Subsection 2.4.3, Probable Maximum Flood on Streams and Rivers. This Supplement materially alters LMEs PMP and PMF analyses for the proposed LMGS. The original PSAR provided that the Guadalupe Rivers left bank is at elevation 33.91 ft NAVD 88,11 but PSAR Supplement 2 changes this assumed elevation to 41.72 ft NAVD 88.12 As Mr. Mitman explains, This change in the assumed elevation has a significant effect on what flood waters would reach the LME site and inundate it.13 Section 2.4.3.3, Additional PMF Analysis on Guadalupe and San Antonio Watersheds, illustrates the significance of the change to this critical assumption.14 Mr.
Mitman describes, This section presents a new analysis, whereby Long Mott purports to evaluate flooding of the LME site from PMP/PMF events on the Guadalupe and San Antonio Rivers.15 Within, LME states, A barge canal is located between the Guadalupe River and LMGS site with embankment elevation at 41.72 ft. (12.71 m) NAVD 88.
Therefore, this embankment is not inundated with a margin of 11 in. (28 cm).16 10 Enclosure 5 to LME PSAR Supplement 2 (Nov. 20, 2025) (ML25324A312) (hereinafter Enclosure 5).
11 See, e.g., LME PSAR Revision 0, Section 2.4.3.1, Summary of VCS PMF Analysis, p. 2.4-77.
12 See, e.g., Enclosure 2, at 2.4.3-4; id. at 2.4.3-17.
13 Mitman Declaration, Enclosure A, ¶ 11. Mr. Mitman also underscores that the Supplement fails to provide an explanation or basis for this significant change. Id.
14 Enclosure 2, at 2.4.3-17; Mitman Declaration, Enclosure A, ¶ 12.
15 The models are located in Figures 2.4.3-47, Guadalupe River Basin, and 2.4.3-48, San Antonio River Basin. Mitman Declaration, Enclosure A, ¶ 12.
16 Enclosure 2, at 2.4.3-18.
5 However, as Mr. Mitman explains, the models do not encompass the LME site.
Instead, flood heights are apparently developed on the rivers and then the floods are presumed to not inundate the LME site based on the single elevation at the barge canal located between the Guadalupe River and the LME site.17 This embankment elevation 41.72 ft NAVD 88constitutes LMEs basis for presuming that various floods, including those described in Sections 2.4.3.1 and 2.4.3.3, do not flood the site. However, the source of this critical barrier height is not supplied; nor does the discussion state at what location on the barge canal this elevation is found, or its location relative to the LME site.18 There is also a gap between the Guadalupe River model and the Coloma Creek model contained in Section 2.4.3.2, West Coloma Creek Probable Maximum Flood.19 Mr. Mitman explains:
The model was used to evaluate flood heights from a PMP/PMF event in the Coloma Creek watershed adjacent to and enveloping the LME site. Based on my review of the initial PSAR and Supplement 2 to the PSAR, the models of the Guadalupe River, the San Antonio River and Coloma Creeks are not linked; that is, there is a gap between the Guadalupe River model and the Coloma Creek model. This gap is illustrated by the fact that Green Lake, which is east of the Guadalupe River and west of the LME site, is not contained in either model (see Figures 2.4.3-39, 2.4.3-47, and 2.4.3-48). Thus, the models do not support Long Motts conclusion that a flood on the San Antonio or Guadalupe Rivers do not reach the LME site; the conclusion is unsubstantiated.20 17 Mitman Declaration, Enclosure A, ¶ 13.
18 Id. at ¶ 14. Mr. Mitman also notes that this new barrier height is also used in other Supplement 2 analyses.
Id.
19 Id. at ¶ 16. As Mr. Mitman explains, Section 2.4.3.2, West Coloma Creek Probable Maximum Flood, describes a model developed for the site, including the East and West Coloma Creeks. The area covered by the model is depicted in Figure 2.4.3-39, Computational Mesh Overview. Id.
20 Id. at ¶ 16.
6 There is no valid justification for simply assuming that the flood heights developed in the Guadalupe and San Antonio River models do not progress on to the LME site due to the barge canal barrier,21 and LME offers none. Mr. Mitman opines that, as a professional nuclear engineer with significant experience in risk analysis and the impact of external events on nuclear power plant risk, LME should have performed a more comprehensive analysis to justify its assumptions.22 This, Mr. Mitman explains, would determine whether flooding on the San Antonio and Guadalupe watersheds would reach the site of the proposed LMGS.23 Having failed to conduct such an analysis and present it in its PSAR, LME has offered an unreliable and unjustified conclusion that the site would not become flooded, without a reasonable basis to support it.24
- 2.
LMEs analysis of potential dam failures Next, Waterkeeper addresses Enclosure 3, which amends Subsection 2.4.4, Potential Dam Failures. In this revision to the PSAR, LME for the first time invokes the use of NRCs JLD-ISG-2013-01 Guidance for Assessment of Flooding Hazards Due to Dam Failure, Rev. 0, (2013.07.29) (ML13151A153) for various aspects of its dam failure analysis.25 Therein, the Staffs position regarding hydrologic embankment dam failures is that [a] dam should be assumed to fail due to hydrologic hazard if it cannot 21 Id. at ¶ 17.
