diff --git a/ChangeLog b/ChangeLog
index ccadd40f5..7f6e23350 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2011-03-25 Paul Romano <romano7@mit.edu>
+
+	* physics.f90: Resample outgoing energy if sampled energy is
+	greater than 20 MeV. Some cross sections go up to 150 MeV but
+	others do not.
+	* source.f90: Resample outgoing energy if >= 20 MeV.
+
 2011-03-25 Paul Romano <romano7@mit.edu>
 
 	* ace.f90: Added ability to read delayed neutron energy
diff --git a/src/physics.f90 b/src/physics.f90
index a39252839..385915a6e 100644
--- a/src/physics.f90
+++ b/src/physics.f90
@@ -116,7 +116,7 @@ contains
     if (E < e_grid(1)) then
        IE = 1
     elseif (E > e_grid(n_grid)) then
-       IE = n_grid
+       IE = n_grid - 1
     else
        IE = binary_search(e_grid, n_grid, E)
     end if
@@ -572,11 +572,15 @@ contains
 
           ! sample from energy distribution for group j
           law = table % nu_d_edist(j) % law
-          if (law == 44 .or. law == 61) then
-             call sample_energy(table%nu_d_edist(j), E, E_out, mu)
-          else
-             call sample_energy(table%nu_d_edist(j), E, E_out)
-          end if
+          do
+             if (law == 44 .or. law == 61) then
+                call sample_energy(table%nu_d_edist(j), E, E_out, mu)
+             else
+                call sample_energy(table%nu_d_edist(j), E, E_out)
+             end if
+             ! resample if energy is >= 20 MeV
+             if (E_out < 20) exit
+          end do
 
        else
           ! ==========================================================
@@ -584,11 +588,15 @@ contains
 
           ! sample from prompt neutron energy distribution
           law = rxn % edist % law
-          if (law == 44 .or. law == 61) then
-             call sample_energy(rxn%edist, E, E_out, prob)
-          else
-             call sample_energy(rxn%edist, E, E_out)
-          end if
+          do
+             if (law == 44 .or. law == 61) then
+                call sample_energy(rxn%edist, E, E_out, prob)
+             else
+                call sample_energy(rxn%edist, E, E_out)
+             end if
+             ! resample if energy is >= 20 MeV
+             if (E_out < 20) exit
+          end do
 
        end if
 
diff --git a/src/source.f90 b/src/source.f90
index 783fb03d5..80ddbcdd4 100644
--- a/src/source.f90
+++ b/src/source.f90
@@ -23,6 +23,7 @@ contains
     real(8) :: r(3)       ! sampled coordinates
     real(8) :: phi        ! azimuthal angle
     real(8) :: mu         ! cosine of polar angle
+    real(8) :: E          ! outgoing energy
     real(8) :: p_min(3)   ! minimum coordinates of source
     real(8) :: p_max(3)   ! maximum coordinates of source
     character(250) :: msg ! error message
@@ -81,7 +82,14 @@ contains
              p % alive    = .true.
 
              ! sample energy from Watt fission energy spectrum for U-235
-             p % E = watt_spectrum(0.988_8, 2.249_8)
+             do
+                E = watt_spectrum(0.988_8, 2.249_8)
+                ! resample if energy is >= 20 MeV
+                if (E < 20) exit
+             end do
+
+             ! set particle energy
+             p % E = E
           end do
        end if
     end do