Blue Ridge Environmental Defense League v. Nuclear Regulatory Commission ( 2013 )


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  • United States Court of Appeals
    FOR THE DISTRICT OF COLUMBIA CIRCUIT
    Argued November 19, 2012               Decided May 14, 2013
    No. 12-1106
    BLUE RIDGE ENVIRONMENTAL DEFENSE LEAGUE, ET AL.,
    PETITIONERS
    v.
    NUCLEAR REGULATORY COMMISSION AND THE UNITED
    STATES OF AMERICA,
    RESPONDENTS
    WESTINGHOUSE ELECTRIC COMPANY LLC,
    INTERVENORS
    Consolidated with 12-1151
    On Petition for Review of Orders of the
    United States Nuclear Regulatory Commission
    Diane Curran argued the cause for petitioners. With her
    on the briefs were Mindy Goldstein and John Runkle.
    Robert M. Rader, Senior Attorney, U.S. Nuclear
    Regulatory Commission, argued the cause for respondents.
    With him on the brief were J. David Gunter II, Trial Attorney,
    U.S. Department of Justice, John F. Cordes, Jr., Solicitor,
    2
    U.S. Nuclear Regulatory Commission, and Jeremy M.
    Suttenberg, Attorney.
    Randall L. Speck, David L. Cousineau, M. Stanford
    Blanton, Millicent W. Ronnlund, and Kathryn M. Sutton were
    on the brief for intervenors Westinghouse Electric Company
    LLC, et al., in support of respondents.
    Before: BROWN, Circuit Judge, and EDWARDS and
    SILBERMAN, Senior Circuit Judges.
    EDWARDS, Senior Circuit Judge: This case arises from
    actions taken by the Nuclear Regulatory Commission (“NRC”
    or “Commission”) approving (1) an application by Southern
    Nuclear Operating Company (“Southern”) for combined
    licenses to construct and operate new Units 3 and 4 of the
    Vogtle Nuclear Power Plant and (2) an application by
    Westinghouse Electric Company (“Westinghouse”) for an
    amendment to its already-approved AP1000 reactor design on
    which the Vogtle application relied. In approving the
    applications, NRC applied the regulatory scheme incorporated
    in 10 C.F.R. Part 52 covering the licensing of commercial
    nuclear power reactors. See Nuclear Info. Res. Serv. v. NRC,
    
    969 F.2d 1169
    , 1170 (D.C. Cir. 1992) (en banc) (upholding
    two-part regulatory scheme in 10 C.F.R. Part 52).
    In 2009, after a contested evidentiary hearing in which
    Petitioners participated, NRC granted Southern an early site
    permit for Vogtle Units 3 and 4. In 2008, Southern applied for
    combined licenses. A second contested proceeding was held
    in which Petitioners participated. The application for the early
    site permit was supported by an Environmental Impact
    Statement (“EIS”); the application for combined licenses was
    supported by the initial EIS and an updated EIS. After the
    close of the combined-license hearing record, Petitioners
    sought to reopen the hearing to litigate contentions relating to
    the nuclear accident at the Fukushima Dai-ichi complex in
    3
    Japan on March 11, 2011. In the wake of the Fukushima
    accident, NRC commissioned a Task Force to reevaluate
    nuclear safety regulations in the United States. Petitioners
    unsuccessfully sought to forestall the licensing of the Vogtle
    reactors and the approval of the modified AP1000 design until
    NRC had fully considered and implemented the Task Force
    recommendations.
    After the Task Force recommendations were issued and
    approved by NRC, Petitioners pursued various actions to
    compel the agency to supplement its EIS and to delay any
    action on the combined license and AP1000 design
    rulemaking proceedings until after the agency had
    implemented the Task Force recommendations. Petitioners
    contended, inter alia, that Vogtle’s EIS violated the National
    Environmental Policy Act (“NEPA”), 
    42 U.S.C. §§ 4321
    -
    4347, because it did not address allegedly new and significant
    environmental implications of the Task Force’s
    recommendations after Fukushima. NRC ruled that
    Petitioners’ challenges were premature, that the agency’s
    existing procedural mechanisms were sufficient to ensure
    licensees’ compliance with not-yet-enacted regulatory
    safeguards, and that the licensing and rulemaking proceedings
    could continue without delay. NRC further held that
    Petitioners had failed to satisfy the contention-specificity
    requirements of 
    10 C.F.R. § 2.309
    (f)(1), which state that the
    proponents of contentions must indicate with specificity the
    claims they wish to litigate. See Union of Concerned
    Scientists v. NRC, 
    920 F.2d 50
    , 51-52 (D.C. Cir. 1990). NRC
    also held that Petitioners had failed to identify any
    environmentally significant information from the Task Force
    recommendations suggesting a deficiency in the Vogtle EIS.
    NRC thus declined to reopen the combined-license hearing
    record under 
    10 C.F.R. § 2.326
    .
    4
    In late 2011, NRC issued its rule approving the AP1000
    amended design, and in 2012 it authorized issuance of the
    combined licenses. Petitioners then filed the petitions for
    review giving rise to this action. Petitioners raise three
    principal contentions for consideration by the court. First,
    Petitioners claim that NRC abused its discretion in refusing to
    reopen the hearing record in the Vogtle licensing proceeding.
    Second, Petitioners assert that NRC unreasonably denied
    them a right to participate in a mandatory hearing at which
    NRC technical staff confirmed that the Fukushima accident
    had not presented new and significant information that would
    require a supplemental EIS for Vogtle. Finally, Petitioners
    argue that NRC abused its discretion in approving the
    AP1000 reactor design without first supplementing the
    AP1000 Environmental Assessment (“EA”) that contained
    important information regarding “Severe Accident Mitigation
    Design Alternatives” applicable to Vogtle. Because we find
    no merit in any of these contentions, we deny the petitions for
    review.
    I. REGULATORY BACKGROUND
    A. Reactor Design Certification
    Under 10 C.F.R. Part 52, Subpart B, a party may request
    a “standard design certification” for the approval of a nuclear
    power plant design. See 
    10 C.F.R. § 52.41
    . Once a design is
    certified through this generic process, a future applicant may
    rely on the already-approved design. See 
    id.
     § 52.43(a).
    Design certification by NRC requires notice-and-comment
    rulemaking and culminates in publication in the Federal
    Register as a “design certification rule.” See id. § 52.54.
    When a proposed design certification rule is published,
    NRC’s associated EA is published for comment at the same
    5
    time. See id. § 51.31(b)(1). Because a reactor design is
    certified without reference to any specific plans for its
    construction, NRC has determined by rule that every
    proposed design certification or amendment requires only an
    EA, not a more comprehensive EIS. See id. §§ 51.31(b)(1)(i),
    51.32(b)(1)-(2).
