Whistle-blowers are calling on a key Senate committee to beef up security at nuclear reactors in New York and South Carolina that they say are vulnerable to terrorist attacks, gas pipeline explosions and dam failures.

Two nuclear engineers warned Sen. Joe Lieberman (I-Conn.), the outgoing chairman of the Senate Homeland Security and Governmental Affairs Committee, that a gas pipeline is dangerously close to Entergy Corp.'s Indian Point plant north of New York City and that dams upstream from the Oconee Nuclear Station in South Carolina could fail.

In both cases, the Nuclear Regulatory Commission and the Department of Homeland Security have failed to act, said Lawrence Criscione, a risk engineer at NRC, and Paul Blanch, a former nuclear engineer who now works as an energy consultant.

"Both the NRC and Homeland Security have been aware of these potential threats for years and have as yet failed to determine whether any action is needed to prevent or deter these events," they wrote in a Dec. 18, 2012, letter to Lieberman.

Richard Perkins, with NRC's Division of Risk Analysis, told NRC's inspector general that the agency was withholding information from the public about the threat of flooding at the Oconee plant (Greenwire, Sept. 17, 2012).

NRC maintains the plants are safe. The agency found in 2006 and 2008 that an explosion on the gas pipeline about 600 feet from the Indian Point reactors "would fail to damage safety related systems or components," said NRC spokesman Scott Burnell.

Jim Steets, a spokesman for Entergy in the Northeast, said the pipeline is located at a higher elevation than the reactors and any explosion would not jeopardize the reactors or safety equipment.

"It's old news," Steets said. "This is an issue that was brought up many years ago."

And Burnell said Duke Energy Corp., which operates the Oconee plant, is upgrading flood protection at its plant, should the Jocassee Dam on the Keowee River fail.

But David Lochbaum, a nuclear plant safety expert with the Union of Concerned Scientists, said NRC has redacted or withheld various studies related to the gas pipeline at Indian Point and dam at Oconee, which raises questions about the facilities' safety.

"All we have is their words that it's still OK," he said.

Criscione and Blanch said they plan to take their concerns to Sen. Tom Carper (D-Del.), who is expected to replace Lieberman as the committee's chairman this month. Carper oversaw nuclear issues as chairman of the Clean Air and Nuclear Safety Subcommittee.

"I'm asking the Homeland Security committee to step in because the NRC refuses to do anything about this, other than stick their head in the sand," Blanch said. "It's extremely significant."

Click here to read the whistle-blowers' letter.