From 0bf2d0c4a9559561fc63c458d779946f0d759cb1 Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Fri, 9 Nov 2018 07:56:14 -0600
Subject: [PATCH] Make sure Tally % n_realizations is available on all ranks

---
 src/tallies/tally.F90        | 10 +++++-----
 src/tallies/tally_header.F90 | 36 +++++++++++++++++++-----------------
 2 files changed, 24 insertions(+), 22 deletions(-)

diff --git a/src/tallies/tally.F90 b/src/tallies/tally.F90
index 475c6a60c7..b82837ea1e 100644
--- a/src/tallies/tally.F90
+++ b/src/tallies/tally.F90
@@ -3792,11 +3792,6 @@ contains
 
     ! Accumulate on master only unless run is not reduced then do it on all
     if (master .or. (.not. reduce_tallies)) then
-      ! Accumulate results for each tally
-      do i = 1, active_tallies % size()
-        call tallies(active_tallies % data(i)) % obj % accumulate()
-      end do
-
       if (run_mode == MODE_EIGENVALUE) then
         if (current_batch > n_inactive) then
           ! Accumulate products of different estimators of k
@@ -3820,6 +3815,11 @@ contains
       end do
     end if
 
+    ! Accumulate results for each tally
+    do i = 1, active_tallies % size()
+      call tallies(active_tallies % data(i)) % obj % accumulate()
+    end do
+
   end subroutine accumulate_tallies
 
 !===============================================================================
diff --git a/src/tallies/tally_header.F90 b/src/tallies/tally_header.F90
index 08d3588a5a..f2339d85d5 100644
--- a/src/tallies/tally_header.F90
+++ b/src/tallies/tally_header.F90
@@ -6,7 +6,7 @@ module tally_header
   use error
   use dict_header,         only: DictIntInt
   use hdf5_interface,      only: HID_T, HSIZE_T
-  use message_passing,     only: n_procs
+  use message_passing,     only: n_procs, master
   use nuclide_header,      only: nuclide_dict
   use settings,            only: reduce_tallies, run_mode
   use stl_vector,          only: VectorInt
@@ -182,25 +182,27 @@ contains
       this % n_realizations = this % n_realizations + n_procs
     end if
 
-    ! Calculate total source strength for normalization
-    if (run_mode == MODE_FIXEDSOURCE) then
-      total_source = total_source_strength()
-    else
-      total_source = ONE
-    end if
+    if (master .or. (.not. reduce_tallies)) then
+      ! Calculate total source strength for normalization
+      if (run_mode == MODE_FIXEDSOURCE) then
+        total_source = total_source_strength()
+      else
+        total_source = ONE
+      end if
 
-    ! Accumulate each result
-    do j = 1, size(this % results, 3)
-      do i = 1, size(this % results, 2)
-        val = this % results(RESULT_VALUE, i, j)/total_weight * total_source
-        this % results(RESULT_VALUE, i, j) = ZERO
+      ! Accumulate each result
+      do j = 1, size(this % results, 3)
+        do i = 1, size(this % results, 2)
+          val = this % results(RESULT_VALUE, i, j)/total_weight * total_source
+          this % results(RESULT_VALUE, i, j) = ZERO
 
-        this % results(RESULT_SUM, i, j) = &
-             this % results(RESULT_SUM, i, j) + val
-        this % results(RESULT_SUM_SQ, i, j) = &
-             this % results(RESULT_SUM_SQ, i, j) + val*val
+          this % results(RESULT_SUM, i, j) = &
+              this % results(RESULT_SUM, i, j) + val
+          this % results(RESULT_SUM_SQ, i, j) = &
+              this % results(RESULT_SUM_SQ, i, j) + val*val
+        end do
       end do
-    end do
+    end if
   end subroutine tally_accumulate
 
   subroutine tally_write_results_hdf5(this, group_id)