Watts Bar Unit 2 License a Critical Success

More Work Ahead for Fuel Load and Commercial Operations

In one of the most critical steps on its path to commercial operations, Watts Bar Unit 2 has received an operating license from the Nuclear Regulatory Commission.

“Today we are here to celebrate a milestone for TVA and for the people of the Tennessee Valley,” said TVA President and CEO Bill Johnson. “Receipt of the license validates that Unit 2 has been built in a manner to ensure regulatory compliance and excellence in operations.”


But this is not the end of the Watts Bar Unit 2 story; in many ways, it’s the beginning of a new chapter.

“Readying to load fuel in Unit 2 will require several more weeks of demanding work and ongoing NRC inspections and reviews,” explains Joe Grimes, TVA’s Chief Nuclear Officer. “Only when the required activities are complete and our readiness verified will we load the initial fuel into Unit 2.”

The fuel load will be followed by several months of Power Ascension Testing—an extension of pre-operation testing on those systems that require fuel in the core in order to be tested.

Pre-operational tests have included:

  • Integrated Safeguards Testing, which demonstrated that electrical systems that
    provide power to engineered safety features would operate correctly and the safety features would shut down the reactor and maintain it safely during abnormal conditions.
  • Hot Functional Testing, which demonstrated the integrated operation of the primary coolant system and the steam supply system at design temperature and pressure with no fuel in the reactor.
  • Containment Leak Rate Testing, which demonstrated the integrity of the steel containment structure and the associated systems, structures and components designed to contain accidental releases of radioactive material.
  • Cold Hydrostatic Testing, which demonstrated the integrity of Watts Bar Unit 2’s primary coolant system. A separate secondary cold hydrostatic test confirmed the integrity of the steam supply systems.
  • Open Vessel Testing, which demonstrated that the flow paths of water from key safety systems into the reactor vessel are not blocked or constricted and that the pumps, motors, valves, pipes, and other components of the systems function as designed.

When Power Ascension Testing is complete, TVA will put its newest generation asset in service. Once Unit 2 joins Unit 1 in full operation, Watts Bar Nuclear Plant will generate nearly 2,300 MW of clean, carbon-free power—enough to power 1.3 million homes in the Tennessee Valley.