diff --git a/InnerDetector/InDetCalibAlgs/SCT_CalibAlgs/src/SCTCalib.cxx b/InnerDetector/InDetCalibAlgs/SCT_CalibAlgs/src/SCTCalib.cxx
index 9bd82f5a789cc5fac9169e4bd102c72298503aba..91fa265a58a6ccf85343ea21d8fa5916aa4e04f0 100644
--- a/InnerDetector/InDetCalibAlgs/SCT_CalibAlgs/src/SCTCalib.cxx
+++ b/InnerDetector/InDetCalibAlgs/SCT_CalibAlgs/src/SCTCalib.cxx
@@ -1837,16 +1837,16 @@ StatusCode SCTCalib::getBSErrors ATLAS_NOT_THREAD_SAFE () {
                         std::string profnameAltShort = detectorStems[stemIndex] + streamHistAlt.str();
 
                         TProfile2D* prof_tmp = (TProfile2D*) m_inputHist->Get( profname.c_str() );
-                        if(prof_tmp ==NULL) {
+                        if(prof_tmp ==nullptr) {
                            prof_tmp = (TProfile2D*) m_inputHist->Get( profnameShort.c_str() );
                         }
-                        if(prof_tmp ==NULL) {
+                        if(prof_tmp ==nullptr) {
                            prof_tmp = (TProfile2D*) m_inputHist->Get( profnameAlt.c_str() );
                         }
-                        if(prof_tmp ==NULL) {
+                        if(prof_tmp ==nullptr) {
                            prof_tmp = (TProfile2D*) m_inputHist->Get( profnameAltShort.c_str() );
                         }
-                        if(prof_tmp ==NULL) {
+                        if(prof_tmp ==nullptr) {
                            msg( MSG::ERROR ) << "Unable to get profile for BSErrorsDB : " << profname << endmsg;
                            return StatusCode::FAILURE;
                         }
@@ -1922,10 +1922,10 @@ StatusCode SCTCalib::getBSErrors ATLAS_NOT_THREAD_SAFE () {
                      std::string profnameShort = "/run_" + std::to_string(m_runNumber.value()) + "/SCT/SCTB/errors/" + streamHist.str();
 
                      TProfile2D* prof_tmp = (TProfile2D*) m_inputHist->Get( profname.c_str() );
-                     if(prof_tmp ==NULL) {
+                     if(prof_tmp ==nullptr) {
                         prof_tmp = (TProfile2D*) m_inputHist->Get( profnameShort.c_str() );
                      }
-                     if(prof_tmp ==NULL) {
+                     if(prof_tmp ==nullptr) {
                         msg( MSG::ERROR ) << "Unable to get profile for BSErrorsDB : " << profname << endmsg;
                         return StatusCode::FAILURE;
                      }
@@ -3084,7 +3084,7 @@ SCTCalib::getNoisyChips(const std::set<Identifier>& stripIdList) const {
          IdentifierHash waferHash{m_pSCTHelper->wafer_hash(m_pSCTHelper->wafer_id(stripId))};
          const InDetDD::SiDetectorElement* pElement{elements->getDetectorElement(waferHash)};
          if (!pElement) {
-            ATH_MSG_FATAL("Element pointer is NULL");
+            ATH_MSG_FATAL("Element pointer is nullptr");
             continue;
          }
          int stripOnline{(pElement->swapPhiReadoutDirection()) ? lastStrip - stripOffline : stripOffline};
@@ -3124,7 +3124,7 @@ SCTCalib::getNoisyLB(const Identifier& moduleId, int& chipId) const {
    std::set<int> LBList;
    LBList.clear();
    if (!m_calibLbTool) {
-      ATH_MSG_ERROR("NULL pointer m_calibLbTool line " <<__LINE__);
+      ATH_MSG_ERROR("nullptr m_calibLbTool line " <<__LINE__);
       return std::make_pair(defectLB, defectLBFrac);
    }
 