22 Id.
23 Id.
24 Using Google Earth Pro, Mr. Mitman illustrated why this critical input assumption must have a well-documented basis before acceptance of these flooding analyses and their impact on the LME site. Id. at ¶20.
25 Mitman Declaration, Enclosure A, ¶ 21.
7 withstand its basin specific PMF, with associated effects.26 Its position on seismic failures is that [a] dam should be assumed to fail if it cannot withstand the relevant seismic hazards (e.g., vibratory ground motion at spectral frequencies of importance, fault displacement, loss of strength) with an annual exceedance probability of 1x10-4 per year.27 In its Guadalupe River Basin Dam Failure Modeling, LME states, For Canyon Dam, the failure method is failure mode by piping with a factor of 1 and side-slope ratio of 1.28 However, this analysis alone is inadequate. Mr. Mitman explains in his Declaration:
Both the original and Supplement 2 to the PSAR are silent regarding other dam failure modes, e.g., hydraulic and seismic failures, for the Guadulupe River and San Antonio River and Coloma Creek watersheds. Thus, this analysis on the Canyon Dam, the largest dam in the vicinity and presumably the one having the largest flooding potential at the LME site, only addresses a piping failurea type of sunny day failure. The PSAR discussion gives no justification for this failure to consider a hydrologic or seismic failure of this dam.29 Furthermore, Waterkeeper challenges LMEs conclusion that the LMGS is not impacted by upstream dam failure. LME states that [t]he maximum water surface elevation is 38.42 ft (11.71 m) NAVD 88 with still and wave runup considerations, which is lower than the left riverbank elevation of 41.72 ft (12.71 m) NAVD 88 with a margin of 3.3 ft.30 However, as discussed above and as explained by Mr. Mitman, this left riverbank canal elevation, which is based on a single point elevation as justification for not routing 26 JLD-ISG-2013-01, Guidance for Assessment of Flooding Hazards Due to Dam Failure, Rev. 0, (July 29, 2013) (ML13151A153), Section 1.4.2, Hydrologic Failure, pp. 1-8.
27 Id. at Section 1.4.3, Seismic Failure, pp. 1-8.
28 Enclosure 3, at 2.4.4-7.
29 Mitman Declaration, Enclosure A, ¶ 24; id. at ¶ 25 (LMEs failure to address both hydraulic and seismic failures is inconsistent with NRC guidance. LME offers no justification for ignoring these significant dam failure modes.).
30 Enclosure 3, at 2.4.4-13.
8 the dam failure analysis across the land between the Guadalupe River models eastern extremity and the LME site, is inadequate and not supportable.31 This failure to adequately and comprehensively analyze dam failures is a significant deficiency. This is because an overtopping failure of the Canyon Dam puts more water in the watershed than the sunny-day, piping failure event analyzed in LMEs PSAR Supplement 2. Thus, the result of an overtopping failure will lead to more water downstream and will almost certainly lead to higher flood levels near the LME site, than the sunny-day piping failure event included in LMEs PSAR Supplement 2. Because the PSAR Supplement 2 analysis fails to address overtopping of the largest dams, it is inadequate and deficient.32
- 3.
LMEs flood protection analysis Lastly, Waterkeeper addresses Enclosure 5, which amends Subsection 2.4.10, Flooding Protection Requirements. This section summarizes both Section 2.4.3 on PMP/PMF33 and Section 2.4.4 on dam failures.34 Mr. Mitman again opines, As with my comment on Enclosure 2 above regarding this left riverbank canal elevation, relying on a single point ground elevation at a single point location as justification for not routing the 31 Mitman Declaration, Enclosure A, ¶ 27.
32 Id. at ¶ 28 (An overtopping failure of the Canyon Dam puts more water in the watershed than a piping failure. Thus, the result of an overtopping failure will lead to more water downstream and will almost certainly lead to higher flood levels near the LME site.).
33 Enclosure 5, at 2.4.10-1 (The maximum PMF flooding water level at LMGS is postulated to be at elevation 40.8 ft (12.44 m) NAVD 88. This is lower than the left bank elevation at this location, 41.72 ft (12.71 m) NAVD 88, by 11 in (28 cm). Therefore, the left bank of the river is not overtopped by wind-wave runup effect. The site will not be flooded during a Guadalupe River PMF event.).
34 Id. (Dam failures within the Guadalupe River basin and the failure of the on-site basin embankment are evaluated in Section 2.4.4. The maximum dam failure water level at LMGS is at elevation 38.42 ft (11.71 m). Therefore, the left bank of the river, which is at elevation 41.72 ft (12.72 m), is not overtopped by wind-wave runup effect. The site is not flooded during a Guadalupe River dam failure event.).
