Startup profile for Radiant: latest funding, latest known valuation, total disclosed funding, investors, status, sources, and why the company is interesting. Part of the Venture Capital Tracker startup directory.

Startup profile · funding coverage

Radiant funding, valuation and investors

Portable micro-nuclear reactors for remote power and defense applications.

Keep track of Radiant

Save this profile to your VCT watchlist for a quick return.

View watchlist

Funding, valuation & investors

Answer-first snapshot

Latest funding

Series D

$300M · December 2025

Latest known valuation

$1.8B

Series D · December 2025

Total disclosed equity funding

$440M

Excludes debt, grants, acquisitions, secondaries, and IPO proceeds.

Current status

private

growth · El Segundo, California

Investors in latest funding

Lead: Draper Associates

Other: Founders Fund

Sources: latest funding Last verified: 2026-07-25

Overview

Radiant Nuclear designs factory-built, transportable microreactors using liquid-metal-cooled technology intended to replace diesel generators at remote industrial and defense sites. Founded by SpaceX engineers Doug Bernauer and Paul Lichtman, the company raised a $40M Series B in April 2023 led by a16z American Dynamism, a $100M Series C in October 2024, and a $300M Series D in December 2025 at a $1.8B valuation led by Draper Associates.

Why Radiant is interesting

Radiant targets factory-built transportable microreactors to replace diesel generators — a16z American Dynamism led Series B before a $300M Series D at $1.8B in December 2025.

Product & use cases

Radiant's Kaleidos microreactor is factory-built, transportable by truck, and designed for megawatt-scale power at remote sites — data centers, mining, defense outposts, and disaster relief.

  • Remote industrial site power replacing diesel generators
  • Defense and military forward operating base energy
  • Data center backup and primary power
  • Disaster relief and emergency power deployment

Key facts

  • Series D (Dec 2025): $300M at $1.8B — Radiant press
  • Series C (Oct 2024): $100M led by DCVC
  • Series B (Apr 2023): $40M led by a16z American Dynamism
  • Founded by SpaceX engineers

Funding history (newest first)

Investors in our directory

Funds linked from Radiant's profile — open a fund page for stage focus and related deal articles.

Competitive landscape

Edge: SpaceX engineering pedigree and factory-built transportable design — targets faster deployment than conventional nuclear plants.

Nuclear startup landscape is capital-intensive with long regulatory timelines. Radiant's $300M Series D at $1.8B reflects AI/data-center power demand tailwinds. Must navigate NRC licensing — years from commercial deployment.

  • Oklo direct

    Public microreactor company (NYSE: OKLO) with Aurora design.

  • NuScale direct

    Small modular reactor developer.

  • Diesel generators incumbent

    Default remote power source Radiant aims to replace.

  • Last Energy / other microreactor startups adjacent

    Competing SMR/microreactor designs.

Notable stories

  • Radiant's founders Doug Bernauer and Paul Lichtman are SpaceX alumni — applying aerospace manufacturing discipline to nuclear reactor production.
  • The December 2025 $300M Series D at $1.8B came as data-center power demand made micro-nuclear a hot investor thesis.

Industries

Deep Tech Defense Tech Climate Tech

Related funding articles

Venture Capital Tracker pieces that cover Radiant's financing or category context.

FAQs about Radiant

Practical answers founders, operators, and investors typically search for.

Designs factory-built portable micro-nuclear reactors (Kaleidos) for remote power.
a16z (/fund/andreessen-horowitz), Founders Fund (/fund/founders-fund), USV (/fund/union-square-ventures), Cantos (/fund/cantos). Draper led Series D.
$1.8B — December 2025.
Both microreactor startups; Oklo is public (NYSE: OKLO), Radiant private.
Radiant's transportable microreactor design.
Doug Bernauer and Paul Lichtman — SpaceX alumni.
Prototype/testing phase — NRC licensing timeline extends years.
Remote military base power is a stated use case.
Investor thesis ties micro-nuclear to AI data-center energy demand.
$440M+ across B, C, and D rounds.

By Venture Capital Tracker

Last updated:

Editorial note: AI tools assisted with research, structure, or drafting. Venture Capital Tracker retains human editorial responsibility for factual accuracy, relevance, and source quality before publication.