EXHIBIT 21.1

BWX TECHNOLOGIES, INC.

SIGNIFICANT SUBSIDIARIES OF THE REGISTRANT

YEAR ENDED DECEMBER 31, 2020

NAME OF COMPANY			JURISDICTION OF ORGANIZATION			PERCENTAGE OF OWNERSHIP INTEREST
BWXT Investment Company			Delaware			100
BWXT Canada Ltd.			Canada			100
BWXT Government Group, Inc.			Delaware			100
BWXT Nuclear Operations Group, Inc.			Delaware			100
BWXT Nuclear Energy, Inc.			Delaware			100
Nuclear Fuel Services, Inc.			Delaware			100
BWXT Modular Reactors, LLC			Delaware			100
BWXT mPower, Inc.			Delaware			100
BWXT Nuclear Energy Canada Inc.			Canada			100
BWXT ITG Canada, Inc.			Canada			100
BWXT Advanced Technologies LLC			Delaware			100

The subsidiaries omitted from the foregoing list, considered in the aggregate as a single subsidiary, do not constitute a significant subsidiary.