Comparison of Natural Background Dose Rates for Residents of the Amargos Valley, NV, To Those in Leadville, CO, and the States of Colorado and Nevada

摘要

In the latter half of 2005, the U.S. Environmental Protection Agency (USEPA) published a Proposed Rule (40 CFR Part 197) for establishing a dose rate standard for limiting radionuclide releases from the proposed Yucca Mountain high-level radioactive waste repository during the time period from 10(sup 4) to 10(sup 6) years after closure. The proposed standard was based on the difference in the estimated total dose rate from natural background in the Amargosa Valley and the average annual background radiation for the State of Colorado. As defined by the USEPA, natural background radiation consists of external exposures from cosmic and terrestrial sources, and internal exposures from indoor exposures to naturally-occurring radon. On the basis of its assessments, the USEPA estimated that the difference in the dose rate in the two identified areas was 3.5 mSv y(sup -1). The purpose of this review was to provide an independent evaluation and review of this estimate.