Watts Bar Unit 2 Focused on Licensing Readiness

With five critical pre-operational testing milestones achieved, Watts Bar Nuclear Plant Unit 2 is focused on the final phase of completion and activities that will support license readiness and fuel load.

License readiness will be determined by TVA completing complex work, rigorous pre-operational testing and other specific activities in a safe and high-quality manner. These activities were detailed by TVA in the letter it sent to the Nuclear Regulatory Commission in August to say the unit is substantially complete.

In order to receive the NRC’s approval for an operating license, TVA also must successfully demonstrate that Watts Bar Unit 2 can be operated safely. Watts Bar Unit 2 continues to work within the NRC oversight and inspection process to provide assurance and documentation that the plant can operate safely according to design and regulatory requirements.

As part of the comprehensive, pre-operational testing program, the site completed Integrated Safeguards Testing on September 18. The testing 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 in a safe condition during abnormal conditions.


Previous major, pre-operational testing milestones that demonstrated that Unit 2 systems have been built to high standards of quality were:

  • Hot Functional Testingcompleted in August 2015—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—completed in August 2015—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—completed in October 2014—demonstrated the integrity of the Watts Bar Unit 2 primary coolant system. A separate, secondary cold hydrostatic test completed in December 2014 confirmed the integrity of the steam supply systems.
  • Open Vessel Testing—completed in July 2014—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.

Read more about the construction and history of Watts Bar Unit 2 on our comprehensive timeline

Want more detail? Get the vital statistics on Watts Bar Unit 2.

Get the bigger picture on our Watts Bar Nuclear Plant page.

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