---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-25-118387"
form_type: "8-K"
ticker: "FISN"
cik: "0001918102"
company_name: "DEEP FISSION, INC."
filed_at: "2025-12-04T23:59:59+00:00"
generated_at: "2026-05-16T14:55:20.945255+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Deep Fission selects Kansas site for DOE advanced reactor pilot; groundbreaking Dec 9

## Summary
- Pilot site selected at Great Plains Industrial Park in Parsons, Kansas; groundbreaking Dec 9, 2025.
- Targets reactor criticality by July 4, 2026, pending DOE authorization under Reactor Pilot Program.
- Holds letters of intent for ~12.5 GW of potential future commercial demand.
- Signed LOI with Great Plains Development Authority for full-scale commercial project at same site.

## SEC filing metadata
- accession: 0001104659-25-118387
- form_type: 8-K
- ticker: FISN
- cik: 0001918102
- company_name: DEEP FISSION, INC.
- filed_at: 2025-12-04T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1918102/000110465925118387/0001104659-25-118387-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1918102/000110465925118387/tm2532758d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-25-118387
- JSON: https://secwatch.observer/filing/0001104659-25-118387.json
- Plain text: https://secwatch.observer/filing/0001104659-25-118387.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.