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Crews complete closed vessel and safety testing on Vogtle nuclear unit 3 reactor

Courtesy Georgia Power and Southern Nuclear.

Georgia Power moved one step closer to fuel loading for its 2.2-GW Vogtle nuclear plant expansion project by completing closed vessel testing on Unit 3.

The $25 billion construction project to add Units 3 and 4 in Waynesboro, Ga., is the first new U.S. nuclear power plant addition in numerous years. Lead partner Georgia Power hopes to bring 1,117-MW Unit 3 into commercial operation next year and same-capacity Unit 4 by 2022.

The completion of closed vessel testing on Unit 3 prepares it for cold hydro testing, which is a major step ahead of initial fuel load. The closed vessel testing verifies that pipes and valves in the reactor coolant system were installed as designed and ensures safety functions.

Workers installed the vessel reactor head, as well as the lower and upper reactors internals and flow restrictors, which will be used in hot functional testing to mimic flow through the reactor core.

“The completion of closed vessel testing is a major milestone for the project, as we continue to make progress with critical testing and in our transition from construction towards system operations,” said Glen Chick, Executive Vice President of Vogtle 3 & 4 Construction.

The passive safety systems are unique to the Westinghouse AP1000 reactor design and require no operator actions. These systems use only natural forces such as gravity, natural circulation and compressed gas to achieve their safety function.

Click here to follow Vogtle’s progress and challenges through the years.

No pumps, fans, diesel engines, chillers or other active machinery are used, except for a few simple valves that automatically align and activate the passive safety systems, according to the utility. Georgia Power, as well as parent Southern Co., are lead partners on the Vogtle 3 and 4 expansion, while other owners include Dalton Power, Oglethorpe Power and Municipal Electric Authority of Georgia.

A crew of about 7,000 is still on the site bringing Vogtle closer to completion and commercial operation. The project has achieved numerous construction milestones this year despite the COVID-19 workforce challenges which has forced some delays.

Among those 2020 milestones include completion of the structural integrity and integrated leak rate tests, placement of the final module for Unit 3 and placed of the same unit’s integrated head package (at left) atop the reactor vessel.

In addition, 12 of the 16 shield building courses of panels that surround the Unit 4 containment vessel have been placed. The shield building is a unique feature of the Westinghouse AP1000 reactor design for Vogtle 3 & 4, providing an additional layer of safety around the containment vessel and nuclear reactor to protect the structure from any potential impacts.

In April, publicly traded parent company Southern Co. alerted the U.S. Securities and Exchange Commission that it would reduce workforce 20 percent to enable social distance practices at the Vogtle site. The changes could add another $15 million to $30 million in costs, but that’s barely one tenth of one percent compared to the long-term project’s overall cost.

Southern has stayed the course with Vogtle 3 and 4 despite numerous setbacks, cost overruns and delays since work began during the previous decade. Three years ago, lead contractor Westinghouse departed the project during its Chapter 11 bankruptcy reorganization process.

Engineering, procurement and construction firm Bechtel took over the lead EPC duties, while Georgia Power, Dalton, Olgethorpe and MEAG reaffirmed their financial commitment to the massive effort.

Nuclear energy accounts of close to one-fifth of the U.S. electricity generation capacity, although it accounted for nearly 22 percent of actual net generation in April, according to figures from the federal Energy Information Administration.