diff --git a/InnerDetector/InDetCalibAlgs/SCT_CalibAlgs/src/SCT_CalibLbTool.cxx b/InnerDetector/InDetCalibAlgs/SCT_CalibAlgs/src/SCT_CalibLbTool.cxx
index 622c924fb42804dae4e585a224ce9ca4a9b75dc1..920d0eb9f975ec9c383c9ace191d6867cbf76102 100644
--- a/InnerDetector/InDetCalibAlgs/SCT_CalibAlgs/src/SCT_CalibLbTool.cxx
+++ b/InnerDetector/InDetCalibAlgs/SCT_CalibAlgs/src/SCT_CalibLbTool.cxx
@@ -220,7 +220,7 @@ SCT_CalibLbTool::fill(const bool fromData) {
 bool
 SCT_CalibLbTool::fillFromData() {
    if (!m_evtInfo) {
-      ATH_MSG_ERROR("The evtInfo pointer is NULL");
+      ATH_MSG_ERROR("The evtInfo pointer is nullptr");
       return false;
    }
    m_lumiBlock=m_evtInfo->lumiBlock();
diff --git a/InnerDetector/InDetConditions/SCT_ConditionsAlgorithms/src/SCT_ConfigurationCondAlg.cxx b/InnerDetector/InDetConditions/SCT_ConditionsAlgorithms/src/SCT_ConfigurationCondAlg.cxx
index c0e883ef568a97f7b7f39c0ff4405452bd1d76ab..4be4d13b7d50b41398c566a582793c58bad4634d 100644
--- a/InnerDetector/InDetConditions/SCT_ConditionsAlgorithms/src/SCT_ConfigurationCondAlg.cxx
+++ b/InnerDetector/InDetConditions/SCT_ConditionsAlgorithms/src/SCT_ConfigurationCondAlg.cxx
@@ -427,7 +427,7 @@ SCT_ConfigurationCondAlg::getStripId(const unsigned int truncatedSerialNumber, c
 
   const InDetDD::SiDetectorElement* pElement{elements->getDetectorElement(waferHash)};
   if (!pElement) {
-    ATH_MSG_FATAL("Element pointer is NULL in 'getStripId' method");
+    ATH_MSG_FATAL("Element pointer is nullptr in 'getStripId' method");
     return invalidIdentifier;
   }
   strip = (pElement->swapPhiReadoutDirection()) ? (lastStrip-strip) : strip;
diff --git a/InnerDetector/InDetConditions/SCT_ConditionsTools/src/SCT_ConfigurationConditionsTool.cxx b/InnerDetector/InDetConditions/SCT_ConditionsTools/src/SCT_ConfigurationConditionsTool.cxx
index 05e7e867fa7c50b4b815060d983b17ef8b8fe695..01cb66d16d8cc6aafe95b64062d823ca5222a772 100644
--- a/InnerDetector/InDetConditions/SCT_ConditionsTools/src/SCT_ConfigurationConditionsTool.cxx
+++ b/InnerDetector/InDetConditions/SCT_ConditionsTools/src/SCT_ConfigurationConditionsTool.cxx
@@ -161,7 +161,7 @@ int SCT_ConfigurationConditionsTool::getChip(const Identifier& stripId, const Ev
   const IdentifierHash waferHash{m_pHelper->wafer_hash(m_pHelper->wafer_id(stripId))};
   const InDetDD::SiDetectorElement* pElement{getDetectorElement(waferHash, ctx)};
   if (pElement==nullptr) {
-    ATH_MSG_FATAL("Element pointer is NULL in 'badStrips' method");
+    ATH_MSG_FATAL("Element pointer is nullptr in 'badStrips' method");
     return invalidChipNumber;
   }
   strip = (pElement->swapPhiReadoutDirection()) ? lastStrip - strip: strip;
diff --git a/InnerDetector/InDetDetDescr/InDetTrackingGeometry/src/SiLayerBuilder.cxx b/InnerDetector/InDetDetDescr/InDetTrackingGeometry/src/SiLayerBuilder.cxx
index 387696487eb21e0dd719335d92ff0077d1015308..d64ab8734f80e513691fa36fa6b8ad3b16c8f32f 100755
--- a/InnerDetector/InDetDetDescr/InDetTrackingGeometry/src/SiLayerBuilder.cxx
+++ b/InnerDetector/InDetDetDescr/InDetTrackingGeometry/src/SiLayerBuilder.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -301,7 +301,7 @@ const std::vector< const Trk::CylinderLayer* >* InDet::SiLayerBuilder::cylindric
        if (takeIt) (layerSurfaces[currentlayer]).push_back(surfaceOrder);
      
