Startup of the first of two new reactors at the Vogtle nuclear plant in Georgia is being pushed back to at least April, one month after officials with Georgia Power had planned to start generating electricity from the unit.

Georgia Power, part of Atlanta-based Southern Co., announced the latest setback for the oft-delayed two-unit expansion project at Plant Vogtle in Waynesboro, Georgia. The company on Jan. 11 said startup will be delayed due to a vibrating pipe in the cooling system, which was noted during recent testing of the Unit 3 reactor.

Georgia Power spokesperson Jacob Hawkins said the problem is “not a safety issue.”

Two New Reactors

The expansion project involves construction of two, 1,100-MW AP1000 reactors at Vogtle. 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%.

The Vogtle expansion is the first new, large nuclear power plant construction project in the U.S. in more than 30 years. Georgia Power is continuing construction on Unit 4 at the site, and officials have said that reactor should enter operation next year.

Hawkins said the problem with Unit 3 was found during startup testing. The vibrating pipe is part of the reactor’s automatic depressurization system. A brace is needed to provide the pipe with more support, according to Hawkins.

New Filing with Federal Regulators

“Southern Nuclear expects to file a license amendment request with the U.S. Nuclear Regulatory Commission to help expedite the remediation,” Georgia Power said Wednesday. The company also said it expects initial criticality for Unit 3 will happen next month, with the reactor ready to begin operating in April. Southern Nuclear will operate the reactor on behalf of Georgia Power and the project’s other power utility owners, including Oglethorpe Power, the Municipal Electric Authority of Georgia (MEAG), and the city of Dalton.

Fuel was loaded into Unit 3 in October of last year, with testing taking place over the past few months. Cold hydro testing of Unit 4 was completed in December.

Georgia Power said that moving the in-service date for Unit 3 past the first quarter of 2023 “is estimated to result in additional base capital costs for Georgia Power of up to $15 million pretax per month, as well as the related allowance for funds used during construction and any additional related construction, support resources, or testing costs.”

The Vogtle expansion project was approved by state regulators in 2012. The first of the two new reactors was supposed to begin operating in 2016, but numerous delays have pushed the startup date back several times. Delays also have contributed to cost overruns; the expected original cost of $14 billion has more than doubled to more than $30 billion.