X0609 4 2026-10-06 0 0001918080 Deep Isolation Nuclear, Inc. DBHL 0001208752 HORNBAKER RENEE J false C/O DEEP ISOLATION NUCLEAR, INC. 5717 LEGACY DRIVE, STE 250, OFFICE 2079 PLANO TX 75024 1 0 0 0 0 Common Stock 2026-10-06 4 A 0 15476 0 A 128809 D Represents a grant of restricted stock units ("RSUs") to the Reporting Person pursuant to the Deep Isolation Nuclear, Inc. 2025 Equity Incentive Plan. Each RSU represents a contingent right to receive one share of common stock upon vesting. The RSUs shall vest on September 29, 2027, subject to the Reporting Person's continued service through each vesting date. Conversion of the RSUs into shares of common stock of the Issuer upon vesting is deferred until the earliest of the following events to occur: (i) a change of control of the Issuer, (ii) a separation of service as a director by the Reporting Person, or (iii) death of the Reporting Person. /s/ Renee Hornbaker 2026-10-08