This is one of the most challenging decommissioning plans in Europe and the Valencia-based business group GDES has been actively engaged since 2020 as a subcontractor of Uniper Nuclear Services (UNS) at Barsebäck (BKAB U1/U2) and Oskarshamn (OKG U1/U2).
The large-scale decommissioning of the four units started in 2020 and is scheduled to end in 2028. BKAB and OKG are handling the radiological demolition work as part of a joint project divided into several work packages. Each package may involve segmentation and removal of reactor vessels or of turbine and generator components. This type of planning is a strategic advantage that optimises resources, time and logistics, improves learning and reduces risk compared to other possible approaches.
BKAB had two twin BWR reactors of 600 MWe each, which were shut down respectively in 1999 (U1) and 2005 (U2); the two OKG reactors that are being dismantled also used BWR technology, with an installed capacity of 494 MWe for Unit 1 and 664 MWe for Unit 2.
Within the framework of this broad German-Spanish collaboration, particular mention should be made of the WP1 and PSWP6 projects. WP1 includes post-segmentation of the RPVs and the cutting of the drywell heads at BKAB/OKG as well as segmentation of the CRDHs at BKAB. PSWP6 consists of dismantling the reactor water recirculation system as well as other systems within the BKAB drywell.
The decommissioning service is executed in two separate phases – approximately two years at BKAB and two years at OKG – and entails the installation, operation, and maintenance of the handling, lifting, and cutting equipment designed and supplied by UNS, as well as in the dismantling and disposal of radioactive waste.
This sophisticated engineering project is a prime example of how to combine, for challenges of this nature, high-tech solutions (robotic system in case of more significant radiologic risks) with off-the-shelf tools (manual thermal/mechanical cutting for low radioactive materials).
The similarities between the reactors, a key element of the project, facilitate the implementation of synergies in decommissioning strategies, both in terms of methodologies and tools, as well as the reduction of costs and continuous improvement in the quality and speed of the service provided, by building on the lessons learned on site.
The work at Barsebäck has been successfully completed and the work at Oskarshamn has begun. Post-segmentation work on the two Oskarshamn reactors currently in decommissioning phase (the third reactor is still in operation) is expected to be completed in 2024.
This service is yet another tangible demonstration of the Spanish nuclear industry’s capacity to deliver value to international projects that require a significant deployment of technology and qualified personnel, and of the confidence that leading global technology companies place in the Spanish industry.
