; . (e) Dates of operation of uranium mine Section 5(a)(2)(A) is amended by striking December 31, 1971 and inserting December 31, 1990 . (f) Special rules relating to combined work histories Section 5(a) is amended by adding at the end the following: (4) Special rule relating to combined work histories for individuals with at least one year of experience An individual meets the requirements of this paragraph if the individual worked in one or more of the positions referred to in paragraph (1)(A)(ii)(III)(bb) for a period of at least one year during the period described in paragraph (1)(A)(i)(I). (5) Special rule relating to combined work histories for miners An individual meets the requirements of this paragraph if the individual, during the period described in paragraph (1)(A)(i)(I), worked as a miner and was exposed to such number of working level months of radiation that the Attorney General determines, when combined with the exposure of such individual to radiation through work as a miller, core driller, or ore transporter during the period described in paragraph (1)(A)(i)(I), results in such individual being exposed to a total level of radiation that is greater or equal to the level of exposure of an individual described in paragraph (4) . . (g) Definition of Core driller Section 5(b) is amended— (1) by striking and at the end of paragraph (7); (2) by striking the period at the end of paragraph (8) and inserting ; and ; and (3) by adding at the end the following: (9) the term core driller means any individual employed to engage in the act or process of obtaining cylindrical rock samples of uranium or vanadium by means of a borehole drilling machine for the purpose of mining uranium or vanadium. . 6. Expansion of use of affidavits in determination of claims