Karlsruhe. Block I of the Neckarwestheim Nuclear Power Station (GKN I) has been on line again since weekend. after its annual inspection. Test and maintenance work has been undertaken on the plant and several technical projects were realised over the last few weeks. During the inspection, the experts at GKN were supported by more than 1,000 additional employees from manufacturing and specialist companies. The total workforce completed around 4,000 separate tasks.
Since Block I entered service, more than €800 million has been invested in retrofitting. This is more than twice the original costs for constructing the plant. "With the inspection and modernisation work, we have again invested tens of millions in our plant," explains Jörg Michels, Technical Director of the Neckarwestheim nuclear power station. "Consequently, we are continuing our efforts to operate all our power stations to the highest levels of technical safety, both according to German and international requirements and constantly continuing to improve them. At present, we are already operating at the level of safety required for new plants by the International Atomic Energy Agency (IAEA)." After an inspection lasting several weeks in 2009, the IAEA concluded that GKN I could be operated for a total of 60 years compared to international standards.
Block I will initially continue to be operated at a minimum load level. This corresponds to production of around 250 Megawatts. "As a result of the operating methods applied in the weeks before the inspection, we have maintained some room for manoeuvre for GKN I until the political change of direction regarding the continued operation of German nuclear power stations, as announced by the Government," continues Jörg Michels.
Successful cooperation between the experts at GKN and more than 1,000 external specialists
"I am very pleased with the implementation of the work and collaboration between our team and the employees from manufacturer and specialist companies," reports Helmut Scherla, head of the Block I power station. "Among other things, we have carried out a general overhaul of one of the three main coolant pumps. General overhauls were also implemented on various other pumps, such as a main feed pump, a secondary cooling water pump and a cooling tower pump. We have also carried out a leak test on the containment shell, on all three steam generators and performed an internal inspection of a steam generator. The largest projects also included optimising piping brackets and maintenance and modernisation work in the area of emergency power generation."
The inspection work was monitored by the Baden-Württemberg Ministry for the Environment, Conservation and Transport, and was also attended by experts from TÜV and KeTAG (Kerntechnik-Gutachterarbeitsgemeinschaft Baden-Württemberg). After the work had been inspected, the Ministry approved the restart of the plant.
Block 1 of the Neckarwestheim Nuclear Power Station is a pressurised water reactor with an electrical output of 840 megawatts. The plant was commissioned in 1976 and in 2009 has generated around four and a half billion kilowatt hours.
Block I is operated by EnBW Kernkraft GmbH (EnKK). EnKK operates the nuclear power stations in Neckarwestheim and Philippsburg, as well as the nuclear power station currently being decommissioned in Obrigheim. In mathematical terms, the sites at Neckarwestheim and Philippsburg generate around half of the electricity required by Baden-Württemberg.