United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued March 20, 2018                  Decided July 20, 2018

                        No. 17-1059

                   OGLALA SIOUX TRIBE,
                       PETITIONER

                              v.

       U.S. NUCLEAR REGULATORY COMMISSION AND
               UNITED STATES OF AMERICA,
                     RESPONDENTS

                  POWERTECH (USA), INC.,
                      INTERVENOR


        On Petition for Review of an Order of the
       United States Nuclear Regulatory Commission


    Jeffrey C. Parsons argued the cause for petitioner. With
him on the briefs was Travis Stills. Roger Flynn entered an
appearance.

      James E. Adler, Senior Attorney, U.S. Nuclear Regulatory
Commission, argued the cause for respondents. With him on the
brief were Jeffrey H. Wood, Acting Assistant Attorney General,
U.S. Department of Justice, Eric Grant, Deputy Assistant
Attorney General, Lane N. McFadden, Attorney, and Andrew P.
Averbach, Solicitor, U.S. Nuclear Regulatory Commission.
                                2

    Christopher S. Pugsley argued the cause for intervenor-
respondent. With him on the brief was Anthony J. Thompson.

    Before: GARLAND, Chief Judge, and HENDERSON and
GRIFFITH, Circuit Judges.

    Opinion for the Court filed by Chief Judge GARLAND.

     GARLAND, Chief Judge: Powertech (USA), Inc. applied to
the Nuclear Regulatory Commission for a license to construct a
uranium mining project in the Black Hills of South Dakota. The
Oglala Sioux Tribe, which has historical ties to the proposed
project area, intervened in opposition because it feared the
destruction of its cultural, historical, and religious sites. The
staff of the Commission granted the license.

     On administrative appeal, the Commission decided to leave
the license in effect -- notwithstanding its own determination
that there was a significant deficiency in its compliance with the
National Environmental Policy Act -- pending further agency
proceedings to remedy the deficiency. The Commission
grounded this decision on the Tribe’s inability to show that
noncompliance with the Act would cause irreparable harm. In
so doing, the Commission was following what appears to be the
agency’s settled practice to require such a showing.

     The National Environmental Policy Act, however, obligates
every federal agency to prepare an adequate environmental
impact statement before taking any major action, which includes
issuing a uranium mining license. The statute does not permit
an agency to act first and comply later. Nor does it permit an
agency to condition performance of its obligation on a showing
of irreparable harm. There is no such exception in the statute.
                                3

     In fact, such a policy puts the Tribe in a classic Catch-22.
In order to require the agency to complete an adequate survey of
the project site before granting a license, the Tribe must show
that construction at the site would cause irreparable harm to
cultural or historical resources. But without an adequate survey
of the cultural and historical resources at the site, such a
showing may well be impossible. Of course, if the project does
go forward and such resources are damaged, the Tribe will then
be able to show irreparable harm. By then, however, it will be
too late.

     The Commission’s decision to let the mining project
proceed violates the National Environmental Policy Act.
Indeed, it vitiates the requirements of the Act. We therefore find
the decision contrary to law and grant the petition for review in
part. The Tribe also challenges other aspects of the
Commission’s order but, as we explain, we lack jurisdiction to
consider those rulings.

                                I

     The Atomic Energy Act, 42 U.S.C. § 2011 et seq.,
authorizes the Nuclear Regulatory Commission (NRC) to issue
licenses to qualified applicants to transfer, deliver, or receive
source material from in-situ leach uranium mining (also known
as ISL or ISR mining), a process used to recover underground
uranium for subsequent use in nuclear power plants. 42 U.S.C.
§ 2092; see Va. Uranium, Inc. v. Warren, 848 F.3d 590, 596 (4th
Cir. 2017). No one can conduct such activities without an NRC
license. 42 U.S.C. § 2092. The Act also creates hearing rights.
Anyone “whose interest may be affected by [a] proceeding” to
grant a license has the right to intervene and present
“contentions” challenging the license. Id. § 2239(a)(1)(A); 10
C.F.R. § 2.309(a), (f).
                                4

     The licensing process involves three relevant components
of the NRC.

     The first is the Commission Staff, which is responsible for
reviewing a license application, analyzing the environmental
effects and other features of the proposed project, and issuing an
initial decision approving or denying the application. 10 C.F.R.
§§ 2.103, 51.80, 51.102.

     The second is an Atomic Safety and Licensing Board
(ASLB), a panel that can be designated to preside over a
licensing hearing, at which the Board hears contentions from
intervenors and then issues an initial decision on those
contentions. Id. §§ 2.313(a), 2.321, 2.1210. Through the Board
hearing process, intervenors can challenge the agency’s
compliance with the National Environmental Policy Act
(NEPA), which requires federal agencies to prepare a detailed
Environmental Impact Statement (EIS) for any “proposed”
major federal action that “significantly affect[s] the quality of
the human environment,” 42 U.S.C. § 4332(2)(C), including
granting the kind of license at issue here, see 10 C.F.R.
§ 51.20(b)(8).

     Third is the Commission itself. Once the Board issues an
initial decision on the contentions before it, parties can seek
review from the Commission. Id. § 2.341(b). The Commission
“may adopt, modify, or set aside” the Board’s decision. Id.
§ 2.344(b).

     In 2009, Powertech applied for an NRC license authorizing
it to “construct and operate” a uranium mining project, called
the “Dewey-Burdock project,” in the southwest corner of South
Dakota. NRC, Record of Decision for the Dewey-Burdock
Uranium In-Situ Recovery Project at 1 (2014) (“Record of
                                    5

Decision”) (J.A. 738). The NRC described the project as
follows:

            The proposed facility will encompass
            approximately . . . 10,580 acres[,] which consists of
            two contiguous mining units . . . . Powertech intends
            to recover uranium and produce yellowcake at the
            Dewey-Burdock site. Powertech’s proposed activities
            include construction, operation, aquifer restoration, and
            decommissioning of its ISR facility. In addition,
            Powertech has proposed that liquid wastewater
            generated during uranium recovery be disposed of
            through one of the following methods: (i) deep well
            disposal via Class V injection wells, (ii) land
            application, or (iii) a combination of deep well disposal
            and land application.

Id. at 1-2 (J.A. 738-39).1 The NRC’s chief administrative judge
established an Atomic Safety and Licensing Board to preside
over Powertech’s licensing proceeding.




1
    The NRC further explained the ISR process as follows:

            [A]n oxidant-charged solution, called a lixiviant, will be
            injected into the production zone aquifer (uranium orebody)
            through injection wells. . . . As the lixiviant circulates
            through the production zone, it will oxidize and dissolve the
            mineralized uranium . . . . The resulting uranium-rich
            solution will be drawn to recovery wells by pumping and
            then transferred to a processing facility via a network of
            underground pipelines. At the processing facility, the
            uranium will be removed from solution via ion exchange.