    The EA for a design certification addresses only one
    topic: the costs and benefits of any Severe Accident
    Mitigation Design Alternatives that were considered and not
    incorporated into the final design. See id. § 51.30(d). When a
    proposal is made to modify an approved design certification
    rule, the amendment may rely on the EA generated for the
    original design certification rule and need only consider (1)
    whether the proposed design change renders any previously
    rejected design alternatives cost-beneficial and (2) whether
    the design change results in the identification of any new
    design alternatives that necessitate a previously unperformed
    cost-benefit analysis. See id. § 51.30(d). In other words,
    modifications to the original EA are necessary only if the
    proposed design change amendment alters the cost-benefit
    calculus concerning any Severe Accident Mitigation Design
    Alternatives.
    B. Combined Operating Licenses
    The Atomic Energy Act authorizes NRC to issue a
    combined operating license for both the construction and
    operation of new reactors after a public hearing. See 
    42 U.S.C. § 2235
    (b). Any such license must be accompanied by
    a full EIS, 
    10 C.F.R. §§ 51.75
    , 51.92(b), (d), (e), and may rely
    on and incorporate by reference an approved standard design
    certification, 
    id.
     § 51.75(c)(2).
    NRC must afford interested parties an opportunity to
    participate in a contested hearing subject to additional
    procedural requirements. See 
    42 U.S.C. § 2239
    (a). However,
    6
    in order to initiate such a contested hearing, NRC regulations
    require that interested parties submit contentions that are
    supported by “sufficient information to show that a genuine
    dispute exists with the applicant/licensee on a material issue
    of law or fact.” 
    10 C.F.R. § 2.309
    (f)(1)(vi). In addition,
    interested parties “must set forth with particularity the
    contentions sought to be raised” and must:
    (ii) Provide a brief explanation of the basis for the
    contention;
    ***
    (v) Provide a concise statement of the alleged facts or
    expert opinions which support the requestor’s/petitioner’s
    position on the issue and on which the petitioner intends to
    rely . . . together with references to the specific sources and
    documents [at issue]; [and]
    ***
    (vii) In a [combined license] proceeding . . . the
    information must be sufficient, and include supporting
    information showing, prima facie, that one or more of the
    acceptance criteria in the combined license have not been
    met . . . .
    
    Id.
     § 2.309(f)(1)(ii), (v), (vii). When interested parties are
    allowed to intervene, “[t]he scope of the Intervenors’
    participation in adjudications is limited to their admitted
    contentions, i.e., they are barred from participating in the
    uncontested portion of the hearing.” Exelon Generation Co.,
    LLC, 
    62 N.R.C. 5
    , 49 (2005).
    NRC also holds a separate “mandatory” hearing before
    issuing a combined license. See 
    42 U.S.C. §§ 2235
    (b),
    2239(a); see also Exelon Generation, 62 N.R.C. at 49-50. The
    mandatory hearing does not address contentions raised by the
    parties, and participation is limited to the applicant and NRC
    staff. See Exelon Generation, 62 N.R.C. at 49-50. The
    7
    mandatory NRC hearing determines the adequacy of the NRC
    staff’s review of the application.
    Separate regulations govern when NRC must reopen a
    closed hearing. See 
    10 C.F.R. § 2.326
    (a). In their briefs to this
    court, the parties focused on NRC’s application of its
    contention-admissibility standards, not on whether the agency
    erred in declining to reopen the combined-license hearing
    record. Because we find that NRC properly denied
    Petitioners’ contentions, and because the standards for
    reopening a closed proceeding are higher than those for
    admitting a new contention, see Luminant Generation Co.,
    LLC, CLI-12-07, slip op. at 14 n.47 (Mar. 16, 2012), we need
    not reach the application of NRC’s reopening regulations.
    C. Environmental Requirements
    NEPA mandates that a federal agency take a “hard look”
    at any major undertaking by assembling an EIS. This
    ensures that the agency, in reaching its decision, will have
    available, and will carefully consider, detailed information
    concerning significant environmental impacts; it also
    guarantees that the relevant information will be made available
    to the larger audience that may also play a role in both the
    decisionmaking process and the implementation of that
    decision.
    Robertson v. Methow Valley Citizens Council, 
    490 U.S. 332
    ,
    349 (1989). The EIS must address all reasonably foreseeable
    environmental impacts, including reactor accidents, even if
    the probability of such an occurrence is low. See 
    40 C.F.R. § 1502.22
    (b).
    As a major federal action, NRC’s issuance of a combined
    operating license requires an EIS. See 
    10 C.F.R. § 51.20
    (b).
    NRC regulations require preparation of an EIS both at the
    early site permit stage and at the combined operating license
    stage. See 
    10 C.F.R. § 51.75
    (b) (requiring EIS for early site
    8
    permit); 
    id.
     § 51.75(c)(1) (requiring supplementation for
    combined operating license).
    Once NRC has prepared an EIS, it must continue to
    evaluate the environmental consequences of the project and
    supplement the EIS, as necessary, even after initial approval.
    See Marsh v. Or. Natural Res. Council, 
    490 U.S. 360
    , 370-78
    (1989). This ongoing duty is mitigated, however, by a “rule of
    reason,” which excuses the agency from supplementing an
    environmental report based only on “remote and highly
    speculative consequences.” Deukmejian v. NRC, 
    751 F.2d 1287
    , 1300 (D.C. Cir. 1984) reh’g granted and opinion
    vacated on other grounds sub nom. San Luis Obispo Mothers
    for Peace v. NRC, 
    760 F.2d 1320
     (D.C. Cir. 1985) and on
    reh’g sub nom. San Luis Obispo Mothers for Peace v. NRC,
    
    789 F.2d 26
     (D.C. Cir. 1986).
    The EIS must be submitted for public comment. See
    TOMAC, Taxpayers of Mich. Against Casinos v. Norton, 
    433 F.3d 852
    , 861 (D.C. Cir. 2006); 
    40 C.F.R. § 1502.9
    . Although
    Petitioners contend that similar public comment is mandatory
    for all EAs, we have held that “the agency has significant
    discretion in determining when public comment is required
    with respect to EAs.” TOMAC, 
    433 F.3d at 861
    .
