diff --git a/example/Example_MultiplicativeError.cxx b/example/Example_MultiplicativeError.cxx
index 3a68b58507fc4d4e9a6998ea01f223ccfe5723b8..aab7c542aee3e9d5ba962c54d008d0056f8d5fdd 100644
--- a/example/Example_MultiplicativeError.cxx
+++ b/example/Example_MultiplicativeError.cxx
@@ -106,7 +106,7 @@ int main(int argc, char** argv)
 	//##########################################################################################
 
 	int Std_output_level 	= 0;
-	int File_output_level 	= 0;
+	int File_output_level 	= 2;
 	CLASSLogger *Logger 	= new CLASSLogger("CLASS_OUTPUT.log",Std_output_level,File_output_level);
 
 	//##########################################################################################
diff --git a/source/src/Reactor.cxx b/source/src/Reactor.cxx
index fca30b948c8964044bbcc4d3e091be572b67c6ab..b12af0d8c588545a0a09dc3c854a94461a931203 100644
--- a/source/src/Reactor.cxx
+++ b/source/src/Reactor.cxx
@@ -542,7 +542,10 @@ void Reactor::Dump() {
     {
 			//here change fInsideIV
 			if(fIVMultiplicativeError.GetZAIQuantity()>0){
+				double MassOfIVbeforeError=fInsideIV.GetTotalMass();
 				fInsideIV=fInsideIV+fIVMultiplicativeError*fInsideIV-fIVMultiplicativeError_with1s*fInsideIV;
+				double MassOfIVafterError=fInsideIV.GetTotalMass();
+    			WARNING << " Taking into account multiplicative error on IV leaving the reactor lead to a change of the mass of the fuel :"<< MassOfIVafterError-MassOfIVbeforeError<<" tons"<< endl;		
 			}
       fOutBackEndFacility->AddIV(fInsideIV);
       AddCumulativeIVOut(fInsideIV);
@@ -553,7 +556,10 @@ void Reactor::Dump() {
   {
 			//here change fIVOutCycle
 		if(fIVMultiplicativeError.GetZAIQuantity()>0){
+			double MassOfIVbeforeError=fInsideIV.GetTotalMass();
 			fIVOutCycle=fIVOutCycle+fIVMultiplicativeError*fIVOutCycle-fIVMultiplicativeError_with1s*fIVOutCycle;
+			double MassOfIVafterError=fInsideIV.GetTotalMass();
+    		WARNING << " Taking into account multiplicative error on IV leaving the reactor lead to a change of the mass of the fuel :"<< MassOfIVafterError-MassOfIVbeforeError<<" tons"<< endl;		
 		}
     fOutBackEndFacility->AddIV(fIVOutCycle);
     AddCumulativeIVOut(fIVOutCycle);
@@ -564,7 +570,10 @@ void Reactor::Dump() {
   {
 		//here change fInsideIV
 		if(fIVMultiplicativeError.GetZAIQuantity()>0){
+			double MassOfIVbeforeError=fInsideIV.GetTotalMass();		
 			fInsideIV=fInsideIV+fIVMultiplicativeError*fInsideIV-fIVMultiplicativeError_with1s*fInsideIV;
+			double MassOfIVafterError=fInsideIV.GetTotalMass();
+   			WARNING << " Taking into account multiplicative error on IV leaving the reactor lead to a change of the mass of the fuel :"<< MassOfIVafterError-MassOfIVbeforeError<<" tons"<< endl;		
 		}
     fOutBackEndFacility->AddIV(fInsideIV);
     AddCumulativeIVOut(fInsideIV);