The USA Environmental Protection Agency (EPA) expects to complete its radiation standards for nuclear waste storage at the Yucca Mountain waste repository by September.
The move, which is a few months later than expected, follows a federal appellate court rejection of the EPA's radiation standards for up to 10,000 years for the Yucca Mountain site.
The standards, established in 2001, were deemed to be inconsistent with National Academy of Sciences recommendations on setting standards related to the peak dose.
Since last December the EPA has been working to revise the standards and is focusing on three alternatives. These include: a clear restatement of the radiation standards and their objectives; continuation of the 10,000 year standard; and development of a more more qualitative standard for the post-10,000 year timeframe.