Record of Decision at 2 (J.A. 739).
                                  6

     The petitioner here, the Oglala Sioux Tribe, intervened to
challenge Powertech’s application. The Tribe’s Pine Ridge
Reservation is located roughly fifty miles from the project site,
Powertech USA, Inc., 81 N.R.C. 618, 656 (2015) (“ASLB Initial
Decision”) (J.A. 455), and the project lands are within the
Tribe’s traditional territory, see Trina Lone Hill Decl. ¶ 5. A
sizable number of cultural, historical, and archaeological sites
have already been identified in the project area, including burial
sites. EIS for Dewey-Burdock Project, NUREG-1910 at 4-159
to -182 (Jan. 2014) (“EIS”) (J.A. 655-78). The Tribe also owns
lands near the proposed project, which it has “leased for
domestic, agricultural, water development, conservation, and
other purposes.” Oglala Br. 4. The Tribe’s primary concerns
regarding the project are protecting the Tribe’s cultural and
historical resources, as well as protecting groundwater from
mining contamination. Id.

     While the Board set the stage for the Powertech hearing, the
Commission Staff drew up environmental documents for the
Dewey-Burdock project, including an EIS, which it published in
2014. See EIS, NUREG-1910 (J.A. 567-737).2 After publishing
the EIS, the Staff granted Powertech’s application and issued the
requested license. Record of Decision at 1 (J.A. 738).

    The Tribe promptly moved to stay the license. Without
assessing the merits of the Tribe’s contentions, the Board denied


2
  Technically, this was the Final Supplemental Environmental Impact
Statement (FSEIS) for the project. The Staff first published a draft
supplemental EIS, which built on the Commission’s generic EIS for
in-situ leach uranium mining facilities. In 2014, it issued the FSEIS,
which is the document most relevant to this case. The NRC brief
occasionally refers to the document as the “EIS.” See, e.g., NRC Br.
49-52. For purposes of clarity, we will do so consistently throughout
this opinion.
                                  7

the stay. It did so on the ground, inter alia, that the Tribe’s
allegations “lack[ed] the specificity needed to demonstrate a
serious, immediate, and irreparable harm to cultural and historic
resources.” Order, Powertech USA, Inc., No. 40-9075-MLA at
6 (May 20, 2014) (“ASLB Stay Denial Order”) (J.A. 516).

    After denying the stay, the Board held a hearing on the
merits of the contentions pending before it. The Board ruled
against the Tribe, and in favor of the Staff and Powertech, on the
bulk of those contentions.3 However, on two of the Tribe’s
contentions, Contentions 1A and 1B, the Board ruled in favor of
the Tribe. ASLB Initial Decision, 81 N.R.C. at 708-10 (J.A.
507-09).

     In Contention 1A, which is most significant for our
purposes, the Tribe charged that the EIS did not satisfy NEPA
because it failed to adequately address the environmental effects
of the Dewey-Burdock project on Native American cultural,
religious, and historical resources. The Board agreed with this
charge, finding that:

          [T]he [EIS] in this proceeding does not contain an
          analysis of the impacts of the project on the cultural,
          historical, and religious sites of the Oglala Sioux Tribe


3
  As relevant to the Tribe’s petition in this court, the Board ruled
against the Tribe on: Contention 2, regarding the sufficiency of
baseline groundwater quality information; Contention 3, concerning
the EIS’s analysis of features that could permit groundwater
migration; and Contention 6, relating to the EIS’s analysis of proposed
mitigation measures. ASLB Initial Decision, 81 N.R.C. at 708-09
(J.A. 507-08). The ASLB had previously found against the Tribe on
Contention 7, with respect to the adequacy of a plan for disposing of
byproduct material; and Contention 8, regarding the scoping process.
See Powertech (USA), Inc., 84 N.R.C. 219, 226 (2016) (J.A. 243).
                                 8

         and the majority of the other consulting Native
         American tribes. . . . Because the cultural, historical,
         and religious sites of the Oglala Sioux Tribe have not
         been adequately catalogued, the [EIS] does not include
         mitigation measures sufficient to protect this Native
         American tribe’s cultural, historical, and religious sites
         that may be affected by the Powertech project.

         Accordingly, as to Contention 1A, the Board finds and
         concludes that the [EIS] has not adequately addressed
         the environmental effects of the Dewey-Burdock
         project on Native American cultural, religious, and
         historic resources. . . . NEPA’s hard look requirement
         has not been satisfied.

Id. at 655 (citations omitted) (J.A. 454).

     In Contention 1B, the Tribe charged that the NRC Staff had
failed to fulfill its responsibilities regarding consultation with
Native American tribes under the National Historic Preservation
Act (NHPA), 54 U.S.C. § 306108. For a variety of reasons, the
Board agreed that the consultation process between the NRC
Staff and the Tribe was inadequate to satisfy the statute. ASLB
Initial Decision, 81 N.R.C. at 655-57 (J.A. 454-56).

     Despite what the Board concluded was a “significant
deficiency in the NRC Staff’s NEPA review,” it did not suspend
Powertech’s previously issued license. Id. at 658 (J.A. 457).
Instead, it retained jurisdiction and directed the Staff to cure “the
deficiencies in Contentions 1A and 1B.” Id. In the interim, it
said, the Tribe “may . . . petition this Board for a stay of the
license’s effectiveness, as may be necessary to halt ground
disturbing activities,” but only “if the . . . Tribe can identify
specific cultural, historic, or religious sites that are subject to
immediate and irreparable harm by the Powertech project.” Id.
                               9

     The action then moved to the Commission. The Tribe, the
Staff, and Powertech all petitioned the Commission for review
of the Board’s decision. The Staff and Powertech challenged
the Board’s partial resolution of Contentions 1A and 1B in favor
of the Tribe. With respect to those same contentions, the Tribe
argued that NEPA and the National Historic Preservation Act
“prohibit[ed] the Board from leaving [Powertech’s] license in
place,” given the project’s inadequate environmental review.
Powertech (USA), Inc., 84 N.R.C. 219, 245 (2016) (“NRC
Order”) (J.A. 268). The Tribe also challenged the Board’s
rejection of its other contentions. Id. at 224-26 (J.A. 240-43).

      The Commission generally upheld the Board’s rulings. Id.
It left in place the findings that the Staff had failed to comply
with NEPA and the National Historic Preservation Act. See id.
at 248 (J.A. 272). Nonetheless, it affirmed the Board’s decision
to leave the license in effect because the Tribe “has not
articulated any harm or prejudice” from the Staff’s failure. Id.
at 245 (J.A. 268). The Commission then directed that the
proceeding “remain open for the narrow purpose of resolving
the deficiencies identified by the Board.” Id. at 262 (J.A. 292).
And it denied the Tribe’s other challenges. Id. at 229, 237, 253,
256, 262 (J.A. 246, 258, 279-80, 283, 291-92).

     Commissioner Baran dissented on the point that is now at
issue before us:       the Commission’s decision to leave
Powertech’s license in effect while the Staff attempted to
resolve the deficiencies in its NEPA review. His dissent stated
as follows:

         [A] core requirement of NEPA is that an agency
         decisionmaker must consider an adequate
         environmental review before making a decision on a
         licensing action. If the Commission allows a Board to
         supplement and cure an inadequate NEPA document
                                10

         after the agency has already made a licensing decision,
         then this fundamental purpose of NEPA is frustrated.

