6. LEASES

Effective September 21, 2021, the Company entered into a lease agreement (the “Property Lease”) for real property, including land and buildings in Upton, Wyoming for the Demonstration Plant. The Property Lease, which had an initial 12-month term, allows for annual renewals, which at the Company’s option can be renewed for as long as the facility is needed. In June 2025, the Property Lease was renewed, extending the termination date to September 30, 2026. The Property Lease, which is classified as an operating lease, generally provides for base rent, and requires the Company to pay all insurance, personal property taxes on any structure or improvements made by the Company and other maintenance costs. The Property Lease provides for an annual cost of living adjustment but contains no residual value guarantees or restrictive covenants. Pursuant to the Property Lease, the Company is obligated to remove certain Company completed property improvements, though those items requiring removal, if any, will be confirmed with the lessor prior to the termination of the Property Lease.

On May 14, 2024, the Company entered into a second lease agreement for modular office units for use at its Demonstration Plant site in Upton, Wyoming (the “Office Lease”). The Office Lease, which was for an initial 12-month term and provided for monthly extension options thereafter, was classified as an operating lease, and generally provided for base rent, and required the Company to pay all insurance, property taxes and other applicable costs, including the transportation charges to return the units to their original point of origin in an amount not to exceed $7. As of December 31, 2025, the Office Lease was terminated with the Company’s purchase of these modular office units for $131.

For purposes of the following table, payments under the Property Lease are assumed to run through September 30, 2027.  If the completion of the Demonstration Plant operations dictates further extensions beyond this date, the Company may seek to extend the term of the Property Lease.

Total future minimum lease payments under the Property Lease as of December 31, 2025 were as follows:

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For the years ended December 31, 2025 and 2024, $168 and $134, respectively, were included in operating cash flows for amounts paid for operating leases.

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For the years ended December 31, 2025 and 2024, the Company incurred interest expense on lease liabilities of $23 and $32, respectively, and right of use asset amortization expense of $162 and $142, respectively. 

As of December 31, 2025 and 2024, the weighted average lease terms for the Company’s operating leases were 1.75 years and 1.58 years (including renewal options), respectively, and the weighted average discount rate was estimated at 12% for both years.