More power for Forsmark 3

22 September 2014

Vattenfall's Forsmark 3 has returned to service with 17 MWe more power after work to replace the unit's high-pressure turbine.

Forsmark 3 (Image:Vattenfall)

The uprate work took place during the unit's scheduled annual outage which began on 27 July and lasted 54 days. The high-pressure turbine converts the steam produced in the boiling water reactor to the mechanical energy that is ultimately used to turn the turbogenerator, producing electricity. Forsmark 3's capacity now stands at 1187 MWe.

Forsmark 3's new high-pressure turbine has more closely-spaced blades, allowing a higher flow of steam and in turn increased electricity production. Forsmark 2 underwent similar upgrading work in 2009, but problems with intense vibrations at the turbine inlet valves meant the unit had to work at reduced power for much of the following year. Vattenfall subsequently decided to postpone uprate work on units 1 and 3 to give it time to address those issues.

The scheduled maintenance and refuelling outage also saw the replacement of modules through which cables pass into the reactor containment, with new seals which are expected to allow a further 30 years of operation for the unit. The outage also included reviews of three of the reactor's eight main circulation pumps, inspection of all 169 control rods, and testing of the reactor vessel including checking of weld joints. Two of the unit's low-pressure turbines also underwent maintenance inspections.

The unit's next scheduled outage is due in August 2015.

Researched and written
by World Nuclear News