; or (B) the date that is 10 years after the date of enactment of this Act. (2) Contents If the Administrator decides not to implement a recommendation in the safety research report described in subsection (a), the Administrator shall provide, as a part of the report required under paragraph (1), a description of why the Administrator did not implement such recommendation. 322. Study on radiation exposure (a) Study Not later than 120 days after the date of enactment of this Act, the Secretary shall seek to enter into appropriate arrangements with the National Academies of Sciences, Engineering, and Medicine under which the National Research Council of the National Academies shall conduct a study on radiation exposure to crewmembers onboard various aircraft types operated under part 121 of title 14, Code of Federal Regulations. (b) Scope of study In conducting the study under subsection (a), the National Research Council shall assess— (1) radiation concentrations in such aircraft at takeoff, in-flight at high altitudes, and upon landing; (2) the health risks and impact of radiation exposure to crewmembers onboard aircraft operating at high altitudes