      } else if (!(*sidetIter)) // barrel chek and screen output
-        ATH_MSG_WARNING("NULL pointer to Barrel module given by SiDetectorManager! Please check db & dict.xml");
+        ATH_MSG_WARNING("nullptr to Barrel module given by SiDetectorManager! Please check db & dict.xml");
   
   } // SiDet Loop
 
@@ -541,7 +541,7 @@ const std::vector< const Trk::DiscLayer* >* InDet::SiLayerBuilder::discLayers()
 std::vector< const Trk::DiscLayer* >* InDet::SiLayerBuilder::createDiscLayers(std::vector<const Trk::DiscLayer*>* dLayers) const {
  
   // this is the DBM flag
-  bool isDBM = (dLayers!=NULL);
+  bool isDBM = (dLayers!=nullptr);
   
   // get general layout
   InDetDD::SiDetectorElementCollection::const_iterator sidetIter = m_siMgr->getDetectorElementBegin();
@@ -671,7 +671,7 @@ std::vector< const Trk::DiscLayer* >* InDet::SiLayerBuilder::createDiscLayers(st
             takeBigger(discRingMaxR[currentlayer][currentring],currentRmax);
         }
      } else if (!(*sidetIter))
-        ATH_MSG_WARNING("NULL pointer to Endcap module given by SCT_DetectorManager! Please check db & dict.xml");
+        ATH_MSG_WARNING("nullptr to Endcap module given by SCT_DetectorManager! Please check db & dict.xml");
   } // DetElement loop 
 
   double minRmin = 10e10;
diff --git a/InnerDetector/InDetDetDescr/SCT_GeoModel/src/SCT_FwdModule.cxx b/InnerDetector/InDetDetDescr/SCT_GeoModel/src/SCT_FwdModule.cxx
index 0537351f32418de04807af27afc7e111a2f53e8d..d6ac1a49cc49abadbfda08b61775a6ecc04fe69f 100644
--- a/InnerDetector/InDetDetDescr/SCT_GeoModel/src/SCT_FwdModule.cxx
+++ b/InnerDetector/InDetDetDescr/SCT_GeoModel/src/SCT_FwdModule.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////
@@ -181,7 +181,7 @@ GeoVPhysVol * SCT_FwdModule::build(SCT_Identifier id)
   // - relative position of component is part of its shape 
   GeoFullPhysVol * module = new GeoFullPhysVol(m_logVolume);
 
-  if (m_connector != NULL) module->add(m_connector->getVolume());
+  if (m_connector != nullptr) module->add(m_connector->getVolume());
   module->add(m_hybrid->getVolume());
   module->add(m_spine->getVolume());
   module->add(m_subspineL->getVolume());
diff --git a/InnerDetector/InDetDetDescr/SCT_GeoModel/src/SCT_FwdSensor.cxx b/InnerDetector/InDetDetDescr/SCT_GeoModel/src/SCT_FwdSensor.cxx
index 9ebc1f0aeda390c32b946dcfb48784338693951e..d81d2ede7f8c907a979d89d8140f37b469e23df2 100644
--- a/InnerDetector/InDetDetDescr/SCT_GeoModel/src/SCT_FwdSensor.cxx
+++ b/InnerDetector/InDetDetDescr/SCT_GeoModel/src/SCT_FwdSensor.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////
@@ -166,7 +166,7 @@ const GeoLogVol * SCT_FwdSensor::preBuild()
     m_inactive = new GeoPhysVol(inactiveLog);
     m_inactive->ref();
   } else {
-    m_inactive = NULL;
+    m_inactive = nullptr;
   }
 
