In 2012 Tetra Tech helped Southern Nuclear Operating Company, a subsidiary of the Southern Company, secure the first operating license approved by the U.S. Nuclear Regulatory Commission (NRC) since 1978. The NRC issued a combined construction and operating license (COL) to Southern Nuclear Operating Company for two new AP-1000 nuclear reactors (Units 3 and 4) at the existing Vogtle Electric Generating Plant in Burke County, Georgia. Tetra Tech helped pave the way for this milestone by preparing the extensive environmental reports required in the COL application and the early site permit (ESP) application that preceded it.

Tetra Tech’s work on the permit and license applications involved detailed analyses as well as active participation in the public meetings and regulatory hearings that made up the application process.

“Thank you for the hard work you all put in over the past few months on the NPDES and Surface Water Withdrawal permit applications for Vogtle Units 3&4. And while I believe the challenges are just beginning, we started off right by sending EPD complete and high quality applications. Thank you Tetra Tech for a job well done!”

Matthew T. Montz, Environmental Specialist, Nuclear Development, Southern Nuclear Operating Company

Water-related issues were top priorities for the environmental review, including impacts of the consumptive use of water lost through evaporation and drift at cooling towers; water quality impacts of discharge (blowdown); and potential impacts on anadromous fish in the Savannah River. Tetra Tech compared consumptive use design parameters with the historic average and drought flows to determine if the loss of river volume at the site would limit the downstream water users’ ability to withdraw adequate water supplies. Tetra Tech also compared the chemical composition and concentration of the proposed discharge to existing river water quality parameters to ensure that the discharge would not change the river’s water quality.

Tetra Tech engineers assessed impacts to fish populations using historic river flow and temperature data, morphometric data of the river shape, the design of the intake and discharge structures and flow rates, and temperatures at input to the U.S. Environmental Protection Agency model CORMIX. We used this information to assess the effect of additional disruption of the river at the site to fish populations, including populations of endangered species.

The environmental reports also reviewed protected species and habitats and assessed the impacts of construction and operation on geology and soils, groundwater, and air quality and meteorology. The reports outlined mitigation options for any potential adverse environmental impacts. The analyses determined that Units 3 and 4 would not have any noticeable adverse impacts to any natural resources. In addition, Tetra Tech supported Southern Nuclear during mitigation discussions with Georgia Environmental Protection Division related to the National Pollutant Discharge Elimination System and Surface Water Withdrawal permits, which were concluded to the satisfaction of both parties.

Tetra Tech also conducted detailed assessments of the project’s socioeconomic impacts. Construction of the new units and transmission lines would involve more than 6,000 construction workers, and operation of the completed units would require a workforce of 800.  A significant portion of the assessments was the data associated with GIS figures and the references used to develop the analysis. Tetra Tech assessed the effects of these influxes of workers and families on traffic and transportation, housing, health care, and taxes and public services, including education and public safety. Tetra Tech evaluated the potential for environmental justice differences for each of these topics as well. The potential impacts on cultural resources (through subcontracts), the effects of various nuclear accident scenarios on the surrounding populations, and operational monitoring programs were all evaluated as part of the National Environmental Policy Act process.

Over the course of the application process, Tetra Tech participated in numerous site visits by NRC and other federal and state regulatory agencies, public meetings, and the NRC hearings that were the final step in the application process. Tetra Tech provided legal and technical expertise and advice, support for interactions with federal and state regulatory agencies, support for appearances before the Atomic Safety Licensing Board panel hearing intervention arguments, and support at public meetings.

An ESP issued by NRC allows the applicant to bank a proposed site as a suitable location for a nuclear facility for up to 20 years. Tetra Tech’s ESP environmental report satisfied the utility’s obligation under the National Environmental Policy Act to determine the impacts of constructing and operating the new generating units at the Vogtle plant site. 

The new AP-1000 reactors—Units 3 and 4—are expected to begin generating electricity in 2021 and 2022, respectively.