The Tennessee Valley Authority (TVA) has completed loading 193 nuclear fuel assemblies into the core of unit 2 of the US Watts Bar nuclear power plant. Power will now be gradually increased at the 1165MWe (net) pressurised water reactor during which the unit’s performance will be tested.

Preparations for fuel loading began in November, when fuel assemblies were staged in the plant’s used fuel pool ready for transfer to the reactor. Construction of Watts Bar 2 began in 1972 but was suspended in 1985 when the unit was about 55% complete. TVA resumed work in 2007, and an engineering, procurement and construction contract was awarded to Bechtel.

Major pre-operational tests were completed in September, verifying the performance of the reactor’s automatic safety features, the structural integrity of the containment structure and leak rate testing. The US Nuclear Regulatory Commission issued a 40-year operating licence for the plant in October. The unit is scheduled to begin operations in early 2016.

Progress was also reported at unit 4 of the Vogtle plant in Georgia as the first of three containment vessel rings was lowered into place. Unit 4 is the second of two Westinghouse-desgined AP1000 reactors under construction at the site, The reactor containment vessel, which will house the reactor itself, is made up of the containment vessel bottom head, three containment vessel rings and the containment vessel top head, or dome. Vogtle 4’s containment vessel bottom head was lifted into place in May 2014. When complete, the containment will stand over 60 metres high with a diameter of about 40 metres.

Construction began on Vogtle 4 in November 2013, following the start of work on unit 3 the previous March. Vogtle 3 is currently expected to begin operation in 2019, and Vogtle 4 in 2020. The units are being built by a contractor consortium of Westinghouse and CB&I/Stone and Webster. Southern Nuclear is overseeing construction and will operate the units on behalf of owners Georgia Power (45.7%), Oglethorpe Power Corporation (30%), Municipal Electric Authority of Georgia (22.7%) and Dalton Utilities (1.6%).

Photo: Watts Bar nuclear plant