# EDGAR Filing Document

**Accession Number:** 0002085363
**File Stem:** 0001213900-25-086216
**Filing Date:** 2025-9
**Character Count:** 17142
**Document Hash:** a762dad821cd875ed242407444f32107
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001213900-25-086216.hdr.sgml**: 20250909

**ACCESSION NUMBER**: 0001213900-25-086216

**CONFORMED SUBMISSION TYPE**: 3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250723

**FILED AS OF DATE**: 20250909

**DATE AS OF CHANGE**: 20250909

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** McCallum Sophie
- **CENTRAL INDEX KEY:** 0002085363

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 000-56406
- **FILM NUMBER:** 251303861

**MAIL ADDRESS:**
- **STREET 1:** 2001 ADDISON STREET
- **STREET 2:** SUITE 300
- **CITY:** BERKELEY
- **STATE:** CA
- **ZIP:** 94704
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Deep Isolation Nuclear, Inc.
- **CENTRAL INDEX KEY:** 0001918080
- **STANDARD INDUSTRIAL CLASSIFICATION:** REFUSE SYSTEMS [4953]
- **ORGANIZATION NAME:** 01 Energy & Transportation
- **EIN:** 874225965
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 2001 ADDISON STREET
- **STREET 2:** SUITE 300
- **CITY:** BERKELEY
- **STATE:** CA
- **ZIP:** 94704
- **BUSINESS PHONE:** 561 464 2841

**MAIL ADDRESS:**
- **STREET 1:** 1761 GEORGE WASHINGTON WAY
- **STREET 2:** #362
- **CITY:** RICHLAND
- **STATE:** WA
- **ZIP:** 99354

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Aspen-1 Acquisition Inc.
- **DATE OF NAME CHANGE:** 20220317

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 3

### INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>McCallum Sophie<br><sub>(Last) (First) (Middle)</sub><br>C/O DEEP ISOLATION NUCLEAR, INC.<br>2001 ADDISON STREET, SUITE 300<br><sub>(Street)</sub><br>BERKELEY, CA 94704<br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>Deep Isolation Nuclear, Inc. [ NONE ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2025-07-23 | **4. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director   [ ] 10% Owner<br>[X] Officer (give title below)   [ ] Other (specify below)<br>_Chief of Staff, Corp. Sec._ | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities Beneficially Owned

---

|  |  |  |  |
| --- | --- | --- | --- |
| 1. Title of Security | 2. Amount of Securities Beneficially Owned | 3. Ownership Form | 4. Nature of Indirect Beneficial Ownership |

---

## Table II - Derivative Securities Beneficially Owned

---

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 3. Title and Amount of Underlying Securities | 3. Title and Amount of Underlying Securities | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| Stock Option (Right to Buy) | 2022-02-15<sup>(1)</sup> | 2028-10-18 | Common Stock | 129186<sup>(2)</sup> | 0.05<sup>(2)</sup> | D |  |
| Stock Option (Right to Buy) | 2022-10-19<sup>(3)</sup> | 2028-12-19 | Common Stock | 129186<sup>(4)</sup> | 0.05<sup>(4)</sup> | D |  |
| Stock Option (Right to Buy) | 2025-01-01<sup>(5)</sup> | 2031-05-17 | Common Stock | 25837<sup>(6)</sup> | 0.19<sup>(6)</sup> | D |  |
| Stock Option (Right to Buy) | 2024-08-15<sup>(7)</sup> | 2031-10-18 | Common Stock | 22608<sup>(8)</sup> | 0.19<sup>(8)</sup> | D |  |
| Stock Option (Right to Buy) | 2025-07-23<sup>(9)</sup> | 2031-10-18 | Common Stock | 22608<sup>(10)</sup> | 0.19<sup>(10)</sup> | D |  |
| Stock Option (Right to Buy) | 2025-07-23<sup>(11)</sup> | 2032-07-18 | Common Stock | 22608<sup>(12)</sup> | 0.20<sup>(12)</sup> | D |  |
| Stock Option (Right to Buy) | 2025-07-23<sup>(13)</sup> | 2033-11-13 | Common Stock | 193780<sup>(14)</sup> | 0.18<sup>(14)</sup> | D |  |
| Stock Option (Right to Buy) | 2025-07-23<sup>(15)</sup> | 2034-05-14 | Common Stock | 77512<sup>(16)</sup> | 0.18<sup>(16)</sup> | D |  |
| Stock Option (Right to Buy) | 2025-07-23<sup>(17)</sup> | 2034-08-19 | Common Stock | 12919<sup>(18)</sup> | 0.18<sup>(18)</sup> | D |  |
| Stock Option (Right to Buy) | 2025-07-23<sup>(19)</sup> | 2035-04-09 | Common Stock | 138875<sup>(20)</sup> | 0.20<sup>(20)</sup> | D |  |

---

### Footnotes:

(1) The option fully vested as of February 15, 2022.

