From a76bd56ecd8f606b2b782805721bc52178971ddf Mon Sep 17 00:00:00 2001
From: Patrick Shriwise <pshriwise@gmail.com>
Date: Fri, 11 Mar 2022 11:56:15 -0600
Subject: [PATCH] Adding check that energy bounds are set

---
 openmc/weight_windows.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/openmc/weight_windows.py b/openmc/weight_windows.py
index b96908747..36c3932fc 100644
--- a/openmc/weight_windows.py
+++ b/openmc/weight_windows.py
@@ -192,6 +192,8 @@ class WeightWindows(IDManagerMixin):
 
     @property
     def num_energy_bins(self):
+        if self.energy_bounds is None:
+            raise ValueError('Energy bounds are not set')
         return self.energy_bounds.size - 1
 
     @property