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ReCore-Reactor

The ReCore-Reactor is the nuclear-island part of an integrated engineering concept (not a commercial plant design ready for procurement). The reference unit is sized around 720 MWth, about 320 MWe when coupled to ReCore-Power.

The design is deliberately conservative in materials and physics but more ambitious in plant arrangement: modular multi-loop layout, metallic fuel suited to recycle, heat rejection to nitrogen rather than water. For the broader rationale — supply chains, construction, and what is still open — see Why?.

Technology readiness

TRL figures below are estimates for building blocks (NASA/EU-style 1–9 scale), not regulator-certified scores.

TechnologyEst. TRLNotes / heritage
SFR sodium primary systems8–9Decades of operation and R&D: EBR-II (US), Phénix / Superphénix (France), BN-600 / BN-800 (Russia); industrial Na chemistry and loop practice
Metallic U-Pu-Zr / U-TRU-Zr fuel7–8EBR-II / IFR metal-fuel campaigns; demonstrated high conductivity and passive feedback behaviour
HT9 ferritic–martensitic cladding7–8Proven SFR metal-fuel cladding path (e.g. FFTF / EBR-II-class experience)
ALIP / EM sodium pumps7–8Used and developed for liquid-metal service; no shaft seals into primary sodium
316LN vessel, piping, HX structure8–9Standard nuclear/process austenitic steel; plate, tube, and weld practice at ~600 °C class
Helical shell-and-tube HX (process)7–8Industrial helical / enhanced tube HX practice; gas-side fins and swirl inserts are conventional
Na→N₂ primary HX in an SFR plant4–6Component HX is industrial; nuclear Na–N₂ coupling at this plant scale is FOAK engineering
Modular prefabricated vessel sectors5–7Prefabrication and high-integrity welding (e.g. EBW/LVEB candidates) exist industrially; nuclear modular SFR assembly is project-specific
Integrated modular SFR FOAK4–5Full plant integration, licensing, and demonstration remain open work

Many historical SFRs used an intermediate sodium loop and water/steam generators — partly for sodium–water chemistry risk, partly for radioactivity isolation, thermal buffering, and other plant reasons. Intermediate loops also add inventory, cost, and leak paths.

This concept explores:

Open work is integration, qualification, and licensing — not inventing a new coolant class.

Design principles

ParameterTarget
Reactor typeModular sodium fast reactor
Thermal power720 MWth
Electrical classabout 320 MWe
Primary pressurenear atmospheric (~1 bar)
Hot sodium (order of)~600 °C
Fuelmetallic U-(TRU)-Zr; U-Pu-Zr bridge cores
Breeding intentnear iso-breeder (conversion ratio ~1)
Primary Na inventorybelow 50 m³ (design envelope)

Fuel and the closed cycle

Metallic fuel supports:

Iso-breeder operation is a design goal: produce roughly as much fissile material as is consumed, reducing dependence on continuous external enrichment for equilibrium cores. First cores would still need a fissile start-up inventory (bridge fuel, e.g. U-Pu-Zr from existing civilian Pu and depleted uranium) while pyroprocessing capacity for full U-TRU-Zr multi-recycle is built.

Heat transport to nitrogen

Primary sodium is intended to transfer heat to nitrogen in Na–N₂ heat exchangers. Because nitrogen is chemically inert toward sodium, eliminating the intermediate sodium loop is a candidate simplification — not an automatic one. Intermediate loops have served purposes beyond Na–water chemistry; any reduced-loop design must still justify radioactivity control, leak behaviour, gas ingress, and licensing. Leak detection, single-wall versus double-wall trade-offs, and safety analysis remain open engineering work.

Safety philosophy

The concept aims for defense in depth: inherent physics, passive heat removal, and engineered barriers. Reactor physics provide strong inherent negative feedbacks that assist safety; they do not make meltdown “impossible” or remove the need for engineered shutdown, decay-heat removal, and licensing.

  1. Inherent / physics-based features — metallic fuel feedbacks; large boiling margin of sodium at atmospheric pressure (~881 °C boiling point vs ~600 °C hot-leg temperature → 281 K margin).
  2. Passive decay-heat removal — natural circulation and dedicated passive loops as design intent.
  3. Engineered barriers — guard vessel, leak detection, argon cover-gas systems, core-catcher / in-vessel retention features as appropriate.
  4. Refueling concept — simplified in-vessel handling is under study (see below).
  5. Operational measures — chemistry control, inspection, coupling to power-cycle load management.

Refueling concept

A simplified in-vessel handling concept (triangular fuel wedges and a single-axis hoist, rather than complex multi-axis in-sodium robotics) is planned as a way to reduce mechanical risk relative to some historical designs. It remains concept-level until engineered and demonstrated.

Materials