Scientists and environmentalists said Monday that radiation limits proposed for the Yucca Mountain (search) nuclear waste dump in Nevada aren't strict enough to protect the public.

"This rule is a transparent attempt to accommodate the industry," Arjun Makhijani, a nuclear physicist who has been critical of the Yucca project, told reporters on a conference call a day ahead of an Environmental Protection Agency hearing on draft regulations.

"In the proposed EPA rule, every norm of radiation protection that has been established for the general public since the late 1950s ... is to be thrown overboard," Makhijani said.

The EPA in August proposed limiting exposure near the planned dump to 15 millirems a year for 10,000 years into the future, then increasing the allowable level to 350 millirems a year for up to 1 million years.

That higher level is more than three times what is allowed from nuclear facilities today by the Nuclear Regulatory Commission (search). A standard chest X-ray is about 10 millirems.

The 350 millirem level is "an extremely unacceptable risk," said Dr. Robert M. Gould, chairman of Physicians for Social Responsibility's security committee. He said that annual exposure to that level of radiation over a lifetime would carry a one in 36 chance for someone to develop cancer.

EPA spokesman John Millett emphasized that the rule is a draft and a final standard won't be issued until after the public comment period ends Nov. 21. Tuesday's meeting at EPA headquarters is the agency's fifth and final public hearing on the rule; the four earlier hearings were in Nevada.

"It's a draft rule at this point, but again, the rationale for the 350 additional millirems from 10,000 years and beyond deals with the amount of uncertainty that we're faced with in projecting out 10,000 years, in addition to being equivalent to radiation levels commonly experienced in other parts of the mountain West," Millett said.

Scientists on Monday's call disagreed with EPA's decision to link its draft rule to so-called "background radiation" that occurs naturally in the environment, arguing that such radiation can be dangerous in itself and that some EPA estimates of it were too high.

The planned Yucca Mountain dump is designed to hold 77,000 tons of radioactive waste, mostly spent fuel from nuclear reactors, beneath a volcanic ridge 90 miles northwest of Las Vegas.

The EPA issued the draft rule now under consideration after a federal court said the agency's first standard was inadequate because it didn't establish exposure limits beyond 10,000 years.

The dump's opening date has been repeatedly delayed and is now expected in 2012 or later.