Filed under Rule 425

under the Securities Act of 1933, as amended

and deemed filed under Rule 14a-12

of the Securities Exchange Act of 1934, as amended

Filing by: Hennessy Capital Investment Corp. VII

Subject Company: Hennessy Capital Investment Corp. VII

SEC File No.: 001-42479

On May 5, 2026, ONE Nuclear Energy published the following post on LinkedIn:

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Forward-Looking Statements

This communication contains forward-looking statements, including but not limited to statements regarding ONE Nuclear Energy LLC’s (“ONE Nuclear”) and Hennessy Capital Investment Corp. VII’s (“HVII”) expectations, beliefs, intentions, strategies, and projections. All statements other than statements of historical facts contained in this communication are forward-looking statements. These statements are based on current expectations and assumptions and are subject to risks and uncertainties that could cause actual results to differ materially. Words such as “anticipate,” “believe,” “expect,” “intend,” “may,” “plan,” “project,” “should,” “will,” and similar expressions are intended to identify forward-looking statements, though not all forward-looking statements contain these identifying words, and the absence of these words does not mean that a statement is not forward-looking. Forward-looking statements include, without limitation, ONE Nuclear’s management team’s expectations concerning the outlook for its business, productivity, plans, growth and capital investments, operational and cost performance, revenue generation, development timelines, potential generation capacities of specific sites, regulatory outlook, future market conditions, success of strategic relationships, developments in the capital and credit markets, expected future financial performance, as well as demand for nuclear energy and the economic outlook for the nuclear energy industry.

Forward-looking statements speak only as of the date of this communication and are based on ONE Nuclear’s and HVII’s current beliefs and assumptions. ONE Nuclear and HVII undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise, except as required by law. Actual results may differ materially due to various risks and uncertainties, including but not limited to: (1) the risk that the proposed business combination (the “Business Combination”) may not be completed in a timely manner or at all, which may adversely affect the price of HVII’s securities; (2) the failure to satisfy the conditions to the consummation of the Business Combination, including the adoption of the definitive agreements related to the Business Combination (the “Business Combination Agreement”) by the shareholders of HVII and the receipt of certain regulatory approvals; (3) market risks; (4) the occurrence of any event, change or other circumstance that could give rise to the termination of the Business Combination Agreement; (5) changes in transaction structure of the Business Combination due to regulatory or legal requirements; (6) the ability to meet listing standards; (7) the effect of the announcement or pendency of the Business Combination on ONE Nuclear’s business relationships, performance, and business generally; (8) failure to realize anticipated benefits from the Business Combination; (9) the outcome of any legal proceedings that may be instituted against ONE Nuclear or HVII related to the Business Combination or the Business Combination Agreement; (10) ONE Nuclear’s ability to execute on its business plan and to develop and maintain key strategic relationships and enter into definitive agreements in connection therewith; (11) competition in ONE Nuclear’s industry; (12) transaction-related costs; (13) the risk that changes in laws or regulations adversely affect ONE Nuclear’s business plans and operations; (14) adverse economic or competitive conditions; (15) the level of redemptions by HVII shareholders in connection with the Business Combination; (16) the risk that ONE Nuclear may not be able to successfully develop its exclusive sites or other sites and the commercial viability of any such site; (17) the risk that ONE Nuclear will be unable to raise additional capital to execute its business plan, which may not be available on acceptable terms or at all; and (18) other risks and uncertainties described in HVII’s Annual Report on Form 10-K for the year ended December, 31, 2025, which was filed with the U.S. Securities and Exchange Commission (“SEC”) on March 6, 2026, and other filings with the SEC, including the registration statement on Form S-4 (the “Registration Statement”), the preliminary proxy statement/prospectus and other relevant materials filed by HVII in connection with the Business Combination from time to time. The foregoing list is not exhaustive, and there may be additional risks that neither HVII nor ONE Nuclear presently know or that HVII and ONE Nuclear currently believe are immaterial. ONE Nuclear and HVII caution you against placing undue reliance on forward-looking statements, which reflect current beliefs and are based on information currently available as of the date a forward-looking statement is made.

