Added parameters to keep all statepoints in transient solves.

include/base/OpenMCProblemBase.h

@@ -445,6 +445,20 @@ class OpenMCProblemBase : public CardinalProblem, public PostprocessorInterface
            std::to_string(_fixed_point_iteration) + ".h5";
   }
 
+  /**
+   * Return path to write current timestep's statepoint to in transient solves.
+   * @return statepoint path
+   */
+  const std::string transientStatepointPath();
+
+  /**
+   * Formats `path_output` so that it is ready to be passed to
+   * openmc::settings::path_output
+   * @param[in] path_output unformatted path
+   * @return formatted absolute path
+   */
+  const std::string formattedOutputPath(const std::string & path_output);
+
   /// Whether to print diagnostic information about model setup and the transfers
   const bool & _verbose;
 
@@ -567,6 +581,12 @@ class OpenMCProblemBase : public CardinalProblem, public PostprocessorInterface
   /// Directory in which OpenMC settings xml files are located
   const std::string & _xml_directory;
 
+  /// Directory to write statepoint file to
+  const std::string & _statepoint_directory;
+
+  /// Parameter determines whether statepoints from all timesteps should be saved in separtate directories to avoid them being overwritten
+  const bool _keep_transient_statepoint;
+
   /// Conversion unit to transfer between kg/m3 and g/cm3
   static constexpr Real _density_conversion_factor{0.001};
 

src/base/OpenMCProblemBase.C

@@ -98,6 +98,17 @@ OpenMCProblemBase::validParams()
       "The number of generations to use with the method of iterated fission probabilities.");
   params.addParam<FileName>(
       "xml_directory", "./", "The directory in which to look for OpenMC XML files.");
+
+  params.addParam<FileName>(
+      "statepoint_directory",
+      "./",
+      "The directory to write statepoint files to. Sets openmc::settings::path_output.");
+
+  params.addParam<bool>("keep_transient_statepoint",
+                        false,
+                        "Whether or not statepoints from all timesteps should be kept, and written "
+                        "to seperate directories.");
+
   return params;
 }
 
@@ -116,7 +127,9 @@ OpenMCProblemBase::OpenMCProblemBase(const InputParameters & params)
     _calc_kinetics_params(getParam<bool>("calc_kinetics_params")),
     _reset_seed(getParam<bool>("reset_seed")),
     _initial_seed(openmc::openmc_get_seed()),
-    _xml_directory(getParam<FileName>("xml_directory"))
+    _xml_directory(getParam<FileName>("xml_directory")),
+    _statepoint_directory(getParam<FileName>("statepoint_directory")),
+    _keep_transient_statepoint(getParam<bool>("keep_transient_statepoint"))
 {
   if (isParamValid("tally_type"))
     mooseError("The tally system used by OpenMCProblemBase derived classes has been deprecated. "
@@ -233,6 +246,22 @@ OpenMCProblemBase::OpenMCProblemBase(const InputParameters & params)
     catchOpenMCError(err, "set the number of batches");
   }
 
+  if (isParamSetByUser("statepoint_directory") && !_keep_transient_statepoint)
+  {
+    /// path_output must end with a "/", otherwise statepoint will not output correctly
+    openmc::settings::path_output = formattedOutputPath(_statepoint_directory);
+
+    /// Need to remove trailing "/" to do "is_regular_file"
+    std::filesystem::path p = openmc::settings::path_output;
+    p = p.filename().empty() ? p.parent_path() : p;
+
+    if (std::filesystem::is_regular_file(p))
+      mooseError("Cannot create directory " + openmc::settings::path_output +
+                 ", as a file with the same name already exists");
+
+    std::filesystem::create_directory(openmc::settings::path_output);
+  }
+
   // The OpenMC wrapping doesn't require material properties itself, but we might
   // define them on some blocks of the domain for other auxiliary kernel purposes
   setMaterialCoverageCheck(false);
@@ -375,6 +404,19 @@ OpenMCProblemBase::externalSolve()
   // update tallies as needed before starting the OpenMC run
   executeEditors();
 
+  if (_keep_transient_statepoint)
+  {
+    openmc::settings::path_output = transientStatepointPath();
+
+    /// Need to remove trailing "/" to do "is_regular_file"
+    std::filesystem::path p = openmc::settings::path_output;
+    p = p.filename().empty() ? p.parent_path() : p;
+    if (std::filesystem::is_regular_file(p))
+      mooseError("Cannot create directory " + openmc::settings::path_output +
+                 ", as a file with the same name already exists");
+    std::filesystem::create_directory(openmc::settings::path_output);
+  }
+
   if (_reset_seed)
   {
     openmc_hard_reset();
@@ -1030,4 +1072,66 @@ OpenMCProblemBase::sendNuclideDensitiesToOpenMC()
     uo->setValue();
 }
 
