Advanced Nuclear Power - The Magazine of Framatome ANP








Four Advanced Mark-BW™ lead test assemblies (LTA) have successfully completed three cycles of irradiation at Dominion Generation's North Anna Unit 1 plant in the US, achieving a peak pin burnup near 56 GWd/mtU. These 17x17 fuel assemblies are designed for operation in Westinghouse-designed reactors. The Advanced Mark-BW LTA program, a cooperative effort with Dominion Generation, features a fuel assembly design that is an evolutionary improvement on Framatome ANP's successful Mark-BW design currently operating at the McGuire, Catawba and Sequoyah plants in the US. The LTA's features resulted from a joint Framatome ANP French and US design team effort to provide a world-class fuel assembly with significant customer benefits. In 2003, a further improved version debuts in batch quantities at North Anna with M5 alloy intermediate spacer grids.

Testing Sequence
Dominion Generation wanted to test the Advanced Mark-BW LTA design thoroughly, through operation for two cycles at very near peak core conditions with a third cycle on the core periphery. In the third cycle, the Framatome ANP LTAs were moved to the core periphery in a region where a competitor assembly design exhibited flow-induced vibration fuel failures on several occasions. In-mast sipping during the fuel off-load confirmed that Framatome ANP's assemblies were leak-free.

"The Framatome ANP fuel assemblies operated defect-free in a production environment," said Kerry Basehore, Director, Nuclear Analysis & Fuel of Dominion Generation. "We are very satisfied with their performance to date."

One of the LTAs is being considered for a fourth cycle of operation to test performance above current licensed burnup limits. Operation for an additional cycle would be subject to Nuclear Regulatory Commission approval.

Framatome ANP constantly works to improve its fuel assemblies to enable its customers to achieve maximum output safely and efficiently. Combining the latest technologies with superior design and paying attention to each detail results in reliability and performance that pays dividends for customers.

Design Features and Benefits

  • NRC-licensed, low-corrosion, low-growth Alloy M5™ material for fuel rod cladding and guide tubes to assure trouble-free, high burnup operation
  • Quick-disconnect top nozzle that provides flexibility and ease of modifications, if needed
  • Mid-span mixing grids with licensed DNB performance for enhanced operating margins supporting higher power operation or increased operating flexibility
  • An improved fuel rod design that reduces fuel cycle costs, making nuclear power an even more economic choice for customers
  • The TRAPPER™ bottom nozzle virtually eliminates potential failures from loose debris in the core
The data herein are solely for your information and are not offered, or to be construed, as a warranty or contractual responsibility.
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