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  <xsd:element id="bwxt_DefinedBenefitPlanAmountsRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveLossIncome" name="DefinedBenefitPlanAmountsRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveLossIncome" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DefinedBenefitPlanAmountsRecognizedInNetPeriodicPensionCostAndOtherComprehensiveIncome" name="DefinedBenefitPlanAmountsRecognizedInNetPeriodicPensionCostAndOtherComprehensiveIncome" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRatetoDetermineInterestCost" name="DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRatetoDetermineInterestCost" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRatetoDetermineServiceCost" name="DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRatetoDetermineServiceCost" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DefinedBenefitPlanIncreaseDecreaseofServiceandInterestCost" name="DefinedBenefitPlanIncreaseDecreaseofServiceandInterestCost" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DefinedBenefitPlanMarkToMarketAdjustment" name="DefinedBenefitPlanMarkToMarketAdjustment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DefinedBenefitPlanObligationTransfers" name="DefinedBenefitPlanObligationTransfers" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DefinedBenefitPlanPercentageOfAssets" name="DefinedBenefitPlanPercentageOfAssets" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="bwxt_DefinedBenefitPlanPercentageOfInvestmentReturnOnPlanAssets" name="DefinedBenefitPlanPercentageOfInvestmentReturnOnPlanAssets" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DefinedBenefitPlanPlansWithAssetsInExcessOfAccumulatedBenefitObligationAggregateAccumulatedBenefitObligation" name="DefinedBenefitPlanPlansWithAssetsInExcessOfAccumulatedBenefitObligationAggregateAccumulatedBenefitObligation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="bwxt_DefinedBenefitPlanPlansWithAssetsInExcessOfAccumulatedBenefitObligationAggregateFairValueOfPlanAssets" name="DefinedBenefitPlanPlansWithAssetsInExcessOfAccumulatedBenefitObligationAggregateFairValueOfPlanAssets" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="bwxt_DefinedBenefitPlanPlansWithAssetsInExcessOfAccumulatedBenefitObligationAggregateProjectedBenefitObligation" name="DefinedBenefitPlanPlansWithAssetsInExcessOfAccumulatedBenefitObligationAggregateProjectedBenefitObligation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="bwxt_DepreciationDepletionAndAmortizationExcludingDiscontinuedOperation" name="DepreciationDepletionAndAmortizationExcludingDiscontinuedOperation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_DisposalGroupIncludingDiscontinuedOperationAdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" name="DisposalGroupIncludingDiscontinuedOperationAdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationCostsAndExpenses" name="DisposalGroupIncludingDiscontinuedOperationCostsAndExpenses" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_DisposalGroupIncludingDiscontinuedOperationCostsAndExpensesAbstract" name="DisposalGroupIncludingDiscontinuedOperationCostsAndExpensesAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationCostsToSpinoff" name="DisposalGroupIncludingDiscontinuedOperationCostsToSpinoff" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationDepreciationDepletionAndAmortization" name="DisposalGroupIncludingDiscontinuedOperationDepreciationDepletionAndAmortization" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationGainsLossesOnDispositionOfAssetsAndImpairments" name="DisposalGroupIncludingDiscontinuedOperationGainsLossesOnDispositionOfAssetsAndImpairments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationGainsLossesOnDispositionOfAssetsAndImpairmentsNoncashItems" name="DisposalGroupIncludingDiscontinuedOperationGainsLossesOnDispositionOfAssetsAndImpairmentsNoncashItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationIncomeLossFromEquityMethodInvestments" name="DisposalGroupIncludingDiscontinuedOperationIncomeLossFromEquityMethodInvestments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationIncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions" name="DisposalGroupIncludingDiscontinuedOperationIncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationOtherIncomeLoss" name="DisposalGroupIncludingDiscontinuedOperationOtherIncomeLoss" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationPaymentsToAcquirePropertyPlantAndEquipment" name="DisposalGroupIncludingDiscontinuedOperationPaymentsToAcquirePropertyPlantAndEquipment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationResearchAndDevelopmentExpense" name="DisposalGroupIncludingDiscontinuedOperationResearchAndDevelopmentExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationRestructuringCharges" name="DisposalGroupIncludingDiscontinuedOperationRestructuringCharges" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_DisposalGroupIncludingDiscontinuedOperationSellingGeneralAndAdministrativeExpense" name="DisposalGroupIncludingDiscontinuedOperationSellingGeneralAndAdministrativeExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_DocumentAndEntityInformationAbstract" name="DocumentAndEntityInformationAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_EffectiveIncomeTaxRateReconciliationDividendsAndDeemedDividendsFromAffiliates" name="EffectiveIncomeTaxRateReconciliationDividendsAndDeemedDividendsFromAffiliates" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_EffectiveIncomeTaxRateReconciliationStatutoryRatePercent" name="EffectiveIncomeTaxRateReconciliationStatutoryRatePercent" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_EffectiveIncomeTaxRateReconciliationTaxCreditsAdjustmentsForeign" name="EffectiveIncomeTaxRateReconciliationTaxCreditsAdjustmentsForeign" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_EliminationofHistoricalInterestIncomeMember" name="EliminationofHistoricalInterestIncomeMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_EnvironmentalMattersMember" name="EnvironmentalMattersMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_EquityMethodInvestmentCombinedBalanceSheetInformationTableTextBlock" name="EquityMethodInvestmentCombinedBalanceSheetInformationTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_EquityMethodInvestmentCombinedIncomeStatementInformationTableTextBlock" name="EquityMethodInvestmentCombinedIncomeStatementInformationTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_EquityMethodInvestmentReconciliationOfNetIncomeToEquityInIncomeTableTextBlock" name="EquityMethodInvestmentReconciliationOfNetIncomeToEquityInIncomeTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_EquityMethodInvestmentsReimbursableCosts" name="EquityMethodInvestmentsReimbursableCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_EquitySecuritiesAndCommingledMutualFundsMember" name="EquitySecuritiesAndCommingledMutualFundsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ExpectedNetPeriodicBenefitCostForOtherPostretirementBenefitsExpectedToBeRecognizedOverNextFiscalYear" name="ExpectedNetPeriodicBenefitCostForOtherPostretirementBenefitsExpectedToBeRecognizedOverNextFiscalYear" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ExpectedNetPeriodicBenefitCostForPensionBenefitsExpectedToBeRecognizedOverNextFiscalYear" name="ExpectedNetPeriodicBenefitCostForPensionBenefitsExpectedToBeRecognizedOverNextFiscalYear" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_FairValueOfPerformanceGuarantees" name="FairValueOfPerformanceGuarantees" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_FinancialAssuranceToPayExpectedCostOfDecommissioning" name="FinancialAssuranceToPayExpectedCostOfDecommissioning" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_FixedIncomeExcludingUSGovernmentSecuritiesMember" name="FixedIncomeExcludingUSGovernmentSecuritiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_FrameworkAgreementMember" name="FrameworkAgreementMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_GEHitachiNuclearEnergyCanadaInc.Member" name="GEHitachiNuclearEnergyCanadaInc.Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_GainsLossesOnDispositionOfAssetsAndImpairments" name="GainsLossesOnDispositionOfAssetsAndImpairments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_GlobalEquityMember" name="GlobalEquityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_GrossMarginRecognitionPercentOfCompletion" name="GrossMarginRecognitionPercentOfCompletion" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_IncomeFromContinuingOperationSpinOffRelatedCosts" name="IncomeFromContinuingOperationSpinOffRelatedCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_IncomeFromDiscontinuedOperationSpinOffRelatedCosts" name="IncomeFromDiscontinuedOperationSpinOffRelatedCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_IncomeRelatedToLitigationProceeds" name="IncomeRelatedToLitigationProceeds" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_IncreaseDecreaseContractsInProgressAndAdvanceBillingsOnContracts" name="IncreaseDecreaseContractsInProgressAndAdvanceBillingsOnContracts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_IncreaseDecreaseInPensionPostretirementAndAccruedEmployeeBenefits" name="IncreaseDecreaseInPensionPostretirementAndAccruedEmployeeBenefits" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_IncreaseinAmortizationExpenseMember" name="IncreaseinAmortizationExpenseMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_IncrementalTermLoansMember" name="IncrementalTermLoansMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_LongTermInvestmentsExcludingInvestmentsInUnconsolidatedAffiliates" name="LongTermInvestmentsExcludingInvestmentsInUnconsolidatedAffiliates" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="bwxt_LongtermDebtGrossCurrent" name="LongtermDebtGrossCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="bwxt_LongtermDebtGrossExcludingCurrentMaturities" name="LongtermDebtGrossExcludingCurrentMaturities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="bwxt_LossContingencySettlementAmount" name="LossContingencySettlementAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_ManagementAndOperationContractsOfUSGovernmentFacilitiesMember" name="ManagementAndOperationContractsOfUSGovernmentFacilitiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_MarkToMarketAdjustments" name="MarkToMarketAdjustments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_MinimumPercentageOfFairMarketValueClosingPrice" name="MinimumPercentageOfFairMarketValueClosingPrice" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_MutualFundsMember" name="MutualFundsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_NrcCategoryOneLicenseMember" name="NrcCategoryOneLicenseMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_NuclearComponentProgramMember" name="NuclearComponentProgramMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_NuclearEnergyMember" name="NuclearEnergyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_NuclearEnvironmentalServicesMember" name="NuclearEnvironmentalServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_NuclearEquipmentMember" name="NuclearEquipmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_NuclearOperationsMember" name="NuclearOperationsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_NuclearPowerGroupMember" name="NuclearPowerGroupMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_NuclearServicesGroupMember" name="NuclearServicesGroupMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_NuclearServicesMember" name="NuclearServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_NuclearServicesandAdvancedReactorDesignandEngineeringMember" name="NuclearServicesandAdvancedReactorDesignandEngineeringMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_NumberOfCasesConsolidated" name="NumberOfCasesConsolidated" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_NumberOfFacilitiesWithGovernmentDecommissioningCostsObligation" name="NumberOfFacilitiesWithGovernmentDecommissioningCostsObligation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_NumberOfFormerNuclearFuelProcessingFacilities" name="NumberOfFormerNuclearFuelProcessingFacilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_NumberOfLargeHeavyComponentsSuppliedToWorldwide" name="NumberOfLargeHeavyComponentsSuppliedToWorldwide" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_OtherAccountsReceivableMember" name="OtherAccountsReceivableMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_OtherAssetCategoryMember" name="OtherAssetCategoryMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_OtherComprehensiveIncomeDefinedBenefitPlansNetGainLossRecognizedInNetPeriodicBenefitCostNetOfTax" name="OtherComprehensiveIncomeDefinedBenefitPlansNetGainLossRecognizedInNetPeriodicBenefitCostNetOfTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_OtherIncomeExpenseNet" name="OtherIncomeExpenseNet" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_OtherNonCurrentAssetsPolicyTextBlock" name="OtherNonCurrentAssetsPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_PartnershipsWithSecurityHoldingsMember" name="PartnershipsWithSecurityHoldingsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_PensionPlansPostretirementAndOtherEmployeeBenefitsLineItems" name="PensionPlansPostretirementAndOtherEmployeeBenefitsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_PensionPlansPostretirementAndOtherEmployeeBenefitsTable" name="PensionPlansPostretirementAndOtherEmployeeBenefitsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_PercentageOfCommonStockDistributedDueToSpinoff" name="PercentageOfCommonStockDistributedDueToSpinoff" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_PercentageOfCommonStockReceivedInSpinOff" name="PercentageOfCommonStockReceivedInSpinOff" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_PerformanceGuaranteesOutstandingAmount" name="PerformanceGuaranteesOutstandingAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_PerformanceLetterOfCreditMember" name="PerformanceLetterOfCreditMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_PowerGenerationBusinessMember" name="PowerGenerationBusinessMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ProductWarrantyAccrualWarrantDiscount" name="ProductWarrantyAccrualWarrantDiscount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ProfessionalServicesSpinOff" name="ProfessionalServicesSpinOff" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_QuarterlyFinancialDataLineItems" name="QuarterlyFinancialDataLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_QuarterlyFinancialDataTable" name="QuarterlyFinancialDataTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_RecognitionOfGainsLossesForPensionAndPostretirementPlans" name="RecognitionOfGainsLossesForPensionAndPostretirementPlans" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ResearchAndDevelopmentExpenseGross" name="ResearchAndDevelopmentExpenseGross" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ResearchAndDevelopmentExpensePaidByCustomers" name="ResearchAndDevelopmentExpensePaidByCustomers" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_RestrictedCashAndCashEquivalentsIncludingPortionFromOtherAssets" name="RestrictedCashAndCashEquivalentsIncludingPortionFromOtherAssets" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="bwxt_RetentionSeveranceChargesSpinOff" name="RetentionSeveranceChargesSpinOff" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_RevenueRecognizedInExcessOfBillingsToCustomer" name="RevenueRecognizedInExcessOfBillingsToCustomer" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="bwxt_RisksAndUncertaintiesTextBlock" name="RisksAndUncertaintiesTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ScheduleOfActuarialGainLossTableTextBlock" name="ScheduleOfActuarialGainLossTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_ScheduleOfAmortizedAndUnamortizedIntangibleAssetsLineItems" name="ScheduleOfAmortizedAndUnamortizedIntangibleAssetsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_ScheduleOfAmortizedAndUnamortizedIntangibleAssetsTable" name="ScheduleOfAmortizedAndUnamortizedIntangibleAssetsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ScheduleOfAssetAllocationByAssetCategoryTableTextBlock" name="ScheduleOfAssetAllocationByAssetCategoryTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ScheduleOfChangesInAccumulatedOtherComprehensiveIncomeLossTableTextBlock" name="ScheduleOfChangesInAccumulatedOtherComprehensiveIncomeLossTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