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Energy & MaterialsNuclear
Radiant
El Segundo, California · Founded 2020
Valuation
—Est.
Raised
$516MEst.
Stage
Series D
Open roles
97
Radiant Nuclear: Making Nuclear Power Portable
Funding History
Series D$300M
Dec 2025 · Lead: Draper Associates, Boost VC
+82% · 1.82x · 7 mo vs. Series C
Series C$165M
May 2025 · Lead: DCVC
Participants: StepStone Group, Giant Ventures, Hanwha Asset Management, SGA, Crossbeam Venture Partners, Align Ventures, ARK Venture Fund, Gigascale Capital, HartBeat Ventures, Pax Ventures
+313% · 4.13x · 25 mo vs. Series B
Series B$40M
Apr 2023 · Lead: Andreessen Horowitz
Participants: Founders Fund, Decisive Point, McKinley Alaska, Draper Associates, Cantos, Boost VC
+264% · 3.64x · 10 mo vs. Series A
Series A$11M
Jun 2022 · Lead: Union Square Ventures
Round Size Change
Latest Round Change
+82%1.82x
$300M Series D vs. $165M Series C
Series A
$11M
Jun 2022
+264% · 3.64x
→
10 mo
Series B
$40M
Apr 2023
+313% · 4.13x
→
25 mo
Series C
$165M
May 2025
+82% · 1.82x
→
7 mo
Series D
$300M
Dec 2025
Open roles at Radiant
Staff Manufacturing Engineer, DFM El Segundo, CASenior Manufacturing Engineer, DFMEl Segundo, CAStaff Nuclear EngineerEl Segundo, CASenior Software Engineer, FrontendEl Segundo, CA2027 New Graduate - Thermal EngineerEl Segundo, CA2027 New Graduate - Supply Chain CoordinatorEl Segundo, CA2027 New Graduate - Tooling EngineerEl Segundo, CA2027 New Graduate - Software EngineerEl Segundo, CA
Showing 8 of 97Careers page ↗
News & press
Kaleidos Has Left the Building - Radiant Nuclear
Aug 13, 2026
Valuation and funding totals are directional estimates and may not reflect confirmed terms.
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