From b3236e434fd1dafee91a8547c9acef22fab64d91 Mon Sep 17 00:00:00 2001
From: Bryan Herman <bherman@mit.edu>
Date: Sun, 2 Mar 2014 19:42:15 -0500
Subject: [PATCH] added fix neutron balance option

---
 src/cmfd_input.F90 | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/cmfd_input.F90 b/src/cmfd_input.F90
index 3309d2d130..4ef30f231f 100644
--- a/src/cmfd_input.F90
+++ b/src/cmfd_input.F90
@@ -172,7 +172,7 @@ contains
         cmfd_downscatter = .true.
     end if
 
-    ! Run an adjoint calc
+    ! Reset dhat parameters 
     if (check_for_node(doc, "dhat_reset")) then
       call get_node_value(doc, "dhat_reset", temp_str)
       call lower_case(temp_str)
@@ -180,6 +180,14 @@ contains
         dhat_reset = .true.
     end if
 
+    ! Enforce perfect neutorn balance
+    if (check_for_node(doc, "balance")) then
+      call get_node_value(doc, "balance", temp_str)
+      call lower_case(temp_str)
+      if (trim(temp_str) == 'true' .or. trim(temp_str) == '1') &
+        cmfd_fix_balance = .true.
+    end if
+
     ! Set the solver type
     if (check_for_node(doc, "solver")) &
       call get_node_value(doc, "solver", cmfd_solver_type)