Core
Nuclear industrial
Small modular reactors, advanced fission, selective fusion where the physics is measured, plus inspection, decommissioning, monitoring, and waste handling. Civil programmes only, and the largest share of the portfolio.
Capital for the civil nuclear stack, underwritten like engineering.
Civil nuclear first — and the energy infrastructure around it.
ORBITAL.SYSCIVIL-ONLY
- Seed through Series B · lead or co-lead
- €5–20M initial
- Europe · Asia · Africa · Gulf · Latin America
We back founders building civil nuclear industry, and the power, storage, and materials businesses around it. What follows is what we publish about ourselves — stage, scope, and how we respond to inbound dealflow.
Mandate
1core + 3
Civil nuclear at the core; grid, storage, and materials adjacent to it.
Sector map
6rings
Reactors, materials, fuel cycle, qualification, grid, and storage — see the atlas.
First read
5days
Business days to a reply on inbound dealflow.
What we invest in
Civil nuclear at the core, with three adjacencies that share its qualification culture and run on different commercial clocks.
Adjacent I
Advanced materials
Alloys, ceramics, composites, and coatings qualified for radiation, heat, and corrosion. The moat is who signs the qualification letter, and on what test matrix.
Adjacent II
Power generation, grid & efficiency
Balance-of-plant equipment, transmission and distribution hardware, protection and control. Grid lead times gate every new generator, nuclear included. Efficiency counts when the saving is metered.
Adjacent III
Energy storage & batteries
Cells with measured full-cell cycle life, grid-scale and long-duration systems with a defended safety case, packs and management electronics that pass type testing.
Technical diligence is led in-house — neutronics, materials qualification, and fuel-cycle governance read as engineering ledgers.
How we differ
- Civil-only mandate, stated publicly.Weapons, munitions, and autonomous lethal pathways are declined without discussion. Dual-use exposure must be resolved before first meeting, not at term sheet.
- One core, three adjacencies.Civil nuclear is the core mandate. Generation and grid hardware, storage, and advanced materials sit next to it because they share one qualification culture — traceability, type testing, regulatory audit — and often the same customers. Adjacent does not mean unfocused: each still has to pass a nuclear-grade evidence bar.
- Qualification is the moat.In materials and fuel-cycle businesses, the investable edge is who signs the qualification letter and on what test matrix. We read ledgers, not adjectives.
- Geography we actually cover.Europe, Asia, Africa, the Gulf, and Latin America. Close enough to visit the plant, meet the regulator, and read the chemistry on site — we add a region when we can do that, not before.
Who reads your deck
3 desks, one memo. Identities are disclosed in the first call — credentials are argued in the objections we send back.
Neutronics & safety case
Source terms, transient analysis, licensing basis documents — read in the original, not in summary.
Published safety analysis and a named competent-authority pathway.
Materials & qualification
Irradiation exposure history, weld procedures, test matrices, and who signs the qualification letter.
Component-scale evidence with a qualification sponsor on record.
Fuel cycle & governance
Safeguards design, material accountancy, export controls, and civil-only corporate structure.
Dual-use ambiguity resolved in writing before the first meeting.
From first email to term sheet
Five stages. Technical passes get technical objections — not template declines.
- 01First read5 business days
- 02Technical diligence4 – 8 weeks
- 03Conviction memoAbout 1 week
- 04Commit≤ 2 weeks
- 05Stay close, stay quietLong-term
A member of the investment team reads the deck and replies. Technical passes get technical objections — not template declines.
Neutronics summaries, materials test matrices, fuel-cycle governance, manufacturing QA. Led in-house — no outsourced reference-call theatre.
Written memo against the standing thesis for the ring. Dissents recorded in the file and re-read at year-end.
What we pass on
Public list. If your company fits one of these, we will not take a meeting.
- Weapons, munitions, or autonomous lethal systems — any dual-use ambiguity unresolved.
- Defence-led programmes masquerading as civil energy or materials plays.
- Offset-led climate business models with no industrial offtake.
- Laboratory-only materials with no qualification sponsor or test matrix.
- Fusion or fission companies whose evidence is fundraising narrative rather than measured physics.
- Cell or storage claims resting on coin-cell data, with no full-cell cycle life or abuse testing.
- Retail energy resellers, trading desks, and efficiency models whose savings are simulated rather than metered.
- Platforms that are dashboards on someone else's sensors, reactors, or meters.
Where we work
Close enough to visit the hot cell, meet the regulator, and read the plant's chemistry.
Regional programmes
6 public energy and radiation-safety programmes in the regions we cover. We back the suppliers and technology inside them — the layer beneath the programme, where qualification decides who wins.
- PROG/CA-01Power generation, grid & efficiencyCentral America
- PROG/CA-02Fuel cycle, safety & monitoringCentral America
- PROG/AF-01Reactor systems & civil nuclearAfrica
- PROG/AS-01Reactor systems & civil nuclearAsia
- PROG/GU-01Power generation, grid & efficiencyGulf region
- PROG/EU-01Energy storage & batteriesEurope
Write to us
First read within five business days. Include what the company does, stage, round size, and where you are on qualification or licensing.
contact@isotope-capital.comSector wire
Live third-party coverage of the mandate. Weapons and munitions reporting is filtered out.
- Livermore Lab, Pacific Fusion advance tech for potential fusion energy production, experiments (opens in a new tab)
- US: Strategic partnership could accelerate 100 MW SMR deployment (opens in a new tab)
- Letters to the Editor: Nuclear energy, (opens in a new tab)