Liquid lead or lead-bismuth eutectic, each requiring its own chemistry, materials, and freeze-protection strategy.
Fission System • Heavy Liquid-Metal Fast Reactor
Lead-Cooled Reactor
Lead-cooled fast reactors use liquid lead or lead-bismuth eutectic as coolant. Those fluids are related but not interchangeable: they differ in melting behavior, chemistry, activation products, materials effects, and operating history.
Lead or Lead-BismuthFast SpectrumResearch & DemonstrationHigh-Temperature Systems
Phase 4 • Page-Specific Technical Summary
What this reactor category means
System definition
A fast-neutron reactor family using a heavy liquid metal for primary heat transport, generally without a moderator.
A fast-neutron reactor family using a heavy liquid metal for primary heat transport, generally without a moderator.
Intended applications
Electricity, compact or modular fast-reactor studies, research facilities, and selected fuel-cycle or remote-power concepts.
Electricity, compact or modular fast-reactor studies, research facilities, and selected fuel-cycle or remote-power concepts.
Public boundary
Technology classification, system relationships, maturity, and engineering challenges only. No design parameters, calculations, control logic, procedures, procurement data, or build instructions.
Technology classification, system relationships, maturity, and engineering challenges only. No design parameters, calculations, control logic, procedures, procurement data, or build instructions.
System Architecture • Public-Level Component Map
Major Components
A second view separates the principal system functions for Lead-Cooled Reactor. The rendering and callouts are conceptual and intended for public engineering orientation.
- Core region
- Heavy-liquid-metal pool and vessel
- Immersed heat exchangers
- Natural or forced circulation path
- Passive decay-heat path
- Power-conversion module
Component boundaries vary by vendor, plant arrangement, coolant choice, power-conversion cycle, site constraints, and licensing basis.
Phase 4 • Concise Comparison
Engineering comparison
Fast-neutron spectrum.
Historical specialized lead-bismuth experience plus current research and demonstration programs; limited civilian deployment.
Fast-spectrum power with low coolant pressure, strong heat capacity, and configuration-specific passive-circulation potential.
Corrosion and erosion, oxygen and chemistry control, coolant mass, high melting temperature, freeze prevention, inspection in opaque coolant, polonium management for lead-bismuth systems, component qualification, licensing, and cost.
Application Context
Where the family fits
Fast-Reactor Development
Demonstration programs assessing heavy-liquid-metal heat transport and fast-spectrum performance.
Compact Power Concepts
Modular and remote-power studies where long refueling intervals and low primary pressure are valued.
Research & Irradiation
Potential fast-neutron test environments for fuels and materials under carefully controlled programs.
10-Phase Reactor Program • Phase 2
Standardized fission technical specification
Standardized public-safe fields support comparison across every fission and fusion family. Values are intentionally qualitative; licensing data, dimensions, operating windows, calculations, control logic, and build instructions remain offline.
Lead or lead-bismuth eutectic
Fast spectrum
Metallic, nitride, or oxide fuels proposed by program
Pool or loop advanced-reactor concept; modular variants studied
Intermediate heat transport to steam, gas, or other cycle
Operational heritage in special applications; civilian power development remains limited
Fast-spectrum missions may support recycling and actinide management. Coolant activation, polonium for LBE, corrosion products, spent fuel, and final disposal remain.
Specification boundary: Family-level technology classification and lifecycle context—not a vendor datasheet, safety analysis, procurement specification, or construction package.
Ten-Phase Reactor Program · Phase 5
Safety, licensing and public-trust boundary
Coolant chemistry, corrosion and erosion, freezing and remelting, heavy-component loads, inspection and repair, activation products, decay heat, leakage, and fuel handling.
U.S. advanced-power candidate: Parts 50 and 52 remain available, and the NRC issued Part 53 as an additional risk-informed, technology-inclusive pathway. The exact design, fuel, mission, and site control the route.
Apply nuclear-material control and accounting, physical protection, cybersecurity, transport security, insider-risk controls, and international safeguards as applicable to the exact material and jurisdiction. Do not publish Safeguards Information or adversary-useful detail.
Eligible SMR, non-light-water, and non-power facilities may use the performance-based 10 CFR 50.160 framework. Emergency-planning scope and zone are consequence-informed and design-specific—not automatically the site boundary.
May say the family has a defined operating or research history and can be evaluated through an applicable licensing pathway. State the exact maturity and unresolved design-specific gates.
Do not claim inherently safe, meltdown-proof, waste-free, proliferation-proof, walk-away, unguarded, zero-emergency-zone, automatically cheaper, or licensed because a related reactor operated.
Classification only: This is not a safety finding, licensing opinion, emergency plan, security plan, or legal determination. Exact obligations belong to the applicable regulator and project authority.