The U.S EPA yesterday set a standard for how much radiation would be allowed to leak into groundwater, air, and soil at the proposed storage facility for nuclear waste at Yucca Mountain, Nev. The standard is similar to the one proposed by the Clinton administration, capping radiation leaks during the facility’s first 10,000 years to no more than what the average American receives in about two weeks from natural and synthetic sources. Nuclear power advocates say the Yucca Mountain facility must be approved if more nuclear plants are to be built in the country. Energy Secretary Spencer Abraham said the standard meant the facility could be launched, but Nevada’s senators said the standard would help their campaign to block the dump. The nuclear industry’s trade association filed suit yesterday to overturn the radiation limits.