Conceptual Design of Mixedspectrum Supercritical Water Reactor

1
Conceptual Design of Mixed-spectrum Supercritical
Water Reactor

• T. K. Kim
• Argonne National Laboratory

2
Challenges of SCWR design in Neutronics

• Axial power shape control
• Large coolant density variation axially
• Smaller control rod worth
• Radioactive waste control
• Fast spectrum of SCWR can burn higher actinides
• Neutronics code system
• Multi-group, 3 dimensional, T/H coupling system
• HTC correlation in supercritical conditions
• Other issues
• Proliferation resistance and economy

3
Mixed Spectrum SCWR Concept

• Advanced spectrum control is needed to maximize
  merits of SCWR
• Mixed-spectrum supercritical water reactor
• Separation fast and thermal spectrum radially
• Smaller power peaking factor and easier
  reactivity control
• Multi-purposed reactor
• Maximize thermal efficiency and economy of SCWR
  concept without additional design features
• Electric production and actinide Burning in fast
  spectral core

4
MS2 core
5
Comparison of SCWR Assemblies
SCLWR-H and INEEL
SCLWR-H old
MS2 assembly
6
Comparison of SCWR Designs

• High Temperature Supercritical thermal reactor
  (O. Oka, "Design Concept of Once-Through Cycle
  Supercritical-Pressure Light Water Reactors,"
  SCR-2000, Tokyo (2000)
• INEEL design (tentative)

7
WIMS8/SOLTRAN Code System

• WIMS8 used for lattice calculations
• Zonal cross sections are functionalized by state
  parameters,
• SOLTRAN used for core calculations
• Interface current nodal formulation of diffusion
  and simplified P2 equation in multi-dimensional
  hex-Z and X-Y-Z geometry
• Multi-group, microscopic depletion
• Single-phase heat balance equation for T/H
  feedback
• HTC is updated by DB-, Modified DB-, and
  Jacksons correlations

8
MS2 Core Analysis (1)

• Burner
• Inner core MOX
• Th/TRU/U 32.5/15/32.5
• Fissile fraction 11
• Outer core MOX
• Th/Pu/U 3/8/89
• Fissile fraction 6.5
• Converter
• Inner core MOX
• Th/Pu/U 3/8/89
• Fissile fraction 6.5
• Outer core MOX
• Th/Pu/U 3/8/89
• Fissile fraction 6.5

9
MS2 Core Analysis (2)
HTC Jacksons correlation
10
Comparison of Axial Power and Temperature
Axial cladding surface temperature distribution
Axial power distribution
Axial coolant temperature distribution
11
Comparison of MS2 Cores

• Burner
• Heterogeneous core (higher TRU and fissile
  content in inner core)
• 40/60 power sharing in inner/outer cores
• Higher power peaking factor in inner core due to
  higher fissile content
• Cladding temperature of outer core is much lower
  than criteria due to lower power peaking factor
• Converter
• Homogeneous core (same fuel composition of inner
  and outer cores)
• 25/75 power sharing in inner/outer cores due to
  coolant density difference
• Higher power peaking factor in outer core, which
  causes higher cladding surface temperature

12
Conclusions and Future Works

• Conceptual design of MS2 core was performed
• WIMS/SOLTRAN code system was developed for
  supercritical water reactor core analysis
• Feasibility of burner and converter with
  mixed-spectrum SCWR was evaluated, but design
  optimizations are necessary
• Future works
• Optimize the core design for burner and converter
• Fuel cycle analysis
• Evaluation of waste and economics