diff --git a/sirepo/package_data/static/css/vtk.css b/sirepo/package_data/static/css/vtk.css
index ca9afb84bf..fab3fb54f4 100644
--- a/sirepo/package_data/static/css/vtk.css
+++ b/sirepo/package_data/static/css/vtk.css
@@ -2,13 +2,6 @@
   display: none;
 }
 
-.vtk-canvas-holder-border {
-    border-color: #cccccc;
-    border-radius: 4px;
-    border-style: solid;
-    border-width: 1px;
-}
-
 .vtk-display {
     padding: 8px;
 }
diff --git a/sirepo/package_data/static/html/vtk-display.html b/sirepo/package_data/static/html/vtk-display.html
index 1a8fbfe9d5..288f5c5ab4 100644
--- a/sirepo/package_data/static/html/vtk-display.html
+++ b/sirepo/package_data/static/html/vtk-display.html
@@ -2,7 +2,7 @@
     <div>
         <div class="viewer-title" style="font-weight: normal; text-align: center"></div>
         <div class="sr-screenshot">
-            <div class="vtk-canvas-holder" data-ng-class="{'vtk-canvas-holder-border': showBorder}"></div>
+            <div class="vtk-canvas-holder"></div>
             <div class="vtk-info-overlay vtk-info-overlay-move" data-ng-attr-style="width: {{ canvasGeometry().size.width }}px; height:{{ canvasGeometry().size.height }}px; top:{{ canvasGeometry().pos.top }}px; left:{{ canvasGeometry().pos.left }}px;">
                 <div data-vtk-axes="" data-ng-if="enableAxes" data-width="canvasGeometry().size.width" data-height="canvasGeometry().size.height" data-bound-obj="axisObj" data-axis-cfg="axisCfg"></div>
                 <div class="vtk-load-indicator">
diff --git a/sirepo/package_data/static/js/openmc.js b/sirepo/package_data/static/js/openmc.js
index 776ed09ad0..fe3eda5993 100644
--- a/sirepo/package_data/static/js/openmc.js
+++ b/sirepo/package_data/static/js/openmc.js
@@ -14,7 +14,10 @@ SIREPO.app.config(() => {
     `;
     SIREPO.appFieldEditors = `
         <div data-ng-switch-when="Point3D" class="col-sm-7">
-          <div data-point3d="" data-model="model" data-field="field"></div>
+          <div data-point3d="" data-model="model" data-field="field" data-type="Float"></div>
+        </div>
+        <div data-ng-switch-when="Size3D" class="col-sm-7">
+          <div data-point3d="" data-model="model" data-field="field" data-type="integer" data-min="1"></div>
         </div>
         <div data-ng-switch-when="MaterialComponents" class="col-sm-12">
           <div data-material-components=""></div>
@@ -1416,7 +1419,7 @@ SIREPO.app.directive('geometry3d', function(appState, openmcService, plotting, p
         },
         template: `
             <div data-vtk-display="" class="vtk-display col-sm-11"
-                  data-ng-style="sizeStyle()" data-show-border="true"
+                  data-ng-style="sizeStyle()"
                   data-model-name="{{ modelName }}"
                   data-reset-side="y" data-reset-direction="-1"
                   data-enable-axes="true" data-axis-cfg="axisCfg"
@@ -2549,12 +2552,15 @@ SIREPO.app.directive('point3d', function() {
         scope: {
             model: '=',
             field: '=',
+            type: '@',
+            min: '@',
         },
         template: `
             <div data-ng-repeat="v in model[field] track by $index"
               style="display: inline-block; width: 7em; margin-right: 5px;" >
-              <input class="form-control" data-string-to-number="Float"
+              <input class="form-control" data-string-to-number="{{ type }}"
                 data-ng-model="model[field][$index]"
+                data-min="min"
                 style="text-align: right" required />
             </div>
         `,
diff --git a/sirepo/package_data/static/js/radia.js b/sirepo/package_data/static/js/radia.js
