Post-irradiation annealing and re-irradiation review

Abstract

This paper summarises the review of 92 papers most of them selected from the ODIN database made within the framework of the project ‘Nuclear Knowledge Preservation & Consolidation, WWER – WS2’ managed by JRC EC. The papers contain the experimental results concerning postirradiation annealing and re-irradiation of WWER RPV materials. The results published in these papers have been obtained in RRC KI, VTT, NRI Rez, Forschungszentrum Dresden-Rossendorf, with the international cooperation between RRC KI, VTT-Fortum, JRC EC and ITEP, RRC KI and ORNL, and IAEA International Project. The following problems are examined in the review: evolution of RPV materials properties and structure under irradiation; recovery of irradiated RPV materials properties and structure under annealing; chemical composition effect on transition temperature of irradiated RPV materials recovery; effect of fluence on WWER RPV materials mechanical properties recovery due to annealing; microstructure evolution due to postirradiation annealing; effect of post-irradiation annealing on mechanical properties of irradiated WWER-1000 RPV materials; re-irradiation behaviour; surveillance programme for the post-annealing operation; assessment of the RPV state; technical problems concerning annealing; and licensing problems for annealing.