Terry Gerton Let’s talk about the Nuclear Regulatory Commission and a new rule that’s out for comment. What exactly here is the NRC proposing to change and why has it generated such a strong reaction from the radiation safety advocacy community?

Edwin Lyman The NRC’s proposed rule takes on a wide range of requirements for protection of the public and workers and the environment against the exposure to ionizing radiation, and this is a very controversial action in part because it was directed by the Trump administration’s executive order 14300, which was issued last May. And which directed the Nuclear Regulatory Commission to take on a large number of activities, including reevaluating the way it regulates radiation risk. And because that is a political mandate and not a technically grounded one, this raises concern that the administration is trying to get not only the Nuclear Regulatory Commission, but also the Department of Energy to reduce its protections for the public and for workers against radiation exposure and the risks that come from that, including the potential for cancer.

Terry Gerton There’s some terminology here in the Union of Concerned Scientists statement that I want to make sure we clarify for our listeners. You note that the NRC continues to accept the linear no-threshold model, and you mentioned ionizing radiation as well. Break down for us what that model says about risk and exposure, and what kind of radiation ionizing radiation is.

Edwin Lyman Ionizing radiation is that kind of radiation which is energetic enough that it can strip electrons from atoms and molecules. And so that kind damage to living things can affect, for instance, DNA and affect the ability of those cells to function properly. And so when radioactive materials decay or undergo fission, they release highly radioactive materials which can affect living things like the human body in different ways. And one of the most dangerous is its potential for disrupting genetic material and affecting cell division and potentially leading to cancer. And ionizing radiation exposure is one of most well understood carcinogens in humans. The linear no-threshold model. Is based on largely extrapolating epidemiological studies. So for instance, the Hiroshima and Nagasaki bombings in Japan in 1945, in addition to killing hundreds of thousands of people outright, also exposed many more to ionizing radiation. And that is leading to an epidemic of cancer among those survivors. And that provided a very good database for trying to understand the impacts of ionizing radiation. But there’s a lower limit … to the exposures to radiation that can be definitively associated with an outcome like cancer. And when you go below that limit, the data itself is not statistically significant. So people speculate about how dangerous radiation is at low doses, lower than what these studies can show. And so some people believe that perhaps there’s a threshold and there’s safe level of radiation. Others might believe that low level radiation is actually good for you. But the general scientific consensus is that even, you know, there’s no safe dose of radiation. And that’s essentially what the linear threshold model says, Not only is there no safe dose, but also that the harm, in particular the risk of cancer, is proportional to the dose.

Terry Gerton And as a result of that model, then, the prevailing practice has been to keep the radiation exposure as low as reasonably achievable, or ALARA. The NRC rule proposes to remove that standard. Why would that be such a significant change?

Edwin Lyman Yes, the ALARA standard actually has been, I think, misconstrued. It was originally introduced as a way to help the operators of nuclear facilities, for example, by not specifying very strict limits for radiation exposure, but allowing them to take economic considerations into account when they set their own radiation limits. So it was actually supposed to be, you know, essentially a relaxation of standards for these facility operators. But it’s been misinterpreted now as an effort to force, again, operators of nuclear facilities to drive down doses as low as possible without regard to the cost. And the claim is that that’s related to the notion that because there’s no safe dose, you might as well try to drive those doses down to zero. But in fact, ALARA was a way to essentially justify not reducing doses all the way to zero, however, it has led to good practices, for instance, for occupational radiation exposure that have led to US nuclear workers receiving relatively low doses compared to the regulatory limits, and that can be attributed to ALARA, but it’s also again, good industrial hygiene practice.

Terry Gerton Dr. Edwin Lyman is director for nuclear power safety at the Union of Concerned Scientists. So Dr. Lyman, put this in practical terms. If these changes move forward, what could happen differently at nuclear facilities or cleanup sites or workplace that concerns you the most?

Edwin Lyman I would sum up this NRC proposed rule as saying that, yes, we understand that there’s no safe dose of radiation, but we don’t have to restrict radiation exposure as much, and we can allow it to increase because the resulting health impacts will be reasonable in comparison to the nation’s or the Trump administration’s goal of greatly expanding nuclear power. So they’re essentially saying that, yes, if we implement this rule, it could lead to more cancers among radiation workers and the public, but that’s okay because we need more nuclear power. And that, to my mind, that is not the appropriate risk-benefit equation here. In fact, the biggest impacts could well be on radiation workers, and as I said, their doses are, on average, pretty low across the United States, but this rule could actually allow them to receive the more than 25 times the current average dose that they get as part of this initiative to relax standards. And by relaxing those standards, it’s simply a way of enabling nuclear facility operators to save money at the expense of providing good protection for workers. And it could lead to sloppier industrial practices, more potential accidents, more spills, less cleanup, and that isn’t exactly an enticing environment for an industry that wants to attract more workers for what they see as a significant expansion. So I think it’s wrong-headed in that respect as well, but we shouldn’t be trying to save a little money at the expense of worker health and safety.

Terry Gerton The rule is currently in its public comment phase. What questions do you think the NRC needs to answer before it makes a final decision here?

Edwin Lyman I think the NRC needs to justify in much greater detail why it thinks the eliminating ALARA is a good idea, independent of the Trump administration’s dictum, because again, it could have a lot of unintended consequences, not only by discouraging more nuclear workers from entering the field, but also by increasing public concern. Possibly reducing public acceptance for nuclear power so that they need to provide a much better justification for why they think they can relax these standards, allow the public workers and the environment to all experience greater levels of radiation, how they can allow that to happen without providing a good technical justification.