The Nuclear Regulatory Commission issued its final environmental report Friday for the license renewal of the nuclear power plant near Richland, finding no issues to prevent extending the license.
The report closes the NRC review process of Energy Northwest's Columbia Generating Station for a 20-year renewal of the plant's 40-year license, said Don Gregoire, Energy Northwest manager of regulatory affairs.
Energy Northwest expects a final decision on extending the plant's license in June.
A license renewal would allow it to operate until 2043.
The 1,150-megawatt plant supplies enough power for about 1 million homes.
Licensing renewal proceeds down dual paths to look at safety and environmental issues, and the release Friday of the final environmental impact statement completes the environmental review.
In early March, the Nuclear Regulatory Commission wrapped up its safety evaluation, concluding there were no open items that would prevent license renewal.
The Advisory Committee on Reactor Safeguards will review the NRC's work on safety evaluation next week, which is the final step before the NRC's decision on license renewal.
"Finally seeing the finish line is thrilling," Gregoire said. Energy Northwest has worked on license renewal for about five years.
That included preparing environmental information to file as an appendix with the license renewal application in January 2010 and then working with the NRC on audits, inspections and reviews of safety and environmental issues.
The environmental study did recommend that Energy Northwest make substantive revisions to the Cultural Resources Protection Plan in coordination with the Washington state Historic Preservation officer and tribes. Energy Northwest identified ways to avoid potential effects on historical and archaeological resources in the area of the nuclear power plant, the study stated.
Before any activities that disturb the ground in the area, staff could be trained on cultural resource awareness and an archaeologist could survey the ground, the study stated.
Energy Northwest has no plans in the near future that would disturb the ground but understands the need for cultural sensitivity and communication with the tribes and staff, Gregoire said.
The environmental study considered information submitted by Energy Northwest, consultation with federal, state, local and tribal government agencies, the NRC staff's own independent environmental review and public comments.
With the NRC review process finished, Energy Northwest staff will continue to work on 55 programs to safely manage aging of the reactor under a license renewal.
Some already are implemented, and staff expects to have all of them in place well before the end of the plant's current 40-year license in December 2023, Gregoire said.