To amend title 38, United States Code, to revise the eligibility criteria for presumption of service-connection of certain diseases and disabilities for veterans exposed to ionizing radiation during military service.

Includes within the definition of a "radiation-risk activity" for purposes of eligibility criteria for veterans' disability compensation the exposure to ionizing radiation due to residual contamination resulting from participation in a nuclear detonation, without regard to whether any particular level of radiation exposure was measured for that individual.