Among the measures taken so far:

• NRC Chairman Richard Meserve has ordered a 60-day top-to-bottom review of safeguard and security issues, including a re-evaluation of the design basis of existing US nuclear plants. The goal is to determine if they could withstand a direct hit from a large, modern fully fuelled commercial jet airplane, such as the ones involved in the 11 September terrorist attacks in New York and Washington.

The National Whistleblowers Center said it would file a lawsuit asking a federal court to order NRC to implement immediate security changes at nuclear plants, including deploying anti-missile weapons and posting armed guards outside spent fuel storage areas. The group cited a 119-page, 1982 Argonne National Laboratory study available in the NRC public documents room which concluded that the impact of a jetliner, coupled with the ignition of fuel, could lead to an explosion that would impose loads on the primary containment, possibly leading to a breach of some of the concrete barriers. Industry spokesmen say a standing order of the Air National Guard to shoot down airliners that are not responding to commands is sufficient.

• The FAA adopted new restrictions regarding air space over US nuclear plants, and the US Coast Guard has established one-mile security zones around nuclear power plants located on waterways. Boats must obtain permission before passing through or anchoring. The FAA’s concerns were heightened by the fact that one of the airplanes hijacked by terrorists flew over the Indian Point nuclear plant north of New York City on its way to the World Trade Center.

• The governors of at least three states – Massachusetts, New Jersey and New York – have called up the National Guard to help protect nuclear plants against a postulated ground attack by a group of terrorists. The guardsmen, toting M16 rifles, represent another layer of security beyond unspecified measures the NRC ordered immediately following the terrorist attacks.

• The NRC closed its website temporarily to edit out information the agency believes could inadvertently prove useful to terrorists. The NRC acted after Sen Frank Murkowski (R-AK), the ranking Republican on the Senate Energy Committee, raised concern about the longitude and latitude location of nuclear plants being readily available on the website.

When the vastly slimmed-down website re-opened, it was also missing such information as NRC’s Plant Status Report and the Daily Event Report, which wholesale electricity traders said they often check to find out which nuclear plants are off line and how long the outages might last. Traders said the uncertainty has affected regional wholesale electric prices which often rise when low-cost, baseload nuclear plants go off line.

• The House Energy & Commerce Committee approved a bill sponsored by Rep Joe Barton (R-Texas), chairman of the panel’s energy and air quality subcommittee, that would widen the authority of contractors at NRC-licensed facilities to carry firearms and authorise them to make arrests without a warrant under specific circumstances. Two other amendments approved by voice vote would raise penalties for attempted nuclear plant sabotage to $1 million and life in prison without parole, and require the NRC to conduct a 90-day study assessing the vulnerabilities of nuclear power plants to potential terrorist attacks. Several amendments offered by Rep Edward M Markey (D-Massachusetts), including one that would require nuclear plants to be able to ward off “20 intruders wielding explosive devices and not afraid to die using them,” were set aside pending the NRC’s ongoing security reassessment.

At the same time, however, federal officials have begun to ease up on some requirements imposed after during the initial confusion in the immediate aftermath of the terrorist attacks. On 27 September, DoE lifted a two-week moratorium it had imposed on the shipment of low-level nuclear waste to disposal and storage sites.