Notice 2026-17626

May a permanent structure be built before the permit issues — the four factors asking whether it can be undone

Nuclear Regulatory Commission Published Aug 28, 2026 91 FR 55628

The Nuclear Regulatory Commission issued an exemption allowing permanent excavation support walls at a small modular reactor site before a limited work authorization issues. The test turns on whether environmental effects can be redressed and whether alternatives would be foreclosed.

Document overview (primary data)

  • Document typeNotice
  • AgencyNuclear Regulatory Commission
  • Citation91 FR 55628

Key points

  • The Nuclear Regulatory Commission issued an exemption allowing permanent excavation support walls at two small modular reactor units before a limited work authorization issues.
  • The walls remain in place after construction, which called for a different determination than temporary shoring.
  • General requirements are that the exemption be authorized by law, present no undue risk to public health or safety, be consistent with the common defense and security, and involve special circumstances.
  • The framework here comprises four factors, two of which ask whether environmental effects can be redressed and whether alternatives would be foreclosed.
  • The fourth factor is the effect of delay on the public interest, including power needs and costs to the applicant and consumers.

1How much may be built before the permit

Building a nuclear plant requires permits in stages. Some construction work, though, is inefficient to hold until formal approval — excavating ground and shoring the walls so they do not collapse, for instance. A mechanism therefore exists to allow limited work before a permit issues. This exemption widens that scope.

2What was at issue

Ordinary preliminary workThe work sought here
Temporary shoring removed once construction endsPermanent support walls that remain in place afterward
Can be taken out laterWill not be taken out
Comparatively easy to allow before a permitRequires a fresh exemption determination

The question turns on the walls being permanent. Temporary works can simply be removed if plans change. A permanent structure stays, so what happens if the permit does not issue becomes the question.

3The four factors ask whether it can be undone

  1. 1First factorWhether the proposed activities give rise to a significant adverse environmental impact, and its nature and extent
  2. 2Second factorWhether redress of any adverse environmental impact can reasonably be effected should redress be necessary
  3. 3Third factorWhether the activities would foreclose subsequent adoption of alternatives
  4. 4Fourth factorThe effect of delay on the public interest, including power needs, alternative sources and costs to applicant and consumers

The second and third factors both ask about reversibility. If harm occurs, can it be put right? Does building first make it impossible to choose a different course later? The framework thus conditions preliminary work on its not pre-empting the final decision.

4Not prejudging the outcome

Only the fourth factor runs the other way, counting the cost of waiting: power needs, alternative sources, and delay costs to the applicant and to consumers. Caution has a price, and the framework writes that premise in explicitly. This site also covers Federal Register documents on rulemaking procedure, where the question of what may be done before a decision recurs as a matter of institutional design.

Why it matters

Conditioning preliminary work on its not pre-empting the final decision is one answer to a general problem: how much preparation to permit before a decision. The cost of caution is explicitly counted too.

FAQ

Why can work proceed before a permit?
A mechanism exists to allow limited work before a permit issues, and this exemption widens that scope.
What do the four factors decide?
Two ask about reversibility — whether environmental effects can be redressed and whether alternatives would be foreclosed. The others concern the extent of the impact and the effect of delay on the public interest.

Sources (primary)

Source: Federal Register (federal documents, public domain). Links go to the official site.

#Nuclear Regulatory Commission#Small modular reactors#Exemptions#Nuclear power#Licensing
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