Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Hennessy Thomas D 2. Issuer Name and Ticker or Trading Symbol ONE Nuclear Energy Inc. [ONEN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner _____ Officer (give title below) __X__ Other (specify below) See Remarks (Last) (First) (Middle) 195 US HWY 50, SUITE 207 3. Date of Earliest Transaction (Month/Day/Year) 09/23/2026 (Street) ZEPHYR COVE, NV 89448 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Class A ordinary shares(1)(3) 09/23/2026 M(1)(2) 750,000 A (1)(2) 750,000 D Class A ordinary shares(1)(3) 09/23/2026 M(1)(2) 5,203,333 A (1)(2) 5,703,333 I See Explanation of Responses(4) Class A ordinary shares(1)(3) 09/23/2026 M(1)(7) 41,666 A (1)(7) 5,744,999 I See Explanation of Responses(4)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Class B ordinary shares

(1)(2)

09/23/2026

M(1)(2)

750,000

(1)(2)

(1)(2)

Class A ordinary shares(1)(3)

750,000

$ 0

0

D

Class B ordinary shares

(1)(2)

09/23/2026

M(1)(2)

5,203,333(5)

(1)(2)

(1)(2)

Class A ordinary shares(1)(3)

5,203,333(5)

$ 0

0

I

See Explanation of Responses(4)

Rights to receive Class A ordinary shares(1)(6)

(1)(7)

09/23/2026

M(1)(7)

500,000

(1)(7)

(1)(7)

Class A ordinary shares(1)(3)

41,666

$ 0

0

I

See Explanation of Responses(4)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Hennessy Thomas D 195 US HWY 50 SUITE 207 ZEPHYR COVE, NV 89448				See Remarks

Signatures

/s/ Thomas D. Hennessy		09/23/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Pursuant to the business combination agreement dated October 22, 2025 (the "Merger Agreement"), among other things, at the closing of the transactions contemplated thereby (the "Closing," and the date on which the Closing occurred, the "Closing Date") and following the Domestication (as defined below), Hennessy Capital Investment Corp. VII, a Cayman Islands exempted company with limited liability (the "Predecessor Issuer"), was renamed "ONE Nuclear Energy Inc." ("Successor Issuer") and consummated its initial business combination with ONE Nuclear Energy LLC, a Delaware limited liability company ("ONE Nuclear"), with ONE Nuclear being the surviving company. Following the Closing, ONE Nuclear became a direct wholly-owned subsidiary of the Successor Issuer.
(2)	Pursuant to the Merger Agreement, on the Closing Date prior to the Closing, each then issued and outstanding Class B ordinary share, par value $0.0001 per share, of the Predecessor Issuer (each a "Class B Ordinary Share") converted (the "Sponsor Share Conversion") automatically, on a one-for-one basis, into one Class A ordinary share, par value $0.0001 per share, of the Predecessor Issuer (each a "Class A Ordinary Share").
(3)	Pursuant to the Merger Agreement, immediately after the Sponsor Share Conversion, the Predecessor Issuer transferred by way of continuation and deregistration to and domesticated as a Delaware corporation (such continuation and domestication, the "Domestication"). In connection with, and after giving effect to, the Domestication, each then issued and outstanding Class A Ordinary Share converted automatically, on a one-for-one basis, into one share of common stock, par value $0.0001 per share, of the Successor Issuer (each, a "Successor Share"), and the Successor Issuer became the successor issuer to the Predecessor Issuer. The conversion of the Class A Ordinary Shares into Successor Shares did not alter the proportionate interests of the security holders, and accordingly the conversion is exempt from Section 16 of the Securities Exchange Act of 1934, as amended (the "Exchange Act").
(4)	HC VII Sponsor LLC ("Sponsor") is the record holder of the securities reported herein. Hennessy Capital Group LLC is the sole manager of Sponsor. Daniel J. Hennessy, the Predecessor Issuer's Chairman and Chief Executive Officer, and Thomas D. Hennessy, the Predecessor Issuer's President, Chief Operating Officer and a director, are the sole managing members of Hennessy Capital Group LLC. Consequently, each of Mr. Daniel Hennessy and Mr. Thomas Hennessy may be deemed the beneficial owner of securities held by Sponsor and have shared voting and dispositive control over such securities. Mr. Thomas Hennessy disclaims beneficial ownership over any securities owned by Sponsor in which he does not have any pecuniary interest.
(5)	Amount has been adjusted to reflect the forfeiture of 375,000 Class B Ordinary Shares for no further consideration on January 21, 2025, upon the expiration of the underwriters' over-allotment option, which was partially exercised in connection with the Predecessor Issuer's initial public offering. Such forfeiture was exempt from Section 16 pursuant to Rule 16b-6(d) and Rule 16a-4(d) promulgated under the Exchange Act.
(6)	Pursuant to the Merger Agreement, in connection with, and after giving effect to, the Domestication, each then issued and outstanding right (each, a "Predecessor Right") that were automatically convertible into one-twelfth (1/12) of one Class A Ordinary Share upon consummation of the Predecessor's initial business combination converted automatically into a right to acquire one-twelfth (1/12) of one Successor Share (each, a "Successor Right"). The conversion of Predecessor Rights into Successor Rights did not alter the proportionate interests of the rights holders, and accordingly the conversion is exempt from Section 16 of the Exchange Act.
(7)	Pursuant to the Merger Agreement, each twelve Successor Rights were automatically surrendered in exchange for one Successor Share at the Closing.
Remarks: Mr. Thomas was the Predecessor Issuer's President, Chief Operating Officer and a director and a 10% owner of the Predecessor Issuer by virtue of the securities held by Sponsor. Sponsor and Hennessy Capital Group LLC file Section 16 reports for each of the Predecessor Issuer and the Successor Issuer separately from Mr. Thomas Hennessy.

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