9 dam failure analysis across the land between the Guadalupe River models eastern extremity and the LME site is inadequate and deficient.35 In sum, Waterkeeper maintains that the LMGS PSAR with the referenced Supplements is deficient and does not support a conclusion that the proposed facility, as currently designed, is adequately safenor that it demonstrates acceptable environmental impacts, under either 10 C.F.R. § 50.34 or NEPA.36 III.
Waterkeepers motion to amend Contention 4 Waterkeepers Contention 4 claimed that the PSAR failed to consider the effects of climate change in its analysis. Supplements 2 and 3 and Enclosure 6 to Supplement 4 fail to remedy this deficiency. None includes an analysis of the effects of climate change.
Accordingly, Waterkeeper seeks to amend Contention 4 to make clear that this critique extends to Supplements 2 and 3 and Enclosure 6 to Supplement 4. Mr. Mitmans Declaration is offered in support of this proposed amendment to Contention 4.37 IV.
Good cause exists for this filing.
Waterkeeper respectfully submits that it satisfies the good cause standard in 10 C.F.R. § 2.309(c)(i)-(iii) for its proposed new contention and amended Contention 4.
LMEs PSAR Supplements 2 and 3 and Enclosure 6 to Supplement 4 present new informationmuch of which is materially different from what was presented in the original PSAR, as discussed above. Indeed, the Staff continues to review the adequacy of Supplement 2.
35 Mitman Declaration, Enclosure A, ¶ 30.
36 Id. at ¶ 33; see supra notes 2-3.
37 Mitman Declaration, Enclosure A, ¶¶ 7, 8.
10 This filing is being submitted in a timely fashion. The Boards August 28, 2025 Initial Prehearing Order set the deadline for filing new/amended contentions within 30 days of the date upon which the information that is the basis of the motion becomes available to the petitioner/intervenor. LME submitted Supplement 2 to the PSAR by cover letter dated November 20, 2025 (ML25324A307). The Supplement was added to the Commissions ADAMS Public Search database on December 1, 2025. 38 Accordingly, the deadline for filing a new/amended contention based on Supplement 2 is December 31, 2025. 39 Therefore, this filing is timely.
V.
Conclusion For the foregoing reasons and those described in its Motion, Waterkeepers Motion to Add a New Contention and Amend Contention 4 Based on Long Motts Supplements to the PSAR should be granted.
Date: December 31, 2025 Respectfully submitted, Signed (electronically) by Marisa Perales Marisa Perales Texas Bar No. 24002750 marisa@txenvirolaw.com PERALES, ALLMON & ICE, P.C.
1206 San Antonio St.
Austin, Texas 78701 512-469-6000 (t) l 512-482-9346 (f)
Counsel for San Antonio Bay Estuarine Waterkeeper 38 LME submitted PSAR Supplement 3 by cover letter dated December 4, 2025 (ML25338A310), which was added to ADAMS December 5, 2025. LME submitted PSAR Supplement 4 by cover letter dated December 12, 2025 (ML25346A257), which was added to ADAMS December 17, 2025.
39 The deadline for filing a new/amended contention based on Supplement 3 is January 5, 2026. The deadline for filing a new/amended contention based on Supplement 4 is January 16, 2026.
11 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)
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§ Docket No. 50-614-CP ASLBP No. 25-991-01-CP-BD01 December 31, 2025 CERTIFICATE OF SERVICE Pursuant to 10 C.F.R. § 2.305, I hereby certify that, on December 31, 2025, copies of the foregoing San Antonio Bay Estuarine Waterkeepers Motion to Add a New Contention and Amend Contention 4 Based on Long Motts Supplements to the PSAR were served upon the Electronic Information Exchange (the NRCs E-Filing System), in the above-captioned docket.
Signed (electronically) by Marisa Perales Marisa Perales Texas Bar No. 24002750 marisa@txenvirolaw.com PERALES, ALLMON & ICE, P.C.
1206 San Antonio St.
Austin, Texas 78701 512-469-6000 (t) l 512-482-9346 (f)
Counsel for San Antonio Bay Estuarine Waterkeeper
ENCLOSURE A
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)
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§ Docket No. 50-614-CP ASLBP No. 25-991-01-CP-BD01 December 31, 2025 DECLARATION OF JEFFREY T. MITMAN IN SUPPORT OF MOTION TO ADD A NEW CONTENTION AND AMEND CONTENTION 4 I, Jeffrey T. Mitman, declare as follows:
- 1. My name is Jeffrey T. Mitman. I am over eighteen (18) years of age and of sound mind, have never been convicted of a felony, and am otherwise capable of making this declaration. The information in this declaration is based on my personal experience and my review of documents filed in this proceeding and publicly available information.
Expert Qualifications and Relevant Experience
- 2. By education and experience, I am a nuclear engineer, with a significant level of expertise in nuclear power, risk analysis and the impact of external events on nuclear power plant risk.
- 3. As set forth in my attached Curriculum Vitae (Enclosure A-1), I have more than 40 years of experience in the nuclear industry and 16 years as a regulator with the U.S.