(2) Received in accordance with the terms of the Merger Agreement (as defined herein), in exchange for outstanding options to acquire 5,000 shares of Deep Isolation, Inc. ("Deep Isolation") common stock at an exercise price of $1.35 per share. Pursuant to the terms of the Merger Agreement, at the effective time of the Issuer's merger (the "Merger"), with Deep Isolation, the number of shares of Deep Isolation common stock subject to each outstanding but unexercised option to purchase Deep Isolation common stock (each such option, an "Outstanding Option," and such number of shares of Deep Isolation common stock subject to such Outstanding Option, the "option shares") was converted into an option to purchase the number of shares of the Issuer's common stock equal to the option shares multiplied by 25.837283 (the "Conversion Ratio"), rounded to the nearest whole share, and the exercise price of each Outstanding Option was divided by the Conversion Ratio, rounded to the nearest whole cent.

(3) The option fully vested as of October 19, 2022.

(4) Received in connection with the Merger in accordance with the terms of the Agreement and Plan of Merger and Reorganization dated as of July 23, 2025, by and among the Issuer (f/k/a Aspen-1 Acquisition Inc.), Deep Isolation Acquisition Corp. and Deep Isolation (the "Merger Agreement") in exchange for Outstanding Options to acquire 5,000 shares of Deep Isolation common stock at an exercise price of $1.35 per share. Pursuant to the terms of the Merger Agreement, at the effective time of the Merger, the number of option shares subject to each Outstanding Option was converted into an option to purchase the number of shares of the Issuer's common stock equal to the option shares multiplied by the Conversion Ratio, rounded to the nearest whole share, and the exercise price of each Outstanding Option was divided by the Conversion Ratio, rounded to the nearest whole cent.

(5) The option fully vested as of January 1, 2025.

(6) Received in connection with the Merger in accordance with the terms of the Merger Agreement in exchange for Outstanding Options to acquire 1,000 shares of Deep Isolation common stock at an exercise price of $4.88 per share. Pursuant to the terms of the Merger Agreement, at the effective time of the Merger, the number of option shares subject to each Outstanding Option was converted into an option to purchase the number of shares of the Issuer's common stock equal to the option shares multiplied by the Conversion Ratio, rounded to the nearest whole share, and the exercise price of each Outstanding Option was divided by the Conversion Ratio, rounded to the nearest whole cent.

(7) The option fully vested as of August 15, 2024.

(8) Received in connection with the Merger in accordance with the terms of the Merger Agreement in exchange for Outstanding Options to acquire 875 shares of Deep Isolation common stock at an exercise price of $4.88 per share. Pursuant to the terms of the Merger Agreement, at the effective time of the Merger, the number of option shares subject to each Outstanding Option was converted into an option to purchase the number of shares of the Issuer's common stock equal to the option shares multiplied by the Conversion Ratio, rounded to the nearest whole share, and the exercise price of each Outstanding Option was divided by the Conversion Ratio, rounded to the nearest whole cent.

(9) In accordance with the terms of the Merger Agreement and effective as of immediately prior to the effective time of the Merger, Deep Isolation's Board approved the accelerated vesting of all Outstanding Options previously issued under Deep Isolation's 2018 Equity Incentive Plan (the "2018 EIP"). Prior to such acceleration, the stock option was subject to a 4-year vesting schedule, whereby 25% of the option shares vested as of August 15, 2022 and 1/48th of the remaining shares were scheduled to vest monthly over the 36-month period thereafter, subject to the Reporting Person's continued service through each vesting date.

(10) Received in connection with the Merger in accordance with the terms of the Merger Agreement in exchange for Outstanding Options to acquire 875 shares of Deep Isolation common stock at an exercise price of $4.88 per share. Pursuant to the terms of the Merger Agreement, at the effective time of the Merger, the number of option shares subject to each Outstanding Option was converted into an option to purchase the number of shares of the Issuer's common stock equal to the option shares multiplied by the Conversion Ratio, rounded to the nearest whole share, and the exercise price of each Outstanding Option was divided by the Conversion Ratio, rounded to the nearest whole cent.

(11) In connection with the Merger and effective as of immediately prior to the effective time of the Merger, Deep Isolation's Board of Directors approved the accelerated vesting of all outstanding and unexercised stock options previously issued under Deep Isolation's 2018 EIP, including the stock options reported herein. Prior to such acceleration, the stock option was subject to a 4-year vesting schedule, whereby 25% of the option shares vested as of August 15, 2023 and 1/48th of the remaining shares were scheduled to vest monthly over the 36-month period thereafter, subject to the Reporting Person's continued service through each vesting date.

