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ICE SFR Object Model

Revision as of 14:16, 7 February 2015 by Paul.roubekas.org (Talk | contribs)

This page is under construction and can be considered... indecent. All numerical values listed are assumed to be under cold operating conditions.
SFRSystemDiagram.png
== Reactor Core Model ==
ABTR FullCoreAssemblyLayout.png
The SFR core is the highest level structure provided in the ICE object model hierarchy for sodium-cooled fast reactor modeling. The SFR reactor core is modeled as a radial arrangement hexagonal assemblies. Convention dictates assemblies are ordered with the center-most assembly being "row 1," the subsequent ring of assemblies surrounding it being "row 2," and so forth, iterating in concentric circles outwards.

The radial view of a SFR core is typically divided into five regions:

  • inner core
  • outer core
  • radial blanket (optional)
  • control assemblies
  • radial reflectors

In addition to these, the entirety of the SFR core is contained within a shielding structure called the radial shield. The shield's purpose is to limit the amount of radiation that passes between the internal and external environments of the reactor core, although is not always depicted as part of a reactor core model. Additional assemblies may be included for fuel testing and materials testing.

In addition to fissile materials, an SFR can also contains fertile materials (such as U-238 or Pu-240) to be converted to fissile materials via neutron absorption (a process referred to as fuel breeding). The blanket regions of a reactor core are reserved exclusively for this purpose. A homogeneous core layout entails an even distribution of fertile material throughout the core fuel region by including an axial level of blanket within each assembly. This differs from a heterogeneous core layout which employs alternating concentric rows of pure fissile and fertile materials within the core region.

The presence of blanket materials inside a liquid-metal cooled reactor is the distinguishing factor between a breeder- and burner-type reactor. A breeder reactor contains fertile materials for fuel breeding, whereas a burner reactor does not, and simply burns through it's available fuel supply. At this time, the ICE SFR object model is assumed to handle burner-type reactors. However, the ability to include blanket assemblies is included for future modeling possibilities.

Objects of the reactor core include:

  • Fuel Assemblies - Nuclear fuel components including inner core, outer core and—optionally—blanket assemblies. Inner and outer cores regions can contain both fissile and fertile materials, while the blanket region materials are exclusively fertile.
  • Control Assemblies - Includes primary control rods, secondary (shutdown) control rods. Primary and secondary control rods are made of neutron-absorptive materials.
  • Test Assemblies - Any fuels or materials included in the reactor core for the purpose testing during operations.
  • Reflector Assemblies - A structure made of neutron-reflective material, causing subcritical fuels to become critical.
  • Shield Assemblies - A stainless steel structure to shield the reactor core and external environments from irradiation.

Properties of the reactor core include:

  • Type (SFR)
  • Size - Total number of assemblies contained in the reactor core.
  • Number and Location of Fuel Assemblies - Position of inner and outer core fuel assemblies at the core view, also called the core loading pattern.
  • Number and Location of Control Assemblies - Position of control/shutdown rod assemblies at the core view.
  • Number and Location of Testing Assemblies - Position of material and/or fuel testing assemblies at the core view.
  • Number and Location of Reflector Assemblies - Position of radial reflector assemblies at the core view.
  • Number and Location of Shield Assemblies - Position of shield assemblies at the core view.
  • Inter-assembly Gap (cm) - Distance between the external walls of adjacent assemblies to allow for interstitial coolant flow.
  • Lattice Pitch (cm) - Also called assembly pitch. The shortest distance between the centers of adjacent assemblies (also equivalent to the assembly outer flat-to-flat plus inter-assembly gap).
  • Thermal Power (MWth) - Maximum heat the reactor is designed to generate.
  • Electrical Power (MWe) - Maximum electricity the reactor is designed to generate.
  • Thermal Efficiency - The ratio of thermal power to usable electrical power generated.
  • Primary Coolant - Liquid sodium coolant.
  • Inlet Temperature (°C) - Coolant temperature as it enters the bottom inlet of an assembly.
  • Outlet Temperature (°C) - Coolant temperature as it exits the top outlet of an assembly.
  • Reactor Temperature ΔT (°C) - Temperature difference between assembly inlets and outlets.
  • Core Average Temperature (°C) - Average of inlet and outlet temperatures.
  • Cycle Length - The length of time corresponding to one iteration of a fuel cycle.

Typical values are shown below:

Due to the migration of our wiki articles from MediaWiki to Markdown, the "locations" will not be displayed correctly. We will soon move back to MediaWiki, at which point this injustice will be righted.

  • Type = SFR
  • Size = 199
  • Locations of Fuel Assemblies (1/3rd symmetry of reactor core):
               O - I I -
                   O I - I I
               O - I I - I
                   O O - I I -
                       O O - O O
                           O O - -
            - - - - -

I = Inner core assembly (24 total); O = Outer core assembly (30 total)

  • Locations of Control Assemblies (1/3rd symmetry):
                               P
                   P - - S -
                               P - -
            - - - - -

P = Primary control assembly (7 total); S = Secondary control assembly (3 total)

  • Location of Test Assemblies (1/3rd symmetry):
                   M - - -
                           F - -
                           F - - M
            - - - - -

F = Fuel test assembly (6 total); M = Material test assembly (3 total)

  • Locations of Reflector Assemblies (1/3rd symmetry):
       R R - - - - -
           R R - - - - -
       R R - - - - - -
           R R - - - - - -
           R R R - - - - -
           R R R R - - R R
               R R R R R R R
                   R R R R - -

R = Radial reflector assembly (78 total)

  • Locations of Shield Assemblies (1/3rd symmetry):
   S - - - - - - -
   S - - - - - - -
   S - - - - - - - -
   S - - - - - - - -
   S - - - - - - - -
   S - - - - - - - -
   S S - - - - - - -
   S S - - - - S S
   S S S S S

S = Shield assembly (48 total)

  • Inter-assembly Gap = 0.4000 cm
  • Lattice Pitch = 14.5980 cm
  • Thermal Power = 250 MWth
  • Electrical Power = 95 MWe
  • Thermal Efficiency = 38%
  • Primary Coolant = Na
  • Inlet Temperature = 355°C
  • Outlet Temperature = 510°C
  • Reactor Temperature ΔT = 155°C
  • Core Average Temperature = 432.5°C
  • Cycle Length = 4 months

Reactor Assembly Model

<<<<stopped here>>>>>

Fuel Assembly

Control Assembly

Reflector Assembly

Shield Assembly

Test Assembly

Reactor Pin Model

Fuel Pin

Control Pins

Shield Pins

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