diff --git a/example/SimpleReactor.cxx b/example/SimpleReactor.cxx
index b297637ff09cfd12e3f14b616fc46126e6cfb9c3..0bfff8bc463d285859df0228d559c872ab43c085 100644
--- a/example/SimpleReactor.cxx
+++ b/example/SimpleReactor.cxx
@@ -1,3 +1,16 @@
+/*************************************************/
+//              DESCRIPTION
+// Simple scenario :
+// This park is constituted by a simple PWR UOX
+// Reactor and a Storage.
+//   _______     _______
+//  |       |   |       |
+//  |Reactor| =>|Storage|
+//  |_______|   |_______|
+//
+// The spent fuel goes to a Storage
+//The scenario is run for 40 years
+/*************************************************/
 #include "CLASSHeaders.hxx"
 #include <sstream>
 #include <iomanip>