(12) Received in connection with the Merger in accordance with the terms of the Merger Agreement in exchange for Outstanding Options to acquire 875 shares of Deep Isolation common stock at an exercise price of $5.20 per share. Pursuant to the terms of the Merger Agreement, at the effective time of the Merger, the number of option shares subject to each Outstanding Option was converted into an option to purchase the number of shares of the Issuer's common stock equal to the option shares multiplied by the Conversion Ratio, rounded to the nearest whole share, and the exercise price of each Outstanding Option was divided by the Conversion Ratio, rounded to the nearest whole cent.

(13) In connection with the Merger and effective as of immediately prior to the effective time of the Merger, Deep Isolation's Board of Directors approved the accelerated vesting of all outstanding and unexercised stock options previously issued under Deep Isolation's 2018 EIP, including the stock options reported herein. Prior to such acceleration, the stock option was subject to a 4-year vesting schedule, whereby 25% of the option shares vested as of February 2, 2024 and 1/48th of the remaining shares were scheduled to vest monthly over the 36-month period thereafter, subject to the Reporting Person's continued service through each vesting date.

(14) Received in connection with the Merger in accordance with the terms of the Merger Agreement in exchange for Outstanding Options to acquire 7,500 shares of Deep Isolation common stock at an exercise price of $4.61 per share. Pursuant to the terms of the Merger Agreement, at the effective time of the Merger, the number of option shares subject to each Outstanding Option was converted into an option to purchase the number of shares of the Issuer's common stock equal to the option shares multiplied by the Conversion Ratio, rounded to the nearest whole share, and the exercise price of each Outstanding Option was divided by the Conversion Ratio, rounded to the nearest whole cent.

(15) In connection with the Merger and effective as of immediately prior to the effective time of the Merger, Deep Isolation's Board of Directors approved the accelerated vesting of all outstanding and unexercised stock options previously issued under Deep Isolation's 2018 EIP, including the stock options reported herein. Prior to such acceleration, the stock option was subject to a 4-year vesting schedule, whereby 25% of the option shares vested as of June 1, 2025 and 1/48th of the remaining shares were scheduled to vest monthly over the 36-month period thereafter, subject to the Reporting Person's continued service through each vesting date.

(16) Received in connection with the Merger in accordance with the terms of the Merger Agreement in exchange for Outstanding Options to acquire 3,000 shares of Deep Isolation common stock at an exercise price of $4.61 per share. Pursuant to the terms of the Merger Agreement, at the effective time of the Merger, the number of option shares subject to each Outstanding Option was converted into an option to purchase the number of shares of the Issuer's common stock equal to the option shares multiplied by the Conversion Ratio, rounded to the nearest whole share, and the exercise price of each Outstanding Option was divided by the Conversion Ratio, rounded to the nearest whole cent.

(17) In connection with the Merger and effective as of immediately prior to the effective time of the Merger, Deep Isolation's Board of Directors approved the accelerated vesting of all outstanding and unexercised stock options previously issued under Deep Isolation's 2018 EIP, including the stock options reported herein. Prior to such acceleration, the stock option was subject to a 4-year vesting schedule, whereby 1/48th of the option shares vested monthly over a 48-month period beginning on May 1, 2024, subject to the Reporting Person's continued service through each vesting date.

(18) Received in connection with the Merger in accordance with the terms of the Merger Agreement in exchange for Outstanding Options to acquire 500 shares of Deep Isolation common stock at an exercise price of $4.61 per share. Pursuant to the terms of the Merger Agreement, at the effective time of the Merger, the number of option shares subject to each Outstanding Option was converted into an option to purchase the number of shares of the Issuer's common stock equal to the option shares multiplied by the Conversion Ratio, rounded to the nearest whole share, and the exercise price of each Outstanding Option was divided by the Conversion Ratio, rounded to the nearest whole cent.

(19) In connection with the Merger and effective as of immediately prior to the effective time of the Merger, Deep Isolation's Board of Directors approved the accelerated vesting of all outstanding and unexercised stock options previously issued under Deep Isolation's 2018 EIP, including the stock options reported herein. Prior to such acceleration, the stock option was subject to a 4-year vesting schedule, whereby 25% of the option shares were scheduled to vest as of April 1, 2026 and 1/48th of the remaining shares were scheduled to vest monthly over the 36-month period thereafter, subject to the Reporting Person's continued service through each vesting date.

(20) Received in connection with the Merger in accordance with the terms of the Merger Agreement in exchange for Outstanding Options to acquire 5,375 shares of Deep Isolation common stock at an exercise price of $5.13 per share. Pursuant to the terms of the Merger Agreement, at the effective time of the Merger, the number of option shares subject to each Outstanding Option was converted into an option to purchase the number of shares of the Issuer's common stock equal to the option shares multiplied by the Conversion Ratio, rounded to the nearest whole share, and the exercise price of each Outstanding Option was divided by the Conversion Ratio, rounded to the nearest whole cent.

**Signature:** /s/ Sophie McCallum  
**Date:** 2025-09-09

### Remarks:

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.**