diff --git a/AmpTools/IUAmpTools/NormIntInterface.h b/AmpTools/IUAmpTools/NormIntInterface.h
index d702f155..07e028d0 100644
--- a/AmpTools/IUAmpTools/NormIntInterface.h
+++ b/AmpTools/IUAmpTools/NormIntInterface.h
@@ -91,7 +91,6 @@ class NormIntInterface
   
   void invalidateTerms();
 
-  // needs different implementations in MPI so make virtual
   virtual void loadMC() const;
 
 #endif
diff --git a/AmpTools/IUAmpToolsMPI/AmpToolsInterfaceMPI.cc b/AmpTools/IUAmpToolsMPI/AmpToolsInterfaceMPI.cc
index 91ee339c..28f69543 100644
--- a/AmpTools/IUAmpToolsMPI/AmpToolsInterfaceMPI.cc
+++ b/AmpTools/IUAmpToolsMPI/AmpToolsInterfaceMPI.cc
@@ -123,6 +123,8 @@ AmpToolsInterfaceMPI::AmpToolsInterfaceMPI(ConfigurationInfo* configurationInfo)
     NormIntInterface* normInt = NULL;
     if (genMCRdr && accMCRdr && intenMan && !(reaction->normIntFileInput())){
       normInt = new NormIntInterfaceMPI(genMCRdr, accMCRdr, *intenMan);
+      // no need to call loadMC() here because the constructor of 
+      // NormIntInterfaceMPI calls it through setupMPI()
       m_normIntMap[reactionName] = normInt;
       if (reaction->normIntFile() == "")
 	report( WARNING, kModule ) << "no name given to NormInt file for reaction "
diff --git a/AmpTools/IUAmpToolsMPI/NormIntInterfaceMPI.cc b/AmpTools/IUAmpToolsMPI/NormIntInterfaceMPI.cc
index a998f1b5..70a9b911 100644
--- a/AmpTools/IUAmpToolsMPI/NormIntInterfaceMPI.cc
+++ b/AmpTools/IUAmpToolsMPI/NormIntInterfaceMPI.cc
@@ -130,6 +130,8 @@ NormIntInterfaceMPI::setupMPI()
     
     // load the MC into CPU memory on the follower nodes -- this is effectively
     // a copy from the DataReaderMPI cache to the AmpVecs structure
+    // and it is only run on the followers to avoid large memory
+    // usage on the lead node
     loadMC();
 
     long int thisEvents;
@@ -203,9 +205,10 @@ NormIntInterfaceMPI::sumIntegrals( IntType type ) const
 }
 
 void
-NormIntInterfaceMPI::loadMC() const
-{
-  // avoids large memory allocations on the lead node
+NormIntInterfaceMPI::loadMC() const{
+ 
+  // do not load MC on the leader node 
+  // only the followers need the MC
   if( !m_isLeader ) NormIntInterface::loadMC();
 }
 
diff --git a/AmpTools/IUAmpToolsMPI/NormIntInterfaceMPI.h b/AmpTools/IUAmpToolsMPI/NormIntInterfaceMPI.h
index 3f450586..067c047f 100644
--- a/AmpTools/IUAmpToolsMPI/NormIntInterfaceMPI.h
+++ b/AmpTools/IUAmpToolsMPI/NormIntInterfaceMPI.h
@@ -59,7 +59,7 @@ class NormIntInterfaceMPI : public NormIntInterface
   void forceCacheUpdate( bool normIntOnly = false ) const;
 
   void loadMC() const;
-  
+
 private:
   
   void setupMPI();