   // Make the moduleside design for this sensor
diff --git a/InnerDetector/InDetEventCnv/InDetEventAthenaPool/src/SCT_RDO_ContainerCnv.cxx b/InnerDetector/InDetEventCnv/InDetEventAthenaPool/src/SCT_RDO_ContainerCnv.cxx
index c7bc62d85e919f84d8de9b516cc128d54dce5c00..3357baf29b5b7d77e51f130f23e570cba0216e79 100644
--- a/InnerDetector/InDetEventCnv/InDetEventAthenaPool/src/SCT_RDO_ContainerCnv.cxx
+++ b/InnerDetector/InDetEventCnv/InDetEventAthenaPool/src/SCT_RDO_ContainerCnv.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "SCT_RDO_ContainerCnv.h"
@@ -28,7 +28,7 @@ namespace {
       }
     }
     else {
-      os<<" [SCT_RDO_Container==NULL]";
+      os<<" [SCT_RDO_Container==nullptr]";
     }
     return os.str();
   }
diff --git a/InnerDetector/InDetEventCnv/InDetEventAthenaPool/src/SCT_RDO_ContainerCnv_p0.cxx b/InnerDetector/InDetEventCnv/InDetEventAthenaPool/src/SCT_RDO_ContainerCnv_p0.cxx
index 4228ff089e618cbfae37daf371d4ca30078bb377..3d2848f9a1b04ba550748b3a8c61ddd31dcae4e9 100644
--- a/InnerDetector/InDetEventCnv/InDetEventAthenaPool/src/SCT_RDO_ContainerCnv_p0.cxx
+++ b/InnerDetector/InDetEventCnv/InDetEventAthenaPool/src/SCT_RDO_ContainerCnv_p0.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "SCT_RDO_ContainerCnv_p0.h"
@@ -22,7 +22,7 @@ SCT_RDO_Container* SCT_RDO_ContainerCnv_p0::createTransient(const SCT_RDO_Contai
     const InDetRawDataCollection<SCT1_RawData>* rdoCollOld = *it;
     
     if (rdoCollOld==nullptr) {
-      throw std::runtime_error("Got NULL collection reading old format SCT_RDO_Container");
+      throw std::runtime_error("Got nullptr of collection reading old format SCT_RDO_Container");
     }
 
     // Ugly cast...  The new format does not need it in its converters.
diff --git a/InnerDetector/InDetEventCnv/InDetJiveXML/src/SCTRDORetriever.cxx b/InnerDetector/InDetEventCnv/InDetJiveXML/src/SCTRDORetriever.cxx
index a66b99baca8229f85428967a496336c3f97d0305..6b70be5054a61606d63667a85b3ffa660f04a54c 100755
--- a/InnerDetector/InDetEventCnv/InDetJiveXML/src/SCTRDORetriever.cxx
+++ b/InnerDetector/InDetEventCnv/InDetJiveXML/src/SCTRDORetriever.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "InDetJiveXML/SCTRDORetriever.h"
@@ -108,7 +108,7 @@ namespace JiveXML {
         //Get the hit detector element
         const InDetDD::SiDetectorElement *element = elements->getDetectorElement(waferHash);
         //Make sure we got the detector element
-        if (element == NULL){
+        if (element == nullptr){
           msg(MSG::WARNING) << "Unable to obtain detector element for SCT_RDO hit with id " << id << endmsg;
           continue ;
         }
diff --git a/InnerDetector/InDetEventCnv/SCT_RawDataByteStreamCnv/src/SCT_RodEncoder.cxx b/InnerDetector/InDetEventCnv/SCT_RawDataByteStreamCnv/src/SCT_RodEncoder.cxx
index 04e2be4d1212b8313173b6a5be30f56c67c78a49..fdb9536be3ae39956df56a8a02514b6d77d8ccf3 100644
--- a/InnerDetector/InDetEventCnv/SCT_RawDataByteStreamCnv/src/SCT_RodEncoder.cxx
+++ b/InnerDetector/InDetEventCnv/SCT_RawDataByteStreamCnv/src/SCT_RodEncoder.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "SCT_RodEncoder.h" 
@@ -125,7 +125,7 @@ void SCT_RodEncoder::fillROD(std::vector<uint32_t>& vec32Data, const uint32_t& r
   for (unsigned int iRDO1{0}; iRDO1<vecRDOs.size(); iRDO1++) {
     const SCT_RDORawData* rdo1{vecRDOs.at(iRDO1)};
     if (rdo1 == nullptr) {
-      ATH_MSG_ERROR("RDO pointer is NULL. skipping this hit.");
+      ATH_MSG_ERROR("RDO pointer is nullptr. skipping this hit.");
       vec_isDuplicated.at(iRDO1) = true;
       continue;
     }
diff --git a/InnerDetector/InDetG4/SCT_G4_SD/test/SctSensorSD_gtest.cxx b/InnerDetector/InDetG4/SCT_G4_SD/test/SctSensorSD_gtest.cxx
index 3e6f9dcc56e90f4d512a230fd2d52c270bb5a182..b058ab89fc4242476506d2e492e0bb596797e8bc 100644
--- a/InnerDetector/InDetG4/SCT_G4_SD/test/SctSensorSD_gtest.cxx
+++ b/InnerDetector/InDetG4/SCT_G4_SD/test/SctSensorSD_gtest.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "src/SctSensorSD.h"
@@ -118,7 +118,7 @@ TEST_F( SctSensorSDtest, indexMethod )
   G4String name = "logicalName";
   G4LogicalVolume fLogical(box, material, name);
   G4String name1 = "physicalName";
-  G4VPhysicalVolume* pPhysical = NULL;
+  G4VPhysicalVolume* pPhysical = nullptr;
   G4MyPhysicalVolume physicalVolume(0, G4ThreeVector(0,0,0), name1, &fLogical, pPhysical);
   physicalVolume.SetCopyNo(1000);
   G4int nReplica = 2;
diff --git a/InnerDetector/InDetMonitoring/SCT_Monitoring/scripts/CheckReprocessing/src/HistogramOperations.cpp b/InnerDetector/InDetMonitoring/SCT_Monitoring/scripts/CheckReprocessing/src/HistogramOperations.cpp
index 8409bc5d9f533332b71153acabff2bfaa1b69fe6..c3ba56d7bda8854a522e8c73c3a12deae99151c5 100644
--- a/InnerDetector/InDetMonitoring/SCT_Monitoring/scripts/CheckReprocessing/src/HistogramOperations.cpp
+++ b/InnerDetector/InDetMonitoring/SCT_Monitoring/scripts/CheckReprocessing/src/HistogramOperations.cpp
@@ -42,7 +42,7 @@ double HistogramOperations::BinwiseCompare( TH1 * NewInput, TH1 * OldInput, stri
 	if ( newX == oldX && newY == oldY && newZ == oldZ )
 	{
 		//Parse the argument as the allowed percentage change in each bin value
-		double allowedDiff = strtod( Argument.c_str(), NULL );
+		double allowedDiff = strtod( Argument.c_str(), nullptr );
 
