Add check that cell added for pellet region has fissile material. Refs …

…enrico-dev#55

include/enrico/cell_instance.h

@@ -38,6 +38,10 @@ class CellInstance {
   //! \return cell density in [g/cm^3]
   double get_density() const;
 
+  //! Check if the cell is fissionable
+  //! \return whether the cell contains fissionable material
+  bool is_fissionable() const;
+
   //! Check for equality
   bool operator==(const CellInstance& other) const;
 

src/cell_instance.cpp

@@ -60,6 +60,13 @@ double CellInstance::get_density() const
   return rho;
 }
 
+bool CellInstance::is_fissionable() const
+{
+  bool fissionable;
+  err_chk(openmc_material_get_fissionable(material_index_, &fissionable));
+  return fissionable;
+}
+
 bool CellInstance::operator==(const CellInstance& other) const
 {
   return index_ == other.index_ && instance_ == other.instance_;

src/openmc_heat_driver.cpp

@@ -89,6 +89,19 @@ void OpenmcHeatDriver::init_mappings()
             tracked[c] = openmc_driver_->cells_.size() - 1;
           }
 
+          // ensure that the cell being mapped for the pellet region contains
+          // a fissionable material as a way to check that the T/H geometry of the
+          // pellet region is sufficiently refined to account for all OpenMC cells.
+          // This check does not ensure that we have accounted for
+          // _all_ fissionable cells, just that the models line up in the pellet region,
+          // from which we can infer that the general geometry lines up (because otherwise
+          // we could be mapping fluid cells to the surrogate pins, etc.)
+          if (k < heat_driver_->n_fuel_rings_) {
+            Ensures(c.is_fissionable());
+          } else {
+             Ensures(!c.is_fissionable());
+          }
+
           // Map OpenMC material to ring and vice versa
           int32_t array_index = tracked[c];
           cell_inst_to_ring_[array_index].push_back(ring_index);