Jan. 15 (Bloomberg) -- Federal regulators' narrow approach to solving one of the U.S.'s biggest post-Sept. 11 fears -- a terrorist flying a plane into a nuclear power plant -- is under attack for adding to public safety concerns.

Comments filed with the U.S. Nuclear Regulatory Commission last month were critical of the agency's Oct. 3 proposal, which directs that only some new plant designs be assessed for risk to air attack, for not going far enough.

``By requiring only a limited subset of anticipated new reactors (less than half of the currently announced plants) to address aircraft impacts as part of the design, the NRC's proposed rule could undermine public confidence in new nuclear power plants,'' George Vanderheyden, president and chief executive officer of Unistar Nuclear Energy of Baltimore, told the agency in Dec. 17 comments.

Public acceptance of plant safety is considered critical to the rebirth of the nuclear industry, where there has been a de facto moratorium on new construction since the Three Mile Island accident in 1979.

The 104 existing reactors, which supply 20 percent of U.S. electricity needs, aren't covered by the proposed rule. Neither are unbuilt reactors whose designs already have been approved by the NRC.

Unistar intends to build a new reactor at Calvert Cliffs, Maryland, one of 32 planned by 17 utilities. Its design hasn't been approved by the NRC yet, so it would need to assess the risk of a plane attack under the proposed rule.

Voluntary Risk Assessments

Other nuclear industry officials agreed with Vanderheyden. Westinghouse Electric Co. and GE-Hitachi Nuclear Energy, whose designs already have NRC approval and thus aren't covered by the proposal, said they would do the risk assessments anyway.

``We don't have to do it, but our customers would have had questions from the public on why that (plant) won't withstand an airplane crash,'' Ed Cummins, vice president of regulatory affairs and standardization at Monroeville, Pennsylvania-based Westinghouse, said in an interview. The Westinghouse design is scheduled to be used in 14 reactors now in the planning stage.

The commission and the industry say security at nuclear plants has been increased since the 2001 terrorist attacks. The agency ordered operators to do more to respond to explosions, fires and other threats.

Adding protection from air attack, such as an extra containment structure, could cost more than $100 million per reactor, according to Adrian Heymer, senior director of new plant deployment at the Nuclear Energy Institute trade group in Washington.

``This proposed rule is not necessary for adequate protection, but rather is an enhancement that will result in newly designed facilities being more inherently robust against aircraft impacts than the facilities not subject to this proposed rule,'' the agency said in introducing it.

No Radioactivity

``The NRC remains confident that even though the impact of a large aircraft would be a large industrial accident, the probability of a crash that would lead to radioactivity getting into the environment is very low,'' said spokesman Scott Burnell.

Nuclear activists scoff at the proposal.

``They are trying to conceal that they really aren't doing anything,'' said Edwin Lyman, senior staff scientist for the Union of Concerned Scientists in Washington.

The office of New York Attorney General Andrew Cuomo filed comments saying, ``It is folly to impose requirements necessary to fend off potential terrorist attacks only on new plants that won't be built for another 10-20 years, but to leave vulnerable to attack the existing fleet of 104 reactors.''

New York has four nuclear facilities, including Indian Point Energy Center in Buchanan, 24 miles north of New York City, which is owned by Entergy Corp. of New Orleans.

Hijackers over Indian Point

The Cuomo office comments noted that two of the hijacked planes on Sept. 11 flew near or over Indian Point on their way to the World Trade Center. It recommended that all aircraft be covered, not just the large jetliners cited in the proposal.

Opponents say it is imperative that a new generation of nuclear reactors be built to withstand an air attack.

``If you build in a post-9/11 world, you better damn well be able to withstand an airliner attack,'' said Jim Riccio, nuclear policy analyst for Greenpeace USA in Washington.

Some critics, including one NRC commissioner, complained that the proposal doesn't compel reactor designers to take any specific action and lacks enforcement requirements.

``What if they do an assessment and it crumples like a piñata??'' said Lyman. ``Does it have to be fixed? There is no requirement to take action on the results.''

When the agency voted to go ahead with the proposal last April, Commissioner Gregory Jaczko was the only ``No'' vote. He said the proposal didn't require applicants ``to make one single design modification.'' And he criticized exempting already- approved designs.

In its comments, the Nuclear Energy Institute agreed that only new reactor designs should be required to do the risk analysis. The trade group said its members may voluntarily take part.

``Everyone will do an assessment,'' said the insitute's Heymer.

To contact the writer of this column: Cindy Skrzycki at cskrzycki@bloomberg.net

Last Updated: January 15, 2008 00:12 EST