SCHEDULE 13G/A

ONE Nuclear Energy Inc.

Common Stock, par value $0.0001 per share · CUSIP: 68253E100

Event date: 2026-09-30

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• HC VII Sponsor LLC

  Shares: 5,744,999.00 · Class: 5.3%

• Hennessy Capital Group LLC

  Shares: 5,744,999.00 · Class: 5.3%

• HENNESSY DANIEL J

  Shares: 5,744,999.00 · Class: 5.3%

• Hennessy Thomas D

  Shares: 6,494,999.00 · Class: 6.0%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.