diff --git a/armi/reactor/blueprints/__init__.py b/armi/reactor/blueprints/__init__.py
index 3633c0bcd..36d1d33c7 100644
--- a/armi/reactor/blueprints/__init__.py
+++ b/armi/reactor/blueprints/__init__.py
@@ -92,9 +92,6 @@
 from armi.scripts import migration
 from armi.utils import textProcessors
 
-from armi.reactor.converters.axialExpansionChanger import AxialExpansionChanger
-from armi.reactor.flags import Flags
-
 # NOTE: using non-ARMI-standard imports because these are all a part of this package,
 # and using the module imports would make the attribute definitions extremely long
 # without adding detail
@@ -300,7 +297,6 @@ def _prepConstruction(self, cs):
 
         This method should not be called directly, but it is used in testing.
         """
-        axialExpChngr = AxialExpansionChanger(cs["detailedAxialExpansion"])
         if not self._prepped:
             self._assignTypeNums()
             for func in self._resolveFunctions:
@@ -311,11 +307,6 @@ def _prepConstruction(self, cs):
 
             for aDesign in self.assemDesigns:
                 a = aDesign.construct(cs, self)
-                if not cs["inputHeightsConsideredHot"]:
-                    if not a.hasFlags(Flags.CONTROL):
-                        axialExpChngr.setAssembly(a)
-                        axialExpChngr.expansionData.computeThermalExpansionFactors()
-                        axialExpChngr.axiallyExpandAssembly(thermal=True)
                 self._assembliesBySpecifier[aDesign.specifier] = a
                 self.assemblies[aDesign.name] = a
 
diff --git a/armi/reactor/reactors.py b/armi/reactor/reactors.py
index d7bb47f6b..46288a571 100644
--- a/armi/reactor/reactors.py
+++ b/armi/reactor/reactors.py
@@ -55,6 +55,7 @@
 from armi.utils import directoryChangers
 from armi.utils.iterables import Sequence
 from armi.utils.mathematics import average1DWithinTolerance
+from armi.reactor.converters.axialExpansionChanger import AxialExpansionChanger
 
 # init logger
 runLog = logging.getLogger(__name__)
@@ -2235,6 +2236,17 @@ def processLoading(self, cs):
         updateAxialMesh : Perturbs the axial mesh originally set up here.
 
         """
+        if not cs["inputHeightsConsideredHot"]:
+            runLog.header(
+                "=========== Axially expanding all (except control) assemblies from Tinput to Thot ==========="
+            )
+            axialExpChngr = AxialExpansionChanger(cs["detailedAxialExpansion"])
+            for a in self.getAssemblies(includeAll=True):
+                if not a.hasFlags(Flags.CONTROL):
+                    axialExpChngr.setAssembly(a)
+                    axialExpChngr.expansionData.computeThermalExpansionFactors()
+                    axialExpChngr.axiallyExpandAssembly(thermal=True)
+
         runLog.header(
             "=========== Initializing Mesh, Assembly Zones, and Nuclide Categories =========== "
         )