Index: Ringtoets/DuneErosion/test/Ringtoets.DuneErosion.IO.Test/DuneLocationsWriterTest.cs
===================================================================
diff -u -rd18995d638a6c3f99cb7a8419107bb4148420301 -rf43c22c9f5dc04d352988510303fcfe12d712be8
--- Ringtoets/DuneErosion/test/Ringtoets.DuneErosion.IO.Test/DuneLocationsWriterTest.cs	(.../DuneLocationsWriterTest.cs)	(revision d18995d638a6c3f99cb7a8419107bb4148420301)
+++ Ringtoets/DuneErosion/test/Ringtoets.DuneErosion.IO.Test/DuneLocationsWriterTest.cs	(.../DuneLocationsWriterTest.cs)	(revision f43c22c9f5dc04d352988510303fcfe12d712be8)
@@ -115,6 +115,24 @@
         }
 
         [Test]
+        public void WriteDuneLocations_FileInUse_ThrowCriticalFileWriteException()
+        {
+            // Setup
+            string filePath = TestHelper.GetScratchPadPath(Path.GetRandomFileName());
+            using (new FileDisposeHelper(filePath))
+            using (new FileStream(filePath, FileMode.Open))
+            {
+                // Call
+                TestDelegate call = () => DuneLocationsWriter.WriteDuneLocations(Enumerable.Empty<DuneLocation>(), filePath);
+
+                // Assert
+                var exception = Assert.Throws<CriticalFileWriteException>(call);
+                Assert.AreEqual($"Er is een onverwachte fout opgetreden tijdens het schrijven van het bestand '{filePath}'.", exception.Message);
+                Assert.IsInstanceOf<IOException>(exception.InnerException);
+            }
+        }
+
+        [Test]
         public void WriteDuneLocations_ValidData_ValidFile()
         {
             // Setup
Index: Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/Exporters/PipingConfigurationWriterTest.cs
===================================================================
diff -u -rd18995d638a6c3f99cb7a8419107bb4148420301 -rf43c22c9f5dc04d352988510303fcfe12d712be8
--- Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/Exporters/PipingConfigurationWriterTest.cs	(.../PipingConfigurationWriterTest.cs)	(revision d18995d638a6c3f99cb7a8419107bb4148420301)
+++ Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/Exporters/PipingConfigurationWriterTest.cs	(.../PipingConfigurationWriterTest.cs)	(revision f43c22c9f5dc04d352988510303fcfe12d712be8)
@@ -62,6 +62,10 @@
                 yield return new TestCaseData("calculationWithoutSoilProfile",
                                               PipingTestDataGenerator.GetPipingCalculationWithoutSoilProfile())
                     .SetName("calculationWithoutSoilProfile");
+
+                yield return new TestCaseData("calculationWithNaNs",
+                                              PipingTestDataGenerator.GetPipingCalculationWithNaNs())
+                    .SetName("calculationWithNaNs");
             }
         }
 
@@ -145,6 +149,24 @@
         }
 
         [Test]
+        public void Write_FileInUse_ThrowCriticalFileWriteException()
+        {
+            // Setup
+            string filePath = TestHelper.GetScratchPadPath(Path.GetRandomFileName());
+            using (new FileDisposeHelper(filePath))
+            using (new FileStream(filePath, FileMode.Open))
+            {
+                // Call
+                TestDelegate call = () => PipingConfigurationWriter.Write(new CalculationGroup(), filePath);
+
+                // Assert
+                var exception = Assert.Throws<CriticalFileWriteException>(call);
+                Assert.AreEqual($"Er is een onverwachte fout opgetreden tijdens het schrijven van het bestand '{filePath}'.", exception.Message);
+                Assert.IsInstanceOf<IOException>(exception.InnerException);
+            }
+        }
+
+        [Test]
         public void Write_CalculationGroupsAndCalculation_ValidFile()
         {
             // Setup
Index: Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/test-data/PipingConfigurationWriter/calculationWithNaNs.xml
===================================================================
diff -u
--- Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/test-data/PipingConfigurationWriter/calculationWithNaNs.xml	(revision 0)
+++ Ringtoets/Piping/test/Ringtoets.Piping.IO.Test/test-data/PipingConfigurationWriter/calculationWithNaNs.xml	(revision f43c22c9f5dc04d352988510303fcfe12d712be8)
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <berekening naam="PK001_0001 W1-6_0_1D1">
+    <toetspeil>NaN</toetspeil>
+    <profielschematisatie>PK001_0001</profielschematisatie>
+    <intredepunt>NaN</intredepunt>
+    <uittredepunt>NaN</uittredepunt>
+    <ondergrondmodel>PK001_0001_Piping</ondergrondmodel>
+    <ondergrondschematisatie>W1-6_0_1D1</ondergrondschematisatie>
+    <stochasten>
+      <stochast naam="polderpeil">
+        <verwachtingswaarde>NaN</verwachtingswaarde>
+        <standaardafwijking>NaN</standaardafwijking>
+      </stochast>
+      <stochast naam="dempingsfactor">
+        <verwachtingswaarde>NaN</verwachtingswaarde>
+        <standaardafwijking>NaN</standaardafwijking>
+      </stochast>
+    </stochasten>
+  </berekening>
+</root>
\ No newline at end of file
Index: Ringtoets/Piping/test/Ringtoets.Piping.Integration.TestUtils/PipingTestDataGenerator.cs
===================================================================
diff -u -r69617e58c64b2b6a92da02e30c308e77f9176968 -rf43c22c9f5dc04d352988510303fcfe12d712be8
--- Ringtoets/Piping/test/Ringtoets.Piping.Integration.TestUtils/PipingTestDataGenerator.cs	(.../PipingTestDataGenerator.cs)	(revision 69617e58c64b2b6a92da02e30c308e77f9176968)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Integration.TestUtils/PipingTestDataGenerator.cs	(.../PipingTestDataGenerator.cs)	(revision f43c22c9f5dc04d352988510303fcfe12d712be8)
@@ -23,6 +23,7 @@
 using Core.Common.Base.Geometry;
 using Ringtoets.Common.Data.Calculation;
 using Ringtoets.Common.Data.Hydraulics;
+using Ringtoets.Common.Data.Probabilistics;
 using Ringtoets.Piping.Data;
 using Ringtoets.Piping.Data.TestUtil;
 using Ringtoets.Piping.KernelWrapper.TestUtil;
@@ -159,6 +160,30 @@
         }
 
