Sizewell B, the UK's only pressurised water reactor (PWR), is to remain offline pending the development of techniques to repair a pressurizer, part of the unit's cooling circuit. According to a report to the London Stock Exchange by Lake Acquisitions Ltd, the subsidiary through which Electricité de France (EdF) purchased British Energy in 2009, the unit was manually shut down on 9 March when higher than normal moisture conditions were detected in the containment building. Early indications had suggested that repairs could be carried out in a relatively short timescale using techniques already deployed at similar power plants. However, detailed inspections have now shown that the techniques will need to be further developed before they can be deployed in this case. According to Lake Acquisitions, the total loss of generation could be in the region of 2-3 TWh. Sizewell B generated a total of 9.65 TWh in 2009, so the as yet indeterminate outage could represent the loss of nearly a third of a year's output. The 1188 MWe unit, which entered service in 1995, is the newest of the UK's operating nuclear fleet.