Hearth Microreactor, Series A

Preferred equity in a five megawatt heat-pipe reactor with a witnessed prototype and no pumps to fail.

Heat pipes move heat by evaporation and condensation inside a sealed tube. No pumps, no coolant loop, no loss-of-flow accident to design against. Hearth has demonstrated a full-power thermal prototype under third-party witness at a national laboratory and is preparing a construction permit application for a five megawatt unit at Idaho Falls.

Idaho Innovation Campus · Idaho Falls, IDConstruction permit filedEscrow: Cadence Escrow Services

TRL 6 of 9, band 5.4 to 6.5, signed by Dr. Samuel Adeyemi, PhD Nuclear Engineering; ASME Section III reviewer, on Jun 9, 2026.See the evidence it rests on

$3,860,000 committed of $5,000,000

$1,930,000 released · 77% subscribed

Released to the issuerCommitted, held in escrowRemaining

Minimum: $100
Instrument: Preferred equity
Term: None
Investors: 1,412

Closes October 15, 2026 · 32 days remaining

Eligibility depends on residency, accreditation status and how much you have already invested this year.
You can read everything about this offering without an account. Committing capital requires one.

Open an account

Open an account to invest

Demo · viewing as

Browsing without an account. Everything is visible; nothing is purchasable until you verify who and where you are.

Or answer the questions yourself

No money will move

No payment processor is connected. The commitment flow runs end to end, through amount, agreement, signature and receipt, and records a simulated position rather than a charge.

TRL assessment

Technology readiness level, 1 to 9

Confidence band 5.4 – 6.5

A full-power thermal prototype has operated under third-party witness at a national laboratory, which is what TRL 6 means and no more than that. The honest part of this assessment is what sits outside the score: the reactor works thermally, and the fuel supply, the license and the customer do not yet exist. Investors in this offering are buying an engineering result, not a business.

At TRL 6, the ladder permits Preferred equity and releases up to 50% of committed capital. This offering is structured as a preferred equity, which is consistent with that band.

Signed and published

Reviewer: Dr. Samuel Adeyemi
Credential: PhD Nuclear Engineering; ASME Section III reviewer
Signed: June 9, 2026
Published: June 10, 2026
Methodology: v1.4
Model: ci-trl-2026.06
Generated: Jun 2, 2026

How scoring works

Evidence

Every score cites the documents it was derived from, with the weight each carried. An assessment without evidence is an opinion.

Source	Document	Date	Weight
Independent test report	Full-power thermal prototype, witnessed test campaign National laboratory test report, independent witness Heat pipe array sustained rated thermal output for 720 hours without degradation.	Apr 21, 2026	38%
National lab result	TRISO compact irradiation data, partial burnup Advanced test reactor campaign, interim results Fission product retention within specification to 42% of target burnup. Campaign continuing.	Jan 30, 2026	26%
NRC docket	Construction permit application filed NRC pre-application and docketed submittal Application accepted for docketing. Review not commenced.	May 28, 2026	21%
Patent	Heat pipe wick geometry, granted claims Two granted US patents, one continuation pending Claims cover the capillary structure central to the thermal performance result.	Jul 15, 2025	15%

Score history

A score changes on the day a reviewer signs a new assessment, which is why this is a step line rather than a curve.