ScheduleOfChangesInCarryingAmountOfOtherIntangibleAssetsTableTextBlock" name="ScheduleOfChangesInCarryingAmountOfOtherIntangibleAssetsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ScheduleOfContractsInProgressAndAdvanceBillingsTableTextBlock" name="ScheduleOfContractsInProgressAndAdvanceBillingsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ScheduleOfDiscontinuedOperationsCashFlowStatementTableTextBlock" name="ScheduleOfDiscontinuedOperationsCashFlowStatementTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ScheduleOfDiscontinuedOperationsIncomeStatementTableTextBlock" name="ScheduleOfDiscontinuedOperationsIncomeStatementTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ScheduleOfIntangibleAssetsTableTextBlock" name="ScheduleOfIntangibleAssetsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ScheduleOfInvestmentsMeasuredAtFairValueTableTextBlock" name="ScheduleOfInvestmentsMeasuredAtFairValueTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_ScheduleOfResultsRelatedToEquityAccountedInvesteesLineItems" name="ScheduleOfResultsRelatedToEquityAccountedInvesteesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_ScheduleOfResultsRelatedToEquityAccountedInvesteesTable" name="ScheduleOfResultsRelatedToEquityAccountedInvesteesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ScheduleOfRetainagesOnContractTableTextBlock" name="ScheduleOfRetainagesOnContractTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirationPeriodMaximum" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirationPeriodMaximum" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentToAssumedVesting" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentToAssumedVesting" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentToAssumedVestingWeightedAverageGrantDateFairValue" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentToAssumedVestingWeightedAverageGrantDateFairValue" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_ShareRepurchaseProgramMember" name="ShareRepurchaseProgramMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_SpinOffPolicyTextBlock" name="SpinOffPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_SpinoffCosts" name="SpinoffCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_StockRepurchaseProgramAdditionalAuthorizedAmountForShareRepurchaseProgram" name="StockRepurchaseProgramAdditionalAuthorizedAmountForShareRepurchaseProgram" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_SummaryOfProceedsGrossRealizedGainsAndGrossRealizedLossesOnSalesOfAvailableForSaleSecuritiesTableTextBlock" name="SummaryOfProceedsGrossRealizedGainsAndGrossRealizedLossesOnSalesOfAvailableForSaleSecuritiesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_TaxCutsAndJobsActOf2017IncompleteAccountingChangeInTaxRateDeferredTaxAssetProvisionalIncomeTaxExpense" name="TaxCutsAndJobsActOf2017IncompleteAccountingChangeInTaxRateDeferredTaxAssetProvisionalIncomeTaxExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_TaxCutsAndJobsActOf2017IncompleteAccountingProvisionalIncomeTaxExpenseBenefit" name="TaxCutsAndJobsActOf2017IncompleteAccountingProvisionalIncomeTaxExpenseBenefit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_TaxCutsandJobsActIncompleteAccountingChangeinTaxRateValuationAllowanceProvisionalIncomeTaxBenefit" name="TaxCutsandJobsActIncompleteAccountingChangeinTaxRateValuationAllowanceProvisionalIncomeTaxBenefit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="bwxt_TaxSharingAgreementPercentage" name="TaxSharingAgreementPercentage" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_TechnicalServicesMember" name="TechnicalServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_TermLoanCreditFacilityMember" name="TermLoanCreditFacilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_ThirtyDayLondonInterbankOfferedRateLiborPlusMember" name="ThirtyDayLondonInterbankOfferedRateLiborPlusMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_ThriftPlanAndMiiThriftPlanMember" name="ThriftPlanAndMiiThriftPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_ThriftPlanMember" name="ThriftPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_TradingSecuritiesAccumulatedGrossUnrealizedGainbeforeTax" name="TradingSecuritiesAccumulatedGrossUnrealizedGainbeforeTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="bwxt_TradingSecuritiesAccumulatedGrossUnrealizedLossbeforeTax" name="TradingSecuritiesAccumulatedGrossUnrealizedLossbeforeTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="bwxt_TwoThousandAndTenLongTermIncentivePlanMember" name="TwoThousandAndTenLongTermIncentivePlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_TwoThousandTwelveLongTermIncentivePlanMember" name="TwoThousandTwelveLongTermIncentivePlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_U.S.DollarTermLoanFacilityMember" name="U.S.DollarTermLoanFacilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_UnconsolidatedAffiliatesMember" name="UnconsolidatedAffiliatesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="bwxt_UnrecognizedTaxBenefitsIncreaseResultingFromOther" name="UnrecognizedTaxBenefitsIncreaseResultingFromOther" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_UnsuccessfulOutcomeofFrameworkAgreementMember" name="UnsuccessfulOutcomeofFrameworkAgreementMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_UsEquityMember" name="UsEquityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="bwxt_UsGovernmentSecuritiesMember" name="UsGovernmentSecuritiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
</xsd:schema>
