In essence, it has not been dropped, but stymied. EPA was not able to get OMB approval for the rule, so EPA has been trying to use other means to establish 15 mrem as a standard. Part of that effort has been directed at NRC. NRC's response is that the cleanup standard contained in 40 CFR 192 (5 pCi/g Ra-226 above background in the first 6 inches, 15 pCi/g in any subsequent 6-inch layer) calculates to more than 15 mrem/year. EPA then published a dose calculation supposedly showing that the 5/15 standard calculates to a dose of about 20 mrem/year, which according to EPA is the "same as" 15 mrem/year. In response to this and other issues, EPA, NRC, DOE and others established the Interagency Steering Committee on Radiation Safety (ISCORS). That group is alive and active today.
John Hamrick
Manager HS&EA
Umetco Minerals Corp.
Chairman, Uranium Environmental Subcommittee
National Mining Association
hamricjs@ucarb.com