The public’s perceptions about nuclear power have been shaped to some extent by its associations with other nuclear technologies, particularly nuclear weapons, and also by the occurrence of high-profile accidents at nuclear plants: Three Mile Island (TMI) in 1979, Chernobyl in 1986, and Fukushima in 2011.2 Less serious incidents that resulted in unintended and unmonitored releases of radioactive materials from operating plants (e.g., releases of tritium from operating nuclear plants; see Chapter 2) have reinforced these perceptions. Although nuclear accidents are uncommon occurrences, they can have very severe consequences. Moreover, they suggest to some that nuclear technologies are poorly understood and unpredictable and that the nuclear industry and its regulator cannot be trusted to protect the public from these technologies.

The question “Is it safe?3” is perhaps of greatest concern to individuals who have experienced cancer or have family members or neighbors who have experienced cancer. Reassurances by the nuclear industry and its regulator that facility operations are “low risk” are not always seen as credible. In fact, the USNRC has sponsored the present study in an effort to address such concerns. Engaging with members of the public in a Phase 2 study will be important for understanding their concerns about cancer risks.


The risk assessment community usually defines risk in terms of the following three questions, referred to as the risk triplet (Kaplan and Garrick, 1981):

What can happen (i.e., what can go wrong?)?

How likely is it that that will happen?

If it does happen, what are the consequences?

Scientists and policy makers usually view risk in terms of the likelihood of harm from a hazard. In other words, the definition of risk is intertwined with the notion of probability. Technical experts may use probability estimates (for example, one-in-a-million chance of harm) to convey the risk of dying from cancer. However, public perceptions of risks are not shaped solely on the endpoint of a technical analysis, such as the number of cancer deaths in a population near a nuclear plant. Some members of the public

2 The Three Mile Island accident resulted in no discernible health effects from radiation releases, but it nevertheless served to galvanize opposition to the expansion of nuclear power (Walker, 2004).

3 The term “safe” has different meanings to different people. Some people view safety in terms of probability and consequences, whereas others view safety in terms of whether an organization responsible for controlling a hazard is trustworthy.

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