Aug. 22--The rate of cancer deaths near nuclear reactors will be the subject of a major national study to be conducted by federal regulators.

In 1990, a National Cancer Institute report on the subject found cancer mortality rates were "generally not elevated for people living in the 107 U.S. counties containing or closely adjacent to 62 nuclear facilities," according to information provided by the Nuclear Regulatory Commission's Office of Regulatory Research.

Since data used in that study relies on records from 1950 to 1984, the NRC decided last year it was time to revisit the controversial issue, with an eye to its impact on human health, said Scott Burnell, a spokesman for the NRC.

"It hasn't been a formal request, but the topic comes up often enough (at public meetings) that the staff said, 'Yes, it's about time we come up with an up-to-date work product we can refer people to.' When 20 years have passed and research methods and tools have evolved over time, it's reasonable to see if there's a more refined research project that can be put together."

Still in the early stages, the new study began last October and is scheduled to result in a final report two years from now. The primary focus would be to look at cancer mortality in the counties that have nuclear reactors, Burrell said. Using new scientific tools to narrow the scope from counties to smaller geographical units like towns or ZIP codes is also a possibility as the study evolves, he said.

What the study would not address, but could become a topic for future scrutiny, depending on the findings, would be whether any specific effluent or radiation dose from particular operating and closed plants causes cancer, he said.

However, this study could lead to another one on the incidence of cancer around nuclear power plants, which would likely cover people diagnosed with the disease, Burrell said.

The nuclear industry measures and monitors radiation releases to make sure they are below what have historically been considered safe thresholds, but the subject continues to attract the critical attention of nuclear watchdogs such as Beyond Nuclear and the Connecticut Coalition Against Millstone.

Millstone Power Station in Waterford is home to two operating reactors and one that is shut down. The Connecticut Yankee reactor in Haddam Neck has been shut down, also. Dominion regularly updates its Web site with data on atmospheric radioactive releases, a requirement added in state law last year.

Watchdog Paul Gunter, Beyond Nuclear's director of reactor oversight, cited conflicting results from other studies done as far away as Germany and as close as Massachusetts.