High-performance Optimized Recycled Nuclear Isotopes for Gen IV reactors (HORNIG): eligibility, deadline, and how to apply (2026)

The High-performance Optimized Recycled Nuclear Isotopes for Gen IV reactors (HORNIG) is a federal funding opportunity administered by Advanced Research Projects Agency Energy. This guide covers everything you need to know to determine whether you qualify and how to submit a competitive application before the August 6, 2026 deadline.

Use our free Grant Finder to discover additional programs you may be eligible for based on your organization type and location.

Eligibility requirements

To qualify for the High-performance Optimized Recycled Nuclear Isotopes for Gen IV reactors (HORNIG), applicants must meet the following criteria:

Unrestricted (i.e., open to any type of entity above), subject to any clarification in text field entitled "Additional Information on Eligibility"

Eligibility requirements can change between funding cycles. Always verify the current criteria on the official Grants.gov listing before beginning your application.

If you are not sure whether your organization qualifies, review our guide on best small business grants for alternative programs that may be a better fit.

How to apply: step by step

1. Register on SAM.gov. Every federal grant applicant needs an active SAM (System for Award Management) registration. Allow 2-4 weeks for new registrations to process. Existing registrations must be renewed annually.
2. Get a UEI number. Your Unique Entity Identifier is assigned through SAM.gov and replaces the old DUNS number. You will need this on every federal application.
3. Review the Notice of Funding Opportunity (NOFO). Download the full NOFO from Grants.gov. Pay close attention to review criteria, budget limits, and required attachments.
4. Prepare your application package. Most federal grants require a project narrative, budget justification, organizational capacity statement, and supporting documents. Follow the page limits and formatting rules exactly.
5. Submit through Grants.gov. Create a workspace, upload all required forms and attachments, and submit before the August 6, 2026 deadline. The system timestamps your submission, and late applications are automatically rejected.
6. Confirm receipt. You will receive a tracking number and confirmation email. Check back in 1-2 business days to verify your application passed the Grants.gov validation checks.

For detailed guidance on writing a winning narrative, see our grant writing tips article.

Grant details

Federal grant budgets and priorities shift each fiscal year. The amounts listed above reflect the most recent funding cycle. For the latest figures, check the official program page.

If you are exploring business financing beyond grants, the team at CeoCult covers loans, lines of credit, and alternative funding for founders.

Frequently asked questions