Nuclear Regulatory Commission (NRC). My experience includes 16 years on the technical staff of the NRC as a Reliability and Risk Analyst. During my last 15 years at the NRC, I served as Senior Reliability and Risk Analyst, with significant responsibility for managing a number of risk analysis projects and teams.
- 4. During my employment in the nuclear industry and the NRC, I became very familiar with NRC regulations and guidance regarding nuclear power plant safety, and with
Declaration of Jeffrey T. Mitman Page 2 the application of risk analysis to reactor safety analysis. I am also familiar with the NRCs requirements regarding Preliminary and Final Safety Analysis Reports.
- 5. As an NRC Staff member, I participated in NRC safety reviews and performed risk analysis on U.S. nuclear reactors. I also participated in reviews related to the risk to Oconee Nuclear Plant, Units 1, 2 and 3 (Oconee) posed by potential failure of the upstream Jocassee Dam. In addition, I coauthored a generic study by NRC of dam failure risk, with particular application to Oconee. I also worked on the NRC post-Fukushima analysis, which included preparing and reviewing flooding analysis methodologies and procedures.
- 6. In 2021, I retired from the NRC and became a private consultant. In that role, I have participated as an expert consultant to environmental organizations in the subsequent license renewal proceedings for the Oconee and North Anna reactors and in the administrative proceeding for revisions to the License Renewal Generic Environmental Impact Statement.
Contention 4 and PSAR Supplements 2, 3, and Enclosure 6 to Supplement 4: Climate Change
- 7. Following my review of Long Motts initial construction permit application, I provided a Declaration in support of Waterkeepers Petition to Intervene, explaining, in part, that Long Motts PSAR was deficient for failing to consider the effects of climate change on the safety of the proposed facility: With the exception of a single input into the hurricane analysis, the PSAR contains no discussion of the effects of climate change on the safety of the proposed LMGS. This is a serious deficiency, because the LMGS site is vulnerable to multiple climate change effects, including flooding and hurricanes.
- 8. Having reviewed Supplements 2 and 3, and Enclosure 6 to Supplement 4 to the PSAR, my professional opinion remains the same. That is, the PSAR, as supplemented, remains deficient because it fails to consider the effects of climate change on the safety of the proposed facility. The supplements to the PSAR did not remedy this deficiency.
Declaration of Jeffrey T. Mitman Page 3 Supplement 2, Enclosure 2: Analysis of PMP/PMF on Streams and Rivers
- 9. Based on my review of Supplement 2 to Long Motts PSAR, I have additional concerns regarding Long Motts Probable Maximum Precipitation (PMP) and Probable Maximum Flood (PMF) analyses.
- 10. For context, in PSAR Revision 0, Long Mott states that the Guadalupe Rivers left bank is at elevation 33.91 ft NAVD 88. See, e.g., PSAR Section 2.4.3.1, Summary of VCS PMF Analysis, p. 2.4-77.
- 11. In its PSAR Supplement 2, Long Mott has changed this assumed elevation to 41.72 ft NAVD 88. See, e.g., PSAR Supplement 2, Enclosure 2 at Section 2.4.3.1, p. 2.4.3-4, and Supplement 2, Enclosure 2 at p. 2.4.3-18. This change in the assumed elevation has a significant effect on what flood waters would reach the LME site and inundate it. Yet, based on my review, Supplement 2 is devoid of any explanation or basis for this significant change to the assumed left bank elevation.
- 12. The significance of the change to this critical assumption is illustrated in Section 2.4.3.3, Additional PMF Analysis on Guadalupe and San Antonio Watersheds.
Supp. 2, Enclosure 2, p. 2.4.3-17. This section presents a new analysis, whereby Long Mott purports to evaluate flooding of the LME site from PMP/PMF events on the Guadalupe and San Antonio Rivers. The models are shown in Figures 2.4.3-47 Guadalupe River Basin and 2.4.3-48 San Antonio River Basin. The analysis states:
A barge canal is located between the Guadalupe River and LMGS site with embankment elevation at 41.72 ft. (12.71 m) NAVD 88. Therefore, this embankment is not inundated with a margin of 11 in. (28 cm). Supp. 2, p. 2.4.3-18.
- 13. It should be noted that the models do not encompass the LME site. Instead, flood heights are apparently developed on the rivers and then the floods are presumed to not inundate the LME site based on the single elevation at the barge canal located between the Guadalupe River and the LME site.
- 14. This un-cited embankment elevation (i.e., 41.72 ft NAVD 88) is presented as Long Motts basis for presuming that various floods, including those described in Sections 2.4.3.1 and 2.4.3.3, do not flood the site. However, the source of this critical barrier
Declaration of Jeffrey T. Mitman Page 4 height is not supplied; nor does the discussion state at what location on the barge canal this elevation is found, or its location relative to the LME site. This new barrier height is also used in other Supplement 2 analyses.