 		//Compare each bin
 		double totalMismatch = 0.0;
@@ -104,7 +104,7 @@ double HistogramOperations::BinwiseHackCompare( TH1 * NewInput, TH1 * OldInput,
 	vector<double> binChange;
 	for ( int argumentIndex = 0; argumentIndex < splitArgument.size(); argumentIndex++ )
 	{
-		binChange.push_back( strtod( splitArgument[argumentIndex].c_str(), NULL ) );
+		binChange.push_back( strtod( splitArgument[argumentIndex].c_str(), nullptr ) );
 	}
 
 	int newX = NewInput->GetNbinsX();
@@ -175,7 +175,7 @@ double HistogramOperations::BinwiseHackCompare( TH1 * NewInput, TH1 * OldInput,
 double HistogramOperations::KolmogorovTest( TH1 * NewInput, TH1 * OldInput, string Argument )
 {
 	//Parse the argument as the minimum allowed probability of match
-	double threshold = strtod( Argument.c_str(), NULL );
+	double threshold = strtod( Argument.c_str(), nullptr );
 
 	//Perform the Kolmogorov-Smirnov test
 	NewInput->Sumw2();
@@ -221,7 +221,7 @@ double HistogramOperations::CompareMean( TH1 * NewInput, TH1 * OldInput, string
 	else
 	{
 		comparison = 0;
-		allowedDiff = strtod( Argument.c_str(), NULL );
+		allowedDiff = strtod( Argument.c_str(), nullptr );
 	}
 
 	//Loop over all axes
@@ -284,7 +284,7 @@ double HistogramOperations::CompareSigma( TH1 * NewInput, TH1 * OldInput, string
 	else
 	{
 		comparison = 0;
-		allowedDiff = strtod( Argument.c_str(), NULL );
+		allowedDiff = strtod( Argument.c_str(), nullptr );
 	}
 
 	//Loop over all axes
@@ -322,7 +322,7 @@ double HistogramOperations::CompareSigma( TH1 * NewInput, TH1 * OldInput, string
 double HistogramOperations::CompareTotalEntries( TH1 * NewInput, TH1 * OldInput, string Argument )
 {
 	//Parse the argument as the allowed percentage change
-	double percentChange = strtod( Argument.c_str(), NULL );
+	double percentChange = strtod( Argument.c_str(), nullptr );
 
