Korea Hydro and Nuclear Power's Innovative Small Modular Reactor (SMR)

Key Features and Safety Enhancements

• Size Reduction and Safety Increase: SMR reduces the size while integrating major devices for increased safety.
• Containment Vessel: Key structure protecting the reactor.
  • Dimensions: 34.9 m high, 9 m upper exterior diameter, 5 m lower exterior diameter.
  • Design Tolerance: 5 MPa pressure, 350°C temperature.
  • Construction: Cylindrical steel shell with hemispherical upper/lower heads maintaining structural integrity during accidents.
  • Function: Prevents uncontrolled release of radioactive materials; withstands internal pressure/temp rise from coolant loss.

Reactor Vessel

• Core: Location of nuclear reactions.
  • Dimensions: 30 m high, 5.5 m upper outer diameter, 4 m lower outer diameter, 7.6 m maximum outer diameter.
  • Design Tolerance: 17 MPa pressure.
  • Construction: Hemispherical lower head welded to vertical cylindrical vessel; forms primary boundary with head.
  • Functions: Endures thermal energy, shields radiation/materials.

Pressurizer

• Function: Pressurizes reactor coolant system.
  • Location: Top of reactor vessel.
  • Volume: 64.3 cubic m.
  • Purpose: Keeps coolant supercooled under high-temperature conditions.

Reactor Coolant System

• Components:
  • Pressurizer (details above).
  • 4 Reactor Coolant Pumps:
    • Installation: Vertically on upper reactor structure.
    • Design: Rated flow 5,580 CB mph, 17 MPa pressure, 360°C temperature.
    • Specs: 1,7 1880 RPM; sensor-installed motor.
    • Function: Circulates coolant to steam generator for heat exchange.

Reactor Opening and Closing Head

• Components:
  • Power cable of Control Element Drive Mechanism (CEDM).
  • Cable assembly for positioning.
  • Design: Outer diameter 190 mm for penetration nozzles.
  • Total: 28 through nozzles installed; supports 49 CEDMs.

Control Element Drive Mechanism (CEDM)

• Installation: Under cable assembly.
• Design: 360°C temperature, 17 MPa pressure, 2.4 m stroke.
• Function: Controls linear motion of control element assembly.
• Operation: Utilizes magnetic fields to activate components.

Steam Generator

• Location: Surrounds CEDM inside reactor vessel.
• Design: Spiral profusion type, 17 MPa pressure, 360°C temperature.
• Components: 5,128 heat transfer tubes, 8 water supply headers, 8 steam headers.
  • Function: Turns water into superheated steam; removes residual heat.

Nuclear Fuel Assembly

• Location: Bottom of reactor vessel.
• Design: 17x17 nuclear dioxide fuel rods.
  • Components: 260 fuel rods, 28 guide tubes, instrumentation tubes.
  • Function: Flexible load operation range (20-100%).