- 15. This barrier height (i.e., 41.72 ft NAVD 88) was not in the initial PSAR; rather it is new information supplied in Supplement 2.
- 16. Section 2.4.3.2, West Coloma Creek Probable Maximum Flood, describes a model developed for the site, including the East and West Coloma Creeks. The area covered by the model is depicted in Figure 2.4.3-39, Computational Mesh Overview. The model was used to evaluate flood heights from a PMP/PMF event in the Coloma Creek watershed adjacent to and enveloping the LME site. Based on my review of the initial PSAR and Supplement 2 to the PSAR, the models of the Guadalupe River, the San Antonio River and Coloma Creeks are not linked; that is, there is a gap between the Guadalupe River model and the Coloma Creek model.
This gap is illustrated by the fact that Green Lake, which is east of the Guadalupe River and west of the LME site, is not contained in either model (see Figures 2.4.3-39, 2.4.3-47, and 2.4.3-48). Thus, the models do not support Long Motts conclusion that a flood on the San Antonio or Guadalupe Rivers do not reach the LME site; the conclusion is unsubstantiated.
- 17. Instead of simply assuming that the flood heights developed in the Guadalupe and San Antonio River models do not progress onto the LME site due to the barge canal barrier, in my professional opinion and based on my experience, a more comprehensive analysis should have been performedone that links the river models with the Coloma Creek model (after modeling the gap between the models) and routing the river flooding into the Coloma Creek model. This additional modeling would determine whether flooding on the San Antonio and Guadalupe watersheds would reach the LME site.
- 18. In my professional opinion and based on my experience, there is good reason to question the reliability of Long Motts elevation assumption and to demand more information to support this assumption.
Declaration of Jeffrey T. Mitman Page 5
- 19. To illustrate, a cursory evaluation of the LME area between the Guadalupe River using Google Earth Pro indicates that there are numerous paths between the Guadalupe River and LME site where the highest elevation between the two is on the order of 34 to 36 feet and not the 41.72 ft claimed by LME. See Figure 1 below for one example of such a path.
Declaration of Jeffrey T. Mitman Page 6 Figure 1: Example Google Earth Pro Elevation Cross Section between the Guadalupe River and LME
Declaration of Jeffrey T. Mitman Page 7
- 20. While Google Earth Pro is not calibrated to NAVD 88, it does indicate that the vicinity of the reactor building is 27 feet; thus, the calibrated elevation difference between NAVD 88 and Google Earth Pro is minimal. Google Earth Pro may lack the precision of other methods for establishing elevations; however, it illustrates that this critical input assumption must have a well-documented basis prior to acceptance of these flooding analyses and their impact on the LME site.
Supplement 2, Enclosure 3: Discussion of Potential Dam Failures
- 21. In Supplement 2, Enclosure 3, LME for the first time invokes the use of NRCs JLD-ISG-2013-01 Guidance for Assessment of Flooding Hazards Due to Dam Failure, Rev. 0, (2013.07.29) (ML13151A153) for various aspects of its dam failure analysis, i.e., this guidance was not cited in the initial Rev. 0 of the PSAR.
- 22. In NRCs JLD-ISG-2013-01, staffs position regarding hydrologic embankment dam failures is: A dam should be assumed to fail due to hydrologic hazard if it cannot withstand its basin specific PMF, with associated effects. Section 1.4.2, Hydrologic Failure, p. 1-8. Likewise, this NRCs staffs position on seismic failures states: A dam should be assumed to fail if it cannot withstand the relevant seismic hazards (e.g., vibratory ground motion at spectral frequencies of importance, fault displacement, loss of strength) with an annual exceedance probability of 1x10-4 per year. Section 1.4.3, Seismic Failure, p. 1-8.
- 23. In the subsection, Physical Dam Data and Estimates of Breached Sections of Supplement 2, Enclosure 3, LME states: For Canyon Dam, the failure method is failure mode by piping with a factor of 1 and side-slope ratio of 1. PSAR Supp. 2,, p. 2.4.4-7 (emphasis added).
- 24. Both the original and Supplement 2 to the PSAR are silent regarding other dam failure modes, e.g., hydraulic and seismic failures, for the Guadulupe River and San Antonio River and Coloma Creek watersheds. Thus, this analysis on the Canyon Dam, the largest dam in the vicinity and presumably the one having the largest flooding potential at the LME site, only addresses a piping failurea type of sunny
Declaration of Jeffrey T. Mitman Page 8 day failure. The PSAR discussion gives no justification for this failure to consider a hydrologic or seismic failure of this dam.
- 25. LMEs failure to address both hydraulic and seismic failures is inconsistent with NRC guidance. LME offers no justification for ignoring these significant dam failure modes.
- 26. In the subsection, Predicted Water Levels from Upstream Dam Failure, of Supplement 2, Enclosure 3, LME states: The maximum water surface elevation is 38.42 ft (11.71 m) NAVD 88 with still and wave runup considerations, which is lower than the left riverbank elevation of 41.72 ft (12.71 m) NAVD 88 with a margin of 3.3 ft. Therefore, it is concluded that the LMGS is not impacted by upstream dam failure. PSAR Supp. 2, Enclosure 2, p. 2.4.4-13.