index 16e7b6d218..fd48b68b59 100644
--- a/sirepo/package_data/static/js/radia.js
+++ b/sirepo/package_data/static/js/radia.js
@@ -2236,7 +2236,7 @@ SIREPO.app.directive('radiaViewerContent', function(appState, geometry, panelSta
         template: `
             <div data-advanced-editor-pane="" data-view-name="modelName" data-want-buttons="true" data-field-def="basic" data-model-data="modelData" data-parent-controller="parentController"></div>
             <div data-ng-transclude="">
-                <div data-vtk-display="" class="vtk-display" data-ng-class="{'col-sm-11': isViewTypeFields()}" style="padding-right: 0" data-show-border="true" data-model-name="{{ modelName }}" data-enable-axes="true" data-axis-cfg="axisCfg" data-axis-obj="axisObj" data-enable-selection="true" data-reset-side="x"></div>
+                <div data-vtk-display="" class="vtk-display" data-ng-class="{'col-sm-11': isViewTypeFields()}" style="padding-right: 0" data-model-name="{{ modelName }}" data-enable-axes="true" data-axis-cfg="axisCfg" data-axis-obj="axisObj" data-enable-selection="true" data-reset-side="x"></div>
                 <div class="col-sm-1" style="padding-left: 0" data-ng-if="isViewTypeFields()">
                     <div class="colorbar"></div>
                 </div>
diff --git a/sirepo/package_data/static/js/sirepo-plotting-vtk.js b/sirepo/package_data/static/js/sirepo-plotting-vtk.js
index 409a636f17..279c4beaf0 100644
--- a/sirepo/package_data/static/js/sirepo-plotting-vtk.js
+++ b/sirepo/package_data/static/js/sirepo-plotting-vtk.js
@@ -1918,7 +1918,6 @@ SIREPO.app.directive('vtkDisplay', function(appState, utilities, $window) {
             modelName: '@',
             resetDirection: '@',
             resetSide: '@',
-            showBorder: '@',
         },
         templateUrl: '/static/html/vtk-display.html' + SIREPO.SOURCE_CACHE_KEY,
         controller: function($scope, $element) {
diff --git a/sirepo/package_data/static/json/openmc-schema.json b/sirepo/package_data/static/json/openmc-schema.json
index e20cb10306..eebfe33440 100644
--- a/sirepo/package_data/static/json/openmc-schema.json
+++ b/sirepo/package_data/static/json/openmc-schema.json
@@ -51,6 +51,12 @@
             ["sum", "sum"],
             ["macro", "macro"]
         ],
+        "Estimator": [
+            ["default", "Default"],
+            ["analog", "Analog"],
+            ["tracklength", "Track Length"],
+            ["collision", "Collision"]
+        ],
         "EnrichmentType": [
             ["none", ""],
             ["ao", "ao"],
@@ -379,7 +385,7 @@
         },
         "meshFilter": {
             "_super": ["_", "model", "filter"],
-            "dimension": ["Mesh cell count", "Point3D", [10, 10, 10]],
+            "dimension": ["Mesh cell count", "Size3D", [10, 10, 10]],
             "lower_left": ["Mesh lower left [cm]", "Point3D", [-5.0, -5.0, -5.0]],
             "upper_right": ["Mesh upper right [cm]", "Point3D", [5.0, 5.0, 5.0]]
         },
@@ -530,7 +536,8 @@
             "filter4": ["Filter", "Filter", {"_type": "None"}],
             "filter5": ["Filter", "Filter", {"_type": "None"}],
             "scores": ["Scores", "SimpleListEditor", [], "", "tallyScore"],
-            "nuclides": ["Nuclides", "SimpleListEditor", [], "List of nuclides to use when scoring results", "nuclide"]
+            "nuclides": ["Nuclides", "SimpleListEditor", [], "List of nuclides to use when scoring results", "nuclide"],
+            "estimator": ["Estimator", "Estimator", "default", "If Default is selected, OpenMC will automatically select an appropriate estimator based on the tally filters and scores with a preference for \"tracklength\"."]
