Dismantling of Oskarshamn reactor internals completed

19 December 2019

GE Hitachi Nuclear Energy (GEH) has completed the segmentation of the reactor internals of units 1 and 2 at the Oskarshamn nuclear power plant in Sweden, fulfilling a contract awarded by plant operator OKG AB in December 2016. Large-scale dismantling and demolition of the two boiling water reactors will begin next year.

Oskarshamn units 1 and 2 (Image: OKG)

GEH began the dismantling and segmentation of the reactor internals of unit 2 in 2017, completing the task in January this year. The company recently completed the segmentation of unit 1's internals. The work included dismantling, cutting and packing the reactor internals for final disposal. All handling and segmentation work was carried out underwater using the GEH Primary Segmentation System.

"By focusing on safety, technical rigour and project execution, our experienced team was able to complete its work on both OKG units on schedule and on budget," said GEH President and CEO Jay Wileman.

Although not part of the contract with GEH, the reactor pressure vessels of the units will also need to be segmented. This work, which is expected to start next year, will mark the start of large-scale decommissioning and demolition of Oskarshamn 1 and 2.

German utility EOn - which owns a 54.5% stake in OKG - decided in October 2015 that Oskarshamn 1 and 2 would be shut down permanently. Unit 3 was unaffected by the decision. At that time it said unit 1 would close between 2017 and 2019, there would be no future investments at unit 2 and the reactor will not be restarted. In February 2016, OKG announced the decision to shut down Oskarshamn 1 in conjunction with a planned outage at the end of June 2017.

Oskarshamn 1, a 473 MWe boiling water reactor (BWR), started up in 1972, while Oskarshamn 2 is a 638 MWe BWR which began operating in 1974. Oskarshamn 3 is a 1400 MWe BWR which began operating in 1985.

Earlier this month, GEH announced that it is to decommission the reactor internals and reactor pressure vessel at the Pilgrim nuclear power plant in Massachusetts, USA under a contract awarded by Holtec International and SNC-Lavalin joint venture Comprehensive Decommissioning International. In July, the company was awarded a contract by CDI to decommission reactor internals and the reactor pressure vessel at the Oyster Creek plant in New Jersey.

Researched and written by World Nuclear News