ERROR: HDF5 data format uses version 2.0 whereas your installation of OpenMC expects version 3.x data

User Support
1

I am a beginner in OpenMC. While learning to build a fuel rod by following the official website examples, I encountered the following error:

  1. ERROR: HDF5 data format uses version 2.0 whereas your installation of OpenMC expects version 3.x data.

    I would like to ask what the problem is. The relevant code is shown below:

import openmc

uo2 = openmc.Material(1, “uo2”)

print(uo2)

mat = openmc.Material()

# Add nuclides to uo2

uo2.add_nuclide(‘U235’, 0.03)

uo2.add_nuclide(‘U238’, 0.97)

uo2.add_nuclide(‘O16’, 2.0)

uo2.set_density(‘g/cm3’, 10.0)

zirconium = openmc.Material(name=“zirconium”)

zirconium.add_element(‘Zr’, 1.0)

zirconium.set_density(‘g/cm3’, 6.6)

water = openmc.Material(name=“h2o”)

water.add_nuclide(‘H1’, 2.0)

water.add_nuclide(‘O16’, 1.0)

water.set_density(‘g/cm3’, 1.0)

water.add_s_alpha_beta(‘c_H_in_H2O’)

materials = openmc.Materials([uo2, zirconium, water])

materials = openmc.Materials()

materials.append(uo2)

materials += [zirconium, water]

isinstance(materials, list)

materials.export_to_xml()

#surface

pitch = 1.26

left = openmc.XPlane(-pitch/2, boundary_type=‘reflective’)

right = openmc.XPlane(pitch/2, boundary_type=‘reflective’)

bottom = openmc.YPlane(-pitch/2, boundary_type=‘reflective’)

top = openmc.YPlane(pitch/2, boundary_type=‘reflective’)

z1 = openmc.ZPlane(5, boundary_type=‘reflective’)

z2 = openmc.ZPlane(-5, boundary_type=‘reflective’)

fuel_outer_radius = openmc.ZCylinder(r=0.39)

clad_inner_radius = openmc.ZCylinder(r=0.40)

clad_outer_radius = openmc.ZCylinder(r=0.46)

# cell

fuel_region = -fuel_outer_radius & +z2 & -z1

gap_region = +fuel_outer_radius & -clad_inner_radius & +z2 & -z1

clad_region = +clad_inner_radius & -clad_outer_radius & +z2 & -z1

water_region = +left & -right & +bottom & -top & +clad_outer_radius & +z2 & -z1

# fill the cell

fuel = openmc.Cell(name=‘fuel’)

fuel.fill = uo2

fuel.region = fuel_region

gap = openmc.Cell(name=‘air gap’)

gap.region = gap_region

clad = openmc.Cell(name=‘clad’)

clad.fill = zirconium

clad.region = clad_region

moderator = openmc.Cell(name=‘moderator’)

moderator.fill = water

moderator.region = water_region

root_universe = openmc.Universe(cells=(fuel, gap, clad, moderator))

geometry = openmc.Geometry()

geometry.root_universe = root_universe

geometry.export_to_xml()

# Create a point source

point = openmc.stats.Point((0, 0, 0))

source = openmc.IndependentSource(space=point)

settings = openmc.Settings()

settings.source = source

settings.batches = 100

settings.inactive = 10

settings.particles = 1000

settings.export_to_xml()

openmc.run(2)

2

Hi jhy, welcome to the forum.

The problem is described in the error message: you are using data stored using an old HDF5 version. You can download the newer version from Cross sections - OpenMC .

For future posts, it is helpful to include some information about your setup, such as the OpenMC version you encountered the error with. Code snippets should be posted using triple backticks: ```

3

Thank you very much for your answer. With your help, my issue has been resolved. I will also pay attention to the content and formatting of my future posts. Thank you for your reminder.