People play at the beach near the San Onofre Nuclear Generating Station… (Allen J. Schaben / Los Angeles…)
The last time federal officials assessed cancer rates in the communities surrounding nuclear power plants, they concluded that radiation releases were insignificant and health risks, if any, were too small to measure.
TheU.S. Nuclear Regulatory Commissionhas been relying on the results of that 1990 National Cancer Institute study ever since to inform the public about cancer risks posed by the 104 licensed reactors it governs nationwide.
Now, in response to growing concerns that using uranium in the production of electrical energy may be dangerous even without accidents, the NRC is trying to decide if it should launch one of the largest epidemiological studies ever conducted to determine if it is a health risk to live near a nuclear facility — such as the San Onofre plant in north San Diego County.
"We can do a far better job of determining cancer risks with the state-of-the-art analytical tools and databases available today," said John Burris, chairman of the team of National Academy of Sciences experts commissioned by the NRC to develop the proposal.
"The 1990 effort had lots of problems," Burris said. For example, it was based on countywide mortality data, which made it difficult to discern effects in the immediate vicinity of nuclear facilities. It also looked at cancer mortality rather than incidents of cancer, which are better indicators of risk because advances in cancer treatments have lowered mortality rates.
Another motivation for wanting to revisit the issue is that recent epidemiological studies in Germany and France found that children living near certain nuclear reactors were twice as likely to develop leukemia.
In the United States, about 1 million people live within five miles of operating nuclear plants, and more than 45 million live within 30 miles, nuclear regulatory officials said.
The five-member NRC is expected to vote later this year on a proposal to investigate cancer rates in each census tract within a 30-mile radius of a nuclear reactor and assess cancers in children younger than 15 years old by reviewing their mothers' proximity to a nuclear facility during pregnancy. It would also review cases of leukemia, a cancer associated with radiation exposure of children.
Should the NRC decide to proceed, the National Academy of Sciences has recommended starting with a pilot study to verify whether those approaches could be conducted on so large a scale and help estimate the time and costs involved. That pilot would focus on seven nuclear facilities representing a variety of engineering designs and operating histories, including San Onofre, the only site west of the Mississippi to be chosen.
San Onofre, which is majority owned and operated by Southern California Edison, has been out of commission for more than six months because of potentially dangerous equipment problems. The study area around it would encompass 2.4 million people in more than 50 cities, including Laguna Beach, Huntington Beach, Costa Mesa, Santa Ana, Tustin, Lake Elsinore, Temecula, Oceanside, Escondido, Solana Beach and all of Camp Pendleton.
In a prepared statement, Edison spokeswoman Jennifer Manfre said the utility "looks forward to the study results."
Challenges to carrying out the study include that the availability and quality of data on radiation released by nuclear facilities and on cancer mortality and incidents of cancer vary from reactor to reactor and state to state. Another problem would be population mobility, which could make it difficult to determine exactly where an individual lived when contracting cancer.
In addition, the effects of low doses of radiation from nuclear facilities could be masked by histories of smoking, drinking or working under potentially toxic conditions, as well as exposure to other sources, such as CT scans and other medical procedures, officials said.
Given the uncertainties, "It's a risky study because nobody will be completely happy with the results, that's for sure," said Daniel O. Stram, associate professor of preventive medicine, division of biostatistics, USC Keck School of Medicine and Children's Cancer Group.
Many people living near San Onofre believe that's a risk worth taking.
"The implications of this study could be profound," said Roger Johnson, a retired neuroscience professor and member of the nonprofit environmental group San Clemente Green. "If it finds higher cancer risks at one or more nuclear power plants, there will be enormous public pressure to shut down all of them."
Laguna Beach environmental activist Marion Pack, however, expressed mixed feelings about the proposal. "An epidemiological study might answer some questions about long-term effects, but it would take millions of dollars and years to complete," she said. "I'd rather see that time and money spent on dealing with immediate concerns such as the possibility of radiation exposure in the event of an earthquake or an accident."
San Onofre has been out of service since Jan. 31, when operators discovered a small leak in one of the thousands of steam generator tubes that carry hot, radioactive water used to create steam to turn turbines that generate electricity. The NRC has ordered Edison to keep the plant shut down until it has determined the cause and how to fix it.