ROCKVILLE -- After more than 12 years of delay and sometimes acrimonious debate, the Nuclear Regulatory Commission issued revised safety regulations yesterday that it said would reduce the risk of radiation-induced cancers among people who work in and live near nuclear facilities.
Independent nuclear experts and anti-nuclear groups, however, promptly rejected as inadequate and outdated the NRC's measures, which are the first full-scale revision of U.S. radiation safety regulations in 30 years.
They pointed out that the new standards were based on guidelines drawn up in 1977 by the International Committee on Radiation Protection, which plans to replace the measures with stricter standards early next year.
The NRC's revised standards would allow facilities such as hospitals, laboratories and power plants to discharge radioactive elements into the air, sewers or soil in concentrations high enough to at least pose a lifetime risk of one death in every 286 people exposed, said Diane D'Arrigo of the Nuclear Information and Resource Service.
The commission's policy, she said, showed "callous disregard for the health risks posed by low-level radiation exposure."
But the NRC, which regulates most of the nation's industrial nuclear facilities, said that the new standards "provide for a substantial increase in the overall protection of the public health and safety."
The new measures include:
* Reducing annual radiation exposure limits for individual members of the public to 100 millirems a year -- one-fifth of current levels and roughly the equivalent of exposure to five chest X-rays.
* Lowering worker exposures to a maximum of 5 rems a year (50 times the general public limit) for internal and external doses combined (although companies may be allowed, under special circumstances, to expose a worker to up to 10 rems a year).
* Requiring companies to implement programs that ensure that radiation doses are kept "as low as is reasonably achievable," instead of merely being urged to do so, as is now the practice.
* Exposing pregnant workers to no more than 500 millirems during pregnancy, if the worker tells the employer about her pregnancy.
Ms. D'Arrigo pointed out that, under an exception in the regulations, nuclear plants would still be allowed to discharge radioactivity up to 500 millirems (five times the new public limit) in sewage, maintaining what she said was a potentially serious health threat.
While reducing individual exposure levels, the new regulations would allow plants to raise the concentrations of many radioactive discharges, either in sewage, vapor, water effluents or solids. These would include tritium (which experts say can produce radioactive water) and radioactive forms of phosphorus, carbon, iodine and cobalt. Plutonium and uranium are among the radioactive elements reduced by the regulations.
Harold Peterson, senior health physicist for the NRC, said the new levels were based on medical and scientific evidence acquired over the last several years, which indicated that some radioactive elements were not as dangerous as previously believed while others required tighter controls.
The new rules "reflect changes in the basic philosophy of radiation protection" and provide "a substantial increase in safety," said Donald Cool, head of the NRC's radiation protection and health effects branch.
Pennsylvania-based anti-nuclear authority Judith Johnsrud said the NRC's willingness to allow plants to discharge higher concentrations of radioactive waste indicated that the commission was trying to bail the industry out of a nuclear waste disposal problem.