ONE Nuclear’s Commercial Agreements are Non-Binding

This communication contains descriptions of certain non-exclusive, key business relationships of ONE Nuclear, including with Rolls-Royce, Black & Veatch, FutureWorx, and other business partners. These descriptions are based on the ONE Nuclear management team’s discussions with such counterparties, the terms of certain existing non-binding collaboration agreements with such counterparties, and the latest available information and estimates as of the date of this communication. In each case, such descriptions are subject to negotiation and execution of definitive agreements with such counterparties, which have not been completed as of the date of this communication. As a result, such descriptions of key business relationships of ONE Nuclear, including with Rolls-Royce, Black & Veatch, and FutureWorx, remain subject to change, and there can be no assurance that definitive agreements with such business partners will be executed or, if executed, that the terms of such definitive agreements will not vary materially from those described herein.

Important Information for Investors and Shareholders

In connection with the Business Combination, HVII has filed with the SEC the Registration Statement, which includes a preliminary prospectus with respect to the securities to be issued in connection with the Business Combination and a proxy statement to be distributed to holders of HVII’s ordinary shares in connection with HVII’s solicitation of proxies for the vote by HVII’s shareholders with respect to the Business Combination and other matters described in the Registration Statement (the “Proxy Statement”). After the SEC declares the Registration Statement effective, HVII plans to file the definitive Proxy Statement with the SEC and to mail copies to shareholders of HVII as of a record date to be established for voting on the Business Combination.

This communication does not contain all the information that should be considered concerning the Business Combination and is not a substitute for the Registration Statement, Proxy Statement or for any other document that HVII may file with the SEC. Before making any investment or voting decision, investors and security holders of HVII and ONE Nuclear are urged to read the Registration Statement and the Proxy Statement, and any amendments or supplements thereto, as well as all other relevant materials filed or that will be filed with the SEC in connection with the Business Combination as they become available because they will contain important information about ONE Nuclear, HVII and the Business Combination.

Investors and security holders will be able to obtain free copies of the Registration Statement, the Proxy Statement and all other relevant documents filed or that will be filed with the SEC by HVII through the website maintained by the SEC at www.sec.gov. In addition, the documents filed by HVII may be obtained free of charge from HVII’s website at https://www.hennessycapital7.com or by directing an email request to info@hennessycapitalgroup.com. The information contained on, or that may be accessed through, the websites referenced in this communication is not incorporated by reference into, and is not a part of, this communication.

Participants in the Solicitation

HVII, ONE Nuclear and their respective directors, executive officers and other members of management and employees may, under the rules of the SEC, be deemed to be participants in the solicitations of proxies from HVII’s shareholders in connection with the Business Combination. For more information about the names, affiliations and interests of HVII’s directors and executive officers, please refer to HVII’s Annual Report on Form 10-K filed with the SEC on March 6, 2026, and the Registration Statement, Proxy Statement and other relevant materials filed with the SEC in connection with the Business Combination from time to time. Additional information regarding the participants in the proxy solicitation and a description of their direct and indirect interests, which may, in some cases, be different than those of HVII’s shareholders generally, are included in the Registration Statement and the Proxy Statement. Shareholders, potential investors and other interested persons should read the Registration Statement and the Proxy Statement carefully before making any voting or investment decisions. You may obtain free copies of these documents from the sources indicated above.

No Offer or Solicitation

This communication shall not constitute a “solicitation” as defined in Section 14 of the Securities Exchange Act of 1934, as amended. This communication shall not constitute an offer to sell or exchange, the solicitation of an offer to buy or a recommendation to purchase, any securities, or a solicitation of any vote, consent or approval, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in which such offer, solicitation or sale may be unlawful under the laws of such jurisdiction. No offering of securities in the Business Combination shall be made except by means of a prospectus meeting the requirements of the Securities Act of 1933, as amended, or an exemption therefrom.

Contacts

For Investors: Caldwell Bailey, ICR, Inc.

For Media: Matt Dallas, ICR, Inc.

onenuclear@icrinc.com