German steam generators arrive in Sweden for recycling

In 2021, PreussenElektra awarded the contract for the dismantling and disposal of a total of 16 steam generators from the Unterweser, Grafenrheinfeld, Grohnde, and Brokdorf plants to Cyclife, a subsidiary of EDF specialising in nuclear power plant decommissioning and waste management. Cyclife is responsible for the entire process, from collection at PreussenElektra plants to the upcoming treatment and the future return delivery of the processed waste.

Steam generators are the heat exchangers in pressurised water reactors (PWRs), producing the steam that turns the turbines to generate the electrical energy in the generator. PreussenElektra said the dismantling and disposal of the steam generators is one of the key projects in the dismantling of its PWRs and will take more than a decade.

The removal of all four steam generators from the reactor building at the Unterweser plant began in mid-May last year. In total, all four steam generators - each measuring 20 metres in height and weighing about 300 tonnes - were removed within four weeks, completing the project on schedule. The actual dismantling was preceded by nearly two years of planning, testing, and implementation of the necessary modifications and additions inside and outside the reactor building, as well as the individual dismantling steps of the large heat exchangers.

Unterweser - a pressurised water reactor with a gross installed capacity of 1410 MWe - operated between 1978 and 2011. It was one of seven nuclear power plants shut down in Germany in March 2011 when it lost its commercial operating licence under the 13th Amendment to the Atomic Energy Act.

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Cyclife Sweden has now successfully completed the transport of the four steam generators from Unterweser to its new facility in Sweden.

"After several months of preparation and coordination, the four steam generators have now arrived at our facility, where they will be processed with the aim of recycling a substantial proportion of the material in our new facility which is doubling our treatment capacity here in Sweden," said Delphine Servot, managing director of Cyclife Sweden. "We worked closely with PreussenElektra throughout the project, from planning to execution, contributing expertise and resources to enable the safe and efficient transport and handling of the components."

Michael Bongartz, member of the board of PreussenElektra, added: "Following the successful shipment of the steam generators from our pilot plant in Unterweser to Sweden, we now look forward to working with Cyclife to transfer the lessons learned and experience to the upcoming steam generator projects. Upon reaching this key milestone, I would also like to express my gratitude to the on-site teams for their professionalism and collaborative spirit."

"Awarding this contract for our nuclear power plants was a strategic decision to accelerate decommissioning," said PreussenElektra CEO Guido Knott. "This will enable us to leverage synergies across all sites and consistently apply the knowledge we have gained. With Cyclife's proven expertise in managing complex decommissioning projects, this partnership sets a benchmark for safe and efficient implementation."

Cyclife says it has developed a process and facilities in Sweden for dismantling and disposing of steam generators that provides a turn-key solution for nuclear operators on retired metallic large components and scrap metal. This includes the management of their transport from/to customer or final depository, the storage on Cyclife's site before and after treatment, a volume reduction up to 95%, the characterisation of secondary waste, associated analysis and conditioning of final packages, and eventually the management of metallic reusable ingots (characterisation, free-release and selling to conventional industries).

To date, Cyclife Sweden has successfully processed more than 30 large components (steam generators, heat exchangers, etc) from Swedish, German, French and British nuclear power plants.