Radiant

Radiant is building the world’s first mass-produced portable nuclear microreactors.

Latest funding

$300M Series B+ · December 17, 2025

Led by Boost VC · Source: fundraisingfox.com

Total raised: $616.2M across 6 sourced rounds

All 6 rounds ↓

Website: radiantnuclear.com.

X: @RadiantNuclear · 12,886 followers.

LinkedIn: linkedin.com.

Categories: Climate and energy Developer tools and cloud Logistics and mobility.

Sectors: Space, Climate.

Stage: Series B+.

Based in: Los Angeles, United States.

Founded: 2019.

Total raised: $616.2M in 6 sourced rounds.

Last round: Dec 17, 2025 · 333 days ago.

Headcount: 101–250 employees.

On Recent Funding since: Sep 30, 2026.

Signals

X account@RadiantNuclear · created Sep 7, 2020 (6 years old) · 12,886 followers

Website registeredApr 10, 2019 (7 years old)

About Radiant

The company’s first reactor, Kaleidos, is a 1 MW failsafe microreactor that can be transported anywhere power is needed. Founded in 2020, Radiant plans to test its first reactor in 2026, with initial customer deployments beginning in 2028.

TIMELINE · MONEY RAISED

Radiant | 531 days from website to first raise on record

@RadiantNuclear·Raised $616M in 6 sourced rounds·2 signals before the first raise

Money raised, round by round (amounts linked to their source). Pins are dated signals; hover the icons for dates.

Funding rounds

Date	Round	Amount	Lead	Source
Dec 17, 2025	Series B+	$300M	BBoost VC	fundraisingfox.com
May 28, 2025	Series B+	$165M	DDCVC	esgtoday.com
Nov 14, 2024	Series B+	$100M	DDCVC	dcvc.com
Apr 24, 2023	Series B+	$40M	AAndreessen Horowitz	linkedin.com
Mar 9, 2022	Series A	$10M	UUnion Square Ventures	usv.com
Sep 22, 2020	Pre Seed	$1.2M	—	powermag.com

Timeline

September 7, 2020
X account created
April 10, 2019
Website created

Founders and team

BU
Bob Urberger Founder

LinkedIn
DB
Doug Bernauer Founder

LinkedIn
CH
Chris Hansen Head of Mechanical Engineering
PK
Paul Keutelian Chief Operating Officer

Investors

Companies like Radiant

GGramiyaa$1.93M Series A · Oct 2026
AAntares$370M Series B+ · Jul 2026
TThe Nuclear Company$51M Series A · May 2025
CClean Core Thorium Energy$15.5M Seed · Feb 2025
BBluecore Energy$50M Seed · Sep 2026
SStandard NuclearSeries A · Jul 2026

Other companies backed by Boost VC

AAIsa$9M Seed · Oct 2026
VVarda$251M Series B+ · Sep 2026
HheXem bio$2M Seed · Sep 2026
EElita$1.35M Seed · Sep 2026
SShipin$52M Series A · Aug 2026
KK2 Space$500M Series B+ · Jul 2026

Boost VC portfolio →

Sources and API

Every amount links to the page it came from. * Estimated from an accelerator's published standard deal, not a company-specific disclosure. How Recent Funding sources and verifies funding data. The same data as JSON: /api/v1/companies/radiant (get a free API key).