Uranium Miners and Workers Act of 2023 This bill extends and expands eligibility for the Radiation Exposure Compensation Program. This program compensates individuals who were exposed to radiation while employed in uranium mining operations and subsequently developed qualifying medical conditions. Specifically, the bill extends the fund that supports the program for the four years following the enactment of the bill. (The fund currently terminates on June 7, 2024.) It also transfers to the fund a specified amount of unobligated funding appropriated for the COVID-19 response. In addition, the bill expands eligibility for the program in multiple ways. Current law limits eligibility to individuals who were employed between January 1, 1942, and December 31, 1971, as uranium miners, millers, or ore transporters. The bill expands the program by (1) making those employed through December 31, 1978, and those employed as core drillers eligible; and (2) providing compensation for kidney cancers and other chronic kidney diseases to all individuals eligible for the program.