U.S. NRC Blog

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Examining the Reasons for Ending the Cancer Risk Study

Scott Burnell
Public Affairs Officer

One way NRC regulations protect communities around U.S. nuclear power plants is by requiring the plants to regularly sample air, water, and vegetation around their sites. Results of this sampling are sent to the NRC (and in some cases state agencies) to show only very tiny amounts of radioactive material are released during normal operations.

Even with this scrutiny — and a 1990 study showing no difference in cancer mortality rates between those living near U.S. reactors and those living elsewhere — questions persist about cancer risk from nearby reactors. The NRC had worked with the National Academy of Sciences (NAS) since 2010 on a study into the potential cancer risk of living near a U.S. nuclear power plant. But we ended this work earlier this month after a hard look at the low likelihood of getting usable results in a reasonable time frame.

radiationsymbolWhy are we comfortable that this decision, also driven by our budget situation, is in line with our mission to protect public health and safety?

First and foremost, the staff considered existing conditions around U.S. reactors, as shown by the ongoing environmental sampling and analysis we mentioned earlier. That evidence supports the conclusion that the average U.S. citizen’s annual radiation dose from natural sources, such as radon and cosmic rays, is about a hundred times greater than the largest potential dose from a normally operating reactor.

This information shows how complicated it would be to single out an operating reactor’s potential contribution to cancer risk. Researchers looking for small effects need a very large study population to be confident in their results. The NAS discussed this issue in its report on Phase 1 of the cancer risk study. The NAS said that the effort “may not have adequate statistical power to detect the presumed small increases in cancer risks arising from… monitored and reported releases.”

The NRC staff examined the NAS Phase 2 report plans to validate the methods recommended in Phase 1. The Academy was very clear that the pilot study at seven U.S. sites was unlikely to answer the basic risk question. The NAS proposal said: “any data collected during the pilot study will have limited use for estimating cancer risks in populations near each of the nuclear facilities or for the seven nuclear facilities combined because of the imprecision inherent in estimates from small samples.”

The pilot study would also examine potential differences between individual states’ cancer registries. Large differences in registry quality or accessibility would hurt the study’s chances of generating useful results.

The NAS concluded they would need more than three years and $8 million to complete the pilot study. If the pilot succeeded, expanding the research to all U.S. operating reactors would require additional years and tens of millions of dollars. The NRC decided that in our current budget environment the time and money would not be well spent for the possible lack of useful results.

The NRC agrees with the NAS that the study’s overall approach is scientifically sound. Interested individuals or groups can examine the NAS Phase 1 and 2 reports for a more detailed discussion of the methods and resources needed to conduct the proposed study. The NRC staff will examine international and national studies on cancer risk to see if we should conduct any future work in this area.

43 responses to “Examining the Reasons for Ending the Cancer Risk Study

  1. Kelly Wilson May 19, 2017 at 1:11 pm

    The NRC is not looking out for the public there supporting the nuclear power industry and not doing their job for Public Safety! This should be criminal they should do their job. With nuclear power plants dotted all over the nation the entire population is at risk. The scientific study must be completed. No excuses!

  2. agustin December 11, 2016 at 9:11 am

    IMO those reactors have been a very good investment in useful infrastructure by our parents generation. Now it is time for us to do even better for our children by investing in modern versions of capable, safe, emission free nuclear power plants. Regarding costs, the cost and risk is already ridiculous for nuclear power, it should be abandoned. Nuclear power is an excuse to generate money for the nuclear energy industry. Current nuclear construction is increasing our power bills. Your comment Mr. Williamson indicates your willingness to sacrifice safety for money savings for the nuclear industry.

  3. Rabby November 3, 2015 at 5:36 am

    It is true that research into the risk of cancer next to nuclear plants is needed, but given the costs outlined of this study is it any surprise that the research has been called off? With budgets like they are, who wouldn’t raise a fuss about these figures? Where would the money be coming from – taken away from another project or program? Hopefully a more cost effective way of treating the research can be developed in the future.

  4. charles ostdiek October 18, 2015 at 11:27 pm


    will you please evaluate this new study?
    –charles ostdiek
    cochair, green party of the u.s.
    cochair, nebraska green party

    • Moderator October 20, 2015 at 8:29 am

      The study made many assumptions about a closely monitored population of radiation workers. From this the researchers concluded that there was an association (not a direct cause and effect) between those workers’ doses and the occurrence of leukemia. It would be difficult to try and apply such study results to the general public. The study included more than 300,000 people from several countries. This is an example of the difficulty in assembling a large enough population to study very small health effects.

      Scott Burnell

      • Garry Morgan October 20, 2015 at 12:37 pm

        Here is a larger group whose health problems have been confirmed. “The above numbers of applications filed represent 108,584 unique individual workers.” Atomic Energy workers – http://www.dol.gov/owcp/energy/regs/compliance/weeklystats.htm

        Two other groups whose ill health effects have been confirmed as a result of low level radiation exposures – 1)Tobacco use group, largest cause of lung cancer: http://www3.epa.gov/radtown/tobacco.html#about 2) Radon exposure group: ” Radon (chemical symbol Rn) is an odorless, colorless, radioactive gas. It is the leading cause of lung cancer for U.S. residents who have never smoked.” http://www2.epa.gov/radiation/radionuclide-basics-radon

        Combine the cumulative effects of Radon exposure and Cigarette smoking, you have an example of the effects of compounding two known causes of cancer, both relate to low level ionizing radiation exposures. Combine the cumulative effects of ionizing radiation from the work place, individual exposures due to close proximity of an ionizing radiation source emitting radionuclides or energy sources such as x-ray or gamma, life styles, and radon exposure, the risk of cancer is greatly increased. This reasoning also dispels the radiation hormesis theory which ‘nuclear fanatics’ embrace and is before the NRC in an attempt to change the “no-threshold dose-response relationship between exposure to ionizing radiation and the development of cancer in humans.”

        Radiation safety and health of the populace – Environmental bioaccumulation, cumulative health effects of pollution in communities where nuclear facilities are proposed or currently located are all issues which are not taken into consideration by the NRC regarding whether a nuclear reactor should be licensed or relicensed. The NRC’s main focus is that of economics, not radiation safety as it applies to community health in licensing approvals.

        The NAS study would have interfered with your base value – money flowing into and from the nuclear industry which finances your existence, instead of studies which support radiation safety, human health and life.

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