* New reactors are for South Texas plant * NRG stopped investing in new reactor project * GE-Hitachi also seeking amended ABWR approval NEW YORK, Nov 1 (Reuters) - The U.S. Nuclear Regulatory Commission (NRC) on Tuesday said it has approved a new version of the Advanced Boiling Water Reactor (ABWR) nuclear power plant design proposed by the South Texas nuclear power project. In a release, the NRC said it directed its staff to publish a final rule amending the ABWR design certification to address the effects of the impact of a large commercial aircraft, in accordance with the NRC's 2009 aircraft impact rule. Once the staff publishes that final rule, nuclear operators can use the amended ABWR design in proposed new projects. South Texas Project Nuclear Operating Co, which includes U.S. power company NRG Energy , submitted an application to amend the ABWR design in June 2009. The NRC's aircraft rules followed the attacks on September 11, 2001. The NRC said the aircraft rule requires new and existing nuclear plants to show that the reactors can withstand an aircraft impact with only minimal operator actions to keep the reactor core and spent fuel cool, among other things. The earthquake and tsunami in Japan in March 2011 that damaged the Fukushima Daiichi nuclear plant showed how radiation can escape from reactors when operators cannot keep the reactor core and spent fuel cool. The approval of the amended ABWR comes as the nuclear industry waits for the NRC to certify Westinghouse Electric's amended AP1000 reactor design, which nuclear power operators have already started building in Georgia and South Carolina. Westinghouse is majority owned by Japan's Toshiba . The NRC is expected to certify the amended AP1000 design later this year. Units of U.S. power companies Southern and Scana are building the new AP1000 reactors. NRG PULLED OUT The NRC moved forward with the approval process for the South Texas amended ABWR even though NRG, the lead partner in the project, stopped investing in the plan to build new reactors at South Texas in April 2011. The ABWR was designed by units of General Electric , Hitachi and Toshiba. General Electric got the design certified in the United States in 1997. NRG told the NRC it wanted to build two 1,350-megawatt ABWRs at South Texas in 2006. In 2007, NRG filed an application to build two of Toshiba's ABWRs at South Texas. Toshiba has built ABWRs in Japan. The GE-Hitachi nuclear venture also markets the ABWR. GE-Hitachi, which is waiting for NRC to certify their next generation Economic Simplified Boiling Water Reactor (ESBWR) design, applied with the NRC in late 2010 to extend the original ABWR design certification for another 15 years beyond June 2012, when it expires. That application also includes an aircraft impact assessment. With NRG no longer funding the new reactor project for South Texas, Toshiba, a minority partner in the project, has been moving that process forward at the NRC. Officials at Toshiba however were not immediately available for comment on the company's future plans for South Texas.