# 2026-19300: Nukes vs. Dam Failures: New Flood Rules Drop Today

2026-19300, Regulatory Guides: Design-Basis Floods for Nuclear Power Plants and Guidance for Assessment of Flooding Hazards Due to Water Control Structure Failures and Incidents, is a Federal Register notice from Nuclear Regulatory Commission published 2026-09-22, effective 2026-09-22 (as of 2026-09-29).

- Canonical: https://policyrisk.com/federal-register/2026-19300
- As of: 2026-09-29
- Plain-text twin of the page above; the HTML and this file carry the same facts.

## Facts
- Document number: 2026-19300
- Title: Regulatory Guides: Design-Basis Floods for Nuclear Power Plants and Guidance for Assessment of Flooding Hazards Due to Water Control Structure Failures and Incidents
- Type: Notice
- Agencies: Nuclear Regulatory Commission
- Citation: 91 FR 60157
- Published: 2026-09-22
- Effective: 2026-09-22
- Comments close: not stated
- Significant: no
- Touches household money: no
- Regulation identifier numbers: none
- Last updated: 2026-09-29

## In one line

Nukes vs. Dam Failures: New Flood Rules Drop Today

## Summary

The Nuclear Regulatory Commission just released two updated guides to help new nuclear power plants plan for floods and assess risks from dam or levee failures. These guides make sure plants are safer by using the best methods to handle flooding hazards. The new rules start on September 22, 2026, and mainly affect companies building or planning nuclear plants, helping them avoid costly flood damage.

## Abstract

The U.S. Nuclear Regulatory Commission (NRC) is issuing two related Regulatory Guides (RGs), namely RG 1.59, Revision 3, "Design- Basis Floods for Nuclear Power Plants," and RG 1.256, Revision 0, "Guidance for Assessment of Flooding Hazards due to Water Control Structure Failures and Incidents." RG 1.59 provides guidance for applicants for new nuclear power plants on acceptable methods for evaluating design-basis floods and RG 1.256 provides guidance for applicants on methods for evaluating flooding hazards due to failure or other incidents at man-made water control structures including, but not limited to, dams and levees.

## Effects PRIA read

No economic effects identified for this document.

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## Sources
- [2026-19300 on federalregister.gov](https://www.federalregister.gov/documents/2026/09/22/2026-19300/regulatory-guides-design-basis-floods-for-nuclear-power-plants-and-guidance-for-assessment-of)
- [2026-19300 as published (PDF)](https://www.govinfo.gov/content/pkg/FR-2026-09-22/pdf/2026-19300.pdf)

## Related
- [Previous: 2026-19299, Self-Regulatory Organizations; Cboe C2 Exchange, Inc.; Notice of Filing and Imm…](https://policyrisk.com/federal-register/2026-19299)
- [Next: 2026-19301, Proposed Data Sharing Activity](https://policyrisk.com/federal-register/2026-19301)
- [All Federal Register documents](https://policyrisk.com/federal-register)

Source: PRIA, https://policyrisk.com/federal-register/2026-19300 (as of 2026-09-29).