Design of record · targets held to an honest ceiling
Specification & engineering drawings.
The HELIX module and core at design-of-record fidelity. Every value is a design target, not field data. Dimensions on the drawings are representative of the current design basis and will be superseded by qualified design documents.
Figure 1 · Module elevation, not to scale · design targets
Figure 2 · Core cross-section, control drums, fuel channels, diverse rod
Specification sheet
Site output
10–16 MWe net (design target)
Configuration
2–4 factory-sealed modules per site
Thermal rating
20–30 MWth per module (tunable)
Heat transport
Low-pressure sodium; EM-pumped pool (evaluated vs heat-pipe)
Fuel
UCO-TRISO, 19.75% HALEU, graphite-moderated
Vessel
316H, ASME III Div 5 (816 °C / 300,000 h coverage)
Reflector
Graphite + thin alumina outer
Control
16 B4C control drums + 1 diverse shutdown rod
Reactivity feedback
−6 to −8 pcm/K (screening)
Core life
8–10 yr swap target at 76–95% fleet rating (screening)
Cooling
Fully dry, forced-draft dry coolers; zero cooling water
Non-safety, observe-only, behind a hardware one-way path
Transport
Road/rail, factory-sealed, set-and-connect
All values are pre-application design targets. Heat-transport architecture (EM-pumped sodium vs heat-pipe) is under final evaluation. Physics figures are unqualified screening, pre-QAPD.
Ask the founder
Every question, answered directly.
The questions a regulator, a partner, or an engineer asks about HELIX, answered by the founder. No forms, no sales pitch.
✓
Jamie KlonczFounder · RankShield Energy
Ask me anything about HELIX, the safety case, verification, or the Part 53 pathway. Tap a question to start.
What exactly is RankShield Energy building?
We are developing HELIX, our own sealed, transportable microreactor, and licensing it under 10 CFR Part 53 with a qualified third-party fabricator manufacturing to our specification. What makes us different is not the reactor. It is that ours can be independently verified. Every module signs its telemetry and is attested from the factory floor to every operating hour.
Is this an operating reactor, or a study?
It is pre-application development, not an operating product. No microreactor of this class has been built or run at its rated life yet, including ours. Every figure we publish is a design target and every physics result is unqualified screening, pre-QAPD. We label all of it honestly. That discipline is what makes the rest credible.
Why should a regulator or partner take a pre-application program seriously?
Because pre-application is exactly where the credible advanced-reactor cohort is. Part 53 only became final in 2026, and the leading microreactor developers are all in pre-application or early licensing. We treat the honest labels as milestones on a defined path we are actively executing, not as caveats.
How does HELIX make power without water?
Heat leaves the core through low-pressure sodium with no water anywhere in the primary. An air-cooled organic Rankine cycle converts it to electricity for the first units, with a funded supercritical-CO2 upgrade path later. All heat is rejected to dry coolers, so there is no cooling tower and no water draw against the community that hosts the plant.
What fuel does it use, and can you actually buy it?
UCO-TRISO at 19.75 percent HALEU in a graphite core. It is the only advanced fuel form that is both NRC-precedented and purchasable from multiple US fabricators today. We also designed a multi-batch factory recharge that reuses partially burned fuel, which cuts how much fresh HALEU each swap needs by roughly three times.
How big is a site and how often do you swap the core?
Two to four sealed modules per site produce 10 to 16 megawatts of electricity. We run each module at 76 to 95 percent of rating so staggered core swaps land on an 8 to 10 year cadence, and reserve margin carries a module outage. Our own depletion screening supports that lifetime target.
What happens in a total loss of power and cooling?
Nothing that matters. Reactivity self-limits on a strongly negative temperature coefficient, the control drums insert fail-safe by spring and gravity with no power needed, and decay heat leaves by natural circulation alone. A total loss of power and cooling is an availability event, not a safety event. The safety case never credits a pump, a valve, an operator, or a network.
Can the verification network ever interfere with safety?
No, by construction of the wiring. The attestation layer is classified non-safety and observe-only. It sits behind a hardware one-way path, so it can prove a module is intact but it physically cannot send a command toward a safety system. The safety systems are local and passive and unreachable from any network.
What does "verifiable" actually mean here?
Each module signs its sensor readings and firmware with post-quantum cryptography and anchors them to an append-only log co-signed by independent off-site witnesses. An operator, an insurer, or a regulator can check a module directly rather than take our word for it. Anyone can write the word secure. Only a verifiable reactor lets you check.
How does a fleet catch a problem before it becomes one?
Each site normalizes its performance against its own environment, then the RankShield Network compares every reactor to what its conditions predict. A reactor that drifts from that expectation stands out against an independent-witness fleet. The elegant part is that the same signal flags both wear and tampering, so one detector serves efficiency and security.
What is the licensing pathway?
We elected 10 CFR Part 53, the risk-informed framework that went final in April 2026. We scoped the topical-report sequence to a verified compliance register and are structuring a DOE-authorized test unit so its data, collected under NQA-1 from day one, credits into the commercial case.
What still has to happen before you build hardware?
A stood-up NQA-1 quality program, independent physics validation with independent codes and ultimately test data, an NRC license under Part 53, and validated demand. All of it is defined and stated on our licensing page. We make no economic, schedule, or performance guarantee, only honest labeled progress.