    D. Fukushima Accident and NRC Fukushima Task
    Force
    On March 21, 2011, a catastrophic accident occurred at
    the Fukushima Dai-ichi Nuclear Power Station in Honshu,
    Japan. See U.S. NUCLEAR REGULATORY COMM’N,
    RECOMMENDATIONS FOR ENHANCING REACTOR SAFETY IN
    ST
    THE 21 CENTURY: THE NEAR-TERM TASK FORCE REVIEW OF
    INSIGHTS FROM THE FUKUSHIMA DAI-ICHI ACCIDENT 7 (July
    12, 2011) (“Task Force Report”). NRC appointed a Task
    Force to study the regulatory implications of the accident for
    the United States. The Task Force was charged to
    9
    conduct a systematic and methodical review of U.S.
    Nuclear Regulatory Commission processes and
    regulations to determine whether the agency should make
    additional improvements to its regulatory system and to
    make recommendations to the Commission for its policy
    direction, in light of the accident at the Fukushima Dai-
    ichi Nuclear Power Plant.
    
    Id.
     at vii. The Commission asked the Task Force to identify
    “potential or preliminary near term/immediate operational or
    regulatory issues” related to natural disasters, severe accident
    mitigation, and emergency preparedness, and to propose other
    improvements in light of the Fukushima accident. Union Elec.
    Co., CLI-11-05, 
    74 N.R.C. 141
    , 147 (2011); see also Task
    Force Report at viii.
    NRC’s Fukushima Task Force issued its report in July
    2011, concluding that NRC’s “current regulatory approach,
    and more importantly, the resultant plant capabilities”
    demonstrate “that a sequence of events like the Fukushima
    accident is unlikely to occur in the United States and some
    appropriate mitigation measures have been implemented,
    reducing the likelihood of core damage and radiological
    releases.” Task Force Report at vii. The Task Force supported
    completing work on the then-pending AP1000 design
    certification rulemaking “without delay” and noted that “all of
    the current early site permits [e.g., Vogtle Units 3 and 4]
    already meet the requirements” of the Task Force Report
    recommendation governing seismic and flooding analysis. 
    Id. at 71-72
    . In sum, the Task Force Report recommended that
    both the AP1000 rulemaking and the Vogtle license
    application proceedings continue without interruption.
    The Task Force offered twelve recommendations which,
    “taken together are intended to clarify and strengthen the
    [NRC’s] regulatory framework.” See 
    id.
     at viii. The Task
    Force grouped these recommendations into five categories:
    10
    “Clarifying the Regulatory Framework,” “Ensuring
    Protection,” “Enhancing Mitigation,” “Strengthening
    Emergency Preparedness,” and “Improving the Efficiency of
    NRC Programs.” 
    Id.
     at ix.
    NRC approved the Task Force’s recommendations and
    urged implementation by 2016. In March 2012, NRC
    implemented two Task Force recommendations, one
    concerning licensees’ abilities to protect spent fuel rods in
    unpredictably dangerous conditions and the other proposing
    development of a new rule to upgrade “station blackout”
    requirements for power failures both within and outside a
    plant.
    II. FACTUAL BACKGROUND
    A. AP1000 Design Certification
    NRC first issued a design certification rule approving
    Westinghouse’s AP1000 design in 2006. Along with this
    design certification rule, NRC prepared an EA that analyzed
    sixteen Severe Accident Mitigation Design Alternatives and
    rejected all sixteen on cost-benefit grounds. See
    Environmental Assessment by the U.S. Nuclear Regulatory
    Commission Relating to the Certification of the AP1000
    Standard Plant Design, Docket No. 52-006 (2006), reprinted
    in J.A. 866-902.
    Westinghouse subsequently applied for an amendment to
    the approved AP1000 reactor design. NRC received and
    considered over 200 public comments, most of which urged
    delaying resolution of the AP1000 design amendment
    proceeding until the lessons learned from the Fukushima
    accident were applied to NRC regulations. See AP1000
    Design Certification Amendment, 
    76 Fed. Reg. 82,079
    -01,
    11
    82,079-81 (Dec. 30, 2011) (outlining history of AP1000
    design certification rule).
    On December 30, 2011, after considering these
    comments, NRC declined to suspend or delay the design
    certification rulemaking proceeding, emphasizing that the
    AP1000 design was already compliant with many of the Task
    Force recommendations. See 
    id.
     NRC concluded that no
    Severe Accident Mitigation Design Alternatives were cost-
    beneficial and that no supplemental EA was necessary. See
    Environmental Assessment by the U.S. Nuclear Regulatory
    Commission Relating to Certification of the Amendment to
    the AP1000 Standard Plant Design, Docket No. 52-006, 5-6
    (Dec. 22, 2011), reprinted in J.A. 224-25.
    NRC certified the AP1000 design and stressed the
    ongoing nature of Commission review of designs, stating that:
    even if the Commission concludes at a later time that some
    additional action is needed for the AP1000, the NRC has
    ample opportunity and legal authority to modify the AP1000
    [design certification rule] to implement NRC-required design
    changes, as well as to take any necessary action to ensure that
    holders of [combined licenses] referencing the AP1000 also
    make the necessary design changes.
    AP1000 Design Certification Amendment, 76 Fed. Reg. at
    82,081. As a result, NRC concluded “that no changes to the
    AP1000 [design certification rule] are required at this time,”
    id., and noted that the Task Force itself endorsed completion
    of the AP 1000 rulemaking “without delay,” id. at 82,083.
    B. Vogtle Combined Operating Licenses
    On August 15, 2006, Southern applied for an early site
    permit for Vogtle Units 3 and 4. A coalition of community
    action organizations, including several Petitioners in this case,
    sought a hearing on the application and intervened on three
    admitted contentions related to NRC’s draft EIS for the site.
    12
    NRC assigned the conduct of the licensure proceeding to a
    three-member Atomic Safety and Licensing Board (“Board”),
    which considered Petitioners’ contentions in a series of on-
    the-record hearings. The Board ruled against Petitioners on all
    three contentions, and NRC denied review, ending the
    contested portion of the hearing. The Board issued its final
    initial decision in August 2009, after holding its mandatory
    sufficiency review and questioning Southern and NRC staff,
    and approved the Vogtle early site application.
    Southern subsequently applied for combined operating
    licenses for Vogtle Units 3 and 4. As with the early site
    permit proceeding, NRC prepared an EIS for this licensing
    action, which included consideration of the potential for
    severe accidents and their consequences. See Environmental
    Impacts of Postulated Accidents, Environmental Impacts of
    Operation at the Vogtle Electric Generating Plant Site, § 5.10
    (Mar. 2011) (“Vogtle EIS”), reprinted in J.A. 805-09;
    Southern Nuclear Operating Company, Inc.; Notice of
    Availability of the Final Supplemental Environmental Impact
    Statement for Vogtle Electric Generating Plant Units 3 and 4;
    Combined License Application Review, 
    76 Fed. Reg. 16,645
    -
    02 (Mar. 24, 2011).
