Latest Round of Major Tests Completed on Vogtle Unit 3 Containment Vessel

Staff Report

Wednesday, July 15th, 2020

A major testing milestone on the Vogtle Unit 3 containment vessel’s structural integrity and safety functions has been completed at Georgia Power’s nuclear expansion project near Waynesboro, Georgia.
The structural integrity test and integrated leak rate test were completed in succession and demonstrated the containment vessel meets construction quality and design requirements. The containment vessel serves as a barrier to protect the public and surrounding communities by containing material produced inside the reactor vessel in the unlikely event of an emergency.
The structural integrity test called for the vessel to be pressurized for the first time and then closely monitored to confirm that it meets industry standards. While pressurized, each accessible weld seam on the containment vessel was inspected by specially trained inspectors.
The integrated leak rate test examined individual component and integrated systems to verify that the containment vessel and its isolation valves, piping and electrical penetrations, and hatches properly performed their intended safety functions. The integrated leak rate test will be performed periodically during the lifetime of the plant.
The completion of this containment vessel milestone marks progress toward hot functional testing and critical testing on the primary and secondary sides of the unit, which are required ahead of initial fuel load. 
“The successful and safe completion of these major tests helps ensure our plant is built to the quality expected of a world-class nuclear facility and demonstrates our continued progress with testing,” said Vogtle 3 & 4 Construction Executive Vice President Glen Chick. 
2020 Key Milestones Achieved
·        Placement of the final module for Unit 3 – The water tank that sits atop the containment vessel and shield building roof, known as module CB-20, is a major part of the AP1000 reactor’s advanced safety system and will hold approximately 750,000 gallons of water ready to flow down in the unlikely event of an emergency to help cool the reactor.
·        Placement of the Unit 3 integrated head package (IHP) atop the reactor vessel  Standing 48 feet tall, weighing 475,000 pounds and containing more than three miles of electrical cables, the IHP will eventually be used by highly-trained nuclear operators to monitor and control the nuclear reaction that will occur inside the Unit 3 reactor vessel. 
·        Completion of Open Vessel Testing for Unit 3 – This successfully demonstrated how water flows from the key safety systems into the reactor vessel ensuring the paths are not blocked or constricted, and confirmed the pumps, motors, valves, pipes and other components of the systems function as designed.
·        Placement of the polar crane and containment vessel top for Unit 4 – This signifies that all major lifts inside the containment vessels for both units are now complete.

With more than 7,000 workers on site, and more than 800 permanent jobs available once the units begin operating, Vogtle 3 & 4 is currently the largest jobs-producing construction project in the state of Georgia.
Benefits to Customers
The new Vogtle units, with regulatory-approved in-service dates of November 2021 for Unit 3 and November 2022 for Unit 4, are an essential part of Georgia Power’s commitment to deliver safe, clean, reliable and affordable energy for customers. Once operating, the two new units at Plant Vogtle will be able to power more than 500,000 homes and businesses and provide customers with a new carbon-free energy source that is expected to put downward pressure on rates for 60 to 80 years. A diverse fuel mix, including nuclear, is also essential to maintaining a reliable and affordable energy infrastructure that attracts new investment, supports economic growth and creates jobs. 
New Aerial Photos Highlight Progress
Georgia Power has released new aerial photos showing the progress being made at the site of the nation's first new nuclear units in more than 30 years. Follow the progress through the Plant Vogtle 3 & 4 Online Photo Gallery and Georgia Power’s YouTube channel.