         In this case, the Board found that the Staff’s [EIS] did
         not meet the requirements of NEPA because the [EIS]
         was deficient with respect to the effects of the licensing
         action on Native American cultural, religious, and
         historic resources. Thus, the agency did not have an
         adequate environmental analysis at the time it decided
         whether to issue the license. In fact, the deficiencies in
         the NEPA analysis remain unaddressed today, and
         therefore the Staff still cannot make an adequately
         informed decision on whether to issue the license. The
         Staff’s licensing decision was based on (and continues
         to rest on) an inadequate environmental review. As a
         result, the Staff has not complied with NEPA.

         The Commission should suspend the license until the
         Staff has . . . demonstrat[ed] that the [EIS] complies
         with NEPA . . . .

Id. at 269 (Commissioner Baran, dissenting in part) (citations
omitted) (J.A. 301-02).

     Thereafter, the Tribe filed a petition in this court for review
of the Commission’s order. Its principal challenge is to the
NRC’s decision to leave the license in effect pending the Staff’s
effort to cure the NEPA deficiencies. The Tribe also challenges
the disposition of its other contentions, which are set out in
footnote 3, supra.
                               11

                                II

    We begin with our jurisdiction.

                                A

     Under the Hobbs Act, this court has jurisdiction to review
“final orders” of the Commission. 28 U.S.C. § 2342(4).
Generally, a final order is “one that disposes of all issues as to
all parties.” Blue Ridge Envtl. Def. League v. NRC, 668 F.3d
747, 753 (D.C. Cir. 2012) (internal quotation marks omitted);
see CSX Transp., Inc. v. Surface Transp. Bd., 774 F.3d 25, 28
(D.C. Cir. 2014). Typically, an order “remanding a matter to an
[administrative law judge, or here, to the ASLB] will not, on its
own, satisfy the principle of finality.” Meredith v. Fed. Mine
Safety & Health Review Comm’n, 177 F.3d 1042, 1050 (D.C.
Cir. 1999).

     Applying this standard, we conclude that the Commission’s
order, as a whole, is not final. It did not consummate the
agency’s decisionmaking process as to all issues, but instead left
the proceeding “open” while the Staff attempted to resolve the
deficiencies in NEPA compliance (Contention 1A) and in the
National Historic Preservation Act consultation process
(Contention 1B). NRC Order, 84 N.R.C. at 262 (J.A. 292).

    In keeping with this instruction, the Atomic Safety and
Licensing Board has continued to oversee the Staff’s efforts to
cure the statutory deficiencies. In October 2017, the Board
granted the Staff’s motion for summary disposition regarding
Contention 1B, concluding that the Staff’s consultation efforts
over the intervening two years had satisfied the National
Historic Preservation Act. Powertech USA, Inc., 86 N.R.C. 167,
173 (2017) (“ASLB Summary Disposition Order”). But the
Board denied the Staff’s motion to dismiss the Tribe’s NEPA
                                  12

contention (Contention 1A), and the adjudication of that
contention remains pending. Id. at 173-74. The Board order set
a schedule contemplating resolution of the outstanding NEPA
contention on or before October 12, 2018, id. at 210, but the
Board has since suspended that schedule without imposing a
new end date, see Order Suspending Scheduled Dates,
Powertech USA, Inc., No. 40-9075-MLA at 2-3 (Apr. 12, 2018).

     Because the Commission’s order did not end the agency
proceeding as to all issues, we do not have jurisdiction to review
the bulk of the rulings challenged by the Tribe.

                                   B

     We do have jurisdiction, however, to review one of the
rulings contained in the NRC order: the decision to leave the
license in effect -- notwithstanding the NRC’s determination that
the agency is not in compliance with NEPA -- pending further
proceedings before the Atomic Safety and Licensing Board.4
That ruling falls within the collateral order doctrine.5



4
  Although the collateral order doctrine might also have given us
jurisdiction over the NRC’s parallel ruling regarding compliance with
the National Historic Preservation Act, the ASLB’s subsequent
determination that the Staff’s consultation efforts satisfied that Act,
ASLB Summary Disposition Order, 86 N.R.C. at 173, means that the
agency is no longer going forward despite an acknowledged NHPA
violation. Thus, the analysis set forth below, which brings the NEPA
contention within the doctrine, applies only to that contention.
5
 Because we find that the ruling is reviewable as a collateral order, we
do not decide whether review of the ruling would also fall within the
scope of this circuit’s “immediate effectiveness” doctrine. See Blue
Ridge Envtl. Def. League, 668 F.3d at 757; Massachusetts v. NRC, 924
F.2d 311, 322 (D.C. Cir. 1991).
                                13



     Pursuant to 28 U.S.C. § 1291, courts of appeals “have
jurisdiction of appeals from all final decisions of the district
courts of the United States.” The Supreme Court, however, “has
long given § 1291 a practical rather than a technical
construction[,] . . . encompass[ing] not only judgments that
terminate an action, but also a small class of collateral rulings
that, although they do not end the litigation, are appropriately
deemed ‘final.’” Mohawk Indus., Inc. v. Carpenter, 558 U.S.
100, 106 (2009) (internal quotation marks omitted). Because the
finality requirement of the Hobbs Act “is the counterpart to that
of 28 U.S.C. § 1291,” we have permitted appeals from the same
small category of interlocutory rulings made by administrative
agencies. Cmty. Broad. of Boston, Inc. v. FCC, 546 F.2d 1022,
1024 (D.C. Cir. 1976) (construing the Hobbs Act); see
CalPortland Co. v. Fed. Mine Safety & Health Review Comm’n,
839 F.3d 1153, 1159-60 (D.C. Cir. 2016) (construing the Mine
Act); Meredith, 177 F.3d at 1050-51 (same). In applying the
collateral order doctrine, we remain mindful of the Supreme
Court’s admonition that “it must never be allowed to swallow
the general rule that a party is entitled to a single appeal, to be
deferred until final judgment has been entered.” Mohawk
Indus., 558 U.S. at 106 (internal quotation marks omitted).

     To effectuate that admonition, the Court has limited
appealable collateral rulings to a “small category [that] includes
only decisions [1] that are conclusive, [2] that resolve important
questions separate from the merits, and [3] that are effectively
unreviewable on appeal from the final judgment in the
underlying action.” Id. (quoting Swint v. Chambers Cty.
Comm’n, 514 U.S. 35, 42 (1995)). Applying these conditions,
we conclude that the ruling before us, which expressly permits
a license to go forward despite the agency’s acknowledgment
                                14

that it has not complied with NEPA, is a reviewable collateral
order.

      First, that ruling is “a fully consummated decision . . . that
conclusively and finally determine[s]” the effectiveness of
Powertech’s license for the foreseeable future. See CalPortland
Co., 839 F.3d at 1160 (internal quotation marks omitted). More
important, it conclusively determines the Commission’s
interpretation of what NEPA requires in this circumstance. The
Commission has decided that a license can remain effective and
that construction can go forward -- despite the agency’s failure
to satisfy the requirements of NEPA -- unless the Tribe can
show irreparable harm from leaving the license in place while
the NEPA violation is cured. There is “no basis to suppose that
the [Commission] contemplate[s] any reconsideration of [the]
decision,” id. (internal quotation marks omitted), to permit such
a license to remain effective unless irreparable harm can be
shown. See NRC Br. 33 (stating that the Tribe can seek a stay
only if a “new development [arises] that could potentially
support an irreparable harm demonstration”). To the contrary,
the “irreparable harm” standard appears to be the agency’s
settled practice. See infra Part III.A.

