The Radiation Exposure Compensation Reauthorization Act extends the period for filing claims under the Radiation Exposure Compensation Act (RECA) and significantly expands its scope. It introduces new compensation for individuals affected by Manhattan Project waste, covering those physically present for at least two years in specified ZIP codes in Missouri, Tennessee, Alaska, and Kentucky who contracted a specified disease. Compensation for these new claimants is $50,000 or documented out-of-pocket medical expenses for living individuals, or $25,000 for surviving spouses or children.

The bill extends the RECA fund's termination by six years and broadens eligibility for individuals exposed to atmospheric nuclear testing. It expands the affected areas and extends the exposure period for "downwinders" to November 6, 1962, while increasing compensation for leukemia and other specified diseases to $100,000. Additionally, chronic lymphocytic leukemia is now included as a compensable specified disease for these claims.

For uranium miners, millers, and ore transporters, the legislation extends the eligible employment period to December 31, 1990, and adds core drillers as a compensable category. It also expands the list of compensable conditions to include renal cancer and other chronic renal diseases, and allows for combined work histories to establish eligibility. The bill expands the use of affidavits as evidence for employment history and physical presence, requiring the Attorney General to issue revised regulations considering tribal customs for proof.

The claim filing period is extended by five years, and claimants previously denied can resubmit their claims up to three times. Successful claimants can also request additional compensation if eligible under the new provisions. Furthermore, the Act establishes a grant program to study the epidemiological impacts of uranium mining and milling on non-occupationally exposed individuals and includes uranium workers in the Special Exposure Cohort under the Energy Employees Occupational Illness Compensation Program Act. A GAO study is mandated to assess unmet medical benefits for radiation-exposed individuals.