         /// <summary>
+        /// Gets a <see cref="PipingCalculation"/> with <c>double.NaN</c> values set.
+        /// </summary>
+        /// <returns>A <see cref="PipingCalculation"/> with <c>double.NaN</c> values.</returns>
+        public static PipingCalculation GetPipingCalculationWithNaNs()
+        {
+            PipingCalculation calculation = GetPipingCalculationWithAssessmentLevel();
+            calculation.InputParameters.AssessmentLevel = RoundedDouble.NaN;
+            calculation.InputParameters.EntryPointL = RoundedDouble.NaN;
+            calculation.InputParameters.ExitPointL = RoundedDouble.NaN;
+            calculation.InputParameters.PhreaticLevelExit = new NormalDistribution
+            {
+                Mean = RoundedDouble.NaN,
+                StandardDeviation = RoundedDouble.NaN
+            };
+            calculation.InputParameters.DampingFactorExit = new LogNormalDistribution
+            {
+                Mean = RoundedDouble.NaN,
+                StandardDeviation = RoundedDouble.NaN
+            };
+
+            return calculation;
+        }
+
+        /// <summary>
         /// Configures a <see cref="PipingFailureMechanism"/> to a fully configured failure
         /// mechanism with all possible parent and nested calculation configurations.
         /// </summary>
Index: Ringtoets/Revetment/test/Ringtoets.Revetment.IO.Test/WaveConditionsWriterTest.cs
===================================================================
diff -u -rd18995d638a6c3f99cb7a8419107bb4148420301 -rf43c22c9f5dc04d352988510303fcfe12d712be8
--- Ringtoets/Revetment/test/Ringtoets.Revetment.IO.Test/WaveConditionsWriterTest.cs	(.../WaveConditionsWriterTest.cs)	(revision d18995d638a6c3f99cb7a8419107bb4148420301)
+++ Ringtoets/Revetment/test/Ringtoets.Revetment.IO.Test/WaveConditionsWriterTest.cs	(.../WaveConditionsWriterTest.cs)	(revision f43c22c9f5dc04d352988510303fcfe12d712be8)
@@ -116,6 +116,24 @@
         }
 
         [Test]
+        public void WriteWaveConditions_FileInUse_ThrowCriticalFileWriteException()
+        {
+            // Setup
+            string filePath = TestHelper.GetScratchPadPath(Path.GetRandomFileName());
+            using (new FileDisposeHelper(filePath))
+            using (new FileStream(filePath, FileMode.Open))
+            {
+                // Call
+                TestDelegate call = () => WaveConditionsWriter.WriteWaveConditions(Enumerable.Empty<ExportableWaveConditions>(), filePath);
+
+                // Assert
+                var exception = Assert.Throws<CriticalFileWriteException>(call);
+                Assert.AreEqual($"Er is een onverwachte fout opgetreden tijdens het schrijven van het bestand '{filePath}'.", exception.Message);
+                Assert.IsInstanceOf<IOException>(exception.InnerException);
+            }
+        }
+
+        [Test]
         public void WriteWaveConditions_ValidData_ValidFile()
         {
             // Setup