diff --git a/smr/fresh/geometry.xml b/smr/fresh/geometry.xml
index 46b80ed..40f5504 100644
--- a/smr/fresh/geometry.xml
+++ b/smr/fresh/geometry.xml
@@ -588,105 +588,105 @@
 106 106 106 106 106 106 106 106 106 106 106 106 106 106 106 106 106 </universes>
   </lattice>
   <lattice id="208" name="baffle south">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 207 207 
 1 1 </universes>
   </lattice>
   <lattice id="211" name="baffle north">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 1 1 
 210 210 </universes>
   </lattice>
   <lattice id="214" name="baffle west">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 1 213 
 1 213 </universes>
   </lattice>
   <lattice id="217" name="baffle east">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 216 1 
 216 1 </universes>
   </lattice>
   <lattice id="220" name="baffle southeast">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 219 207 
 216 1 </universes>
   </lattice>
   <lattice id="223" name="baffle southwest">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 207 222 
 1 213 </universes>
   </lattice>
   <lattice id="226" name="baffle northeast">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 216 1 
 225 210 </universes>
   </lattice>
   <lattice id="229" name="baffle northwest">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 1 213 
 210 228 </universes>
   </lattice>
   <lattice id="232" name="baffle southeast corner">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 231 1 
 1 1 </universes>
   </lattice>
   <lattice id="235" name="baffle southwest corner">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 1 234 
 1 1 </universes>
   </lattice>
   <lattice id="238" name="baffle northwest corner">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 1 1 
 1 237 </universes>
   </lattice>
   <lattice id="241" name="baffle northeast corner">
-    <pitch>10.75182 10.75182</pitch>
+    <pitch>10.751819999999999 10.751819999999999</pitch>
     <dimension>2 2</dimension>
-    <lower_left>-10.75182 -10.75182</lower_left>
+    <lower_left>-10.751819999999999 -10.751819999999999</lower_left>
     <universes>
 1 1 
 240 1 </universes>
   </lattice>
   <lattice id="243" name="Main core">
-    <pitch>21.50364 21.50364</pitch>
+    <pitch>21.503639999999997 21.503639999999997</pitch>
     <dimension>19 19</dimension>
-    <lower_left>-204.28458 -204.28458</lower_left>
+    <lower_left>-204.28457999999998 -204.28457999999998</lower_left>
     <universes>
 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
@@ -714,9 +714,9 @@
   <surface coeffs="0.0 0.0 0.47498" id="4" name="Clad OR" type="z-cylinder" />
   <surface coeffs="0.0 0.0 0.5715" id="5" name="GT IR (above dashpot)" type="z-cylinder" />
   <surface coeffs="0.0 0.0 0.61214" id="6" name="GT OR (above dashpot)" type="z-cylinder" />
-  <surface coeffs="0.0 0.0 0.54019" id="7" name="GT IR (at dashpot)" type="z-cylinder" />
+  <surface coeffs="0.0 0.0 0.50419" id="7" name="GT IR (at dashpot)" type="z-cylinder" />
   <surface coeffs="0.0 0.0 0.61214" id="8" name="GT OR (at dashpot)" type="z-cylinder" />
-  <surface coeffs="0.0 0.0 0.4331" id="9" name="Control Poison OR" type="z-cylinder" />
+  <surface coeffs="0.0 0.0 0.42291" id="9" name="Control Poison OR" type="z-cylinder" />
   <surface coeffs="0.0 0.0 0.43688" id="10" name="CR Clad IR" type="z-cylinder" />