     Second, the order resolves an “important question[] separate
from the merits,” Mohawk Indus., 558 U.S. at 106 (quoting
Swint, 514 U.S. at 42). Powertech now has the right to an
effective license, despite an ongoing NEPA violation that the
agency acknowledges. The Commission’s irreparable harm
standard for vacating the license pending the conclusion of its
administrative adjudication has no bearing on its ultimate
resolution of the merits of the Tribe’s multiple contentions,
including whether NEPA actually has been (or subsequently will
be) satisfied. And the Commission’s resolution of the merits of
those questions will not address the validity of that standard.
                                 15

     Third, the ruling that permits projects to go forward despite
“significant” NEPA violations will be effectively unreviewable
if the Tribe is forced to wait for the conclusion of the agency’s
adjudication before appealing. If we do not hear that issue now,
the ASLB proceedings will continue. At the end of that process,
the agency either will conclude that the Staff has been unable to
satisfy NEPA and will therefore (presumably) vacate the license,
see NRC Br. 8, 30, or it will determine that the Staff has finally
satisfied NEPA and reaffirm the license. If it reaches the former
conclusion, there will be nothing left for the Tribe to petition to
review. If it reaches the latter, our precedent will require denial
of the petition on the ground that -- at that point -- a remand
would be futile. See Friends of the River v. FERC, 720 F.2d 93,
106-08 (D.C. Cir. 1983) (denying as futile a petition for review
when the agency issued a license despite noncompliance with
NEPA, but subsequently complied before the petition for review
was filed); see also Nat. Res. Def. Council v. NRC, 879 F.3d
1202, 1211-12 (D.C. Cir. 2018) (same, citing Friends of the
River, 720 F.2d 93).

     In evaluating this third condition, the Supreme Court has
said that “the decisive consideration is whether delaying review
until the entry of final judgment would imperil a substantial
public interest or some particular value of a high order.”
Mohawk Indus., 558 U.S. at 107 (internal quotation marks
omitted). We know that the environmental values protected by
NEPA are of a high order -- because Congress has told us so.6
We likewise know (as discussed in Part III.A below) that
Congress has directed that, to protect those values, “all agencies


6
  See 42 U.S.C. § 4331 (recognizing “the critical importance of
restoring and maintaining environmental quality to the overall welfare
and development of man,” and declaring the federal government’s
responsibility to “preserve important historic, cultural, and natural
aspects of our national heritage”).
                                16

of the Federal Government” must prepare an environmental
impact statement that satisfies NEPA before taking an action
like granting Powertech’s license. 42 U.S.C. § 4332(2)(C); see
10 C.F.R. § 51.20(b)(8). Delaying review of an action that
concededly was not preceded by a valid EIS would imperil the
public interest in requiring that a valid EIS be prepared before
the agency grants the license. Moreover, if review is delayed
until final judgment, and vulnerable but as-yet-unidentified
historical, cultural, or religious sites are damaged in the interim,
the court will be unable to remedy that injury to the public
interest -- an interest that NEPA’s procedural mandate was
intended to vindicate. See Robertson v. Methow Valley Citizens
Council, 490 U.S. 332, 349-51 (1989).

      Finally, in making the collateral order determination, the
Court has instructed that we “not engage in an individualized
jurisdictional inquiry,” but rather focus on “the entire category
to which a claim belongs.” Mohawk Indus., 558 U.S. at 107
(internal quotation marks omitted). “[T]he chance that the
litigation at hand might be speeded, or a particular injustic[e]
averted, does not provide a basis for . . . jurisdiction.” Id.
(internal quotation marks omitted). Our conclusion in this case
is in accord with that direction as well. Here, we focus not only
on the Tribe’s challenge to the effectiveness of Powertech’s
license, but rather on the entire category of claims that challenge
(and will challenge) NRC’s legal position that it may leave a
license in full effect despite the agency’s failure to comply with
NEPA.

    We therefore have jurisdiction to consider whether the NRC
may authorize a licensee to go ahead with construction --
notwithstanding the Commission’s conclusion that there has
                                 17

been a significant deficiency in its NEPA compliance -- unless
an intervenor demonstrates irreparable harm.7

                                  III

     Our review of this matter is governed by the Administrative
Procedure Act (APA), 5 U.S.C. § 706(2). See Blue Ridge Envtl.
Def. League v. NRC, 716 F.3d 183, 195 (D.C. Cir. 2013). Under
the APA, we must hold an agency’s action unlawful if it is
“arbitrary, capricious, an abuse of discretion, or otherwise not in
accordance with law.” 5 U.S.C. § 706(2)(A).

                                  A

     NEPA requires that “all agencies of the Federal
Government shall . . . include in every recommendation or
report on proposals for . . . major Federal actions significantly
affecting the quality of the human environment, a detailed
statement by the responsible official” on:

          (i) the environmental impact of the proposed action,



7
  We are unpersuaded by NRC counsel’s suggestion that the Tribe
should have raised this challenge when the Staff first made
Powertech’s license effective in 2014. NRC Br. 33. The Tribe did
apply for a stay at that time, and it did not appeal after the ASLB
denied its application. But the question posed at that moment was not
the same as the one raised here. When the Tribe first sought a stay,
neither the Commission nor the Board had yet acknowledged the
NEPA violation and neither had ruled that the license could remain in
effect notwithstanding the violation. See ASLB Stay Denial Order,
No. 40-9075-MLA at 8-9 (J.A. 518-19). Hence, the Tribe could not
have challenged the ruling and policy that it alleges here is unlawful:
letting a project go forward despite the Commission’s
acknowledgment that it has not satisfied NEPA’s requirements.
                               18

         (ii) any adverse environmental effects which cannot
         be avoided should the proposal be implemented,

         (iii) alternatives to the proposed action,

         (iv) the relationship between local short-term uses of
         man’s environment and the maintenance and
         enhancement of long-term productivity, and

         (v) any irreversible and irretrievable commitments of
         resources which would be involved in the proposed
         action should it be implemented.

42 U.S.C. § 4332(2)(C); see New York v. NRC, 681 F.3d 471,
476 (D.C. Cir. 2012). There is no dispute that the NRC’s grant
of a uranium mining license constitutes such a “major Federal
action[] significantly affecting the quality of the human
environment.” 42 U.S.C. § 4332(2)(C); see NRC Br. 5 (“NRC
regulations . . . require NRC to prepare an EIS prior to issuing
an in situ recovery facility license.”); ASLB Initial Decision, 81
N.R.C. at 641 n.123 (J.A. 440) (“Issuing a license to possess and
use source material to a uranium milling facility is identified as
a major federal action.”); 10 C.F.R. § 51.20(b)(8).

