Hot Functional Testing Begins on Unit 4 at Vogtle Nuclear Plant

Georgia Power announced that hot functional testing for Unit 4 at the Vogtle nuclear power plant has begun, as the utility moves closer to bringing both reactors of the two-unit expansion at the facility online.

Hot functional testing marks the last series of major tests for Unit 4 prior to the initial loading of fuel for the reactor. Such testing supports verification for the safe operation of reactor components and systems before fuel is loaded.

Georgia Power, part of Atlanta-based Southern Co., on March 20 said a team at the Vogtle site will begin running systems for Unit 4, without fuel in the reactor, as part of the testing process that eventually will lead to reaching normal operating pressure and temperature for the unit.

The two-unit expansion at Vogtle features construction of two 1,117-MW Westinghouse AP1000 nuclear reactors. The Generation III+ pressurized water reactors are the first of their kind built in the U.S. The project in Waynesboro, Georgia, has been delayed due to numerous issues over the past decade.

Units 1 and 2 at Plant Vogtle have operated since 1987 and 1989, respectively. Georgia Power owns 45.7% of Plant Vogtle. Three other project partners—Oglethorpe Power Corp., the Municipal Electric Authority of Georgia (MEAG), and the City of Dalton Utilities—own the remaining 54.3%.

Initial Criticality for Unit 3

The new Unit 3 at Vogtle recently reached initial criticality, which is an important step during the startup testing sequence. It means that operators have started the nuclear reaction within the reactor, with atoms being split and nuclear heat being generated. That heat will be used to produce steam. Georgia Power has said startup of Unit 3 is expected in May or June of this year.

As part of the testing process for Unit 4, operators “will use the heat generated by the unit’s four reactor coolant pumps to raise the temperature and pressure of plant systems to normal operating levels,” according to Georgia Power. “Once normal operating temperature and pressure levels are achieved and sustained, the unit’s main turbine will be raised to normal operating speed using steam from the plant. During these series of tests, nuclear operators will be able to exercise and validate procedures as required ahead of fuel load.”

Unit 4 could enter service during the fourth quarter of this year, or early in 2024, according to the utility.

Darrell Proctor is a senior associate editor for POWER (@POWERmagazine).

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