   <surface coeffs="0.0 0.0 0.48387" id="11" name="CR Clad OR" type="z-cylinder" />
   <surface coeffs="0.0 0.0 0.214" id="12" name="BA IR 1" type="z-cylinder" />
@@ -762,9 +762,9 @@
   <surface coeffs="252.564" id="52" name="top upper nozzle" type="z-plane" />
   <surface coeffs="786.348" id="69" name="CR bank D top" type="z-plane" />
   <surface coeffs="405.713" id="70" name="CR bank D bottom" type="z-plane" />
-  <surface coeffs="0.0 0.0 85.0" id="71" name="core barrel IR" type="z-cylinder" />
-  <surface coeffs="0.0 0.0 90.0" id="72" name="core barrel OR" type="z-cylinder" />
-  <surface coeffs="0.0 0.0 92.0" id="73" name="neutron shield OR" type="z-cylinder" />
+  <surface coeffs="0.0 0.0 93.98" id="71" name="core barrel IR" type="z-cylinder" />
+  <surface coeffs="0.0 0.0 99.06" id="72" name="core barrel OR" type="z-cylinder" />
+  <surface coeffs="0.0 0.0 101.06" id="73" name="neutron shield OR" type="z-cylinder" />
   <surface coeffs="1.0 1.7320508075688767 0.0 0.0" id="74" name="neutron shield NWbot SEtop" type="plane" />
   <surface coeffs="1.0 0.5773502691896257 0.0 0.0" id="75" name="neutron shield NWtop SEbot" type="plane" />
   <surface coeffs="1.0 -1.7320508075688767 0.0 0.0" id="76" name="neutron shield NEbot SWtop" type="plane" />
@@ -773,8 +773,8 @@
   <surface boundary="vacuum" coeffs="0.0 0.0 135.0" id="79" name="RPV OR" type="z-cylinder" />
   <surface boundary="vacuum" coeffs="272.564" id="80" name="upper problem boundary" type="z-plane" />
   <surface boundary="vacuum" coeffs="0.0" id="81" name="lower problem boundary" type="z-plane" />
-  <surface coeffs="3.15341" id="82" name="baffle north" type="y-plane" />
-  <surface coeffs="-3.15341" id="83" name="baffle south" type="y-plane" />
-  <surface coeffs="3.15341" id="84" name="baffle east" type="x-plane" />
-  <surface coeffs="-3.15341" id="85" name="baffle west" type="x-plane" />
+  <surface coeffs="3.153409999999999" id="82" name="baffle north" type="y-plane" />
+  <surface coeffs="-3.153409999999999" id="83" name="baffle south" type="y-plane" />
+  <surface coeffs="3.153409999999999" id="84" name="baffle east" type="x-plane" />
+  <surface coeffs="-3.153409999999999" id="85" name="baffle west" type="x-plane" />
 </geometry>
diff --git a/smr/fresh/plots.xml b/smr/fresh/plots.xml
index 1720773..da8d102 100644
--- a/smr/fresh/plots.xml
+++ b/smr/fresh/plots.xml
@@ -3,7 +3,7 @@
   <!--radial slice -->
   <plot basis="xy" color_by="material" filename="radial_xy_slice" id="1" type="slice">
     <origin>0.0 0.0 136.282</origin>
-    <width>268.7955 268.7955</width>
+    <width>268.79549999999995 268.79549999999995</width>
     <pixels>1000 1000</pixels>
     <background>255 255 255</background>
     <color id="1" rgb="255 218 185" />
diff --git a/smr/fresh/settings.xml b/smr/fresh/settings.xml
index 7c929f6..42953e6 100644
--- a/smr/fresh/settings.xml
+++ b/smr/fresh/settings.xml
@@ -6,7 +6,7 @@
   <inactive>100</inactive>
   <source strength="1.0">
     <space type="fission">
-      <parameters>-75.26274000000001 -75.26274000000001 36.007 75.26274000000001 75.26274000000001 236.007</parameters>
+      <parameters>-75.26274 -75.26274 36.007 75.26274 75.26274 236.007</parameters>
     </space>
   </source>
   <output>
diff --git a/smr/smr/surfaces.py b/smr/smr/surfaces.py
index d4bebf9..2b36c18 100644
--- a/smr/smr/surfaces.py
+++ b/smr/smr/surfaces.py
@@ -14,6 +14,7 @@ from math import tan, pi
 