     This statutory provision requires agencies to take a “hard
look” at environmental consequences before undertaking any
such action. Robertson, 490 U.S. at 350. The environmental
effects that must be assessed include “aesthetic, historic,
cultural, economic, social, or health” effects. 40 C.F.R.
§ 1508.8(b); see 42 U.S.C. § 4331(b)(4) (declaring that
“preserv[ing] important historic, cultural, and natural aspects of
our national heritage” is an element of national environmental
policy). And the Commission’s regulations expressly require its
Staff to include, in an environmental impact statement, “an
                                19

analysis of significant problems and objections raised by . . . any
affected Indian Tribes.” 10 C.F.R. § 51.71(b).

     The Atomic Safety and Licensing Board ruled that, to
“fulfill the agency’s NEPA . . . responsibilities to protect and
preserve cultural, religious, and historical sites important to the
Native American tribal cultures in the Powertech project area,
the NRC Staff must conduct a study or survey of tribal cultural
resources before granting a license.” ASLB Initial Decision, 81
N.R.C. at 653 (J.A. 452). As discussed in Part I above, the
Board found that “the [EIS] in this proceeding does not contain”
such an analysis. Id. at 655 (J.A. 454). Moreover, “[b]ecause
the cultural, historical, and religious sites of the Oglala Sioux
Tribe have not been adequately catalogued, the [EIS] does not
include mitigation measures sufficient to protect this Native
American tribe’s cultural, historical, and religious sites that may
be affected by the Powertech project.” Id. “Accordingly,” the
Board concluded, “NEPA’s hard look requirement has not been
satisfied.” Id.

     The Board did not find just a technical violation of NEPA.
Rather, it found that “the inadequate discussion of potential
impacts to Sioux cultural, historical, or religious sites in the
[EIS] or Record of Decision is a significant deficiency in the
NRC Staff’s NEPA review.” Id. at 658 (emphasis added) (J.A.
457). And the Commission did not disagree. Refusing to
“second guess the Board’s fact-finding,” the Commission
declined to set aside the Board’s order and denied the Staff’s
petition for review with respect to the Tribe’s NEPA contention.
NRC Order, 84 N.R.C. at 248 (J.A. 272-73).

     For purposes of our review, we accept the Board’s finding
-- undisturbed by the Commission -- that the agency did not
fulfill its NEPA responsibilities. We do not review the merits of
that conclusion.
                                 20

     Notwithstanding the Board’s finding, and in particular its
acknowledgment that the Staff “must conduct a study or survey
of tribal cultural resources before granting a license” in order to
fulfill the agency’s NEPA responsibilities, ASLB Initial
Decision, 81 N.R.C. at 653 (emphasis added) (J.A. 452), the
Board ruled that it would not suspend Powertech’s license
unless the Tribe sought a stay within ten days and showed that
“specific cultural, historic, or religious sites . . . are subject to
immediate and irreparable harm.” Id. at 658 (J.A. 457). The
Commission likewise refused to vacate the license on the ground
that more than just a NEPA violation was required, stating that
there was no need to disturb the license because the “Tribe ha[d]
not articulated any harm or prejudice.” NRC Order, 84 N.R.C.
at 245 (J.A. 268).

     The agency thus conditioned enforcement of NEPA on a
showing of irreparable harm by the Tribe.8 It did so even
though, as Commissioner Baran explained in dissent, the agency
lacked an adequate environmental analysis when it first issued
the license and the significant NEPA deficiencies identified by
the Board “remain[ed] unaddressed” at the time of the

8
   Although the Commission’s order vaguely referred to “harm or
prejudice,” NRC Order, 84 N.R.C. at 245 (J.A. 268), it upheld the
Board’s order requiring a showing of “irreparable harm,” ASLB Initial
Decision, 81 N.R.C. at 658 (J.A. 457). The NRC also noted that the
Tribe “did not request a stay of the effectiveness of the license,” NRC
Order, 84 N.R.C. at 245 (J.A. 268), which the Board had made clear
it would not grant unless the Tribe could identify specific “sites that
are subject to immediate and irreparable harm by the Powertech
project,” ASLB Initial Decision, 81 N.R.C. at 658 (J.A. 457). And the
NRC brief likewise indicates that “irreparable harm” is the
Commission’s own standard. See NRC Br. 1 (emphasizing that “the
Tribe demonstrated no irreparable harm”); id. at 33 (noting that the
Tribe could still seek a stay if “a new development” could support “an
irreparable harm demonstration”).
                                    21

Commission’s decision. Id. at 269 (Commissioner Baran,
dissenting in part) (J.A. 301). Therefore “[t]he Staff’s licensing
decision was based on (and continues to rest on) an inadequate
environmental review.” Id.

     Moreover, this was not a one-off decision by the NRC.
Rather, it appears to reflect the agency’s settled practice. See
Strata Energy, Inc., 83 N.R.C. 566, 595 n.188 (2016) (“It is well
settled that parties challenging an agency’s NEPA process are
not entitled to relief unless they demonstrate harm or
prejudice.”); see also Crow Butte Resources, Inc., 83 N.R.C.
340, 413-14 (2016) (relying on the Powertech precedent to keep
a license in effect, notwithstanding finding that the NRC staff
had not complied with NEPA, and repeating the “irreparable
injury” requirement).

     The agency’s decision in this case and its apparent practice
are contrary to NEPA. The statute’s requirement that a detailed
environmental impact statement be made for a “proposed”
action makes clear that agencies must take the required hard
look before taking that action. See, e.g., Pub. Emps. for Envtl.
Responsibility v. Hopper, 827 F.3d 1077, 1081 (D.C. Cir. 2016)
(holding that an agency’s decision to issue a lease for a
windpower project “without first obtaining sufficient site-
specific data . . . violated” NEPA (internal quotation marks
omitted)); New York, 681 F.3d at 476 (“Under NEPA, each
federal agency must prepare an [EIS] before taking a ‘major
Federal action[] significantly affecting the quality of the human
environment.’” (quoting 42 U.S.C. § 4332(2)(C))).9 Nothing in


9
  See also Marsh v. Or. Nat. Res. Council, 490 U.S. 360, 371 (1989)
(“NEPA ensures that the agency will not act on incomplete
information, only to regret its decision after it is too late to correct.”);
Robertson, 490 U.S. at 349 (explaining that NEPA “focus[es] the
agency’s attention on the environmental consequences of a proposed
                                 22

NEPA’s text suggests that the required environmental analysis
of a “proposed” action is optional if a party does not prove that
“irreparable harm” would result from going forward before the
agency completes a valid EIS.

   The nontextual exception upon which the NRC insists
would vitiate the statute’s “‘action-forcing’ purpose.”
Robertson, 490 U.S. at 349. As the Court explained in
Robertson:

          The statutory requirement that a federal agency
          contemplating a major action prepare such an
          environmental impact statement serves NEPA’s
          “action-forcing” purpose in two important respects. . . .
          It 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.

id. (emphasis added); see Baltimore Gas & Electric Co. v. Nat.
Res. Def. Council, 462 U.S. 87, 97 (1983). If an agency fails to
complete the required review before authorizing a proposed
project -- whether or not a party is able to present evidence of


project” (emphasis added)); Sierra Club v. U.S. Army Corps of Eng’rs,
803 F.3d 31, 37 (D.C. Cir. 2015) (explaining that NEPA requires
agencies to take a “hard look” at environmental consequences of
proposed actions “in advance of deciding whether and how to
proceed”); 40 C.F.R. § 1500.1(b) (Council on Environmental Quality
regulation providing that “NEPA procedures must [e]nsure that
environmental information is available to public officials and citizens
before decisions are made and before actions are taken”).
                                 23

harm at that stage -- it runs the risk “that important effects
will . . . be overlooked or underestimated only to be discovered
after . . . the die [has been] cast.” Robertson, 490 U.S. at 349;
see Winter v. Nat. Res. Def. Council, 555 U.S. 7, 23 (2008); Ill.
Commerce Comm’n v. ICC, 848 F.2d 1246, 1259 (D.C. Cir.
1988).