 	//Calculate the percentage change in number of entries
 	double change = std::abs( NewInput->GetEntries() - OldInput->GetEntries() ) * 100.0 / NewInput->GetEntries();
diff --git a/InnerDetector/InDetMonitoring/SCT_Monitoring/scripts/CheckReprocessing/src/main.cpp b/InnerDetector/InDetMonitoring/SCT_Monitoring/scripts/CheckReprocessing/src/main.cpp
index 9fb9f62b16f8b8ee99a0a45bef02c877f116d84b..9bf92320e2a6e1891c77fc836690caac9ab5a338 100644
--- a/InnerDetector/InDetMonitoring/SCT_Monitoring/scripts/CheckReprocessing/src/main.cpp
+++ b/InnerDetector/InDetMonitoring/SCT_Monitoring/scripts/CheckReprocessing/src/main.cpp
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 /**
@@ -79,7 +79,7 @@ int main( int argc, char * argv[] )
 				directory = opendir( argv[argumentIndex] );
 				if (directory)
 				{
-					while ( ( directoryEntry = readdir(directory) ) != NULL )
+					while ( ( directoryEntry = readdir(directory) ) != nullptr )
 					{
 						string entryName = directoryEntry->d_name;
 						if ( entryName != "." && entryName != ".." )
@@ -108,7 +108,7 @@ int main( int argc, char * argv[] )
 				directory = opendir( argv[argumentIndex] );
 				if (directory)
 				{
-					while ( ( directoryEntry = readdir(directory) ) != NULL )
+					while ( ( directoryEntry = readdir(directory) ) != nullptr )
 					{
 						string entryName = directoryEntry->d_name;
 						if ( entryName != "." && entryName != ".." )
diff --git a/InnerDetector/InDetRecAlgs/InDetPrepRawDataFormation/src/SCT_Clusterization.cxx b/InnerDetector/InDetRecAlgs/InDetPrepRawDataFormation/src/SCT_Clusterization.cxx
index 48e4913f4f8d72860cfdf06893b13eacdf0d65b6..d4304456c733894681100bec6082d536be5fd0b5 100644
--- a/InnerDetector/InDetRecAlgs/InDetPrepRawDataFormation/src/SCT_Clusterization.cxx
+++ b/InnerDetector/InDetRecAlgs/InDetPrepRawDataFormation/src/SCT_Clusterization.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 /**   @file SCT_Clusterization.cxx
@@ -36,7 +36,7 @@ namespace InDet {
     ATH_MSG_INFO("SCT_Clusterization::initialize()!");
 
     // Get the conditions summary service (continue anyway, just check the pointer 
-    // later and declare everything to be 'good' if it is NULL)
+    // later and declare everything to be 'good' if it is nullptr)
     if (m_checkBadModules.value()) {
       ATH_MSG_INFO("Clusterization has been asked to look at bad module info");
       ATH_CHECK(m_pSummaryTool.retrieve());
diff --git a/InnerDetector/InDetRecTools/InDetCompetingRIOsOnTrackTool/src/CompetingSCT_ClustersOnTrackTool.cxx b/InnerDetector/InDetRecTools/InDetCompetingRIOsOnTrackTool/src/CompetingSCT_ClustersOnTrackTool.cxx
index 73b9d65d7b37ed193cc496503495ce4b7c0abaa7..914a4dfdb1810af5ccea22210b20590019890574 100755
--- a/InnerDetector/InDetRecTools/InDetCompetingRIOsOnTrackTool/src/CompetingSCT_ClustersOnTrackTool.cxx
+++ b/InnerDetector/InDetRecTools/InDetCompetingRIOsOnTrackTool/src/CompetingSCT_ClustersOnTrackTool.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -133,10 +133,10 @@ const InDet::CompetingSCT_ClustersOnTrack* InDet::CompetingSCT_ClustersOnTrackTo
     // loop over all given PrepRawData
     std::list<const Trk::PrepRawData*>::const_iterator rioIter = RIO_List.begin();
     for (; rioIter!=RIO_List.end(); ++rioIter) {
-        // check if given pointer is not NULL
+        // check if given pointer is not nullptr
         const InDet::SCT_Cluster* riopointer = dynamic_cast<const InDet::SCT_Cluster*>(*rioIter);
         if (!riopointer) {
-            //ATH_MSG_WARNING("That's mean: given list of PrepRawData* contains a NULL pointer resp. not a SCT_Cluster!");
+            //ATH_MSG_WARNING("That's mean: given list of PrepRawData* contains a nullptr resp. not a SCT_Cluster!");
             ATH_MSG_WARNING("Given list of PrepRawData* contains a non SCT_Cluster!");
             ATH_MSG_WARNING("Entry will therefore be ignored!");
             continue;
diff --git a/InnerDetector/InDetTrigRecAlgs/InDetTrigPrepRawDataFormat/src/SCT_TrgClusterization.cxx b/InnerDetector/InDetTrigRecAlgs/InDetTrigPrepRawDataFormat/src/SCT_TrgClusterization.cxx
index 57cb7654de0f5d02aae0820e1cbe5f3b048c1d90..afd0994945ea1e5eacab77f4544cfcbc92ca2b12 100755
--- a/InnerDetector/InDetTrigRecAlgs/InDetTrigPrepRawDataFormat/src/SCT_TrgClusterization.cxx
+++ b/InnerDetector/InDetTrigRecAlgs/InDetTrigPrepRawDataFormat/src/SCT_TrgClusterization.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 //***************************************************************************
@@ -93,7 +93,7 @@ namespace InDet{
     declareMonitoredStdContainer("SctOccupancyHashId",  m_occupancyHashId);
     