- 27. As I discussed above, related to Supplement 2, Enclosure 2, this left riverbank canal elevation, which is based on a single point elevation as justification for not routing the dam failure analysis across the land between the Guadalupe River models eastern extremity and the LME site, is inadequate and not supportable, in my professional opinion.
- 28. An overtopping failure of the Canyon Dam puts more water in the watershed than a piping failure. Thus, the result of an overtopping failure will lead to more water downstream and will almost certainly lead to higher flood levels near the LME site.
Because the analysis fails to address overtopping of the largest dams, it is inadequate and deficient, in my professional opinion.
Supplement 2, Enclosure 5: Flood Protection Analysis
- 29. This section in its summary of Section 2.4.3 on PMP/PMF states (Page 2.4.10-1):
The maximum PMF flooding water level at LMGS is postulated to be at elevation 40.8 ft (12.44 m) NAVD 88. This is lower than the left bank elevation at this location, 41.72 ft (12.71 m) NAVD 88, by 11 in (28 cm). Therefore, the left bank of the river is not overtopped by wind-wave runup effect. The site will not be flooded during a Guadalupe River PMF event.
Declaration of Jeffrey T. Mitman Page 9
- 30. As with my comment on Enclosure 2 above regarding this left riverbank canal elevation, relying 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 and the LME site is inadequate and deficient.
- 31. This section in its summary of Section 2.4.4 on dam failures states (Page 2.4.10-1):
Dam failures within the Guadalupe River basin and the failure of the on-site basin embankment are evaluated in Section 2.4.4. The maximum dam failure water level at LMGS is at elevation 38.42 ft (11.71 m). Therefore, the left bank of the river, which is at elevation 41.72 ft (12.72 m), is not overtopped by wind-wave runup effect. The site is not flooded during a Guadalupe River dam failure event.
- 32. As with my comment on Enclosure 2 above regarding this left riverbank canal elevation, relying on a 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 and the LME site is inadequate and deficient.
Conclusion
- 33. In my professional opinion, the LMGS PSAR with the referenced supplements remains deficient and does not support a conclusion that the plant as currently designed is adequately safe nor does it demonstrate acceptable environmental impacts for the following reasons:
- 34. It does not address climate change.
- 35. The new modeling of the San Antonio and Guadalupe Rivers and Coloma Creeks contains a significant gap between the Guadalupe River and the LME site, thus, the flood routing across the gap is inadequate.
- 36. The new Guadalupe River left bank barrier height of 41.72 is unsubstantiated.
- 37. The dam failure analysis does not comply with the newly referenced NRC guidance contained in JLD-ISG-2013-01 regarding dam failures from hydrologic and seismic events and no basis is given for not meeting this guidance.
Declaration of Jeffrey T. Mitman Page 10 Declaration Signature
- 38. My name is Jeffrey T. Mitman, my date of birth is January 7, 1957, and my address is 18407 Jerusalem Church Road, Poolesville, Maryland 20837, USA. I declare under penalty of perjury under the laws of the United States of America that the foregoing is true and correct.
Executed on the 31st day of December, 2025, in accordance with 10 C.F.R. § 2.304(d).
Signed (electronically) by Jeffrey T. Mitman Jeffrey T. Mitman 18407 Jerusalem Church Road Pollesville, Maryland 20837, USA 301-633-7525 jmitman@gmail.com
ENCLOSURE A-1
CURRICULUM VITAE FOR JEFFREY T. MITMAN Poolesville, MD December 2025 QUALIFICATIONS Reliability and risk analyst with more than 45 years experience in the nuclear industry. Skills include evaluation of probabilistic risk analyses (PRA) and management of PRA projects and teams. Highly experienced in low power and shutdown (LPSD) risk modeling issues. Solid record of bringing projects in on schedule and budget.
MAJOR ACCOMPLISHMENTS Transitioned NRC to detailed PRA models for LPSD significance determinations process evaluations.
Guided development of and managed industrys first configuration risk management software tool.
Obtained regulatory approval of EPRIs risk informed in-service inspection (RI-ISI) methodology.
Managed first PRA of bolted spent fuel storage cask.
EXPERIENCE PRIVATE CONSULTANT (Poolesville, MD)
Nuclear Risk Analyst 2021-Present Reviewed North Anna Subsequent License Renewal application and prepared technical report on adequacy of environmental and safety analyses.
Reviewed Oconee Subsequent License Renewal application and prepared technical report on adequacy of environmental and safety analyses to address flooding risks.
Reviewed and submitted comments on NRCs draft (2023) Generic Environmental Impact Statement (NUREG-1437 Revision 2).
US NUCLEAR REGULATORY COMMISSION (Rockville, MD) 2005 - 2021 Senior Reliability and Risk Analyst (NRC Office of Nuclear Reactor Regulation)
Conducted Significance Determination Process (SDP) evaluations of reactor events including development and/or modification of required risk models.
