Found a few more leaks in ACE when doing the pincell problem (with many more nuclides), they are all fixed now.

examples/basic/materials.xml

@@ -5,7 +5,10 @@
 
   <material id="40">
     <density value="4.5" units="g/cc" />
+<!--
     <nuclide name="U-235" ao="1.0" />
+-->
+     <nuclide name="Pu-240" ao="1.0" />
   </material>
 
   <material id="41">

examples/pincell/settings.xml

@@ -3,9 +3,9 @@
 
   <!-- Define how many particles to run and for how many batches -->
   <eigenvalue>
-    <batches>100</batches>
-    <inactive>10</inactive>
-    <particles>1000</particles>
+    <batches>5</batches>
+    <inactive>2</inactive>
+    <particles>100</particles>
   </eigenvalue>
 
   <!-- The starting source is a uniform distribution over the entire pin
@@ -29,4 +29,4 @@
     <dimension>10 10 1</dimension>
   </entropy>
 
-</settings>
+</settings>

src/ace_header.F90

@@ -267,7 +267,7 @@ module ace_header
       if (associated(this % next)) then
         ! recursively clear this item
         call this % next % clear()
-        nullify(this % next)
+        deallocate(this % next)
       end if
       
     end subroutine DistEnergy_clear
@@ -348,7 +348,7 @@ module ace_header
       
       if (associated(this % urr_data)) &
         call this % urr_data % clear()
-        nullify(this % urr_data)
+        deallocate(this % urr_data)
         
       if (associated(this % reactions)) then
         do i = 1, size(this % reactions)