{"schema_version":"secwatch.filing_event.v1","accession":"0001104659-26-109201","form_type":"8-K","ticker":"FISN","cik":"0001918102","company_name":"DEEP FISSION, INC.","filed_at":"2026-09-21T15:26:05+00:00","discovered_at":"2026-09-21T15:27:12.608657+00:00","generated_at":"2026-09-21T15:27:22.247832+00:00","sec_items":["7.01","9.01"],"event_type":"other_material","sentiment":"positive","materiality_score":0.5,"calibrated_materiality_score":0.5,"confidence":"high","headline":"Deep Fission completes borehole demo with Youngquist; targets 2027 deployment","bullets":["Collaborated with drilling contractor Youngquist Brothers to evaluate/test deep, large-diameter borehole drilling for underground reactor deployment.","On Sept 3, 2026, in Fort Myers FL, Deep Fission lowered and retrieved its 30-inch full-size prototype reactor canister into a 34-inch borehole to ~100 ft.","Youngquist has drilled large-diameter boreholes to depths >8,000 ft since 1971; partnership applies that expertise to Deep Fission's Gravity™ reactor model.","Company targets commercial deployment as early as 2027; collaboration to continue on drilling and testing."],"urls":{"canonical":"https://secwatch.observer/filing/0001104659-26-109201","json":"https://secwatch.observer/filing/0001104659-26-109201.json","markdown":"https://secwatch.observer/filing/0001104659-26-109201.md","text":"https://secwatch.observer/filing/0001104659-26-109201.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1918102/000110465926109201/0001104659-26-109201-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1918102/000110465926109201/tm2625786d1_8k.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-09-21T15:27:22.247832+00:00"},"review":{"review_status":"machine_generated","human_reviewed":false,"corrected":false,"correction_note":null,"correction_timestamp":null,"superseded_by":null,"related_filings":[]},"source_grounded_claims":[],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}