Watts Bar 2 completes power ascension testing

Power ascension testing has been completed at Watts Bar 2, the Tennessee Valley Authority (TVA) announced yesterday. The unit is now producing over 1150 MWe of energy as it begins preparations for commercial operation.

Power ascension testing has been completed at Watts Bar 2, the Tennessee Valley Authority (TVA) announced yesterday. The unit is now producing over 1150 MWe of energy as it begins preparations for commercial operation.

Watts Bar (Image: TVA)

When Watts Bar 2 reached first criticality in May, it was the first nuclear unit to start up in the USA in a decade. The 1165 MWe (net) pressurized water reactor (PWR) was synchronized to the grid on 3 June and has undergone a series of detailed and highly rigorous tests at various power levels to ensure that all systems operate safely as designed.

The unit successfully completed its final power ascension test - a 50% load rejection from full power, to test the system's ability to withstand a sudden loss of load and return safely to normal operating conditions - on 30 September. It will now begin a pre-commercial period of extended full power operation to further test its reliability.

Power ascension testing was briefly suspended following a switchyard fire at the plant on 30 August. Watts Bar 2's systems were unaffected by the fire and the unit responded as designed, shutting down automatically. The unit was reconnected to the grid on 26 September after TVA completed a program to inspect, repair and test the affected transformer.

Watts Bar, near Spring City, Tennessee, is home to two nuclear reactors. Construction of both units first began in 1972, but was suspended in 1985. TVA subsequently decided to resume work on unit 1, which started up in 1996. In 2007, the authority took the decision to complete Watts Bar 2, which had been about 55% complete when construction was suspended. The unit's completion has incorporated upgrades in response to the Fukushima Daiichi accident of 2011 required by the NRC of all US nuclear power plants.

TVA is a US corporate agency providing electricity to customers across seven south-eastern states as well as providing flood control, navigation and land management for the Tennessee River system. As well as Watts Bar, its generation portfolio includes three boiling water reactors at Browns Ferry in Alabama and two PWRs at Sequoyah in Tennessee.

Researched and written
by World Nuclear News