    In response, Petitioners brought three contentions to the
    Board, which denied two and admitted the third, a safety-
    related contention. After consideration of the contention, the
    Board granted summary disposition against the intervenors,
    finding that the contention failed to present a material factual
    dispute. The Board declined to admit an additional
    environmental contention and concluded the contested portion
    of the proceeding. A second licensing Board was established
    to consider another contention in April 2010; it denied the
    request, and NRC affirmed.
    In April 2011, shortly after the Task Force was
    appointed, Petitioners and other organizations submitted an
    13
    Emergency Petition, asking NRC to suspend all pending
    licensing decisions, including the decision whether to issue a
    combined license for Vogtle 3 and 4, while it investigated the
    implications of the Fukushima accident. The Commission
    denied these requests for a suspension. See generally Union
    Elec. Co., CLI-11-05, 
    74 N.R.C. 144
    , 150-51, 175-76 (2011).
    At the same time, Petitioners submitted a petition
    requesting that NRC immediately suspend the rulemaking for
    the amendment of the AP1000 design certification pending
    evaluation of the implications of the Fukushima accident. 
    Id. at 172-73
    . Petitioners asked NRC to undertake “a
    comprehensive review of the Fukushima accident to develop
    lessons learned for new reactor designs and the subsequent
    development and implementation of new regulatory
    safeguards to protect public health and safety.” 
    Id. at 172
    . The
    Commission denied the request for immediate postponement
    as premature, but directed NRC staff to consider the
    submissions as comments to the AP1000 rulemaking. 
    Id. at 172-73
    . Petitioners filed additional supplemental comments
    requesting that NRC consider the environmental implications
    of the Fukushima accident and the Task Force Report.
    Supplemental Comments by the AP1000 Oversight Group et
    al. Regarding Failure of Rulemaking on Certification, In the
    Matter of AP1000 Design Certification Amendment, NRC-
    2010-0131 (Sept. 29, 2011), reprinted in J.A. 326-36.
    In August 2011, after the Task Force issued its report,
    several Petitioners submitted motions to reopen the record of
    the then-closed Vogtle licensing proceeding and admit
    contentions challenging the failure of NRC to order a
    supplemental Vogtle EIS to address the environmental
    implications of the Task Force Report. See PPL Bell Bend,
    L.L.C., LBP-11-27, slip op. (Oct. 18, 2011). Two groups of
    Petitioners submitted substantively identical proposed
    contentions, which read as follows:
    14
    The EIS for . . . Vogtle fails to satisfy the requirements of
    NEPA because it does not address the new and significant
    environmental     implications    of    the    findings   and
    recommendations raised by NRC’s Fukushima Task Force
    Report, including seismic-flood and environmental justice
    issues. As required by 
    10 C.F.R. § 51.92
    (a)(2) and 
    40 C.F.R. § 1502.9
    (c), these implications must be addressed in a
    supplemental Draft EIS.
    
    Id. at 6
    . The contention was supported by declarations which
    alleged that the Fukushima accident and the Task Force
    Report presented new and significant information about risks
    to public health and safety. See 
    id. at 9-10
     (summarizing
    supporting declarations).
    On September 9, 2011, the Commission denied
    Petitioners’ April 2011 Emergency Petitions with respect to
    the Vogtle licensing decision and the AP1000 rule. The
    Commission concluded that “nothing learned to date requires
    immediate cessation of our review of license applications or
    proposed reactor designs.” Union Elec., CLI-11-05, 74 N.R.C.
    at 161. In addition, the Commission found that there was no
    cause to require a “generic” environmental review because the
    Fukushima accident did not present “new and significant”
    information. Id. at 166-67. The Commission further noted that
    “we do not know today the full implications of the Japan
    events for U.S. facilities. Therefore, any generic NEPA duty –
    if one were appropriate at all – does not accrue now.” Id. at
    167.
    The Commission did, however, leave open the possibility
    that an individual NEPA contention in a particular licensing
    proceeding might require additional review, stating that “[i]f
    the NRC determines that changes to its current environmental
    assessment rules are warranted, we can revisit whether an
    individual licensing review or adjudication should be held in
    15
    abeyance pending the outcome of a relevant rulemaking.” Id.
    at 174.
    On October 18, 2011, the Board rejected as premature
    Petitioners’ August 2011 contentions, “seeking to revive”
    several closed adjudicatory proceedings, including the Vogtle
    licensing. See PPL Bell Bend, LBP-11-27, slip op. at 1. The
    Board read the Commission’s decision in CLI-11-05 as
    instructing “precisely and definitively that it remains much
    too early in the process of assessing the Fukushima event in
    the context of the operation of reactors in the United States to
    allow any informed conclusion regarding the possible safety
    or environmental implications of that event.” Id. at 13. The
    Board also noted that Petitioners did not indicate “any unique
    characteristics of the [Vogtle] site that might make the content
    of the Task Force report of greater environmental significance
    to that reactor than to United States reactors in general.” Id. at
    13-14. Because CLI-11-05 invited contentions in licensing
    proceedings that alleged particular risks from the specific site,
    the Board found this lack of specificity dispositive.
    Also on October 18, 2011, the Commission adopted all of
    the Task Force recommendations and ordered NRC staff to
    implement them within the following five years. See
    Luminant Generation Co., LLC, LBP-11-36, slip op. at 4-5
    (Nov. 30, 2011). Upon the Commission’s adoption of the
    Task Force recommendations, several Petitioners resubmitted
    their contentions and asked the Board to reconsider its denial
    of their contentions in light of the Commission’s decision to
    adopt all of the Task Force recommendations. See id.
    On November 30, 2011, the Board denied the motion to
    reconsider, finding that the Commission’s adoption of the
    Task Force recommendations had not “materially changed
    matters.” Id. at 5. The Board noted that there had been no
    express request that it reconsider the framework underlying its
    16
    prematurity decision in LBP-11-27, and it declined to do so.
    Id. at 3-4.
    On February 9, 2012, the Commission handed down its
    opinion resulting from its September 27 and 28, 2011,
    mandatory hearing on the Vogtle licensing application. See S.