Served as lead analyst for low power and shutdown event issues and concerns.
Guided development of shutdown Standardized Plant Analysis Risk (SPAR) models.
Conducted extensive Human Reliability Analysis (HRA).
Evaluated external event risk from dam failures.
Served on NRCs Japan Team (part of USAID disaster assistance response team for Fukushima Daiichi accident), providing technical advice and support through the U.S. Ambassador to Japanese government.
Participated in post NRCs Fukushima Near Term Task Force (NTTF) flooding guidance development.
Developed NRCs guidance on crediting FLEX in risk-informed regulatory applications.
Advised NRC National Fire Protection Association (NFPA) 805 team on issues related to shutdown fire risk.
Performed evaluations of risk informed license applications.
Reliability and Risk Analyst (NRC Office of Nuclear Regulatory Research)
Project Manager for the development of shutdown SPAR models ERIN ENGINEERING AND RESEARCH, INC. (Walnut Creek, CA) 2004 - 2005 Lead Senior Engineer Prepared configuration risk management evaluation of at-power fire risk.
Prepared configuration risk management evaluation of loss of offsite power.
ABE STAFFING SERVICES (Palo Alto, CA) 2003 - 2005 Consultant to EPRI Brought project and team to closure involving Dry Cask Storage PRA involving Transnuclear bolted cask containing PWR fuel.
J e f f r e y T M i t m a n P a g e l 2 EPRI (Palo Alto, CA) 1998 - 2003 Project Manager Outage Risk Assessment and Management (ORAM-Sentinel)
- Grew first of a kind software application for performing configuration risk management in nuclear power plants.
Conducted research in low power and shutdown risk; shutdown initiating event and event frequency derivation.
Delivered multiple versions (including alpha, beta & production), testing and full documentation.
Administered utility user group, marketing, contract preparation, technology transfer, technical report publication and training.
Actively managed both development and application contracts with multiple suppliers and customers.
Managed annual $1M budget.
Dry Cask Storage PRA: Initiated innovative analysis of Transnuclear cask containing PWR fuel.
Managed unique team with diverse experience in both cask design and PRA backgrounds.
Risk Informed In-service Inspections Project (RI-ISI): Lead team in obtaining regulatory approval of methodology to safely reduce piping weld inspection requirements using combination of probabilistic and degradation analysis.
Responsible for methodology finalization and acceptance by industry and U.S. NRC.
Conducted marketing, sales, contract preparation, technology transfer, training and technical report publication.
Actively managed both development and application contracts with both suppliers and customers.
Managed annual $1M budget.
Human Reliability Analysis Project: Managed project to bring consistency on industry use of HRA methods.
Responsible for EPRI HRA area, including development of HRA Calculator software and establishment of associated users group.
ERIN ENGINEERING AND RESEARCH, INC. (Palo Alto, CA) 1992 - 1998 Lead Senior Engineer Collaborated with EPRI ORAM-SENTINEL Project Manager in project development and administration, user group administration, contract preparation, technology transfer workshops, technical report generation and editing. Performed ORAM analysis of the Diablo Canyon plant. Performed ORAM Probabilistic Analysis of Perry spent fuel pool. Drafted and edited ORAM V2.0 Users Manual. Assisted in ORAM-SENTINEL software design, performed software debugging. Principle researcher and author of BWR outage contingency report. Prepared marketing and training, materials.
ABB IMPELL CORPORATION (King of Prussia, PA) 1990 - 1992 Lead Senior Engineer Design Basis Documentation: directed team of three engineers to review PECO Feedwater System Design. Wrote Design Basis Documentation reports for Limerick and Peach Bottom power plants, identifying licensing and design concerns by reviewing the system design as documented in drawings, calculations, vendor manuals, Technical Specifications, UFSAR, SER, SRP, 10CFR50.59 safety evaluations etc. and by interfacing with utility engineering personnel. Prepared Engineering Change Requests as necessary.
Shift Outages: during Limerick Nuclear Power Plant refueling / maintenance outage. Coordinated all shift maintenance work and testing. Collaborated with all groups in power plant, allocating resources as needed to maintain schedule and reporting to senior plant outage management. Performed system reviews prior to placing them back in service. Conducted shift outage meetings. Tracked work group performance against schedule. Advised utility management on techniques for schedule and outage organizational improvements.
GENERAL ELECTRIC COMPANY (San Jose, CA)
Experience Prior to 1990 Startup-Test Engineer
J e f f r e y T M i t m a n P a g e l 3 Shift Startup Engineer: During power ascension phase coordinated all system testing on shift and startup interface with operations. During preoperational phase, acted as operations shift supervisor responsible for coordinating all system testing and flushing on shift from main control room. Updated senior utility management daily on testing status.
Additional positions: Shift Technical Advisor, Test Engineer, Lead QC / Welding Inspector.
EDUCATION / PROFESSIONAL DEVELOPMENT BSE, Nuclear Engineering, University of Michigan, Ann Arbor, MI.
