US nuclear safety goals are insufficient, and don’t address effects like those seen after the Fukushima disaster in Japan, the head of the US nuclear regulator says.

US nuclear safety goals have to change because, as they now stand, the Fukushima Daiichi accident is “acceptable” because no one was injured or killed by radiation, said US Nuclear Regulatory Commission Chairman Gregory Jaczko.

The goals, which undergird the US regulatory approach, focus on ensuring public health isn’t harmed by nuclear plants, he said. But those goals don’t directly address what is happening today in Japan: radioactive contamination of land that’s preventing up to 90,000 people from returning home, a year after the four-reactor accident.

Jaczko said that shows the goals are “insufficient.”

Evacuation Intolerable

“We somehow have to incorporate what the public is willing to tolerate,” and that “clearly” does not include long-term evacuations that bar people from their land, Jaczko told NRC’s annual Regulatory Information Conference.

The chairman said that setting such a safety goal is a “complex question” and would not be easy, adding he hasn’t figured out the best approach yet. He said “outside groups” will be making proposals this week, but didn’t elaborate.

NRC Commissioner William Magwood said the Department of Energy’s Generation IV reactor design program, which he initiated, had “no off-site accident consequences” as one design criterion. Designers had to show their concepts could withstand worst-case accidents with no effects outside the plant site.

But Gen IV involved designing reactors from scratch. “I’m not sure how you do that for our current reactors,” Magwood said, adding he expects the commissioners to begin tackling the subject this summer.

NRC’s safety goals require nuclear plants to keep the risk of a severe accident, as calculated by engineers using probabilistic risk assessments, below one in 10,000 reactor-years of operation, and to keep any doses to the public to tiny fractions of the radiation everyone receives naturally.

Jaczko said one possible approach is to add a very low probabilistic goal for off-site contamination.

A simpler approach, more easily understood by the public, he said, would be to set a standard of “no evacuations needed.”

All US plants now have detailed evacuation plans, worked out with local, state and federal first responders and tested every two years. Emergency planning became required after the 1979 Three Mile Island-2 accident, when nearby residents faced official confusion and contradiction about whether to evacuate.

Magwood said he couldn’t envision a situation in which NRC would stop that kind of contingency planning, even if a safety goal were set and met.

Hear this reporter discuss safety at nuclear power plants in an Breaking Energy podcast here.

Beyond Design Basis

The NRC has looked at the potential costs of long-term land contamination before. In the early 1980s, when NRC was deciding on what post-TMI safety backfits to require, the commissioners debated including costs, like the losses to displaced residents that Fukushima’s neighbors are now experiencing, in cost-benefit analyses. They found those costs added up so quickly, they overwhelmed everything else, so the commission decided not to use them, over the protests of nuclear critics.

Jazcko has previously questioned that decision, but Tuesday he said cost-benefit applies only to “enhancements.” He said NRC should include off-site consequences in its “basic safety requirements,” which would not be subject to cost-benefit considerations.

The NRC’s staff task force on Fukushima recommended that the agency use the accident to integrate its “patchwork” of regulations developed over the last 30 years, including reconciling the divisions that evolved between “design basis” requirements and “beyond design basis” ones for extreme events like Fukushima.

Commissioner George Apostolakis told the RIC conference that advances in risk analysis give NRC an opportunity to respond by setting up a “risk-informed” framework that focuses on the things that are most important for safety.

Commissioner Kristine Svinicki said, since US plants are operating safely, the commission has time to consider and get this issue right. Taking that time “will serve us well over the long term,” she said.