    Nuclear Operating Co., CLI-12-02, slip op. at 2 (Feb. 9,
    2012). Under Commission precedent, participation in the
    hearing was appropriately limited to Southern and NRC staff,
    and the hearing addressed only the sufficiency of the staff’s
    review of Southern’s license application. See Exelon
    Generation, 62 N.R.C. at 49-50. At the hearing, NRC
    technical staff confirmed that the AP1000 design certification
    and the Vogtle licenses met current safety and environmental
    standards. S. Nuclear Operating Co., CLI-12-02, slip op. at
    22. NRC staff testified that Fukushima-like accidents have an
    “extremely low probability,” despite their “potentially high
    consequences.” Id. at 74. The Commission considered the
    likelihood and consequences of potential severe accidents
    similar to the Fukushima accident and found that the risks to
    the AP1000 reactor design at the Vogtle site were “lower than
    those for current generation plants.” Id. at 72-73.
    NRC approved the combined license applications for the
    Vogtle 3 and 4 reactors at the conclusion of the mandatory
    hearing. The Commission found that the staff’s review
    adequately supported the requisite safety and environmental
    findings under 
    10 C.F.R. §§ 52.97
    , 51.107(a) & (d), and
    50.10, that all NEPA requirements had been met, and that the
    staff had followed an appropriate process for assessing “new
    and significant” information. See 
    id. at 2, 79
    . In addition, the
    Commission restated that no plant, including Vogtle, would
    be exempt from Task Force recommendations enacted in the
    future:
    All affected nuclear plants will be required to comply with
    NRC direction resulting from lessons learned from the
    17
    Fukushima accident, regardless of the timing of issuance of
    the affected licenses. We therefore expect the new Vogtle
    units will comply with all applicable “post-Fukushima”
    requirements.
    
    Id. at 82
    . NRC found it premature to order implementation of
    the Task Force recommendations, as many recommendations
    were still in development and not yet formulated into
    regulations. Instead, the Commission stated that it would not
    establish new regulatory processes or requirements until after
    taking sufficient time to “ensure that any new requirements
    are technically justified and implemented appropriately.” 
    Id.
    Commission Chairman Jaczko dissented from the
    Commission’s decision, stating that he would not “authorize
    issuance of these licenses without any binding obligation that
    these plants will have implemented the lessons learned from
    the Fukushima accident before they operate.” 
    Id.
     (Jaczko, C.,
    dissenting) slip op. at 1. Even Chairman Jaczko, however, did
    not argue that a supplemental EIS was necessary before the
    Vogtle licenses could proceed; his dissent was based solely on
    his belief that the Commission should have demanded
    assurances of compliance with future safety requirements, not
    current environmental shortcomings.
    On March 16, 2012, the Commission upheld the Board’s
    denial of Petitioners’ contention, agreeing that Petitioners had
    “not identified environmental effects from the Fukushima
    Dai-ichi events that can be concretely evaluated at this time,
    or identified specific new information challenging the site-
    specific environmental assessments” for Vogtle. Luminant
    Generation Co., CLI-12-07, slip op. at 9. The Commission
    held that the Task Force’s recommendations did not
    themselves identify any environmentally significant
    information for Vogtle, and Petitioners did not explain how
    any particular recommendation related to the Vogtle licenses
    in a manner that mandated a supplemental EIS. NRC held that
    18
    the Task Force recommendations, standing alone, did not
    provide sufficient support for an admissible contention.
    Rather, the Commission held that a valid contention must
    “include facts sufficient to demonstrate a genuine dispute”
    with the license application; a contention that merely alludes
    to Task Force findings “is too vague . . . for litigation.” 
    Id. at 13-14
    .
    The Commission also found that Petitioners failed to
    demonstrate that the Task Force Report presented a “seriously
    different picture of the environmental impact of the proposed
    project from what was previously envisioned” that would
    necessitate a supplemental EIS. 
    Id. at 10
    . NRC held that
    “reference to the Task Force Report recommendations alone,
    without facts or expert opinion that explain their significance
    for the unique characteristics” of the Vogtle reactors “does
    not provide sufficient support” to demand further NEPA
    review. 
    Id. at 13
    . NRC ruled that the same lack of specificity
    was also fatal to Petitioners’ attempt to meet NRC’s “more
    stringent reopening rule” and to require Southern to
    supplement the Vogtle EIS. 
    Id.
     at 14 n.47.
    On April 16, 2012, the Commission denied Petitioners’
    motion to stay the effectiveness of the Vogtle licensing
    decision, pending review by this court. The Commission
    reiterated its conclusion that Petitioners “have not
    demonstrated that the Fukushima events or any regulatory
    response to those events would raise environmental impacts
    that differ significantly from the impacts that the NRC has
    already reviewed and addressed” in approving the Vogtle
    licenses. See S. Nuclear Operating Co., CLI-12-11, slip op. at
    12-13 (Apr. 16, 2012).
    On February 17, 2012, Petitioners sought review of the
    NRC’s AP1000 rule. A month later, Petitioners sought review
    of the Commission’s decisions rejecting Petitioners’
    contentions and of all the authorizations resulting from the
    19
    approval of the Vogtle licenses. On April 3, 2012, we
    consolidated the petitions for review. After the Commission
    denied Petitioners’ motion for a stay, Petitioners moved for a
    stay in this court, which we denied.
    On appeal before us now are (1) the amended AP1000
    design certification rule, (2) the Commission’s rejection of
    Petitioners’ contentions and motions to reopen the record to
    supplement the Vogtle EIS, and (3) all the licensing
    authorizations resulting from the Commission’s decision to
    allow the Vogtle licenses to go forward. The specific
    decisions implicated are:
       The AP1000 rule, Final Rule, AP1000 Design Certification
    Amendment, 
    76 Fed. Reg. 82,079
     (Dec. 30, 2011); and
       The Commission’s rejection of Petitioners’ contentions and
    motions to reopen the record, and the resulting licenses and
    work authorizations:
    o   Luminant Generation Co., LLC, CLI-12-07, slip op.
    (Mar. 16, 2012);
    o   Luminant Generation Co., LLC, LBP-11-36, slip op.
    (Nov. 30, 2011);
    o   Vogtle Electric Generating Plant, Units 3 and 4;
    Issuance of Combined Licenses and Limited Work
    Authorizations and Record of Decision, 
    77 Fed. Reg. 12,332
    -02 (Feb. 29, 2012);
    o   Combined License No. NPF-91 (Vogtle Electric
    Generating Plant Unit 3) (Feb. 10, 2012), reprinted in
    J.A. 35;
    o   Combined License No. NPF-92 (Vogtle Electric
    Generating Plant Unit 4) (Feb. 10, 2012), reprinted in
    J.A. 53;
    20
    o   Limited Work Authorization No. LWA-001, (Vogtle
    Electric Generating Plant Unit 3) (Feb. 10, 2012),
    reprinted in J.A. 71; and
    o   Limited Work Authorization No. LWA-002, (Vogtle
    Electric Generating Plant Unit 4) (Feb. 10, 2012),
    reprinted in J.A. 83.