Introductory VBA class, University of California, Berkeley, CA.
Misc. business courses at various colleges and universities.
Senior Reactor Operator Certified.
GE Station Nuclear Engineering.
Effective Utilization of PSA, ERIN Engineering & Research, Walnut Creek, CA.
PROFESSIONAL ASSOCIATIONS American Nuclear Society (ANS) member since 1978.
ANS Nuclear elected member of Installation Safety Division Executive Committee 2015 to 2021.
ANS Risk Informed Standards Committee (RISC).
ANS/ASME Risk Informed Standards Writing Group on Shutdown PRA Standard.
ASME Section XI, Working Group on Implementation of Risk Based Examination.
MIT Professional Summer Programs Guest Lecturer at Risk-Informed Operational Decision Management Course.
PAPERS
- 1. Technical Challenges Associated with Shutdown Risk when Licensing Advanced Light Water Reactors, PSAM 12 2014. Co-author.
- 2. Comparing Various HRA Methods to Evaluate Their Impact on the results of a Shutdown Risk Analysis during PWR Reduced Inventory, PSAM11 2012. Co-author.
- 3. Uncertainty Analysis for Large Dam Failure Frequencies Based on Historical Data, PSAM11 2012. Co-author.
- 4. An Assessment of Large Dam Failure Frequencies Based on US Historical Data, PSA 2011. Co-author.
- 5. Development of PRA Model for BWR Shutdown Modes 4 and 5 Integrated in SPAR Model, to be presented at PSAM10 2010. Co-author.
- 6. Development of Standardized Probabilistic Risk Assessment Models for Shutdown Operations Integrated in SPAR Level 1 Model, PSAM9 2008. Co-author.
- 7. Probabilistic Risk Assessment of Bolted Dry Spent Fuel Storage Cask, Presented at ICONE12. 2004. Co-author.
- 8. Low Power and Shutdown Risk Assessment Benchmarking, Presented at PSA 02 2002. Co-author.
- 10. Derivation of Shutdown Initiating Event Frequencies, Presented at PSAM5 2000. Co-author.
- 11. Quantitative Assessment of a Risk Informed Inspection Strategy for BWR Weld Overlays, Presented at ICONE 8 2000. Co-author.
- 12. EPRI RI-ISI Methodology and the Risk Impacts of Implementation, Presented at SMiRT 11 1999. Co-author.
- 13. Application of Markov Models and Service Data to Evaluate the Influence of Inspection on Pipe Rupture Frequencies published. PVP 1999. Co-author.
- 14. Progress in Risk Evaluation of Outages, International Conference on the Commercial and Operational Benefits of PSA. 1997. Co-author.
- 15. Control of Reactor Vessel Temperature/Pressure during Shutdown, GE SIL 357. June 1981. Co-author
J e f f r e y T M i t m a n P a g e l 4 SOFTWARE
REPORTS / STANDARDS
- 1. Requirements for Low Power and Shutdown PRA - ANS/ASME-58.22-2014 (Trial Use Standard).
- 2. Probabilistic Risk Assessment (PRA) of Bolted Storage Casks: Quantification and Analysis Report, EPRI 2003. 1002877. PM.
2002. 1003465. PM and principal investigator.
- 5. Guidance for Incorporating Organizational Factors into Nuclear Power Plant Risk Assessments: Phase 1 Workshop. EPRI and U.S. DOE 2002. 1003322. PM.
- 6. An Analysis of Loss of Decay Heat Removal Trends and Initiating event Frequencies (1989-2000):
- 7. Piping System Failure Rates and Rupture Frequencies for Use in Risk Informed In-service Inspection Applications: TR-111880-NP, EPRI 2000. 1001044. PM
- 8. Application of Risk-Informed Inservice Inspection Alternative Element Selection Criteria. EPRI, Charlotte NC: 2000. TE-11482. PM.
- 9. Revised Risk-Informed Inservice Inspection Evaluation Procedure, EPRI 1999. TR-112657 Revision B-A. PM & co-author.
- 10. Piping System Failure Rates and Rupture Frequencies for Use in Risk Informed In-service Inspection Applications, EPRI 1999. TR-111880. PM
- 11. Comparison between EDF and EPRI of Pipe Inspection Optimization Methods, EPRI Palo Alto, CA; Electricite de France, Paris, France: 1999. TR-113315. PM.
- 13. Evaluation of Pipe Failure Potential via Degradation Mechanism Assessment, EPRI Palo Alto, CA:
1998. TR-110157. PM.
- 15. Piping System Reliability Models and Database for used in Risk Informed Inservice Inspection Applications, EPRI 1998. TR-110161. PM.
- 18. Survey on the Use of Configuration Risk and Safety Management Tools at NPPs, EPRI, 1998. TR-102975. PM.
- 25. Outage Risk Assessment and Management Implementation at Fermi 2, EPRI 1997. TR-109013. Co-author.
TR-102973. Principal investigator.