 
-    m_clusterCollection = NULL;
+    m_clusterCollection = nullptr;
 
     // error strategy
     //
@@ -233,7 +233,7 @@ namespace InDet{
     //initialisation of monitored quantities
     m_numSctIds = 0;
     m_numSctClusters = 0;
-    m_clusterCollection = NULL;
+    m_clusterCollection = nullptr;
     m_listOfSctIds.clear();
     m_ClusHashId.clear();
     m_SctBSErr.clear();
@@ -309,7 +309,7 @@ namespace InDet{
     }
     
     if (!roi){
-      ATH_MSG_WARNING( "Received NULL RoI" );
+      ATH_MSG_WARNING( "Received nullptr RoI" );
       return HLT::NAV_ERROR;
     }
     
diff --git a/InnerDetector/InDetValidation/InDetTrackValidation/src/SCT_ClusterValidationNtupleWriter.cxx b/InnerDetector/InDetValidation/InDetTrackValidation/src/SCT_ClusterValidationNtupleWriter.cxx
index cff0b8d5b91b9b605356f53163deae82fc97d542..f4a4c03cfddf93191775ffcd815302785ebe63e8 100755
--- a/InnerDetector/InDetValidation/InDetTrackValidation/src/SCT_ClusterValidationNtupleWriter.cxx
+++ b/InnerDetector/InDetValidation/InDetTrackValidation/src/SCT_ClusterValidationNtupleWriter.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2018 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -405,11 +405,11 @@ StatusCode InDet::SCT_ClusterValidationNtupleWriter::execute() {
       for (; rioIterator != (*containerIterator)->end(); rioIterator++) {
         // get the surface center of the RIO
         if (!(*rioIterator)) {
-          ATH_MSG_WARNING( "NULL pointer to RIO" );
+          ATH_MSG_WARNING( "nullptr to RIO" );
           continue;
         }
         if (!((*rioIterator)->detectorElement())) {
-          ATH_MSG_WARNING( "in RIO: NULL pointer to detElement" );
+          ATH_MSG_WARNING( "in RIO: nullptr to detElement" );
           continue;
         }
    