    III. STANDARD OF REVIEW
    This court will set aside an agency rule or licensing
    decision only if it is “arbitrary, capricious, an abuse of
    discretion, or otherwise not in accordance with law.” 
    5 U.S.C. § 706
    (2)(A); see also, e.g., Advocates for Highway & Auto
    Safety v. Fed. Motor Carrier Safety Admin., 
    429 F.3d 1136
    ,
    1144 (D.C. Cir. 2005).
    The arbitrary and capricious standard also controls our
    review of agency actions with respect to any substantive
    environmental issues that are properly before the court. We
    may set aside such actions only if we find that NRC
    committed “a clear error of judgment.” Marsh, 
    490 U.S. at 385
    . We owe deference to NRC’s decision not to supplement
    either its EA for the AP1000 reactor design or its EIS for the
    Vogtle reactors. See 
    id.
     (finding that the agency “conducted a
    reasoned evaluation of the relevant information and reached a
    decision that, although perhaps disputable, was not ‘arbitrary
    or capricious’”); see also Great Old Broads for Wilderness v.
    Kimbell, 
    709 F.3d 836
    , 853-55 (9th Cir. 2013) (reviewing
    decision not to supplement an EIS under the deferential
    “arbitrary or capricious” standard).
    To the extent that NRC’s technical judgments and
    predictions are before the court for review, we “must
    generally be at [our] most deferential.” Balt. Gas & Elec. Co.
    v. Natural Res. Def. Council, Inc., 
    462 U.S. 87
    , 103 (1983).
    We are obligated to “defer to the wisdom of the agency,
    21
    provided its decision is reasoned and rational.” Dillmon v.
    Nat’l Transp. Safety Bd., 
    588 F.3d 1085
    , 1089 (D.C. Cir.
    2009).
    In reviewing NRC’s interpretations of its own rules –
    here, notably, its rules governing the reopening of closed
    proceedings and governing contention admissibility – we give
    “controlling weight” to the agency’s constructions unless they
    are “plainly erroneous or inconsistent with the regulation.”
    City of Idaho Falls, Idaho v. FERC, 
    629 F.3d 222
    , 228 (D.C.
    Cir. 2011).
    NRC’s interpretation of its enabling legislation is
    reviewed pursuant to the familiar standards enunciated in
    Chevron, U.S.A., Inc. v. Natural Resources Defense Council,
    Inc., 
    467 U.S. 837
    , 842-45 (1984). See also, e.g., Nuclear
    Info. Res. Serv., 
    969 F.2d at 1173
    . An agency’s interpretation
    of its governing statute is entitled to no judicial deference if
    “Congress has directly spoken to the precise question at
    issue.” Chevron, 
    467 U.S. at 842
    . If, as in this case, “Congress
    has explicitly left a gap for the agency to fill, there is an
    express delegation of authority to the agency to elucidate a
    specific provision of the statute by regulation. Such legislative
    regulations are given controlling weight unless they are
    arbitrary, capricious, or manifestly contrary to the statute.” 
    Id. at 843-44
    . We have previously endorsed NRC’s “high
    standards” for reopening closed hearings and the “stringency
    of those criteria.” Deukmejian, 751 F.2d at 1316. We are
    therefore bound to defer to NRC’s implementation of its
    contention-specificity regulations.
    We are also “obliged to defer to the operating procedures
    employed by an agency when the governing statute requires
    only that a ‘hearing’ be held.” Union of Concerned Scientists,
    
    920 F.2d at 54
    . As a result, we consider with due deference
    NRC’s rejection of Petitioners’ objections to the agency
    procedures at issue here.
    22
    IV. ANALYSIS
    A. NRC’s Refusal to Admit Petitioners’ Contentions
    NRC regulations dictate the criteria that a party’s
    contention must meet in order to initiate a contested hearing.
    See 
    10 C.F.R. § 2.309
    (f)(1). Because we have held that
    NRC’s “procedural rules [under 
    10 C.F.R. § 2.309
    (f)] do not
    facially violate the Atomic Energy Act or the APA [and] they
    are also consistent with NEPA,” Union of Concerned
    Scientists, 
    920 F.2d at 56-57
    , and because we find that NRC
    reasonably applied these rules in evaluating Petitioners’
    contentions, we defer to NRC’s rejection of Petitioners’
    contentions.
    After carefully reviewing the record in this case, we hold
    that the Commission acted reasonably in denying Petitioners’
    contentions on the grounds that they (1) failed to “[p]rovide
    a . . . statement of the alleged facts or expert opinions which
    support the requestor’s/petitioner’s position,” 
    10 C.F.R. § 2.309
    (f)(1)(v), and (2) failed to “include references to
    specific portions of the . . . environmental report . . . that the
    petitioner disputes and the supporting reasons,” 
    id.
    § 2.309(f)(1)(vi). See Luminant Generation Co., CLI-12-07,
    slip op. at 13 n.43.
    1. The Task Force Report Alone Was Not a “New and
    Significant” Circumstance Requiring a Supplemental
    EIS
    Petitioners failed to indicate any environmental data that
    were not considered in the EIS. Because Petitioners failed to
    point to any specific shortcoming in the EIS, NRC reasonably
    found Petitioners’ contentions insufficient to support a
    contested hearing. The Commission clearly stated its reasons
    for refusing to admit Petitioners’ contentions:
    23
    We expect Petitioners to identify information that was not
    considered in the environmental review for the application at
    issue and explain, with asserted facts or expert opinion, how it
    presents “a seriously different picture of the environmental
    impact of the proposed project from what was previously
    envisioned.”
    Id. at 13. This explanation is well-supported by the record and
    represents a reasonable interpretation of NRC’s contention-
    specificity regulations. See 
    10 C.F.R. § 2.309
    (f).
    Under NEPA, NRC is obligated to undertake a
    supplemental EIS only when presented with “substantial
    changes in the proposed action that are relevant to
    environmental concerns” or “new and significant
    circumstances or information relevant to environmental
    concerns and bearing on the proposed action or its impacts”
    after the EIS is assembled. 
    10 C.F.R. § 51.92
    (a)(1)-(2); see
    also 
    id.
