diff --git a/openmc/deplete/flux_operator.py b/openmc/deplete/flux_operator.py
index 3ca046cf2d..37100ac5b5 100644
--- a/openmc/deplete/flux_operator.py
+++ b/openmc/deplete/flux_operator.py
@@ -16,7 +16,7 @@ import pandas as pd
 from uncertainties import ufloat
 
 import openmc
-from openmc.checkvalue import check_type
+from openmc.checkvalue import check_type, check_value, check_iterable_type
 from openmc.data import DataLibrary
 from openmc.exceptions import DataError
 from openmc.mpi import comm
@@ -27,8 +27,19 @@ from .reaction_rates import ReactionRates
 from .results import Results
 from .helpers import ConstantFissionYieldHelper
 
+valid_rxns = list(REACTIONS.keys())
+valid_rxns += ['fission']
 
-class FluxSpectraDepletionOperator(TransportOperator):
+# Convenience function for the micro_xs static methods
+def _validate_micro_xs_inputs(nuclides, reactions, data):
+    check_iterable_type('nuclides', nuclides, str)
+    check_iterable_type('reactions', reactions, str)
+    check_type('data', data, np.ndarray, expected_iter_type=float)
+    [check_value('reactions', reaction, valid_rxns) for reaction in reactions]
+
+
+
+class FluxDepletionOperator(TransportOperator):
     """Depletion operator that uses a user-provided flux spectrum and one-group
     cross sections to calculate reaction rates.
 
@@ -318,15 +329,13 @@ class FluxSpectraDepletionOperator(TransportOperator):
             assert data.shape == (len(nuclides), len(reactions))
         except AssertionError:
             raise SyntaxError(
-                'Nuclides list of length {len(nuclides)} and'
-                'reactions array of length {len(reactions)} do not'
-                'match dimensions of data array of shape {data.shape}')
+                f'Nuclides list of length {len(nuclides)} and '
+                f'reactions array of length {len(reactions)} do not '
+                f'match dimensions of data array of shape {data.shape}')
 
-        check_iterable_type('nuclides', nuclides, str)
-        check_iterable_type('reactions', reactions, str)
-        check_type('data', data, float, expected_iter_type=np.array)
-        check_value('reactions', reactions, chain.REACTIONS)
+        _validate_micro_xs_inputs(nuclides, reactions, data)
 
+        # Convert to cm^2
         if units == 'barn':
             data /= 1e24
 
@@ -351,7 +360,12 @@ class FluxSpectraDepletionOperator(TransportOperator):
             A DataFrame object correctly formatted for use in ``FluxOperator``
 
         """
-        micro_xs = pd.DataFrame.read_csv(csv_file)
+        micro_xs = pd.read_csv(csv_file, index_col=0)
+
+        _validate_micro_xs_inputs(list(micro_xs.index),
+                                  list(micro_xs.columns),
+                                  micro_xs.to_numpy())
+
         if units == 'barn':
             micro_xs /= 1e24
 
diff --git a/tests/micro_xs_simple.csv b/tests/micro_xs_simple.csv
new file mode 100644
index 0000000000..40142f5438
--- /dev/null
+++ b/tests/micro_xs_simple.csv
@@ -0,0 +1,13 @@
+,fission,"(n,gamma)"
+U234,0.1,0.0
+U235,0.1,0.0
+U238,0.9,0.0
+U236,0.4,0.0
+O16,0.0,0.0
+O17,0.0,0.0
+I135,0.0,0.1
+Xe135,0.0,0.9
+Xe136,0.0,0.0
+Cs135,0.0,0.0
+Gd157,0.0,0.1
+Gd156,0.0,0.1
diff --git a/tests/unit_tests/test_flux_deplete_operator.py b/tests/unit_tests/test_flux_deplete_operator.py
new file mode 100644
index 0000000000..a2b1504938
--- /dev/null
+++ b/tests/unit_tests/test_flux_deplete_operator.py
@@ -0,0 +1,73 @@
+"""Basic unit tests for openmc.deplete.FluxDepletionOperator instantiation
+
+Modifies and resets environment variable OPENMC_CROSS_SECTIONS
+to a custom file with new depletion_chain node
+"""
+
+from pathlib import Path
+
+import pytest
+from openmc.deplete.flux_operator import FluxDepletionOperator
+import pandas as pd
+import numpy as np
+
+FLUX_SPECTRA = 5e16
+CHAIN_PATH = Path(__file__).parents[1] / "chain_simple.xml"
+ONE_GROUP_XS = Path(__file__).parents[1] / "micro_xs_simple.csv"
+
+
+def test_create_micro_xs_from_data_array():
+    nuclides = [
+        'U234',
+        'U235',
+        'U238',
+        'U236',
+        'O16',
+        'O17',
+        'I135',
+        'Xe135',
+        'Xe136',
+        'Cs135',
+        'Gd157',
+        'Gd156']
+    reactions = ['fission', '(n,gamma)']
+    # These values are placeholders and are not at all
+    # physically meaningful.
+    data = np.array([[0.1, 0.],
+                     [0.1, 0.],
+                     [0.9, 0.],
+                     [0.4, 0.],
+                     [0., 0.],
+                     [0., 0.],
+                     [0., 0.1],
+                     [0., 0.9],
+                     [0., 0.],
+                     [0., 0.],
+                     [0., 0.1],
+                     [0., 0.1]])
+
+    FluxDepletionOperator.create_micro_xs_from_data_array(
+        nuclides, reactions, data)
+    with pytest.raises(SyntaxError, match=r'Nuclides list of length \d* and '
+                       r'reactions array of length \d* do not '
+                       r'match dimensions of data array of shape \(\d*\,d*\)'):
+        FluxDepletionOperator.create_micro_xs_from_data_array(
+            nuclides, reactions, data[:, 0])
+
+
+def test_create_micro_xs_from_csv():
+    FluxDepletionOperator.create_micro_xs_from_csv(ONE_GROUP_XS)
+
+
+def test_operator_init():
+    """The test uses a temporary dummy chain. This file will be removed
+    at the end of the test, and only contains a depletion_chain node."""
+    nuclides = {'U234': 8.922411359424315e+18,
+                'U235': 9.98240191860822e+20,
+                'U238': 2.2192386373095893e+22,
+                'U236': 4.5724195495061115e+18,
+                'O16': 4.639065406771322e+22,
+                'O17': 1.7588724018066158e+19}
+    micro_xs = FluxDepletionOperator.create_micro_xs_from_csv(ONE_GROUP_XS)
+    my_flux_operator = FluxDepletionOperator(
+        1, nuclides, micro_xs, FLUX_SPECTRA, CHAIN_PATH)