US Georgia Power Company has again delayed the startup for two new units (3&4) under construction at its Vogtle NPP near Augusta. It also added that its share of the costs will rise by an additional $200m.

Parent company Southern Company announced the delays and cost increases during its corporate earnings report for 2022.

Unit 3 may now begin commercial operation in May or June instead of the end of April. Unit 4 will begin commercial operation sometime between November 2023 and March 2024 rather than the end of 2023. The two units will be the first new US reactors in decades. Unit 3’s schedule depends on potential impacts arising from unit 4 testing activities that overlap with unit 3 start-up and commissioning, the utility said. The schedule also hinges on maintaining overall construction productivity and production levels, particularly in subcontractor scopes of work, and maintaining appropriate levels of craft labourers. “Any further delays could result in later in-service dates and cost increases,” it said.

The total cost of the project to build Vogtle 3&4 will cost its owners more than $30bn. Georgia Power owns 45.7% of the project; Oglethorpe Power Corp owns 30%; the Municipal Electric Authority of Georgia (MEAG) owns 22.7%; and the city of Dalton owns 1.6%. Georgia Power wrote off $201m in additional costs on its earning statement, reflecting increased costs. Despite the Vogtle delays, Southern still announced strong revenue and reported profits of $3.5bn for the year.

In January, had Georgia Power notified the US Securities & Exchange Commission that Vogtle 3's initial criticality would be delayed after vibrations in the plant's cooling system were found during start-up and pre-operational testing. Construction workers had failed to install the supports called for on blueprints. Those supports have now been installed.

However, Southern Chairman & CEO Tom Fanning told investors that “we found a few additional issues to address”. These included a slowly dripping valve that required that has since been repaired, as well as a problem involving the flow through the reactor coolant pumps that is still being investigated. This could be a physical issue, or one related to the calibration of flow measurements, he added. “We will continue to take the time to get it right and will not sacrifice safety or quality to meet the schedule,” he said in a conference call. Unit 3 reactor is now expected to achieve criticality, in March or April.

Lessons learned from unit 3 are being applied to unit 4, to avoid any repetition of the same problems. All the systems required for the start of hot functional testing at unit 4 are complete, Fanning said. He added that there was a "marked improvement" in testing results for unit 4 compared with unit 3. Although margin is built into the schedule, however, and its experience at unit 3, the company is "further risk-adjusting our unit 4 schedule to reflect a range of projected in-service dates between later first quarter of 2023 and the end of the first quarter of 2024”.

Georgia Power said it will now spend a projected $10.6bn on construction, not counting some financing costs. This includes $407m million in costs assumed from the other owners, after all three sued to force the company to honour a cost-sharing agreement. Georgia Power has settled its lawsuit with MEAG, but the suits with Oglethorpe and Dalton are still ongoing. The company said it may have to pay those two co-owners another $345m in the dispute.

Georgia Public Service Commission approved the new reactors for the Vogtle expansion in early 2009 and construction activities began ithe same year. At that time, the two 1,117 MWe Westinghouse AP1000 reactors were expected to cost about $14bn and to enter service in 2016 and 2017. Units 1 & 2 at Plant Vogtle have operated since 1987 and 1989.


Image: Vogtle Unit 3 (courtesy of Georgia Power)