The Comanche Peak Nuclear Power Plant’s proposed expansion took another step forward last week.

The U.S. Nuclear Regulatory Commission’s Atomic Safety and Licensing Board panel, which has been considering arguments raised by intervenors against Luminant Generation Co. LLC’s application to build two new nuclear reactors at the site, last week denied and dismissed the rest of their contentions.

The challenges were filed by intervenors Sustainable Energy and Economic Development Coalition, Public Citizen, True Cost of Nukes and Texas State Rep. Lon Burnham, D-Fort Worth.

Before an application can be granted for a nuclear plant, the NRC board’s staff issues an environmental impact statement. It examines the potential impact on the environment if an existing plant is expanded or a new one is to be built. The agency first issues a draft of the impact statement for public comment. It then can accept or dismiss any contentions. Then the agency issues a final environmental impact statement.

The intervenors had raised six new contentions to the NRC staff’s August 2010 draft environmental impact statement. In October three were withdrawn. The three remaining ones were dismissed by the Atomic Safety and Licensing Board’s administrative judges last week.

“We’re pleased with the board’s ruling, which is a positive step toward additional safe, dependable nuclear power in Texas,” Luminant spokeswoman Ashley Monts said. “We’re continuing to pursue the development of the proposed units at Comanche Peak and look forward to moving forward with this strategic project and the significant economic impacts it can bring to this area.”

In the first of the contentions thrown out, the intervenors argued that the draft environmental impact statement used a “flawed, incomplete and internally contradictory” analysis of the need for power. They said the statement understated the continued growth of wind capacity in Texas, did not account for increases in wind-carrying capacity, did not account for increased natural gas generation in a “cost-effective” manner and failed to account for new building codes that are expected to reduce demand.

David Power of the watchdog group Public Citizen had written a report that contended the NRC staff “committed numerous errors in the calculations of the need for power.” The board, however, said the Power did not provide a description of his profession and his references to sources were unclear and incomplete.

In the second contention that the board also dismissed, the intervenors claimed the draft environmental impact statement “distorted” the CO2 emissions in the comparison of nuclear power and the combination of alternatures.

The third contention charged that the draft statement fails to discuss increases in “ambient water temperatures caused by global warming, as such would affect the capacity of the Squaw Creek Reservoir to maintain water temperatures consistent with operational requirements.”

The board concluded: “We find…that none of the contentions is timely, as intervenors have not shown that any of the information on which they are based differs significantly from the data and conclusions” of Luminant’s own environmental report or is “otherwise new or different from information that was previously available.” As a result, the contentions cannot be legally admitted, the board ruled.