[2H01-04] Reactor Pressure Vessel

[2H02] FY2018 Investigation for Improvement of Evaluation Method of Irradiation Effects on Reactor Pressure Vessel and Core Internals

(2)Through-wall distributions of metallographic structure and hardness of decommissioned Zion Unit 1 reactor pressure vessel steel

*Kenji Nishida¹, Tomohiro Kobayashi¹ (1. CRIEPI)

Keywords:Reactor pressure vessel, Through-wall distribution, Metallographic structure , Vickers hardness, Decommissioned reactor pressure vessel material

Through-wall distribution of metallographic structure and hardness of RPV base metal harvested from decommissioned Zion unit 1 was investigated. The elements of nickel, manganese, molybdenum were segregated along the rolling direction. The inner-most layer has the heat affected zone by clad welding. The inner-most layer also has the highest hardness and the hardness gradually decreases depending on the distance in the thickness direction in the area deeper than 15 mm, however the chemical composition was constant regardless of the distance.