+const std::string
+OpenMCProblemBase::transientStatepointPath()
+{
+  if (!isTransient())
+  {
+    mooseWarning("keep_transient_statepoint is set to True, but selected Executioner is Steady. "
+                 "Keeping original statepoint path.");
+    return openmc::settings::path_output;
+  }
+
+  // Get path of current input file
+  std::filesystem::path running_path =
+      std::filesystem::absolute(getMooseApp().getLastInputFileName()).parent_path();
+
+  std::filesystem::path transient_statepoint_path;
+
+  // If user has not set statepoint_directory parameter, or has defined it as './',
+  // use a default
+  if (std::filesystem::weakly_canonical(_statepoint_directory) ==
+      std::filesystem::weakly_canonical(running_path))
+    transient_statepoint_path = "./statepoint_folder";
+  else
+  {
+    transient_statepoint_path = _statepoint_directory;
+
+    // Removes trailing "/" from transient_statepoint_path, if user has left any, ready to append
+    // suffix
+    transient_statepoint_path = transient_statepoint_path.filename().empty()
+                                    ? transient_statepoint_path.parent_path()
+                                    : transient_statepoint_path;
+  }
+
+  std::string timestep_suffix = "_ts_" + std::to_string(timeStep()) + "/";
+
+  transient_statepoint_path += timestep_suffix;
+
+  const std::string transient_statepoint_path_str =
+      formattedOutputPath(transient_statepoint_path.string());
+
+  return transient_statepoint_path_str;
+}
+
+const std::string
+OpenMCProblemBase::formattedOutputPath(const std::string & output_path)
+{
+  std::filesystem::path p = output_path;
+  p = p.lexically_normal();
+
+  if (p.is_relative())
+  {
+    std::filesystem::path input_file_path =
+        std::filesystem::absolute(getMooseApp().getLastInputFileName()).parent_path();
+
+    p = std::filesystem::weakly_canonical(input_file_path / p);
+  }
+
+  if (p.string().back() != '/')
+    p += "/";
+
+  return p.string();
+}
+
 #endif

test/tests/neutronics/openmc_statepoint/openmc_custom_dir.i

@@ -0,0 +1,27 @@
+[Mesh]
+  [sphere]
+    type = FileMeshGenerator
+    file = ../meshes/sphere.e
+  []
+[]
+
+[Problem]
+  type = OpenMCCellAverageProblem
+  statepoint_directory = "./custom_dir"
+  batches = 50 
+[]
+
+[Executioner]
+  type = Transient
+  num_steps = 1
+[]
+
+[Postprocessors]
+  [k]
+    type = KEigenvalue
+  []
+[]
+
+[Outputs]
+  csv = true
+[]

test/tests/neutronics/openmc_statepoint/openmc_custom_dir_filename.i

@@ -0,0 +1,27 @@
+[Mesh]
+  [sphere]
+    type = FileMeshGenerator
+    file = ../meshes/sphere.e
+  []
+[]
+
+[Problem]
+  type = OpenMCCellAverageProblem
+  statepoint_directory = "./existing_file"
+  batches = 50 
+[]
+
+[Executioner]
+  type = Transient
+  num_steps = 1
+[]
+
+[Postprocessors]
+  [k]
+    type = KEigenvalue
+  []
+[]
+
+[Outputs]
+  csv = true
+[]

test/tests/neutronics/openmc_statepoint/tests

@@ -14,4 +14,28 @@
                   "in settings.xml and they are both specified."
     capabilities = 'openmc'
   []
+
+  [check_statepoint_exists_in_directory]
+    type = CheckFiles
+    input = openmc_custom_dir.i
+    check_files = 'custom_dir/statepoint.50.h5'
+    # This test has very few particles, and OpenMC will error if there aren't enough source particles
+    # in the fission bank on a process
+    max_parallel = 8
+    requirement = "A statepoint file must be written to the parameter defined directory when the batches parameter matches the batches "
+                  "in settings.xml and they are both specified."
+    capabilities = 'openmc'
+  []
+
+
+  [check_statepoint_exists_in_directory_w_existing_filename]
+    type = RunException
+    input = openmc_custom_dir_filename.i
+    expect_err = 'a file with the same name already exists'
+    # This test has very few particles, and OpenMC will error if there aren't enough source particles
+    # in the fission bank on a process
+    max_parallel = 8
+    requirement = "The user defined directory has the same name as an existing file. Expect test to throw due to attempting to create directory with the same name as the file."
+    capabilities = 'openmc'
+  []
 []