     Indeed, the nature of the agency action in this case puts the
problem in high relief. As we have noted, the Tribe “has shown
it has the most direct historical, cultural, and religious ties to the
[Dewey-Burdock project] area.” ASLB Initial Decision, 81
N.R.C. at 656 (J.A. 455). A significant number of cultural,
historical, and archaeological sites have already been identified
in the project area, including burial sites. EIS, NUREG-1910 at
4-159 to -182 (J.A. 655-78). The Tribe is concerned that
mining, as well as the construction and other land disturbances
that precede mining, will damage those resources. See Trina
Lone Hill Decl. ¶¶ 5, 28. The purpose of an EIS is, in part, to
determine whether the land contains such resources and where
they are located, so that damage to them can be avoided or
mitigated. If the project is permitted to go forward without the
necessary land survey, such damage may well be done.

    In short, the NRC has placed the Tribe in a classic Catch-
22. It must show irreparable harm to insist that an adequate
survey be completed. But it likely cannot show even the risk of
such harm unless that survey is completed. Of course, if the
project goes forward and the burial or other sites are damaged,
the Tribe will then be able to show irreparable harm -- but by
then, it will be too late to stop it.

     The NRC’s conduct in this case may be compared --
unfavorably -- to that of the Interstate Commerce Commission
in Illinois Commerce Commission v. ICC, 848 F.2d 1246.
There, the court declined to remand the agency’s policy of
                               24

publishing an environmental assessment after publishing notice
of proposed abandonment of a railroad line. But it did so only
because the agency represented that, if environmental issues
were raised, a stay would “automatically be granted until the
concerns are resolved by the [agency],” with “no showing of
irreparable harm or probability of success . . . required.” Id. at
1260. That procedure, we said, “obviate[d] the possibility that
an abandonment would be authorized even though
environmental questions were still outstanding.” Id. Needless
to say, that procedure -- providing for an automatic stay without
the need to show irreparable harm -- stands in stark contrast to
the approach the Commission employed here. And for the
reasons we have stated, the latter is contrary to law.

                                B

    In this subpart, we address the NRC’s defense of its ruling.

     1. The justification upon which the Commission relied in
its order was an analogy to this court’s treatment of “harmless
error” when reviewing an agency decision. NRC Order, 84
N.R.C. at 245 (J.A. 268) (“[F]ederal courts have required that
parties demonstrate harm or prejudice to disturb an agency’s
decision.”). The analogy is inapt.

     The “harmless error” doctrine that this court applies is
compelled by a statute, the Administrative Procedure Act, which
provides that “due account shall be taken of the rule of
prejudicial error,” 5 U.S.C. § 706; see, e.g., First Am. Discount
Corp. v. Commodity Futures Trading Comm’n, 222 F.3d 1008,
1015 (D.C. Cir. 2000). As the Commission itself notes,
however, “the Board and Commission are not courts, and so 5
U.S.C. § 706 does not govern their choices of remedy” for Staff
errors. NRC Br. 34. Nor does NEPA -- or any other statute that
has been called to our attention -- give the NRC authority to
                                  25

forgive “harmless” violations of NEPA. Cf. 38 U.S.C. §
7261(b)(2) (directing the United States Court of Appeals for
Veterans Claims to “take due account of the rule of prejudicial
error”); 28 U.S.C. § 2111 (instructing appellate courts to give
judgment “without regard to errors or defects which do not
affect the substantial rights of the parties”).

    But whether or not that ends the argument -- a question we
do not need to decide -- what the agency has done here looks
nothing like the harmless error review undertaken by this court.

     First, it is true that “[w]e have applied the prejudicial error
rule in the NEPA context where the proposing agency engaged
in significant environmental analysis before reaching a decision
but failed to comply precisely with NEPA procedures.” Nevada
v. Dep’t of Energy, 457 F.3d 78, 90 (D.C. Cir. 2006) (emphasis
added); see, e.g., Int’l Bhd. of Teamsters v. U.S. Dep’t of
Transp., 724 F.3d 206, 217 (D.C. Cir. 2013) (holding that any
“technical error” in the timing of the release of an environmental
assessment was harmless when the agency completed the
assessment “before authorizing any” operations). But the error
here was neither a failure of precision nor a technicality. Rather,
as the Board itself said, it was a “significant deficiency” in the
Staff’s NEPA review. ASLB Initial Decision, 81 N.R.C. at 658
(J.A. 457).10


10
  This circuit has also sometimes regarded deviations from NEPA as
harmless when an agency subsequently completed a comprehensive
environmental review before the matter reached our court. See Nat.
Res. Def. Council, 879 F.3d at 1211-12 (refusing to remand where the
agency “adequately augmented its decision before being challenged
in th[e] court”); Friends of the River, 720 F.2d at 106-08 (declining to
remand when the agency completed a thorough, if belated,
environmental review). In this case, however, the agency has not yet
completed a valid review.
                                26

     The Commission’s order disparaged this error as merely
“procedural.” NRC Order, 84 N.R.C. at 245 (J.A. 268); see
NRC Br. 34, 35. But “NEPA imposes only procedural
requirements.” Winter, 555 U.S. at 23. If even “significant”
deficiencies in NEPA reviews are forgiven because they are
merely procedural, there will be nothing left to the protections
that Congress intended the Act to provide. Moreover, in a
comparable situation, “[w]e have not been hospitable to
government claims of harmless error in cases in which the
government violated [the procedural requirement of APA]
§ 553 . . . by failing to provide notice” of proposed agency
action. Allina Health Servs. v. Sebelius, 746 F.3d 1102, 1109
(D.C. Cir. 2014).

