Control rod assembly parameter renames (#686)

* Control rod parameter renames from `crStartingElevation` and
`crEndingElevation` to `crWithdrawnElevation` and `crInsertedElevation`
for clarity in modeling.

armi/reactor/assemblyParameters.py

@@ -196,9 +196,12 @@ def detailedNDens(self, value):
         )
 
         pb.defParam(
-            "crEndingElevation",
+            "crInsertedElevation",
             units="cm",
-            description="The final elevation of the bottom of the control material when fully inserted.",
+            description=(
+                "The final elevation of the bottom of the control material when fully inserted. Note that this should "
+                "be considered a lower elevation than the ``crWithdrawnElevation`` by definition and modeling semantics."
+            ),
             categories=[parameters.Category.assignInBlueprints],
             saveToDB=True,
         )
@@ -211,9 +214,12 @@ def detailedNDens(self, value):
         )
 
         pb.defParam(
-            "crStartingElevation",
+            "crWithdrawnElevation",
             units="cm",
-            description="The initial starting elevation of the moveable section of a control rod assembly when fully withdrawn.",
+            description=(
+                "The initial starting elevation of the moveable section of a control rod assembly when fully withdrawn.  Note that this should "
+                "be considered a higher elevation than the ``crInsertedElevation`` by definition and modeling semantics."
+            ),
             categories=[parameters.Category.assignInBlueprints],
             saveToDB=True,
         )

doc/release/0.2.rst

@@ -14,6 +14,7 @@ What's new in ARMI
 #. Minor code re-org, moving math utilities into their own module.
 #. Removed the ``PyYaml`` dependency.
 #. Removed all bare ``import armi`` statements, for code clarity.
+#. Renamed control rod assembly parameters for generic implementations of control rod handling.
 #. TBD
 
 Bug fixes