Federal regulators today approved a revised version of the advanced boiling water reactor (ABWR) design and said it has addressed the possible effects of a commercial aircraft impact.

The Nuclear Regulatory Commission originally approved the design in 1997 but said the revised version ensures that only minimal operator action would be necessary to cool the reactor core, ensure the containment remains intact and protect spent fuel pools in the rare event that a plane crashes into the structure.

The commission issued a rule two years ago following the attacks on Sept. 11, 2001, requiring nuclear plants to show reactors can withstand the impact of collision with an aircraft.

South Texas Project Nuclear Operating Co. submitted an application to amend the reactor design in June 2009. In April, the company pulled funding for building two new reactors using the design at its South Texas nuclear plant near Bay City, in Matagorda County (Greenwire, April 20).

But the permitting process has continued with Nuclear Innovation North America, a limited liability company NRG Energy Inc. created in 2008 that includes Toshiba, said David Knox, a spokesman for the group.

Toshiba is now funding the permitting process, and the companies hope to receive a permit to build and operate the reactors by early 2013 with the approved reactor design, Knox said. Although NRG is no longer financing the process, the company and its partners have invested a significant amount and will be part of the project if a license is granted, he added.

Knox said the two reactors will cost at least $10 billion, and South Texas Project Nuclear Operating Co. will operate the units.