Nuclear days ahead

Is completion of Vogtle just the beginning for U.S. nuclear energy?

As the first U.S. commercial nuclear reactors in more than 30 years come online, the U.S. government and energy companies see further development as a major tool in reducing carbon, despite some hiccups along the way.

Georgia Power reported that its Plant Vogtle Unit 3 in Waynesboro, Georgia, entered commercial operation on July 31. The energy utility also said the process has started to load fuel into the Vogtle Unit 4 reactor core, with the unit to be placed into service by the first quarter of 2024.

Vogtle Units 3 and 4 will operate two Westinghouse AP1000 (Advanced Passive) nuclear units of about 1.1 gigawatts each, providing power for 1 million Georgia homes and businesses. The U.S. Department of Energy believes the project will reduce carbon emissions by 1 million metric tons in 2030.

The Westinghouse AP1000 is a Generation III+ advanced pressurized water reactor that relies on gravity and natural circulation for core cooling, even in the absence of operator intervention or mechanical assistance, said Bechtel, the Houston-based engineering, procurement, and construction giant that in 2017 stepped in to complete the Vogtle project. The units are designed and licensed to operate for 60 years.

Modularization Challenges

The Westinghouse AP1000 was seen as an evolutionary approach, which would provide a modular design in which modules would be manufactured off-site and assembled onsite. The plants would have a smaller footprint and simpler design with less piping, valves, and pumps than previous designs.

Work began on Units 3 and 4 in 2009, with Westinghouse responsible for engineering, design and overall management, and Baton Rouge, Louisiana-based Shaw Group (later CB&I) to manufacture the pre-fabricated component modules and manage on-site construction.

Unit 3 was expected to be operational by 2016; Unit 4 by 2017. But the modularization approach did not go as planned. Delays, including redesign of the containment building in 2012, ultimately forced Westinghouse into Chapter 11 bankruptcy in March 2017 when it couldn’t absorb the overruns.

Southern Nuclear, a Southern Co. division, took control of the Vogtle 3 and 4 site July 2017 and selected Bechtel to complete construction in August 2017.

Units 3 and 4 were expected to cost US$14 billion and be operational by 2017. However, the project was completed six years later and US$17 billion over budget.

‘Responsible Partner’

Despite pushback from Georgia electric customers – who will largely foot the bill –Georgia Power and parent company Southern Co. see the project as a triumph.

“The Plant Vogtle 3 and 4 nuclear expansion is another incredible example of how Georgia Power is building a reliable and resilient energy future for our state,” said Kim Greene, chairman, president, and CEO of Georgia Power. “It is important that we make these kinds of long-term investments and see them through so we can continue providing clean, safe, reliable and affordable energy to our 2.7 million customers.”

“Plant Vogtle will generate more carbon-free electricity yearly than any other energy facility currently operating in the country,” said Brendan Bechtel, chairman and CEO of Bechtel. “Its completion reinforces that the United States is the responsible partner of choice for new nuclear energy around the world, and maintains U.S. interests in ensuring strong safety, security, and non-proliferation standards. This is why Vogtle’s impact is much bigger than a single project.”

Bechtel has been a player in the nuclear power industry since the 1950s, creating the world’s first reactor to generate electricity. Bechtel has designed, built, or provided construction services on 150 nuclear plants worldwide, accounting for more than 70 GW of nuclear generating capacity.

Vogtle Unit 3 and 4 ownership breaks down as: Georgia Power, 45.7 percent; Oglethorpe Power, 30 percent; MEAG Power, 22.7 percent; and Dalton Utilities, 1.6 percent.

Georgia Power began planning Plant Vogtle in 1972. Unit 1 began commercial operation in 1987 and Unit 2 became operational in 1989. At the time the 3,100-acre site along the Savannah River was the state’s largest construction program.

Units 1 and 2 use a Westinghouse pressurized water reactor, a General Electric steam turbine and electric generator, to produce a combined capacity of 2.43 GW. The Nuclear Regulatory Commission has licensed the units through Jan. 16, 2047.

New Technology

Meanwhile, potential next-generation nuclear power plants are advancing.

X-energy, a nuclear reactor and fuel design engineering company, is developing Generation IV high-temperature gas cooled nuclear reactors, as well as developing a tri-structural isotropic particle fuel.

Formed in 2009, the Rockville, Maryland, company founded by Kam Ghaffarian, in January 2016 received a matching five-year Advanced Reactor Concept Cooperative Agreement grant of US$400 million to US$4 billion from the DOE to build a demonstration reactor of their Xe-100 design.

The Xe-100 is a pebble bed high-temperature gas-cooled nuclear reactor design, which X-energy says will be smaller, simpler, and safer compared to conventional designs. The reactor is expected to generate 200 MWt (thermal megawatts) and about 76 MWe (electric megawatts).

For fuel, X-energy is developing TRISO-X, a proprietary version, which would be pebbles utilizing tri-structural isotropic, or TRISO, particles. The uranium would be enriched to 20%, so the reactor can go longer times for refueling.

Further, X-energy has developed a portable reactor, Xe-Mobile, a factory-built and fueled reactor that can be transported via rail, truck, or sea transport, to remote locations where electricity needed. The units would produce 2 to 7 MWe of electrical power.

Natrium System

TerraPower, a Bellevue, Washington-based nuclear group that was founded by a group of entrepreneurs including Bill Gates, has developed the Natrium system, which features a sodium fast reactor with an innovative molten salt energy storage system based on those used in solar thermal generation units.

The project would comprise a 345 MWe sodium-cooled reactor with a molten salt energy storage system that can boost the plant’s output to 500 MWe.

A team led by TerraPower was awarded US$80 million in matching funding from the DOE in 2020 for its Advanced Reactor Demonstration Program.

TerraPower purchased land in Kemmerer, WY, near a retiring coal plant, on Aug. 16, where it will build a demonstration project for its Natrium reactor. Under the public-private Energy’s Advanced Reactor Demonstration Program, the plan is to build an operational plant in five to seven years.

TerraPower reported that it selected four partners to support the demonstration program: Bechtel, GE Hitachi Nuclear Energy, PacifiCorp, Energy Northwest, and Duke Energy. Bechtel will be responsible for plant design, licensing, procurement, and construction.

On Aug. 1, TerraPower further announced four vendors to support the project: Western Service Corp.’ James Fisher Technologies; BWXT Canada Ltd.; and Curtiss-Wright Flow Control Service LLC.