Characterization of the Decommissioned Novovoronesh-1 Pressure Vessel Wall Materials by Through-Wall Trepans
SourceMaterial properties of the Novovoronesh-1 pressure vessel were characterized after 20 years of plant operation. The unit was the first commercial PWR unit in Russia producing 210 MW electric power. It was commissioned in 1964 and shut down in 1984. Wall thickness of the vessel is 120 mm, including 20 mm of cladding. The vessel contained only circumferential welds. The coolant temperature was 250°C. Nine through-wall trepans of outer diameter 120 mm were cut out from the vessel both from the weld seams and the base metal forging rings. The trepans were studied by RRC-KI, PROMETEY and VTT. The paper is focusing on the Charpy-V and fracture toughness test data of the critical core weld. Due to the lack of archive material the unirradiated material condition was estimated by a reference annealing procedure.