Advanced Solutions

As industry needs evolve, nuclear fuel providers are being called upon to deliver more without compromising safety or reliability.

The ability to innovate in the nuclear industry is more critical than ever, as the landscape in which we operate continues to shift more rapidly each day. Today’s utilities require the lowest fuel cycle costs possible, increased operational flexibility, higher burnup capability to generate more power with fewer bundles, diversity of supply, accident-tolerant products that provide resilience and survivability, in addition to robust and leak-free fuel performance.

To meet these challenges Westinghouse is developing advanced technologies, practices and manufacturing methods that enhance our ability to produce and service nuclear fuel and provide greater insight into core performance.

Westinghouse’s EnCore Fuel program is centered on the use of high-performance features that are being developed and deployed on a strategic timeline so utilities can gain safety and cost benefits quickly. We have begun with an improved chromium-coated cladding that inhibits the zirconium-steam reaction and increases maximum temperature by an additional 300°C. This cladding has been applied to lead test rods (LTRs) loaded with our ADOPT™ fuel pellets – a mature design that increases density, allowing more uranium for a higher burnup, and has been fueling BWRs in Europe for 10 years. These LTRs were inserted into Exelon’s Byron Unit 2 in the spring of 2019.

We are also developing advanced fuel rod materials such as silicon-carbide cladding, which has an extremely high melting point and minimal reaction with water and steam. EnCore Fuel’s long-term portfolio will also include uranium nitride pellets, which offer 40% higher uranium density over UO2 (equivalent to 7% U235 enrichment) and significantly improved thermal properties, with either option translating to higher safety and economic benefits.

With our TRITON11 BWR fuel, utilities can decrease fuel cycle costs by up to $4 million per cycle while increasing capacity factors. Our innovative, best-in-class TRITON11 design improves nuclear and thermal-hydraulic performance over any existing 11x11 or 10x10 BWR fuel design. With a distortion-resistant fuel channel, superior debris filter and advanced sleeve-type spacer grids that resist debris capture.

Reduced fuel cycle costs while maintaining high-quality performance are achieved by:

• More efficient use of uranium through better thermal margins
• Fewer fresh assemblies loaded
• Increased operational flexibility
• Improved debris resistance

Our TRITON11 fuel design is built on proven components, mechanical design solutions and materials with known reliability benefits such as a distortion-resistant Low Tin ZIRLO™ fuel channel, effective debris filter and advanced sleeve-type spacer grids that resist debris capture. Lead test assemblies of our TRITON11 design were loaded in two BWRs in Europe in 2019, with target for reload introduction in 2023.

AXIOM™ is Westinghouse’s next generation of fuel rod cladding targeting high fuel duties, improved corrosion resistance, lower hydrogen pick-up and lower creep and growth when compared to current Westinghouse products.

AXIOM Cladding Technical Advantages

• Dimensional stability, lower hydrogen pickup, and lower corrosion at high burnups
• Greater flexibility for coolant chemistry changes
• Lower creep rate delays pellet-clad contact resulting in Pellet Clad Interaction (PCI) margin increase
• Increased margin to potential 50.46(c) rule changes
• Increased thermal margin at higher boiling duties
• Recovery of some lost margin due to Thermal Conductivity Degradation (TCD) due to reduced oxide layer

Westinghouse’s PRIME™ advanced fuel features help to improve fuel performance, enhance fuel reliability, enable enhanced fuel cycle economics and provide additional margin at uprated conditions and higher burnup. The package of features includes an optimization of enhancements based on proven Westinghouse fuel reliability and world-class leadership in the design and manufacture of nuclear fuel.

PRIME Key Features:

• Low Tin ZIRLO™ mid grids and intermediate flow mixing grids
• Reinforced dashpot in guide thimble tubes
• PRIME Bottom Nozzle with innovative debris filter side skirt

Westinghouse developed Advanced Doped Pellet Technology (ADOPT) fuel to improve fuel cycle economics and enhance the accident tolerance of conventional uranium dioxide (UO₂) fuel pellets.

ADOPT fuel is a near-term fuel product within Westinghouse’s EnCore^® Fuel program.

As a result of ADOPT fuel’s enlarged grain size and increased density, key benefits include:

• Increased density of fissile material
• Enables higher burnups
• Lower transient fission gas release (FGR)
• Higher thermal stability
• Increased Pellet Clad Interaction (PCI) margins
• Enhanced corrosion & washout resistance