X0609 4 2026-10-06 0 0001918080 Deep Isolation Nuclear, Inc. DBHL 0002085363 McCallum Sophie false C/O DEEP ISOLATION NUCLEAR, INC. 5717 LEGACY DRIVE, STE 250, OFFICE 2079 PLANO TX 75024 0 1 0 0 Chief of Staff 0 Common Stock 2026-10-06 4 A 0 40179 0 A 56846 D Stock Option (right to buy) 3.50 2026-10-06 4 A 0 62206 0 A 2036-09-29 Common Stock 62206 62206 D Stock Option (right to buy) 3.50 2026-10-06 4 A 0 2301 0 A 2036-09-29 Common Stock 2301 2301 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 as follows: 10,045 RSUs on September 29, 2027, 10,045 RSUs on September 29, 2028, 10,044 RSUs on September 29, 2029 and 10,045 RSUs on September 29, 2030, in each case subject to the Reporting Person's continued service through each vesting date. Represents a grant of incentive stock option pursuant to the Deep Isolation Nuclear, Inc. 2025 Equity Incentive Plan. The option shall vest as follows: 16,127 option shares on September 29, 2027, 1,344 option shares on October 29, 2027, 386 option shares on November 29, 2027, and the remaining option shares in monthly installments on the 29th day of each month (or the last day of the month, if earlier) from January 29, 2028 through September 29, 2030, in each case subject to the Reporting Person's continued service through each vesting date. Represents a grant of non-qualified stock option pursuant to the Deep Isolation Nuclear, Inc. 2025 Equity Incentive Plan. The option shall vest as follows: 958 option shares on November 29, 2027 and 1,343 option shares on December 29, 2027, in each case subject to the Reporting Person's continued service through each vesting date. /s/ Sophie McCallum 2026-10-08