diff --git a/model/cartesian_grid/pvd_mod.f b/model/cartesian_grid/pvd_mod.f
index aeb71898e..3cec2dc4a 100644
--- a/model/cartesian_grid/pvd_mod.f
+++ b/model/cartesian_grid/pvd_mod.f
@@ -45,7 +45,7 @@ CONTAINS
          IF(RUN_TYPE == 'NEW'.OR.RUN_TYPE=='RESTART_2')THEN
 ! For a new or RESTART_2 run, the pvd file should not exist, and is created with appropriate header
             IF (.NOT.PVD_EXISTS) THEN
-               OPEN(UNIT = UNIT_PVD, FILE = TRIM(PVD_FILENAME))
+               OPEN(UNIT = UNIT_PVD, FILE = TRIM(PVD_FILENAME),ACTION='READWRITE')
                WRITE(UNIT_PVD,100) '<?xml version="1.0"?>'
                WRITE(UNIT_PVD,100) '<VTKFile type="Collection" version="0.1" byte_order="BigEndian">' 
                WRITE(UNIT_PVD,100) '<Collection>'
@@ -58,14 +58,14 @@ CONTAINS
 ! For a restart_1 run, if the pvd file does not exist, create it
 ! (It must be a new vtk region)
             IF (.NOT.PVD_EXISTS) THEN
-               OPEN(UNIT = UNIT_PVD, FILE = TRIM(PVD_FILENAME))
+               OPEN(UNIT = UNIT_PVD, FILE = TRIM(PVD_FILENAME),ACTION='READWRITE')
                WRITE(UNIT_PVD,100) '<?xml version="1.0"?>'
                WRITE(UNIT_PVD,100) '<VTKFile type="Collection" version="0.1" byte_order="BigEndian">'
                WRITE(UNIT_PVD,100) '<Collection>'
                PVD_FILE_INITIALIZED(VTK_REGION)=.TRUE.
             ELSE
 ! If it already exists, go to the bottom of the file and prepare to append data (remove last two lines)
-               OPEN(UNIT=UNIT_PVD,FILE = TRIM(PVD_FILENAME),POSITION="APPEND",STATUS='OLD')
+               OPEN(UNIT=UNIT_PVD,FILE = TRIM(PVD_FILENAME),POSITION="APPEND",STATUS='OLD',ACTION='READWRITE')
                BACKSPACE(UNIT_PVD)
                BACKSPACE(UNIT_PVD)
                PVD_FILE_INITIALIZED(VTK_REGION)=.TRUE.
@@ -74,7 +74,7 @@ CONTAINS
       ELSE
 ! When properly initialized, open the file and go to the
 ! bottom of the file and prepare to append data (remove last two lines)
-         OPEN(UNIT=UNIT_PVD,FILE = TRIM(PVD_FILENAME),POSITION="APPEND",STATUS='OLD')
+         OPEN(UNIT=UNIT_PVD,FILE = TRIM(PVD_FILENAME),POSITION="APPEND",STATUS='OLD',ACTION='READWRITE')
          BACKSPACE(UNIT_PVD)
          BACKSPACE(UNIT_PVD)
       ENDIF
diff --git a/model/des/vtp_mod.f b/model/des/vtp_mod.f
index 3f36225b7..51251c48c 100644
--- a/model/des/vtp_mod.f
+++ b/model/des/vtp_mod.f
@@ -462,7 +462,7 @@ CONTAINS
                IF(EXISTS_PVD) THEN
                   IER = 1
                ELSE
-                  OPEN(UNIT=UNIT_PVD,FILE=FNAME_PVD,STATUS='NEW')
+                  OPEN(UNIT=UNIT_PVD,FILE=FNAME_PVD,STATUS='NEW',ACTION='READWRITE')
                   WRITE(UNIT_PVD,"(A)")'<?xml version="1.0"?>'
                   WRITE(UNIT_PVD,"(A)")'<VTKFile type="Collection" &
                      &version="0.1" byte_order="BigEndian">'
@@ -474,8 +474,7 @@ CONTAINS
             ELSE ! a restart run
                IF(EXISTS_PVD) THEN
 ! Open the file at the beginning.
-                  OPEN(UNIT=UNIT_PVD,FILE=FNAME_PVD,&
-                     POSITION="REWIND",STATUS='OLD',IOSTAT=IOS)
+                  OPEN(UNIT=UNIT_PVD,FILE=FNAME_PVD,POSITION="REWIND",STATUS='OLD',IOSTAT=IOS,ACTION='READWRITE')
                   IF(IOS /= 0) IER = 2
                ELSE ! a pvd file does not exist
                   IER = 3
@@ -518,8 +517,7 @@ CONTAINS
             ENDIF ! run_type new or restart
 
          ELSE ! not FIRST_PASS
-            OPEN(UNIT=UNIT_PVD,FILE=FNAME_PVD,&
-               POSITION="APPEND",STATUS='OLD',IOSTAT=IOS)
+            OPEN(UNIT=UNIT_PVD,FILE=FNAME_PVD,POSITION="APPEND",STATUS='OLD',IOSTAT=IOS,ACTION='READWRITE')
             IF (IOS /= 0) IER = 2
          ENDIF