resove #820

armi/reactor/blueprints/tests/test_blockBlueprints.py

@@ -321,9 +321,6 @@ def test_explicitFlags(self):
 
     # TODO: This test passes, but shouldn't.
     def test_densityConsistentWithComponentConstructor(self):
-        # when comparing to 3D density, the comparison is not quite correct.
-        # We need a bigger delta, this will be investigated/fixed in another PR
-        biggerDelta = 0.001  # g/cc
         a1 = self.blueprints.assemDesigns.bySpecifier["IC"].construct(
             self.cs, self.blueprints
         )
@@ -336,7 +333,6 @@ def test_densityConsistentWithComponentConstructor(self):
         self.assertAlmostEqual(
             clad.getMassDensity(),
             clad.material.density3(Tc=clad.temperatureInC),
-            delta=biggerDelta,
         )
 
         self.assertAlmostEqual(

armi/reactor/components/component.py

@@ -232,27 +232,11 @@ def __init__(
         self.temperatureInC = Thot
         self.material = None
         self.setProperties(material)
-        self.tInputWarning(Tinput)
         self.applyMaterialMassFracsToNumberDensities()  # not necessary when duplicating...
         self.setType(name)
         self.p.mergeWith = mergeWith
         self.p.customIsotopicsName = isotopics
 
-    def tInputWarning(self, Tinput):
-        """
-        Check whether thermal expansion factor is 0.0% exactly at T=Tinput
-        """
-        expansionFactor = (
-            self.material.linearExpansionPercent(Tc=self.inputTemperatureInC) / 100.0
-        )
-        if not (abs(expansionFactor) < 1.0e-6):
-            runLog.warning(
-                f"Thermal expansion for {self.material} at Tinput = {Tinput} is non-zero "
-                f"({expansionFactor}). The modeled density for this material will be off "
-                f"by a factor of {(1 + expansionFactor) ** 2}.",
-                single=True,
-            )
-
     @property
     def temperatureInC(self):
         """Return the hot temperature in Celsius."""
@@ -360,14 +344,15 @@ def applyMaterialMassFracsToNumberDensities(self):
         """
         # note, that this is not the actual material density, but rather 2D expanded
         # `density3` is 3D density
+        # call getProperty to cache and improve speed
         density = self.material.getProperty("density", Tc=self.temperatureInC)
 
         self.p.numberDensities = densityTools.getNDensFromMasses(
             density, self.material.p.massFrac
         )
-        self.applyHotHeightDensityReduction()
+        self.applyHotHeightDensityReduction(initialColdMaterialExpansion=True)
 
-    def applyHotHeightDensityReduction(self):
+    def applyHotHeightDensityReduction(self, initialColdMaterialExpansion=False):
         """
         Adjust number densities to account for hot block heights (axial expansion)
         (crucial for preserving 3D density).
@@ -382,13 +367,24 @@ def applyHotHeightDensityReduction(self):
         --------
         self.applyMaterialMassFracsToNumberDensities
         """
-        # this is the same as getThermalExpansionFactor but doesn't fail
-        # on non-fluid materials that have 0 or undefined thermal expansion
-        # (we don't want materials to fail on  __init__ which calls this)
-        axialExpansionFactor = 1.0 + self.material.linearExpansionFactor(
-            self.temperatureInC, self.inputTemperatureInC
-        )
-        self.changeNDensByFactor(1.0 / axialExpansionFactor)
+        if initialColdMaterialExpansion:
+            # material needs to be expanded from the material's cold temp to hot,
+            # not components cold temp, so we don't use mat.linearExpansionFactor or
+            # component.getThermalExpansionFactor.
+            # materials don't typically define the temperature for which their ref dens
+            # is defined so linearExpansionPercent must be called
+            coldMatAxialExpansionFactor = (
+                1.0 + self.material.linearExpansionPercent(Tc=self.temperatureInC) / 100
+            )
+            self.changeNDensByFactor(1.0 / coldMatAxialExpansionFactor)
+        else:
+            # this is the same as getThermalExpansionFactor but doesn't fail
+            # on non-fluid materials that have 0 or undefined thermal expansion
+            # (we don't want materials to fail on  __init__ which calls this)
+            # axialExpansionFactor = 1.0 + self.material.linearExpansionFactor(
+            #     self.temperatureInC, self.inputTemperatureInC
+            # )
+            self.changeNDensByFactor(1.0 / self.getThermalExpansionFactor())
 
     def getProperties(self):
         """Return the active Material object defining thermo-mechanical properties."""

armi/reactor/tests/test_components.py

@@ -499,7 +499,6 @@ def test_changeNumberDensities(self):
 class TestComponentExpansion(unittest.TestCase):
     # when comparing to 3D density, the comparison is not quite correct.
     # We need a bigger delta, this will be investigated/fixed in another PR
-    biggerDelta = 0.01  # g/cc
     tWarm = 50
     tHot = 500
 
@@ -547,15 +546,16 @@ def test_ExpansionConservationHotHeightDefined(self):
                 circle.getMassDensity(),
                 circle.material.density(Tc=circle.temperatureInC),
             )
-            # 2D density is off by the thermal exp factor
+            # 2D density is off by the material thermal exp factor
+            percent = circle.material.linearExpansionPercent(Tc=circle.temperatureInC)
+            thermalExpansionFactorFromColdMatTemp = 1 + percent / 100
             self.assertAlmostEqual(
-                circle.getMassDensity() * circle.getThermalExpansionFactor(),
+                circle.getMassDensity() * thermalExpansionFactorFromColdMatTemp,
                 circle.material.density(Tc=circle.temperatureInC),
             )
             self.assertAlmostEqual(
                 circle.getMassDensity(),
                 circle.material.density3(Tc=circle.temperatureInC),
-                delta=self.biggerDelta,
             )
         # Change temp forward and backward and show equal
         oldArea = circle1.getArea()
@@ -604,7 +604,6 @@ def test_ExpansionConservationHotHeightDefined(self):
         self.assertAlmostEqual(
             circle1.getMassDensity(),
             circle1.material.density3(Tc=circle2.temperatureInC),
-            delta=self.biggerDelta,
         )
         # change back to old temp
         circle1.changeNDensByFactor(circle1.getThermalExpansionFactor())
@@ -650,7 +649,6 @@ def test_ExpansionConservationColdHeightDefined(self):
             self.assertAlmostEqual(
                 circle.getMassDensity(),
                 circle.material.density3(Tc=circle.temperatureInC),
-                delta=self.biggerDelta,
             )
             # total mass consistent between hot and cold
             # Hot height will be taller
@@ -660,7 +658,6 @@ def test_ExpansionConservationColdHeightDefined(self):
                 * circle.getArea(cold=True)
                 * circle.material.density3(Tc=circle.inputTemperatureInC),
                 hotHeight * circle.getArea() * circle.getMassDensity(),
-                delta=self.biggerDelta,
             )