The fault was discovered during a routine inspection at the firm’s Heysham 1 power plant (pictured), where one of the two reactors has been offline since June after discovery of a boiler spine defect. In what it called a “conservative decision”, today EDF said it has also decided to proactively shut down a further three reactors of similar design for inspection and testing.
During the shutdowns the company says it will “carry out further inspections in order to satisfy itself and the regulator that the reactors can be safely returned to service.” The company estimates that the reactors will be back online in about eight weeks.
The reactors taken offline are at Heysham 1 and the firm's Hartlepool power station. Both plants were commissioned in 1983 and are due for decommissioning in 2019.
Meanwhile, EDF has announced that it is undertaking a £20m ($34m) overhaul of its Hunterston B nuclear power plant in Ayreshire, Scotland.
Hunterston B was commissioned in 1976 and was previously due to go offline in 2011, but is now scheduled to run until 2023 after a decision to extend the plant’s life.
One of the plant’s two advanced gas-cooled reactors will be offline until October, bringing the total taken offline to over one quarter of EDF’s generating capacity in the UK.