     Given the significant deficiency at issue in this case, the
harmless error doctrine cannot justify the agency’s ruling. As
we have noted, the Board found that the EIS “does not contain
an analysis of the impacts of the project on the cultural,
historical, and religious sites of the Oglala Sioux Tribe and the
majority of the other consulting Native American tribes.” ASLB
Initial Decision, 81 N.R.C. at 655 (J.A. 454). As a consequence,
“the EIS does not include mitigation measures sufficient to
protect this Native American tribe’s cultural, historical, and
religious sites that may be affected by the Powertech project.”
Id. That assessment of the risks to the Tribe’s sites is consistent
with the Commission’s generic EIS for these kinds of mining
projects: “[D]epending on local conditions,” the agency has
explained, ISL facility construction can cause a “large” impact
on “ecological, historical, or cultural resources” because of the
“potential for unidentified resources to be altered or destroyed
during excavation, drilling, and grading.” Generic EIS for In-
Situ Leach Uranium Milling Facilities, NUREG-1910 at xlii
(May 2009) (J.A. 531).
                               27

      In this context, the agency may not properly conclude that
its failure to comply with NEPA is harmless simply because the
Tribe cannot point to specific historical sites that are at risk.
Indeed, placing the burden on the Tribe to show harm was
especially inappropriate because the inadequate EIS may well
make doing so impossible. See Winter, 555 U.S. at 23
(“[W]ithout [an EIS], there may be little if any information
about prospective environmental harms and potential mitigating
measures.”); cf. Pub. Emps. for Envtl. Responsibility, 827 F.3d
at 1082 (refusing to “excuse the [agency] from its NEPA
obligation to gather data about the seafloor” before issuing a
lease for a wind turbine project because “[w]ithout adequate
geological surveys, the [agency] cannot ensure that the seafloor
[will be] able to support wind turbines” (internal quotation
marks omitted)).

     Second, the point at issue here is not simply forgiveness of
a single error. As we have explained, it appears to be the NRC’s
settled practice to keep licenses in effect, notwithstanding
significant NEPA deficiencies, unless an intervenor shows
irreparable harm. See supra Part III.A. That does not represent
the application of a harmless error exception to a statutory
violation. It represents a wholesale rewrite of NEPA.

     Third, the standard of review the Commission approved is
not just a “harmless” error standard -- it is an “irreparable harm”
standard. See supra note 8. The harmless error standard of the
APA merely requires a showing of prejudice. That standard
does not “impose a . . . particularly onerous requirement.”
Shinseki v. Sanders, 556 U.S. 396, 410 (2009); see Jicarilla
Apache Nation v. U.S. Dep’t of Interior, 613 F.3d 1112, 1121
(D.C. Cir. 2010) (“If prejudice is obvious to the court, the party
challenging agency action need not demonstrate anything
further.”).
                               28

      The irreparable harm standard applied by the Board, in
contrast, derives from the standard courts must apply in granting
injunctive relief. See Monsanto Co. v. Geertson Seed Farms,
561 U.S. 139, 156-57 (2010); Winter, 555 U.S. at 20, 22. It is
not the standard for the “less drastic” APA remedy of vacatur,
see Monsanto, 561 U.S. at 165-66, nor is it the standard applied
under the APA’s harmless error provision, see Shinseki, 556
U.S. at 410. Rather, it requires a substantially higher showing.
See Chaplaincy of Full Gospel Churches v. England, 454 F.3d
290, 297-98 (D.C. Cir. 2006). Here, it requires a well-nigh
impossible one. How, after all, can the Tribe show that
Powertech’s project will irreparably damage its cultural artifacts
if there has not been a survey adequate to determine where those
artifacts are located?

     2. NRC counsel -- but not the Commission itself -- also
analogize the Commission’s treatment of the erroneous Staff
decision to the analysis this court applies when considering
whether to vacate or merely remand erroneous agency actions.
NRC Br. 34-39. As counsel correctly note, “[t]his Court has
long held when considering remedies under § 706 that the
‘decision whether to vacate depends on the seriousness of the
order’s deficiencies (and thus the extent of doubt whether the
agency chose correctly) and the disruptive consequences of an
interim change that may itself be changed.’” Id. at 34 (quoting,
inter alia, Allied-Signal, Inc. v. NRC, 988 F.2d 146, 150-51
(D.C. Cir. 1993)); see Allina Health Servs., 746 F.3d at 1110-11.

     Because the NRC order appealed here does not rely upon
this reasoning, see NRC Order, 84 N.R.C. at 245 (J.A. 268),
neither can we. SEC v. Chenery Corp., 318 U.S. 80, 87-88
(1943) (“The grounds upon which an administrative order must
be judged are those upon which the record discloses that its
action was based.”); see NLRB. v. CNN Am., Inc., 865 F.3d 740,
751 (D.C. Cir. 2017). In any event, this argument-by-analogy
                                 29

has flaws that are similar to those of the Commission’s harmless
error argument.

     As is true of this court’s “harmless error” analysis, our
remand practice is informed by the APA. Compare 5 U.S.C.
§ 706(2)(A) (“[T]he reviewing court shall . . . hold unlawful and
set aside agency action . . . found to be . . . not in accordance
with law . . . .”), with id. § 702 (“Nothing herein . . . affects . . .
the power or duty of the court to . . . deny relief on any other
appropriate . . . equitable ground . . . .”). But once again, the
agency fails to identify any statute that authorizes it not to
comply with NEPA on equitable grounds.

     Without resolving whether the absence of statutory
authority is sufficient to reject the analogy to judicial remand-
without-vacatur, what the agency has done here does not mirror
the court’s decisionmaking process in that regard.

     As the above quotation from Allied-Signal indicates, in
deciding whether vacatur is required, we first consider the
“seriousness of the order’s deficiencies.” 988 F.2d at 150.
Here, the NRC acknowledged a “significant deficiency in the
NRC Staff’s NEPA review.” ASLB Initial Decision, 81 N.R.C.
at 658 (J.A. 457). It nonetheless left the license in place, in part
because it regarded the failure to comply with NEPA as merely
a “procedural deficienc[y].” NRC Br. 34; see id. at 37. But as
we have just underlined, NEPA is a purely procedural statute
and taking such an approach would vitiate it. Nor is it true, as
counsel claim, that this court routinely remands (without
vacatur) violations of procedural requirements. See NRC Br. 37.
To the contrary, in the comparable circumstance of the APA’s
procedural requirements, we have held that “deficient notice is
a ‘fundamental flaw’ that almost always requires vacatur.”
Allina Health Servs., 746 F.3d at 1110 (quoting Heartland Reg’l
Med. Ctr. v. Sebelius, 566 F.3d 193, 199 (D.C. Cir. 2009)).
                                30

     The seriousness of the NEPA deficiency is particularly clear
here because the point of NEPA is to require an adequate EIS
before a project goes forward, so that construction does not
begin without knowledge of the affected cultural and historical
sites. “Part of the harm NEPA attempts to prevent in requiring
an EIS is that, without one, there may be little if any information
about prospective environmental harms and potential mitigating
measures.” Winter, 555 U.S. at 23 (emphasis added). As the
ASLB acknowledged, “[b]ecause the cultural, historical, and
religious sites of the Oglala Sioux Tribe have not been
adequately catalogued, the [EIS] does not include mitigation
measures sufficient to protect this Native American tribe’s
cultural, historical, and religious sites that may be affected by
the Powertech project.” ASLB Initial Decision, 81 N.R.C. at
655 (J.A. 454). Indeed, even when we have remanded without
vacatur, we have considered this kind of concern and
conditioned the remand accordingly. Cf. Pub. Emps. for Envtl.
Responsibility, 827 F.3d at 1084 (declining to vacate a
windpower project owner’s lease for a deficient EIS, but
vacating the agency’s impact statement and requiring it “to
supplement [the impact statement] with adequate geological
surveys before [the project] may begin construction”). The
Commission did not do that here.11

