Southern Nuclear unveils FLEX Dome emergency facility at Georgia plant

Courtesy of the NRC

In a move toward great safety, Southern Nuclear and Georgia Power debuted its new Vogtle FLEX Dome storage building this week at the Alvin W. Vogtle Electric Generating Plant near Waynesboro, Georgia.

The FLEX Dome will store portable equipment -- including pumps, generators, refueling equipment, communication equipment and necessities should the power supply that supports the two Vogtle reactors get interrupted.

“The dome provides multiple sets of equipment needed to respond to an extreme event,” Michelle Johnson Tims, senior communications specialist for the Southern Company, parent of Southern Nuclear, said. “The equipment will provide reliable event response well past three days. In addition, extra sets of on-site equipment will be provided to the site in the case of an extreme event causing a complete loss of AC power. With this set of equipment, the plants are capable of safely protecting the fuel and containment at the sites for an indefinite time.”

Protecting the fuel and providing emergency support are a direct response to the 2011 Fukushima Daiichi nuclear plant accident in Japan, in which power needed to operate its safety cooling systems was lost after a nearby earthquake. The Fukushima disaster caused industry leaders in the U.S. to carefully reexamine safety procedures for nuclear power plants. Together, they worked to develop flexible and diverse strategies for protecting U.S. plants. These efforts are referred to as the FLEX strategy.

The FLEX Domes are a result of those efforts.

“The domes are a tangible example of Southern Nuclear’s commitment to ensuring our plants – and our neighbors – are even safer than they were before Fukushima," Tims said. "They provide a visible reminder that our nuclear facilities are safe – and that the nuclear industry is ready for virtually anything. The backup equipment – both at our plants and at the emergency-response centers – ensures that plant operators can maintain key safety functions, even if off-site power sources are curtailed. In addition, Southern Nuclear’s plant operators, as well as the rest of our plant employees, are highly trained and able to respond to an extreme event with proven emergency plans.”

Indeed, Southern Nuclear has not only intensively trained its safety crews and plant employees to respond to extreme events, but also invested in modifying and upgrading its nuclear plants and building other domes.

“Southern Nuclear has incorporated our preparations for an extreme event into our policy on nuclear-safety culture," Tims said. "We have procured additional response equipment, implemented interim actions and conducted 10-02 and basic FLEX training of emergency-response personnel at all sites and at corporate."

Plants Farley (in Columbia, Alabama) and Vogtle have completed physical modifications for both units to improve plant hookups of the portable equipment stored in the domes. The plants have developed procedures and training on the use of the portable equipment to respond to extreme events. Plant Hatch (in Baxley, Georgia) will complete the Unit 1 changes in February 2016 and Unit 2 will complete the changes later in 2016.

Farley and Vogtle have finished construction of their FLEX Dome storage buildings, and the equipment has been stored. Construction on the dome at Hatch is underway and will be complete in early December.

“We have developed the associated procedures necessary for our operational and emergency response at Vogtle," Tims said. "We will complete this for the Farley and Hatch sites in early 2016. Training has been completed at Vogtle and Farley, and is expected to be complete at Hatch in spring 2016."

In the event of an extreme emergency, the plant will respond with installed equipment and the on-site portable-equipment procedures performed by trained and skilled individuals. The equipment will provide water to cool the fuel in the reactor and the spent fuel pool, and it will provide backup electrical power for required instruments. These provide the resources to safely take the plant to a long-term stable condition, Tims said.

Tims said each procedure and piece of equipment have been field-tested, and the plants have periodic preventive-maintenance programs in place to test the function and capabilities of the equipment.

This attention to safety has garnered favorable reception from various groups, Tims said.

“The ability to respond to an extreme event by adding portable equipment and plant connections for that equipment has been well-received by safety groups, public and energy sector,” Tims said.