Ringhals 2 was successfully phased into the Swedish power grid on 26 November and has now reached 100 per cent of its capacity. For the first time in over two years, all Ringhals’ reactor units are in production again and nuclear power now accounts for over 50 per cent of Vattenfall’s Nordic electricity generation.
Torbjörn Wahlborg, Head of BA Generation, recently met Sweden’s Energy Minister Ibrahim Baylan to update him about the generation situation before winter sets in.
“I was able to explain to the energy minister that our nuclear reactors are well prepared for the coming winter,” says Torbjörn Wahlborg, and went on to congratulate Ringhals’ managing director Björn Linde and all his colleagues at Ringhals for the successful restart.
The phasing was carried out with great precision – it’s not just a matter of pressing a button to start up a nuclear reactor.
For shift manager Christina Markusson, Saturday morning began with a review together with the shift team. Everything was ready and the reactor power was 5 per cent. The steam flowed through the turbines to go straight into the turbine condenser to be cooled down. At exactly 9 a.m., the decision was given to let the steam start turbine 21. At 500 revolutions per minute, the turbine operator brought the power increase to a halt.
“The turbine remained at that point to allow the shaft to be realigned. After half an hour, the rotation was increased to 3,000 revolutions per minute,” explains Mats Ladeborn, Head of Vattenfall Fleet Management, who was present in the control room.
At 3,000 revolutions per minute, Christina Markusson went up to the whiteboard in the control room and marked yet another milestone. It was then time for the phasing. Christina Markusson again gathered the shift team together and told them that the gradient, i.e. the rate of power increase, was to be 2 MW per minute. The reactor operator, assistant reactor operator and turbine operator repeated – “2 MW per minute” and the turbine operator could then order the phasing.
Ringhals 2 has not been in operation since summer 2014 after damage to the reactor containment’s bottom plate that has now been remedied.