Sec Form 3 Filing - Hendrix Thomas Edward @ Standard Nuclear, Inc. - 2026-07-15

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Hendrix Thomas Edward 2. Issuer Name and Ticker or Trading Symbol Standard Nuclear, Inc. [ STDN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chairman of the Board (Last) (First) (Middle) C/O STANDARD NUCLEAR, INC., 200 EUROPIA AVE 3. Date of Earliest Transaction (MM/DD/YY) 07/15/2026 (Street) OAK RIDGE, TN37830 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 common stock 5,754,000 ( 1 ) I Held by Standard Nuclear Trust ( 2 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 Common Stock ( 3 ) ( 3 ) ( 3 ) Class A common stock 5,754,000 D Convertible preferred stock ( 4 ) ( 4 ) ( 4 ) Class A common stock 50,000 ( 1 ) I Held by Standard Nuclear Trust ( 2 ) Convertible preferred stock ( 5 ) ( 5 ) ( 5 ) Class A common stock 20,308 ( 1 ) I Held by Standard Nuclear Trust ( 2 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Hendrix Thomas Edward C/O STANDARD NUCLEAR, INC. 200 EUROPIA AVE OAK RIDGE, TN37830 X Chairman of the Board Signatures /s/ Thomas Hendix 07/15/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Pursuant to an Exchange Agreement entered into between the Issuer and the trust, all 5,824,308 shares of Class A Common Stock to be held by the trust after giving effect to the Preferred Conversion will be exchanged for an equivalent number of newly issued shares of Class B Common Stock on a one-for-one basis upon the effectiveness of the Issuer's Sixth Amended and Restated Certificate of Incorporation to be filed in connection with the completion of the Issuer's initial public offering (the "IPO") of its Class A Common Stock. ( 2 )Andrew Price is the trustee of the trust and may be replaced at the discretion of the Reporting Person. Pursuant to a voting agreement entered into with the trust, the Reporting Person has sole voting and dispositive control over such securities. By virtue of his relationship with the trust, the Reporting Person is deemed to have an indirect beneficial interest in the shares held by the trust. ( 3 )Each outstanding share of Class B Common Stock is convertible into one share of the Issuer's Class A common stock at any time, (i) at the option of the Reporting Person, (ii) automatically upon any transfer, whether or not for value (except for certain permitted transfers), or (iii) upon the occurrence of certain events or conditions, as described further in the Issuer's Fifth Amended and Restated Certificate of Incorporation. ( 4 )Pursuant to the Issuer's Fifth Amended and Restated Certificate of Incorporation, each share of Series Seed-1 Preferred Stock ("Series Seed-1 Preferred Stock") may be converted, at the option of the holder, at any time. In connection with the completion of the IPO, each share of Series Seed-1 Preferred Stock shall automatically convert into shares of Class A Common Stock at a ratio of 1-for-1. The securities have no expiration date. ( 5 )Pursuant to the Issuer's Fifth Amended and Restated Certificate of Incorporation, each share of Series Seed Preferred Stock ("Series Seed Preferred Stock") may be converted, at the option of the holder, at any time. In connection with the completion of the IPO, each share of Series Seed Preferred Stock shall automatically convert into shares of Class A Common Stock at a ratio of 1-for-1. The securities have no expiration date

Remarks: The Reporting Person serves as Executive Chairman and Director, Chairman of the Board.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* 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).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.