Continued from page 1

The industry expects to meet the 2016 timeline “with the current understood requirements,” Mr. Pollock said. If the requirements change or new regulations are added, “then obviously we would have to review that,” he said.

Even before the new rules are completely in place, the NRC is considering a new regulation related to the Japan disaster: requiring nuclear operators to spend tens of millions of dollars to install filtered vents at two dozen reactors.

NRC staff recommended the filters as a way to prevent radioactive particles from escaping into the atmosphere after a core meltdown. The filters are required in Japan and throughout much of Europe, but U.S. utilities say they are unnecessary and expensive.

The Nuclear Energy Institute said filters may work in some situations, but not all. The group is calling for a “performance-based approach” that allows a case-by-case determination of whether filtering is the best approach to protect public safety and the environment.

“We’re not against filtering. It’s how you achieve it,” said Marvin Fertel, the group’s president and CEO.

The filter issue has ignited a debate on Capitol Hill. Lawmakers from both parties have sent out a flurry of dueling letters for and against the proposal. Twenty-eight Republicans in the House and Senate, joined by more than two dozen House Democrats, have sent letters opposing the requirement as hasty and unnecessary.

A dozen Democratic senators and five House members have written letters backing the requirement, which they say will ensure public safety in the event of a Japan-style accident. The five-member commission is expected to vote on the issue in the next few weeks.

“It’s not the time to be rash with hasty new rules, especially when the NRC has added 40-plus ‘safety enhancements’” to its initial requirements following the Japan disaster, said Sen. David Vitter, Louisiana Republican and ranking member on the Senate Environment and Public Works Committee.

Sen. Barbara Boxer, California Democrat, who chairs the committee, said the filters were needed to protect the 31 U.S. nuclear reactors that have similar designs to the ones that melted down in Japan.

The filters “world reduce the amount of radioactive material released into the environment” in a severe nuclear accident, Mrs. Boxer wrote in a letter signed by 11 fellow Democrats. “These technologies have been demonstrated in nuclear plants around the world.”

Mrs. Boxer, whose committee has held seven oversight hearings since the Japan disaster, has asked the NRC to report to her on the agency’s progress implementing the post-Fukushima safety reforms.

“It is vital that U.S. nuclear power plants fully incorporate the lessons learned from this disaster,” she said.