test/tests/neutronics/openmc_statepoint_transient/geometry.xml

@@ -0,0 +1,16 @@
+<?xml version='1.0' encoding='utf-8'?>
+<geometry>
+  <cell id="1" material="1" region="-1" universe="1" />
+  <cell id="2" material="2" region="-2" universe="1" />
+  <cell id="3" material="3" region="-3" universe="1" />
+  <cell id="4" material="4" region="1 2 3 4 -5 6 -7 8 -9" universe="1" />
+  <surface coeffs="0.0 0.0 0.0 1.5" id="1" type="sphere" />
+  <surface coeffs="0.0 0.0 4.0 1.5" id="2" type="sphere" />
+  <surface coeffs="0.0 0.0 8.0 1.5" id="3" type="sphere" />
+  <surface boundary="reflective" coeffs="-2.5" id="4" name="minimum x" type="x-plane" />
+  <surface boundary="reflective" coeffs="2.5" id="5" name="maximum x" type="x-plane" />
+  <surface boundary="reflective" coeffs="-2.5" id="6" name="minimum y" type="y-plane" />
+  <surface boundary="reflective" coeffs="2.5" id="7" name="maximum y" type="y-plane" />
+  <surface boundary="reflective" coeffs="-2.0" id="8" type="z-plane" />
+  <surface boundary="reflective" coeffs="10.0" id="9" type="z-plane" />
+</geometry>

test/tests/neutronics/openmc_statepoint_transient/materials.xml

@@ -0,0 +1,40 @@
+<?xml version='1.0' encoding='utf-8'?>
+<materials>
+  <material depletable="true" id="1">
+    <density units="g/cc" value="10.0" />
+    <nuclide ao="9.051308944870946e-05" name="U234" />
+    <nuclide ao="0.010126612654073502" name="U235" />
+    <nuclide ao="0.9897364895065476" name="U238" />
+    <nuclide ao="4.63847499302226e-05" name="U236" />
+    <nuclide ao="1.999242" name="O16" />
+    <nuclide ao="0.000758" name="O17" />
+  </material>
+  <material depletable="true" id="2">
+    <density units="g/cc" value="10.0" />
+    <nuclide ao="0.0004523305496680539" name="U234" />
+    <nuclide ao="0.05060678290832386" name="U235" />
+    <nuclide ao="0.948709083169038" name="U238" />
+    <nuclide ao="0.00023180337297007338" name="U236" />
+    <nuclide ao="1.999242" name="O16" />
+    <nuclide ao="0.000758" name="O17" />
+  </material>
+  <material depletable="true" id="3">
+    <density units="g/cc" value="10.0" />
+    <nuclide ao="0.0009040745407538578" name="U234" />
+    <nuclide ao="0.10114794158928406" name="U235" />
+    <nuclide ao="0.8974846777145036" name="U238" />
+    <nuclide ao="0.00046330615545845175" name="U236" />
+    <nuclide ao="1.999242" name="O16" />
+    <nuclide ao="0.000758" name="O17" />
+  </material>
+  <material depletable="true" id="4">
+    <density units="g/cc" value="1.0" />
+    <nuclide ao="1.99968852" name="H1" />
+    <nuclide ao="0.00031148" name="H2" />
+    <nuclide ao="0.999621" name="O16" />
+    <nuclide ao="0.000379" name="O17" />
+    <nuclide ao="5.4e-05" name="U234" />
+    <nuclide ao="0.007204" name="U235" />
+    <nuclide ao="0.992742" name="U238" />
+  </material>
+</materials>

test/tests/neutronics/openmc_statepoint_transient/openmc.i

@@ -0,0 +1,27 @@
+[Mesh]
+  [sphere]
+    type = FileMeshGenerator
+    file = ../meshes/sphere.e
+  []
+[]
+
+[Problem]
+  type = OpenMCCellAverageProblem
+  keep_transient_statepoint = true
+  batches = 50 
+[]
+
+[Executioner]
+  type = Transient
+  num_steps = 2 
+[]
+
+[Postprocessors]
+  [k]
+    type = KEigenvalue
+  []
+[]
+
+[Outputs]
+  csv = true
+[]

test/tests/neutronics/openmc_statepoint_transient/openmc_user_dir.i

@@ -0,0 +1,28 @@
+[Mesh]
+  [sphere]
+    type = FileMeshGenerator
+    file = ../meshes/sphere.e
+  []
+[]
+
+[Problem]
+  type = OpenMCCellAverageProblem
+  keep_transient_statepoint = true
+  statepoint_directory = "./mystatepoints/"
+  batches = 50
+[]
+
+[Executioner]
+  type = Transient
+  num_steps = 2 
+[]
+
+[Postprocessors]
+  [k]
+    type = KEigenvalue
+  []
+[]
+
+[Outputs]
+  csv = true
+[]

test/tests/neutronics/openmc_statepoint_transient/settings.xml

@@ -0,0 +1,16 @@
+<?xml version='1.0' encoding='utf-8'?>
+<settings>
+  <run_mode>eigenvalue</run_mode>
+  <particles>100</particles>
+  <batches>50</batches>
+  <inactive>10</inactive>
+  <source strength="1.0">
+    <space type="fission">
+      <parameters>-5.0 -5.0 0 5.0 5.0 12.0</parameters>
+    </space>
+  </source>
+  <temperature_default>600.0</temperature_default>
+  <temperature_method>nearest</temperature_method>
+  <temperature_multipole>false</temperature_multipole>
+  <temperature_range>294.0 1600.0</temperature_range>
+</settings>