Deep Fission (FISN) Registration filing summary

Company overview and business model

• Early-stage nuclear technology platform based on established PWR technology; Gravity Reactor places reactors in boreholes ~1 mile underground, using water-column pressure for operating pressure and cooling and surrounding geology for confinement and shielding.

• Each 3x3 reactor targets up to 15 MWe; standalone or clustered deployments are designed to scale to hundreds or potentially thousands of MWe per site.

• Phased plan: validate drilling and emplacement, pursue DOE authorization and pilot wells, then seek high-volume commercial licensing for clustered and multi-site deployment.

• Kansas Site includes a long-term lease for ~100 acres; first data well reached 6,000 feet, and a full-size prototype canister was lowered into and retrieved from a 34-inch borehole in September 2026.

• IP portfolio includes issued patents and pending applications covering reactor configuration, underground emplacement, drilling, casing, thermal-hydraulic performance, instrumentation and monitoring.

Financial performance and metrics

• Development-stage operations; no commercial reactor constructed or operated and no revenue generated to date.

• A 150 MW Master Energy Purchase Agreement with Great Plains Development Authority targets commercial operation in September 2028; initial 5 MWe deployment is a separate plan.

Use of proceeds and capital allocation

• Net proceeds from future security sales are designated for purposes to be specified in the applicable prospectus supplement.

• Near-term development priorities include proof-of-concept wells, reactor design and safety analysis, site work, and delivery of casing, reactor canister and heat exchanger components, plus low-enriched uranium fabrication and loading.