THE RECENT federal approval of an evacuation plan for Indian Point is a monument to wishful thinking – to the point of straining credulity.

Both the Nuclear Regulatory Commission and the Federal Emergency Management Agency approved the plan within hours of each other, reflecting economic realities and practical considerations. But they ignored local safety concerns over the nuclear power plant, located on the Hudson River 15 miles north of New Jersey.

Although both agencies called the plan reasonable and adequate, a study commissioned by New York State concluded just the opposite earlier this year, finding that “the current radiological response system and capabilities are not adequate to … protect the people from an unacceptable dose of radiation in the event of a release from Indian Point, especially if the release is faster or larger than [planned for].”

The geographic reality is that more than 300,000 people live within a 10-mile radius of the Westchester County facility, and it would be virtually impossible to respond quickly and effectively in the event of a major radioactive emergency. Major highways are already congested. While the best response in many cases would be for people to stay home until well after the initial radioactive release, that’s not how many people would respond. If you take into account human nature and thousands of cars with panicked drivers, chaos would be inevitable.

The economic reality is that Indian Point, which the Entergy Corp. bought from Con Ed two years ago, provides 2,000 megawatts of clean (and relatively inexpensive to produce) power to New York City and its northern suburbs. That’s enough electricity for 2 million homes.

Opponents of Indian Point say that if the power plant were shut down, the power loss could be compensated for through conservation and other measures. But given the increasing demand for electricity and spiraling energy costs, this doesn’t appear to be a very realistic alternative. Energy prices are market-driven, and they would likely increase for everyone in the region if that much electricity were removed from the power grid.

Federal regulators are justifiably reluctant to pull the plug on a source of so much electricity – especially since they believe that a major radiation release as a result of an accident or terrorist attack is unlikely. But by essentially rubber-stamping the evacuation plan last month in a two-page letter to New York Gov. George Pataki, federal regulators have given themselves a substantial credibility gap. They point out they have already addressed the concerns raised by the earlier New York State study, but they haven’t persuaded anybody.

Regulators must now do their utmost to make sure that Entergy follows through on its promises to make the plant as safe and secure as possible, to address the concerns of people in this region, and to do a much better job of educating the public on evacuation planning.

The $3.5 million that FEMA recently allocated to improve emergency readiness around Indian Point is a step in the right direction, but questions and skepticism from the public remain, and they must be thoroughly addressed.