The working vocabulary.

FOAK

First-of-a-kind. The first built unit of a new design, carrying cost and schedule risk that later units do not. We expect FOAK economics modelled as the central case, not a footnote.

SMR

Small modular reactor. A reactor designed for factory fabrication and modular site assembly. Licensing cadence and supply-chain depth usually matter more to bankability than nameplate capacity.

Gen-IV

Fourth-generation reactor designs — molten salt, high-temperature gas, sodium-cooled and others. Investable where chemistry and materials are the moat, not slideware thermal-efficiency comparisons.

Safety case

The structured body of evidence a regulator accepts to license a nuclear facility: design basis, transient analysis, defence in depth. The document set behind every 'our reactor is safe' claim.

Competent authority

The national regulator empowered to license nuclear activity. A programme without a named competent-authority pathway is a programme without a schedule.

Hot cell

A heavily shielded chamber for handling irradiated material with remote manipulators. Where materials claims go to be verified — evidence that survives the hot cell survives diligence.

Qualification matrix

The agreed grid of tests, conditions, and acceptance criteria a material or component must pass for nuclear service. Who signs it, and on what test plan, is often the investable edge.

Irradiation history

Documented neutron exposure of a material sample or component — fluence, spectrum, temperature. Coupon strength without exposure history is table stakes, not evidence.

NDT

Non-destructive testing — ultrasonic, eddy-current, radiographic and CT inspection that finds flaws without destroying the part. At production scale, the choke point between prototype and fleet.

CMC

Ceramic matrix composite. Ceramic fibres in a ceramic matrix, used where metals fail on creep and oxidation simultaneously. Reproducible densification and inspectability decide scale-up.

Primary loop

The coolant circuit in direct contact with the reactor core. Its chemistry is unforgiving — coatings and alloys validated only in deionised water have not been validated.

LOCA

Loss-of-coolant accident. A design-basis event electronics and materials inside containment must survive. 'Rad-hard' claims are read against LOCA regimes, not benign lab conditions.

Fuel cycle

The industrial chain around nuclear fuel: fabrication, handling, storage, reprocessing, waste. We invest in civil, safeguarded segments only — never enrichment with unresolved dual-use ambiguity.

Safeguards

The accounting and inspection regime (IAEA and national) that verifies nuclear material stays in civil use. In our diligence, safeguards design is read as seriously as yield.

Decommissioning

Taking a nuclear facility apart safely at end of life — characterisation, segmentation, waste routing. A growing market that pays regardless of which new-build design wins.

Dosimetry

Measurement of absorbed radiation dose, for people and equipment. Dose is an economic variable: technology that cuts person-rem per task changes outage economics.

Plant-life extension

Engineering and licensing work that keeps an existing reactor running beyond its original design life. The installed base is large and ageing — the quiet end of the market.

Tritium breeding

Producing tritium fuel inside a fusion machine's blanket. Breeding ratio, inventory, and permeation are measured quantities — fusion teams in mandate publish them.

A term you expected is missing? Tell us when you write — the glossary grows with the questions we get.