     § 51.72(a)(1)-(2). “New and significant” information
    presents “a seriously different picture of the environmental
    impact of the proposed project from what was previously
    envisioned.” Hydro Res., Inc., 
    50 N.R.C. 3
    , 14 (1999); see
    also Marsh, 
    490 U.S. at 374
     (looking to “the value of the new
    information to the still pending decisionmaking process” and
    requiring a supplemental EIS only if the new information is
    sufficient to show environmental effects “in a significant
    manner or to a significant extent not already considered”).
    The determination as to whether information is either new or
    significant “requires a high level of technical expertise”; thus,
    we “defer to the informed discretion of the [Commission].”
    Marsh, 490 U.S. at 377.
    Petitioners contend that the Task Force recommendations
    give rise to an obligation to supplement the Vogtle EIS
    because the recommendations may alter NRC regulations in
    the years ahead. Thus, in Petitioners’ view, the Vogtle
    licenses necessarily must be delayed until the
    24
    recommendations are finalized. We rejected a similar line of
    reasoning in Union of Concerned Scientists:
    Information raised in the environmental reports does not
    amount to a new material “issue” simply because it adds
    marginal weight to the case of an opponent or a proponent of a
    license; the reports instead raise a new “issue” only when the
    argument itself (as distinct from its chances of success) was
    not apparent at the time of the application. Although the
    concepts of new issues and new evidence are analytically
    distinct, we recognize that in practice they can converge – the
    demarcation line may depend on how the “issue” is stated.
    Still, whether an actual new “issue” is raised is a matter for the
    NRC to determine in the first instance and is reviewed
    deferentially.
    
    920 F.2d at 55
    .
    It is also noteworthy that the position taken by the
    Commission in this case is consistent with holdings reached
    by Atomic Safety and Licensing Boards in licensing
    proceedings for other locations. In these proceedings, the
    Boards have found that the Task Force Report alone does not
    provide a sufficient foundation for an admissible contention.
    See Pac. Gas & Elec. Co., LBP-11-32, slip op. at 19 (Nov. 18,
    2011) (finding a proposed contention inadmissible because
    the petitioner “offer[ed] nothing to link the outcome of the
    Fukushima events” to the pending license renewal
    application), review denied at Pac. Gas & Elec. Co., CLI-12-
    13 (Jun. 7, 2012); Fla. Power & Light Co., LBP-11-33, slip
    op. at 8 (Nov. 21, 2011) (rejecting proposed contention
    because the petitioners “allege[d] no facts linking the events
    at Fukushima to the sufficiency of NEPA-related documents”
    for the pending combined license application). Obviously,
    these Board decisions do not control the disposition of this
    case, but they do give further credence to the view that the
    Task Force Report alone does not support Petitioners’
    position.
    25
    In this case, NRC’s original EIS for Vogtle considered
    precisely the types of harm that occurred as a result of the
    Fukushima accident. The EIS considered consequences and
    mitigation of severe accidents involving reactor core damage
    and the release of fission products. See Vogtle EIS at § 5.10,
    reprinted in J.A. 805-09; see also Final Environmental Impact
    Statement for an Early Site Permit (ESP) at the Vogtle
    Electric Generating Plant Site, § 5.10.2 (Aug. 2008) (“Vogtle
    ESP EIS”), reprinted in J.A. 835-44. In addition, the EIS for
    the Vogtle early site permit evaluated the human health
    impacts, economic costs, and land contamination risks,
    concluding that the environmental risks associated with
    severe accidents from an AP1000 reactor at the Vogtle site
    “would be small compared to risks associated with operation
    of the current-generation reactors at [Vogtle]” and were “well
    below NRC safety goals.” Vogtle ESP EIS at 5-81, 5-89,
    reprinted in J.A. 836, 844.
    Petitioners’ contentions provide no explanation as to how
    the Task Force Report recommendations raise previously
    unaddressed issues. See Union of Concerned Scientists, 
    920 F.2d at 55
    . The Commission reasonably concluded that, for
    their contentions to be admitted for consideration, Petitioners
    were required to cite particular information that was missing
    from the Vogtle EIS based on particular recommendations
    from the Task Force. See Luminant Generation Co., CLI-12-
    07, slip op. at 13; PPL Bell Bend, LBP-11-27, slip op. at 13.
    Petitioners failed to do this.
    Petitioners argue that, once NRC described the
    Fukushima accident as “significant,” the agency was
    obligated to generate new environmental reports for all
    implicated pending sites and reactor designs. This argument is
    clearly unavailing, as it relies on Petitioners’ elision of “safety
    significance” with “environmental significance.” In the case
    on which Petitioners chiefly rely, San Luis Obispo Mothers
    26
    for Peace v. NRC, 
    449 F.3d 1016
     (9th Cir. 2006), NRC had
    categorically declined to consider any environmental
    consequences resulting from terrorism-related threats. The
    Ninth Circuit thus overturned the Commission’s decision. 
    Id. at 1031
    . The situation here is quite different. In this case,
    NRC thoroughly analyzed the environmental consequences of
    severe accidents for Vogtle. See Vogtle ESP EIS at § 5.10.2,
    reprinted in J.A. 835-44; Vogtle EIS at § 5.10, reprinted in
    J.A. 805-09. Chairman Jaczko, the lone dissenter from the
    issuance of the Vogtle licenses, objected because he sought
    greater assurances that the Vogtle reactors would remain in
    compliance with future safety regulations. The Chairman did
    not contend that his concerns about safety standards created
    present environmental concerns; and he did not claim that
    there were any present shortcomings at the Vogtle site or any
    need for additional NEPA review. See generally S. Nuclear
    Operating Co., CLI-12-02, slip op. (Jaczko, C., dissenting).
    “[N]ew information about nuclear power plant safety
    arising between the time of the initial application and the
    commencement of operations” does not necessarily provide
    cause for additional NEPA review. Union of Concerned
    Scientists, 
    920 F.2d at 55
    . And it does not create such cause
    here because the EIS addressed and dismissed precisely the
    risks that gave rise to the Fukushima accident. The
    Commission reasonably found that it was not obligated to
    postpone its decision “until inchoate information matures into
    something that might later affect [its] review.” Luminant
    Generation Co., CLI-12-07, slip op. at 14; see also N.J. Dep’t
    of Envtl. Prot. v. NRC, 
    561 F.3d 132
    , 143 (3d Cir. 2009)
    (holding that “precautionary actions to guard against a
    particular risk do not trigger a duty to perform a NEPA
    analysis”).
