Following Japan's nuclear plant disaster, operators at some U.S. plants have been running scenarios of the accident through their computer simulators, to see how they would respond to the unprecedented chaos.

Yesterday, U.S. nuclear industry leaders told them to cut it out.

Stay focused on running your plants safely, said Tony Pietrangelo, chief nuclear officer of the Nuclear Energy Institute, and Charles "Chip" Pardee, chief operating officer of Exelon Generation Co., the largest U.S. nuclear plant operator.

Their admonition was part of the goals for a new nuclear industry program to respond to the Fukushima Daiichi accident that was announced yesterday by NEI, collaborating with the Institute of Nuclear Power Operations (INPO), the industry-funded safety assessment organization, and the Electric Power Research Institute, the primary industry research and development group.

The Fukushima Response Steering Committee formed by the three groups will look at whether the current guidelines for dealing with extreme threats to the plants -- the so-called Severe Accident Management Guidelines, or SAMGs -- should remain voluntary. The committee will consider ways of strengthening cooling systems for spent fuel pools; whether emergency generators need to be prepared to run longer when outside power supplies are cut off, and whether the industry should standardize key backup equipment to enable plants to share equipment in crises.

The first of the industry group's strategic goals, surprisingly, instructed U.S. plant operators to stop reacting to the Japanese disaster.

"We cannot forget about the 104 [U.S.] plants," Pietrangelo said. "That is our top priority. While we recognize we have to do a response to the events at Fukushima, it can't be at the expense of the attention of the current operating fleet." The message was: Let the Fukushima committee deal with the Japanese accident consequences.

"The first goal is to assure that our station operating staffs are focused on running our stations to the very best of their abilities," said Pardee.

Concern about a shift of training focus

"The last thing we can do at this point in time is allow ourselves to become distracted, shift our focus to events that are occurring 14,000 miles away, as opposed to what is occurring at our stations on a day-to-day basis," he said.

Since Fukushima, U.S. nuclear plants have undergone detailed checks of emergency response equipment and procedures by resident Nuclear Regulatory Commission (NRC) inspectors and INPO peer group evaluators. But Pardee said that was not the distraction he referred to.

"We have had the temptation at some of our stations, in a relatively impromptu fashion, to start running simulator scenarios of what happened over there, which is really fascinating," Pardee said. "We have the ability with our simulators to program in that sequence of events and watch our operators respond," he said. The simulators are essential to the training plant operators receive in emergency responses.

"While there is an extraordinary temptation to go do that, we think it would be a mistake to deviate from the very well-thought-out training plans that we have in a knee-jerk fashion. The day will come when the industry does in fact spend more time on those extraordinary events, that we think have a very, very low probability of occurring, but if we don't know what we're looking for, if we don't confirm that the simulators really are programmed correctly for those way-beyond design basis events, it becomes counterproductive," he said.

The Fukushima steering committee's assignment will be to assess whether the Japanese calamity requires U.S. plants to install additional layers of defenses against the "unthinkable," Pardee said.

One of the post-Fukushima investigations ordered by the NRC looked at the procedural guidelines at each of the 66 U.S. reactor plants for dealing with "severe accidents" involving damage to the reactor fuel core. The SAMG instructions are not part of the mandatory safety measures plants must have in place that are subject to regular NRC inspection, because the NRC regulation is predicated on preventing such an "unthinkable" meltdown. Instead, the industry adopted the guidelines on a voluntary basis in the 1990s.

Confronting a difficult balance

David Lochbaum, who heads the nuclear safety program of the Union of Concerned Scientists, told a congressional panel month: "The [NRC] staff concluded that regular inspection of SAMGs was not appropriate because the guidelines are voluntary and have no regulatory basis."

"The NRC never checks -- repeat, never checks -- the guidelines to see if they would be effective under severe accident conditions," Lochbaum emphasized.

The NRC reported this week that its review of the SAMG procedures found that only 42 percent of the plants included the SAMGs in their periodic reviews of emergency procedures, and that only 61 percent of plants periodically include the guidelines in their emergency drills.

"While overall we believe plants are safe and all of the NRC's efforts aim to ensure the plants never need to use these guidelines, we are concerned that our inspectors found many of the plants have work to do in either training their staff on these procedures or ensuring the guidelines are appropriately updated," said Eric Leeds, director of NRC's Office of Nuclear Reactor Regulation.

An NRC task force is making a short-term assessment of the implications of the Fukushima accident for U.S. plants and is expected to report findings to the NRC commissioners in mid-July. A longer-term assessment of lessons and possible policy changes will follow.

"We have this constant debate as to whether we should be training on the more probable, less severe events, or the less probable, more severe events," Pardee said. "I think the NRC inspection report will cause us to step back and look at that balance across the industry."