Segmentation of the reactor vessel internals has begun at Sweden's Oskarshamn 2 boiling water reactor.
Oskarshamn 2 was retired in December 2016 after OKG's shareholders voted to close the units 1&2 at the plant citing concerns about their economic viability. In September 2017, Oskarshamn 2 entered the post-operation phase. Last month, after requesting supplementary information from OKG, the Swedish nuclear regulator approved the safety analysis report for segmentation of the reactor internals and fuel boxes at Oskarshamn 2.
GE Hitachi Nuclear Energy (GEH) won a contract in December 2016 to dismantle the reactor internals of Oskarshamn 1& 2. The work involves dismantling, cutting and packing the reactor internals for final disposal and will be carried out entirely underwater.
In April, OKG said the equipment for segmentation arrived at the reactor site from the USA and was installed and tested.
Cutting work officially started on 14 May. The first parts to be segmented are the moderator tank upper head and steam separators. The work is being carried out using a circular saw and plasma under water. Segmentation is due to continue for the next 12 months with completion scheduled for next spring if all goes to plan.
"After solid preparations that go far back to before the department for decommissioning was formed in 2016, we now look forward with both excitement and caution to see how segmentation functions in our plant," said OKG's decommissioning manager Andreas Roos.
Photo: Segmentation of the reactor internals at Oskarshamn 2 started in May (Photo: OKG)