11
   NRC counsel maintain that the Board “determined that vacating the
license would not prevent potential harm to the Tribe’s cultural
resources.” NRC Br. 35. The Board did conclude, more than two
years before the order at issue here, that a stay would be of only
“limited and incomplete effect.” ASLB Stay Denial Order, No. 40-
9075-MLA at 7-8 (J.A. 517-18). But that 2014 order was based on an
assessment of ground-disturbing work expected only “for the next few
months,” id. at 7 (J.A. 517), and there is no reason to believe its
reasoning remained relevant to the status of construction in 2016.
Indeed, that explanation was not repeated in either the Board’s 2015
decision or the 2016 Commission order that upheld the 2015 decision
and is now under review. We are therefore unable to evaluate its
                                   31

     As Allied-Signal further indicates, we also evaluate the
“disruptive consequences of an interim change.” Allied-Signal,
988 F.2d at 150-51 (internal quotation marks omitted). But
here, neither the Commission’s nor the Board’s order examined
what the consequences would be for Powertech were its license
vacated or suspended until the NRC completed its NEPA
review. See NRC Order, 84 N.R.C. at 245 (J.A. 268); ASLB
Initial Decision, 81 N.R.C. at 657-58 (J.A. 456-57). Nor did
those orders examine the potential consequences for the Tribe.12

     Finally, once again the issue here is not just what to do
about a single agency error, but what to do about the validity of
an NRC practice that permits NEPA-deficient licenses to remain
in place unless an intervenor can show irreparable harm. We
have never turned merely to a remand remedy when an agency
refused to adhere to a statutory command in such an across-the-
board fashion.


validity, which reaffirms the wisdom of adhering to Chenery’s rule
that the soundness of an agency’s decision must rest on the reasoning
contained therein, and not on any post hoc justifications offered by
counsel. Chenery Corp., 318 U.S. at 87-88; see NLRB v. CNN Am.,
Inc., 865 F.3d at 751.
12
   The NRC brief posits that “the Commission reasonably left the
license in place -- thereby ensuring NRC’s continued ability to enforce
the cultural-resource protections the license already imposes on
Powertech -- while allowing the agency to address the procedural
deficiencies identified by the Board.” NRC Br. 35 (citing, by analogy,
Ctr. for Biological Diversity v. EPA, 861 F.3d 174, 188 (D.C. Cir.
2017)). The order makes no mention of this consideration, and we are
unable to evaluate its validity. The Tribe -- which has the most direct
interest in cultural resources protection and yet calls for vacatur of the
license -- obviously feels that the site is better protected without the
license than with whatever limited protections it may impose. This
again shows the wisdom of adhering to Chenery’s rule.
                                32

     3. NRC counsel make two further arguments that are also
not reflected in the Commission’s order. Even if they were
meritorious, Chenery would render them insufficient to uphold
the order.

     First, NRC counsel maintain that the ASLB’s decision to
leave the license in place was justified because it was “based in
part on the Tribe’s own actions making the NHPA consultation
process unnecessarily difficult.” NRC Br. 35. But the
Commission’s order did not rely on this justification and instead
noted that “the Board acknowledged that it could not
definitively determine whether the Staff or the Tribe bore
responsibility for what the Board considered a breakdown in
consultation.” NRC Order, 84 N.R.C. at 244 (J.A. 266-67).

     Second, counsel argue that the agency’s “adjudicatory
hearing process, which led to the identification of deficiencies
in NRC’s compliance with NEPA . . . , did not arise from th[at]
statute[], but, rather, from the Atomic Energy Act.” NRC Br.
38. Whether the Commission could have delegated to its Staff
the final authority to resolve NEPA issues without appeal to the
Commission is a question that we need not answer today. The
fact is that the Commission did not do so, and thus must explain
why it permitted the project to go forward despite its own
determination that the Staff had failed to comply with NEPA.
As we have explained, the Commission has failed to offer a
justification that is consistent with its statutory responsibility.

                                C

     To be clear, today we hold only that, once the NRC
determines there is a significant deficiency in its NEPA
compliance, it may not permit a project to continue in a manner
that puts at risk the values NEPA protects simply because no
intervenor can show irreparable harm. We do not decide that the
                               33

Commission may never leave in place a license that its Staff
previously issued but that the Commission later finds NEPA-
deficient. That is, we do not decide that there is no version of a
harmless error rule that the Commission may apply. Nor do we
decide that there are no protective conditions the Commission
might impose that would justify leaving a license in place during
an administrative remand intended to cure a NEPA deficiency.
Cf. Pub. Utils. Comm’n v. FERC, 900 F.2d 269, 282 (D.C. Cir.
1990) (holding that NEPA did not preclude FERC from issuing
an approval that was “expressly not to be effective until [an]
environmental hearing was completed”).

   Regardless of whether one of those options might pass
muster, the Commission did not follow such a course here.

                               IV

     Because the standard that the Commission applied in
permitting Powertech’s license to remain in effect is inconsistent
with NEPA, we remand this matter to the agency for further
consideration consistent with this opinion. We do not, however,
vacate the agency’s ruling. As we recounted above, an appellate
court’s decision regarding whether to vacate or merely remand
“depends on the seriousness of the order’s deficiencies (and thus
the extent of doubt whether the agency chose correctly) and the
disruptive consequences of an interim change that may itself be
changed.” Allied-Signal, 988 F.2d at 150-51 (internal quotation
marks omitted).

     We have no doubt about the seriousness of the order’s
deficiencies. But we have not been given any reason to expect
that the agency will be unable to correct those deficiencies, and
we are concerned about the disruptive consequences of vacating
the license while the agency proceeds to satisfy NEPA.
Powertech reasonably relied on the NRC’s ruling and settled
                                34

practice that permitted the continued effectiveness of the license
the Staff issued. And it has represented to the court that its stock
price “would plummet” if the license were “suspended, vacated,
or revoked.” Oral Arg. Tr. 30.

     More important, it appears that the Tribe will not suffer
harm -- irreparable or otherwise -- from a disposition that leaves
the license in effect for now. Powertech has further represented
that a South Dakota permitting requirement independently bars
it from moving forward with construction on the site until the
NRC completes its compliance with NEPA. Oral Arg. Tr. 32-
35. We note that the Tribe doubts this representation. Id. at 37.
But for now, we rely on it. If the representation turns out not to
be correct, the Tribe will have grounds to seek further redress
from this court. Cf. Pub. Empls. for Env. Responsibility, 827
F.3d at 1084 (requiring the agency “to supplement [the impact
statement] with adequate geological surveys before [the project]
may begin construction”).

                                 V

     The Nuclear Regulatory Commission’s December 2016
order is not entirely final, and as a consequence we do not have
jurisdiction over the bulk of the rulings challenged by the Oglala
Sioux Tribe. Under the collateral order doctrine, however, we
do have jurisdiction to review the Commission’s decision to
leave Powertech’s license in place -- notwithstanding the NRC’s
acknowledgment that it has not yet complied with the National
Environmental Policy Act -- on the ground that the Tribe failed
to show irreparable harm. Because that decision is contrary to
law, we grant the petition for review in part and remand the case
to the Commission for further proceedings consistent with this
opinion.

                                                       So ordered.