diff --git a/Simulation/Tests/DigitizationTests/src/SCT_RDOsTestTool.cxx b/Simulation/Tests/DigitizationTests/src/SCT_RDOsTestTool.cxx
index 0cd4caf753564ea468ab1459020f55b043c44f90..f30b9d3d8a7287bc938419be5f09804c4ed96350 100644
--- a/Simulation/Tests/DigitizationTests/src/SCT_RDOsTestTool.cxx
+++ b/Simulation/Tests/DigitizationTests/src/SCT_RDOsTestTool.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "SCT_RDOsTestTool.h"
@@ -18,7 +18,7 @@ SCT_RDOsTestTool::SCT_RDOsTestTool(const std::string& type,
                                    const std::string& name,
                                    const IInterface* parent)
   : DigiTestToolBase(type, name, parent),
-    m_sctID(NULL),
+    m_sctID(nullptr),
     m_numberOfEventsSelected(0),
     m_collection("SCT_RDOs"),
     m_nRDO_Colls(0),
@@ -42,10 +42,10 @@ SCT_RDOsTestTool::SCT_RDOsTestTool(const std::string& type,
 {
   for(unsigned int i(0); i<9; ++i)
     {
-      m_h_sct_endcapA_occ_layer[i]=NULL;
-      m_h_sct_endcapC_occ_layer[i]=NULL;
+      m_h_sct_endcapA_occ_layer[i]=nullptr;
+      m_h_sct_endcapC_occ_layer[i]=nullptr;
     }
-  for(unsigned int i(0); i<4; ++i) { m_h_sct_barrel_occ_layer[i]=NULL; }
+  for(unsigned int i(0); i<4; ++i) { m_h_sct_barrel_occ_layer[i]=nullptr; }
   for(unsigned int i(0); i<5; ++i) { m_NumberModulesVetoed[i]=0.0; }
 
 }
@@ -307,7 +307,7 @@ StatusCode SCT_RDOsTestTool::CheckSDOs() {
   m_NoInnerModules.clear();
   m_NoBarrelModules.clear();
 
-  const InDetSimDataCollection* simDataMapSCT(NULL);
+  const InDetSimDataCollection* simDataMapSCT(nullptr);
   if(evtStore()->retrieve(simDataMapSCT,"SCT_SDO_Map").isFailure()) {
     ATH_MSG_WARNING ("Could not find SCT SDO container");
     return StatusCode::SUCCESS;
diff --git a/Tracking/TrkValidation/TrkValHistUtils/Root/IDHitPlots.cxx b/Tracking/TrkValidation/TrkValHistUtils/Root/IDHitPlots.cxx
index 1a8433b37234e9ad1b49ab89d46c97761a125810..57a29a5f01a7799ae77d3df51a32dba78f3ece00 100644
--- a/Tracking/TrkValidation/TrkValHistUtils/Root/IDHitPlots.cxx
+++ b/Tracking/TrkValidation/TrkValHistUtils/Root/IDHitPlots.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "TrkValHistUtils/IDHitPlots.h"
@@ -10,28 +10,28 @@
 namespace Trk {
   void
   IDHitPlots::init() {
-    nBLayerHits = NULL;
-    nPixelHits = NULL;
-    nPixelHoles = NULL;
-    nSCTHits = NULL;
-    nSCTHoles = NULL;
-    nTRTHits = NULL;
-    nTRTHighThresholdHits = NULL;
+    nBLayerHits = nullptr;
+    nPixelHits = nullptr;
+    nPixelHoles = nullptr;
+    nSCTHits = nullptr;
+    nSCTHoles = nullptr;
+    nTRTHits = nullptr;
+    nTRTHighThresholdHits = nullptr;
 
-    nBLayerOutliers = NULL;
-    nBLayerSharedHits = NULL;
-    nBLayerSplitHits = NULL;
-    nPixelOutliers = NULL;
-    nPixelContribLayers = NULL;
-    nPixelSharedHits = NULL;
-    nPixelSplitHits = NULL;
-    nPixelGangedHits = NULL;
-    nSCTOutliers = NULL;
-    nSCTDoubleHoles = NULL;
-    nSCTSharedHits = NULL;
-    nTRTOutliers = NULL;
-    nTRTHighThresholdOutliers = NULL;
-    nPixelGangedHitsFlaggedFakes = NULL;
+    nBLayerOutliers = nullptr;
+    nBLayerSharedHits = nullptr;
+    nBLayerSplitHits = nullptr;
+    nPixelOutliers = nullptr;
+    nPixelContribLayers = nullptr;
+    nPixelSharedHits = nullptr;
+    nPixelSplitHits = nullptr;
+    nPixelGangedHits = nullptr;
+    nSCTOutliers = nullptr;
+    nSCTDoubleHoles = nullptr;
+    nSCTSharedHits = nullptr;
+    nTRTOutliers = nullptr;
+    nTRTHighThresholdOutliers = nullptr;
+    nPixelGangedHitsFlaggedFakes = nullptr;
   }
 
   void