         },
         "tallyReport": {
             "axis": ["Slice axis", "Axis", "y"],
@@ -884,6 +891,7 @@
             "advanced": [
                 ["Main", [
                     "name",
+                    "estimator",
                     "scores"
                 ]],
                 ["Filters", [
diff --git a/sirepo/package_data/template/openmc/parameters.py.jinja b/sirepo/package_data/template/openmc/parameters.py.jinja
index 6f46ba6a3a..3ed9e90614 100644
--- a/sirepo/package_data/template/openmc/parameters.py.jinja
+++ b/sirepo/package_data/template/openmc/parameters.py.jinja
@@ -14,21 +14,16 @@ def create_geometry():
         auto_geom_ids=True,
     )
     {% if reflectivePlanes_useReflectivePlanes == '1' %}
-    # creates an edge of universe boundary surface
-    vac_surf = openmc.Sphere(r=10000, boundary_type="vacuum")
     {{ planes }}
     univ = openmc.Cell(
-        region=-vac_surf {{ region }},
-        fill=univ,
+        region={{ region }},
+        fill=univ.bounded_universe(),
     )
     openmc.Geometry([univ]).export_to_xml()
     {% elif hasGraveyard %}
     openmc.Geometry(univ).export_to_xml()
     {% else %}
-    graveyard = openmc.Sphere(r=10000, boundary_type="vacuum")
-    root = openmc.Universe()
-    root.add_cells([openmc.Cell(region=-graveyard, fill=univ)])
-    openmc.Geometry(root).export_to_xml()
+    openmc.Geometry(univ.bounded_universe()).export_to_xml()
     {% endif %}
 
 
diff --git a/sirepo/sim_data/openmc.py b/sirepo/sim_data/openmc.py
index 659b112f5a..edc5b96b5e 100644
--- a/sirepo/sim_data/openmc.py
+++ b/sirepo/sim_data/openmc.py
@@ -109,6 +109,7 @@ def _fix_val(model, field):
             dm.energyAnimation.tally = dm.openmcAnimation.tally
             dm.energyAnimation.score = dm.openmcAnimation.score
         for t in dm.settings.tallies:
+            cls.update_model_defaults(t, "tally")
             for i in range(1, sch.constants.maxFilters + 1):
                 f = t[f"filter{i}"]
                 y = f._type
diff --git a/sirepo/template/openmc.py b/sirepo/template/openmc.py
index 68b73d4afc..5068c54b0d 100644
--- a/sirepo/template/openmc.py
+++ b/sirepo/template/openmc.py
@@ -892,9 +892,14 @@ def _generate_tally(tally, volumes):
     openmc.ParticleFilter([{'"' + '","'.join(v.value for v in f.bins) + '"'}]),
 """
         else:
-            raise AssertionError("filter not yet implemented: {}".format(f._type))
+            raise AssertionError("Unknown filter selected: {}".format(f._type))
+    if not len(tally.scores):
+        raise AssertionError(f"Tally {tally.name} has no scores defined")
     res += f"""]
 t{tally._index + 1}.scores = [{','.join(["'" + s.score + "'" for s in tally.scores])}]
+"""
+    if tally.estimator != "default":
+        res += f"""t{tally._index + 1}.estimator = "{tally.estimator}"
 """
     if len(tally.nuclides):
         res += f"""
@@ -1121,10 +1126,12 @@ def _prep_standard_material_cache():
 def _region(data):
     res = ""
     for i, p in enumerate(data.models.reflectivePlanes.planesList):
+        if res:
+            res += " & "
         if p.inside == "1":
-            res += f"& +p{i + 1} "
+            res += f"+p{i + 1}"
         else:
-            res += f"& -p{i + 1} "
+            res += f"-p{i + 1}"
     return res