 import openmc
 
+INCHES = 2.54
 
 # Notation
 # GT: Guide Tube
@@ -26,17 +27,24 @@ import openmc
 # FA: Fuel Assembly
 # RPV: Reactor Pressure Vessel
 
+# fuel rod parameters
+pellet_OR          = 0.3195*INCHES/2  # DC, Table 4.1-2
+clad_IR            = 0.326*INCHES/2   # DC, Table 4.1-2
+clad_OR            = 0.374*INCHES/2   # DC, Table 4.1-2
+active_fuel_length = 78.74*INCHES     # DC, Figure 4.2-10
+plenum_length      = 5.311*INCHES     # DC, Figure 4.2-10
+fuel_rod_length    = 85.00*INCHES     # Table 4.1-2
+lower_end_cap      = 0.575*INCHES     # ML17007A001, Table 3-2
+
 # pin cell parameters
-pellet_OR          = 0.405765
-clad_IR            = 0.41402
-clad_OR            = 0.47498
-guide_tube_IR      = 0.5715
-guide_tube_OR      = 0.61214
-guide_tube_dash_IR = 0.54019
-guide_tube_dash_OR = 0.61214
-control_poison_OR  = 0.43310
-control_rod_IR     = 0.43688
-control_rod_OR     = 0.48387
+guide_tube_IR      = 0.450*INCHES/2  # DC, Table 4.1-2
+guide_tube_OR      = 0.482*INCHES/2  # DC, Table 4.1-2
+guide_tube_dash_IR = 0.397*INCHES/2  # DC, Table 4.1-2
+guide_tube_dash_OR = guide_tube_OR
+boron_carbide_OR   = 0.333*INCHES/2  # DC, Table 4.1-3
+ag_in_cd_OR        = 0.336*INCHES/2  # DC, Table 4.1-3
+control_rod_IR     = 0.344*INCHES/2  # DC, Table 4.1-3
+control_rod_OR     = 0.381*INCHES/2  # DC, Table 4.1-3
 burn_abs_r1        = 0.21400
 burn_abs_r2        = 0.23051
 burn_abs_r3        = 0.24130
@@ -45,25 +53,29 @@ burn_abs_r5        = 0.43688
 burn_abs_r6        = 0.48387
 burn_abs_r7        = 0.56134
 burn_abs_r8        = 0.60198
-instr_tube_IR      = 0.5715
-instr_tube_OR      = 0.61214
-plenum_spring_OR   = 0.06459
+instr_tube_IR      = 0.450*INCHES/2  # ML17007A001, Table 3-1
+instr_tube_OR      = 0.482*INCHES/2  # ML17007A001, Table 3-1
+plenum_spring_OR   = 0.06459  # Estimate, actual is ECI
 
 # grid spacer parameters
 rod_grid_side    = 1.24416
+spacer_height = 1.750*INCHES  # DC, Figure 4.2-7
 
-# lattice parameters
-pin_pitch          = 1.25984
-lattice_pitch      = 21.50364
+# assembly parameters
+assembly_length = 95.89*INCHES  # DC, Table 4.1-2
+pin_pitch          = 0.496*INCHES  # DC, Table 4.1-2
+lattice_pitch      = 8.466*INCHES  # DC, Table 4.1-2
 grid_strap_side    = 21.47270
+top_nozzle_height   = 3.551*INCHES  # DC, Figure 4.2-2
+top_nozzle_width    = 8.406*INCHES  # DC, Figure 4.2-2
 
 # core radial parameters
-core_barrel_IR     = 85.0
-core_barrel_OR     = 90.0
-neutron_shield_OR  = 92.0
+core_barrel_IR     = 74*INCHES/2  # DC, Table 4.1-2
+core_barrel_OR     = 78*INCHES/2  # DC, Table 4.1-2
+neutron_shield_OR  = core_barrel_OR + 2.0
 baffle_width       = 2.2225
-rpv_IR             = 120.0
-rpv_OR             = 135.0
+rpv_IR             = 120.0  # Estimate?
+rpv_OR             = 135.0  # Estimate?
 
 # axial parameters
 lowest_extent        =      0.000
@@ -131,7 +143,7 @@ surfs['GT dashpot IR'] = openmc.ZCylinder(
 surfs['GT dashpot OR'] = openmc.ZCylinder(
     R=guide_tube_dash_OR, name='GT OR (at dashpot)')
 surfs['CP OR'] = openmc.ZCylinder(
-    R=control_poison_OR, name='Control Poison OR')
+    R=boron_carbide_OR, name='Control Poison OR')
 surfs['CR IR'] = openmc.ZCylinder(
     R=control_rod_IR, name='CR Clad IR')
 surfs['CR OR'] = openmc.ZCylinder(