    Furthermore, as noted above, both the Task Force and
    NRC noted that further regulatory initiatives would be
    27
    possible, as necessary, after the Commission studied the Task
    Force recommendations. See S. Nuclear Operating Co., CLI-
    12-02, slip op. at 81-82. However, merely because the
    Commission might impose more stringent safety regulations
    after carefully assessing the Task Force recommendations
    does not mean that the agency’s present actions are
    inconsistent with NEPA.
    Without an explanation from Petitioners as to what
    specific “new and significant” environmental information
    NRC failed to consider, or what deficiency in the existing EIS
    it failed to rectify, NRC reasonably found that Petitioners’
    contentions did not warrant a contested hearing. Petitioners’
    attempts to rely on future safety concerns in lieu of present
    environmental risks do not create an obligation for further
    NEPA review.
    2. Petitioners’ Contentions Lacked Specific Links
    Between the Fukushima Accident and the Vogtle Site
    After the Task Force issued its report, the Commission
    rejected as premature Petitioners’ requests for a generic
    NEPA review arising out of the Task Force Report. The
    Commission held that if “new and significant information
    comes to light that requires consideration as part of the
    ongoing preparation of application-specific NEPA documents,
    the agency will assess the significance of that information, as
    appropriate.” Union Elec., CLI-11-05, 74 N.R.C. at 167.
    Petitioners do not challenge this decision on appeal, but
    instead “attempt to distinguish CLI-11-[0]5 by claiming that
    [the Commission’s] holding there rested on a finding that
    sufficient information was not yet available to conduct a
    generic analysis,” and that such information now exists.
    Luminant Generation Co., CLI-12-07, slip op. at 9. The
    Commission rejected this argument and upheld the Board’s
    ruling “that Petitioners did not relate their contention to any
    unique characteristics of the particular site at issue, and
    28
    therefore, the contention was akin to the generic type of
    NEPA review that we declared premature in CLI-11-[0]5.” Id.
    (citing PPL Bell Bend, LBP-11-27, slip op. at 13-14).
    The First Circuit, addressing an appeal from NRC’s
    denial of other post-Fukushima objections to plant licensing
    actions, held that a petitioner’s “mere pointing to a piece of
    information and speculating that the results of the
    [environmental risk analysis] may be different was not
    sufficient to meet” the Commission’s stringent standards for
    reopening a closed proceeding. Massachusetts v. NRC, 
    708 F.3d 63
    , 76-77 (1st Cir. 2013). We agree. We therefore
    uphold NRC’s determination that its rejection of Petitioners’
    contentions as “premature” was governed by its decision in
    CLI-11-05.
    In light of the Commission’s decision in CLI-11-05,
    Petitioners were obligated to present a contention sufficiently
    detailed and specifically related to the challenged reactor
    location to demonstrate how the contention differed from the
    “premature” generic request that the Commission denied in
    CLI-11-05. Absent any evidence – or even allegation –
    linking the conditions at the Vogtle site itself to the Task
    Force recommendations, NRC appropriately applied the
    applicable contention-specificity regulations in declining to
    admit Petitioners’ contentions. We defer to the Commission’s
    judgment. See Idaho Falls, 
    629 F.3d at 228
    .
    B. Declining to Allow Petitioners to Intervene in
    Mandatory Hearing
    Petitioners challenge their exclusion from NRC’s
    mandatory hearing regarding the Vogtle licenses. Their claim
    is meritless. As discussed above, there was no need for an
    additional contested hearing once NRC reasonably denied
    Petitioners’ contentions. Petitioners participated in two
    29
    contested hearings related to the Vogtle licenses. They had no
    right to participate in the Commission’s “mandatory” hearing.
    Mandatory hearings are “sufficiency” reviews, designed
    to assess the efforts of the NRC staff and determine whether
    the safety and environmental record is sufficient to support
    the license. Participation in these hearings is limited to the
    license applicant and NRC staff. Exelon Generation, 62
    N.R.C. at 49-50 (2005) (petitioners are “barred from
    participating in the uncontested portion of the hearing”).
    Petitioners point to no statutory or regulatory provision, nor
    agency practice, affording them a right to participate in a
    mandatory hearing. We therefore reject their claim on this
    point.
    C. Approval of AP1000 Reactor Design Certification
    Finally, we hold that NRC properly declined to
    supplement its existing EA for the AP1000 design
    certification amendment before adopting the final rule. The
    EA for a design certification amendment considers only
    whether the design change that is the subject of the proposed
    amendment renders a previously rejected Severe Accident
    Mitigation Design Alternative cost beneficial or identifies a
    new alternative necessitating its own cost-benefit analysis.
    See 
    10 C.F.R. § 51.30
    (d). The Commission reasonably found
    that the existing AP1000 EA adequately considered Severe
    Accident Mitigation Design Alternatives.
    In considering the AP1000 design certification
    amendment, NRC reexamined the probability that a severe
    accident might occur and concluded that potential design
    changes did not affect its original evaluations. Environmental
    Assessment by NRC Relating to the Certification of the
    Amendment to the AP1000 Standard Plant Design, Docket
    No. 52-006 at 5, (Dec. 22, 2011), reprinted in J.A. 224; see
    also AP1000 Design Certification Amendment, 
    76 Fed. Reg. 30
    at 82,096; NRC Responses to Public Comments, Final Rule:
    Amendment to AP1000 Design Certification Rule at 15-23
    (Dec. 2011), reprinted in J.A. 268-76 (detailing public
    comments and explaining why no supplemental EA was
    necessary); 
    id. at 44-45
    , reprinted in J.A. 280-81 (detailing
    the reasons no additional Severe Accident Design Mitigation
    Alternatives were necessary). NRC erred “on the side of high
    consequences” and concluded that the AP1000 EA “make[s] a
    convincing case that no identified [Severe Accident
    Mitigation Design Alternative] is worth the expense.” NRC
    Responses to Public Comments at 45, reprinted in J.A. 281.
    Petitioners do not challenge this analysis, nor do they connect
    any of the Task Force recommendations to any alternative
    that NRC failed to consider. Without an explicit challenge,
    NRC appropriately relied on its 2011 EA in approving the
    final AP1000 rule amendment. Indeed, the Task Force Report
    “supports completing [the AP1000] design certification
    rulemaking activities without delay.” Task Force Report at
    71-72; see also AP1000 Design Certification Amendment, 76
    Fed. Reg. at 82,083.
    Petitioners have failed to demonstrate that NRC acted
    less than reasonably in declining to order a supplemental EA
    for the AP1000 design certification amendment. We therefore
    defer to the Commission’s conclusion that such a supplement
    was unnecessary.
    V. CONCLUSION
    For the foregoing reasons, the petition for review is
    denied.