Vogtle Unit 3 goes into operation

Similar to other forms of electric generation, nuclear energy centers on heating water to make steam. Water is first pumped through the reactor core, heated by the fission process, pumped through thousands of tubes in the steam generators and back to the reactor in a closed loop. Then cooler water in the steam generator comes into contact with the hot tubes and turns into steam. Next, the steam goes to the turbine and spins the turbine blades that spin the electric generator to produce electricity. After that the steam goes to the condenser where it turns into liquid again to continue the cycle and the water that circulates through the condenser is cooled by the large cooling towers.

Plant Vogtle generates steam with the use of ceramic pellets made of uranium. The uranium ore is mined, processed, enriched and formed into cylindrical fuel pellets. The pellets, each about the size of a pencil eraser, are arranged in long vertical tubes bundled together to form one fuel assembly. There are 193 individual fuel assemblies that make up each reactor core at Plant Vogtle. Our uranium fuel does not burn chemically. The heat needed to create steam comes from the splitting of atoms, a process called fission, inside each pellet. Fission occurs when a uranium atom absorbs a neutron and the atom splits to create heat. Additional neutrons are also released, and they go on to split more atoms, creating a sustainable chain reaction.

Plant Vogtle Units 3 and 4 are the first U.S. deployment of the AP1000 Generation III+ reactor. The AP1000 was designed as the next-generation nuclear reactor that could provide a standardized design for the U.S. utilities market. The reactor is an evolutionary improvement over existing reactors, featuring advanced safety systems. For example, the AP1000 can shut down passively without external power or human intervention. The AP1000 is built with modules manufactured off-site and then assembled onsite. This has the potential to improve quality and eases construction when compared to the last generation of nuclear reactors built in the U.S. In addition, the AP1000 has a smaller footprint and simpler design, and uses less piping, valves, and pumps than older designs.

Once completed, we expect Plant Vogtle Units 1–4 will generate more carbon-free electricity each year than any other energy facility currently operating in the US.

Plant Vogtle Units 3 & 4 are an essential part of our commitment to deliver safe, clean, reliable and affordable energy for customers. The units will also play a significant role in supporting Southern Company’s goal of net-zero carbon emissions by 2050. 

 

Nuclear power units like Vogtle are the most reliable energy source, able to generate electricity at full power 24/7 – more than twice as much as solar and wind resources. Nuclear power units also require fewer maintenance outages than coal or natural gas, making electricity even more reliable for Georgians.

The plant is named for Alvin W. Vogtle, Jr., former executive vice president of Alabama Power, Southern Company and Southern Company Services. He became the president of Southern Company in 1969 and served as the company’s chief executive until his retirement in 1983. Mr. Vogtle led the utility during a time of unprecedented growth and economic challenges and was named Executive of the Year by the National Management Association in 1981. He also achieved a distinguished military record during World War II, flying more than 30 combat missions as a U.S. Army Air Corps pilot. Vogtle became a prisoner of war following a plane crash, and on his sixth attempt, escaped a German prisoner of war camp and reached freedom in Switzerland. He was awarded the Purple Heart and his service was the basis for the 1963 movie, “The Great Escape.” Alvin Vogtle, Jr. passed away in 1994.

Upon completion, Plant Vogtle Units 3 and 4 are expected to generate 17,200,000 megawatt-hours of clean energy and prevent 10 million metric tons of carbon dioxide emissions annually.

Huge! To help put it in perspective, Plant Vogtle Unit 3 includes over 3-million linear feet of cable, 550,000 linear feet of conduit and supports, 250,000 linear feet of pipe and 16,000 tons of structural steel. The entire Plant Vogtle site sits on over 3,000 acres on the banks of the Savannah River.

Unit 3 entered commercial operation in July 2023.

 

Significant progress continues to be made on the Unit 4 nuclear expansion site, and we currently projects a Unit 4 in-service date during late fourth quarter 2023 or during the first quarter 2024.

As outlined in the Unit 3 Rate Adjustment proceeding, $2.1 billion (which relates to Unit 3 capital costs) will be transferred into rate base in August 2023, the month after Unit 3 achieved Commercial Operation. This will add an estimated $5.42 per month, or 3.2% increase, to the typical residential customer’s monthly bill using an average of 1,000 kWh per month. Any additional increase to rates will be decided on by the Georgia PSC at a later date.

Fission is the splitting of atoms into smaller parts.  Some atoms, themselves tiny, split when they are struck by even smaller particles, called neutrons. 

 

Like most U. S. nuclear power plants, the fuel used at Plant Hatch and Vogtle is manufactured using uranium enriched in Uranium-235 (U-235). Fission occurs when a uranium or plutonium atom absorbs a neutron and the atom splits. In the process, the atom produces additional neutrons (an average of 2.5 each fission), which go on to split more U-235 and Pu-239 atoms, which create more neutrons, and so on. The result is a chain reaction. 

 

In a nuclear power plant, the chain reaction is controlled to keep it from releasing too much energy too fast. In this way, the chain reaction continues for a long time. 

 

When a uranium atom is split, it releases a large amount of energy in the form of heat. This heat transfers to the water that is continuously flowing through the reactor, causing it to boil water and create steam. The pressure of the expanding steam turns a turbine that is connected to a generator. 

 

Other than the heat source, a nuclear energy facility operates like any fossil fuel plant: 1) heat is created to boil water 2) to create steam 3) to turn the turbine 4) which spins the generator. The whirling magnetic field of the generator produces electricity. 

The cloud coming from the cooling towers is simply water vapor or steam. The steam contains no radiation or other harmful emissions. 

