New Steam Generators Help Extend Operation of Surry Nuclear Power Plant

Dominion Energy will replace the steam generators at its Surry Nuclear Power Station in Virginia. The project further supports the company’s Subsequent License Renewal (SLR) program to extend the long-term operation of Surry Units 1 and 2 through 2052 and 2053, respectively, when the units’ current licenses expire.

Westinghouse Electric Co. will design and manufacture the replacement steam generators, with delivery expected to start in 2028 and installation to begin in 2029. The steam generators will be fabricated at the Westinghouse Italy (WEI) facility in Monfalcone, Italy, and are based on Westinghouse’s original F-series units with multiple enhancements to maintain an industry-leading best in-service performance, according to the company.

The nuclear units at Surry Power Station (Figure 1) are both three-loop Westinghouse pressurized water reactors (PWRs)—capable of providing 1,676 MW, or about 15% of Dominion Energy’s electricity demand. Like all U.S. nuclear units, the Surry units were originally licensed to operate for 40 years. Following a stringent review process, the units’ licenses were renewed for 20 additional years of operation on March 20, 2003, allowing them to operate through 2032 and 2033, respectively. In May 2021, the Nuclear Regulatory Commission approved Dominion Energy’s application to renew Surry’s operating licenses for an additional 20 years, giving the new end dates in 2052 and 2053.

In a PWR, steam generators play a crucial role, separating the radioactively contaminated primary system from the non-contaminated secondary system. The steam generators are where heat is transferred from the reactor’s primary coolant to the water in the secondary system, producing high-pressure steam to drive a turbine and produce electricity.

Replacing the six steam generators is expected to ensure reliable operation through the plant’s license term. “These industry-leading steam generators will help Dominion deliver safe and efficient nuclear energy into the middle of the 21st century,” Westinghouse President of Operating Plant Services Dan Sumner said in a statement issued on Tuesday.

The new steam generator contract (Figure 2) follows a deal between Westinghouse and Dominion signed in 2021 for a major instrumentation and control (I&C) upgrade. “We are proud to continue supporting Dominion’s modernization efforts,” Sumner added.

“Our long-term partnership with Westinghouse supports our efforts to extend Surry’s nuclear energy production for decades to come,” said Dan Stoddard, senior vice president and Chief Nuclear Officer at Dominion. “Our Surry nuclear station operates year-round at more than 93% capacity, providing our customers with around-the-clock clean, reliable, and affordable energy.”

The project will be at least the second time in Surry’s history that major steam generator work has been done. Previous repairs were completed on June 1, 1981. At that time, the steam generator repair program was necessary to fix “tube degradation caused by corrosion-related phenomena and to restore the integrity of the steam generators to a level equivalent to new equipment,” according to an article published in the journal Nuclear Safety. The repair program consisted of replacing the then-existing lower-shell assemblies with new ones and adding new moisture separation equipment to the upper-shell assemblies. Those tasks required that several pieces of reactor coolant piping, feedwater piping, main steam piping, and the steam generator be cut and refurbished for reinstallation after the new lower shell was in place. Several major changes were also made at that time to avoid recurrence of problems.

—Aaron Larson is POWER’s executive editor (@AaronL_Power, @POWERmagazine).

[Ed. update: This article was first published on May 18, 2023, at 11:20 a.m. EDT, and was revised at 7:20 p.m. EDT to include details about the steam generator repair program work that was completed in 1981.]