19 Sept (NucNet): Recent unplanned shutdowns at nuclear power plants in Sweden have so far cost Fortum a production loss of around 700 million kilowatt hours, the company has said. The loss has been fully compensated by thermal output.
Fortum, a shareholder in both the Forsmark and Oskarshamn nuclear plants, said tests are being carried out and an estimate of the restart dates for units one and two at Forsmark will be given later. Fortum expects a restart of Oskarshamn-1 around the turn of the year.
Forsmark-1 was shut down on 25 July 2006 following a scram and the discovery of a fault in the plant’s power supply backup system.
Forsmark-2 was already undergoing an annual outage at the time of the shut-down and the outage will now include modifications to the unit’s uninterruptible power supply equipment. Forsmark-3 is operating normally.
Following the Forsmark shutdown, units one and two at Oskarshamn were also shut down because they have similar backup power supply systems. At the time, Oskarshamn-2 was undergoing a planned annual outage with generator replacement. Oskarshamn-3 was not affected and is operating normally.
Systems were checked at Oskarshamn earlier this month following the publication of an incident analysis report of the Forsmark-1 scram. The checks showed no implications for Oskarshamn-2, which has now been given the go-ahead by the Swedish Nuclear Power Inspectorate (SKI) to restart after its outage, due to end on 23 September.
The unit will start with testing of a new generator and will initially operate at approximately 30% of maximum power output.
Last week SKI announced a series of measures to be taken before it will allow the restart of Forsmark-1 and -2. Fortum said it had been analysing the consequences of these measures. They include modifying the electrical system, and ensuring that visual displays of electricity supply data “provide an adequate picture” in the event of a loss of power and do not mislead reactor operators. The measures will probably also concern Oskarshamn-1, which is undergoing tests.
