Barsebäck as Research and Development Platform, Extraction and Analysis of Reactor Pressure Vessel Material
Pål Efsing, Magnus Boåsen, Ulla Ehrnstén, Sebastian Lindqvist, Kim Wallin, Mattias Thuvander, Kristina Lindgren,
As part of the NKS-R program, VTT, Chalmers and KTH has performed a baseline study to prepare for a test program to analyze the as aged material properties of the retired reactor pressure vessel, RPV, from Barsebäck unit 2. The project started at July 1st, 2016. The initial activities focused on mapping of possibilities for future work between VTT, Chalmers and KTH, liason activities with Vattenfall to discuss extraction of the test material from the Barsebäck plant and collection of material for the base line testing.
The group has collaboratively prepared an extraction outline to give the basis for further discussions with the Swedish utilities regarding the materials extraction scheme and proposed amounts of materials and positions in the RPV. The work at Chalmers University focused on base-line high resolution atom probe tomography, APT, testing on un-irradiated material as well as sample materials irradiated in a test reactor. In addition to this some samples of thermally aged material was included to visualize the features that develops during both types of ageing. VTT has performed a base-line testing utilizing miniature fracture toughness testing samples of un-irradiated RPV material obtained from the original tests of the RPV of Barsebäck 2.
The actual retrieval of materials from Barsebäck, is foreseen to occur in 2018 and -19. The material harvesting is outside the scope of the research oriented program that was supported in 2016. The work has been supported from both SSM and SKC in Sweden and by the Finnish nuclear safety program, the SAFIR-program.
The main outcome so far apart from the actual data that has been produced and the proposed cutting scheme for materials retrieval, is the fact that the work enhances the collaboration in this technology driven area between two Swedish technical universities KTH and CTH and Aalto University in Finland, and the Finnish research institute VTT. In addition to this, it is functioning as a facilitator for contacts between the research driven academic world, safety and operability driven Finnish and Swedish nuclear operating companies and the Finnish and Swedish nuclear safety authorities.
Low alloy steel, irradiation effects, fracture toughness, ductile to brittle transition temperature, constraint effects, high resolution microscopy