 

After the steam completes the electricity generation process, it enters a condenser where it is cooled back into water for reuse. Cooling water supplied from the cooling towers flows through pipes within the condenser.  

 

This external cooling water never comes in physical contact with the steam. It is warmed in the condenser and returned to the cooling tower a warmer temperature than when it was removed. The excess heat is given up to the atmosphere as steam.

Nuclear power generation is one of the most highly-regulated industries in the country. 

 

The Nuclear Regulatory Commission (NRC) is responsible for oversight of all nuclear plant operations, including licensing and regulating nuclear facilities and materials. These responsibilities include protecting public health and safety, protecting the environment, and protecting and safeguarding nuclear materials and nuclear power plants in the interest of national security. 

 

NRC resident inspectors are on duty at each nuclear facility and have unrestricted access to the facility. 

 

The Federal Emergency Management Agency (FEMA) is responsible for setting standards for off-site emergency preparedness programs and assessing their effectiveness. FEMA's Radiological Emergency Preparedness Program provides assistance to state and local governments in developing emergency plans for nuclear energy facilities, and coordinating response actions among the various agencies. 

 

The Georgia Public Service Commission (PSC) oversees the operations at all Georgia Power generating plants in the state, no matter the fuel source, as they relate to costs and expenses allowed into rate base and charged to Georgia residents. 

 

A multitude of additional agencies have oversight of specific activities at nuclear plants, for example the Environmental Protection Agency, the Department of Homeland Security, the [Georgia] Department of Natural Resources, among others. 

All nuclear plants are designed with defense-in-depth safety systems. This means there are multiple systems, passive and active, in place to protect the reactor and the surrounding public. 

 

Passive systems include physical barriers that would restrict the spread of contamination outside the primary systems. These include such barriers as the fuel's zirconium alloy cladding, the thickness of the reactor vessel and the concrete containment surrounding it. 

 

Active systems are designed to ensure continuous core cooling and safe plant shutdown in the event of an accident. Some of these include the reactor protection system designed to automatically shut down the reactor if needed, multiple core cooling systems designed to replenish cooling water in the reactor if normal cooling water is lost, and containment isolation systems that can close all openings from the containment building to the outside.   

 

Additional redundant systems are in place to detect and mitigate any condition that could pose a threat the public. 

Uranium is a radioactive element found in natural ores. Deposits of these ores are found in the western United States, Canada and Australia, among other locations. 

 

Uranium recovery focuses on extracting (or mining) natural uranium ore from the Earth and concentrating (or milling) that ore. These recovery operations produce a product called "yellowcake" that is transformed into fuel for nuclear power reactors. 

 

The next step is converting the yellowcake into pure uranium hexafluoride (UF6) gas suitable for use in enrichment operations. During this conversion, impurities are removed and the uranium is combined with fluorine to create the UF6 gas. The UF6 is then pressurized and cooled to a liquid. In its liquid state, it is drained into 14-ton cylinders where it solidifies after cooling for approximately five days. The UF6 cylinder in the solid form is then shipped to an enrichment plant. 

 

Enriching uranium increases the proportion of uranium atoms that can be "split" by fission to release energy (in the form of heat) that can be used to produce electricity. 

 

The fuel for nuclear reactors has to have a higher concentration of U235 than exists in natural uranium ore. This is because U235 is "fissionable," meaning that it starts a nuclear reaction and keeps it going. Normally, the amount of the U235 isotope is enriched from 0.7% of the uranium mass to about 5%. 

Federal regulations require a detailed assessment of environmental impacts associated with a nuclear energy facility before it can be licensed to operate. 

 

Because an unintentional leak of radioactivity from nuclear plants is possible, the Nuclear Regulatory Commission (NRC) evaluates the potential impact of such leakage during the initial plant licensing process. The NRC conducted environmental assessments for all 104 operating reactors and is doing so for new reactors now in the licensing phase. 

 

Electric power companies that operate nuclear energy facilities must begin radiological environmental monitoring at least three years before the plant begins operation, and must continue monitoring throughout the plant's lifetime. 

 

Because radiation is naturally present in the environment, pre-operational monitoring establishes a baseline against which plant staff and the regulator can compare subsequent measurements. 

 

The federal limit for annual radiation dose to the public from nuclear plant operations is 25 millirem. A REM (Roentgen Equivalent Man) is a unit of radiation exposure that indicates potential biological effect on human cells. A millirem is equal to one-thousandth of a rem. The average person receives about 300 millirems annually of naturally occurring background radiation from soil, rocks, consumer products, medical procedures, etc.  

 

The average actual dose to the public from a nuclear power plant is about 2 millirem less than 10% of the regulatory limit. 

 

Nuclear plants also are required to conduct radiological monitoring of air, water, land, food and produce grown near nuclear energy facilities. 

When used fuel is removed from a nuclear reactor, it is initially stored in steel-lined concrete vaults filled with water. The water cools the fuel while it decays and becomes less radioactive. 

 

The federal government made a statutory and contractual commitment to begin accepting possession of all used fuel from nuclear power plant sites in 1998 for permanent storage in a central repository. Without that central repository, many nuclear plants have needed to supplement their storage capacity with above-ground, dry storage facilities. 

 

As the used nuclear fuel cools, the fuel rods that have been stored longest in the spent fuel pools are moved to massive concrete and steel sealed containers that have been tested for safety and durability. Spent fuel rods can remain in these canisters for as long as necessary while the federal government reviews various long-term storage options. 

 

Plant Hatch and Plant Vogtle currently use dry storage facilities.