Naslov
Boat Sampling and Inservice Inspections of the Reactor Pressure Vessel Weld No. 4 at Kozloduy NPP, Unit 1

Autori
Cvitanović, Mato ; Oreb, Elidio ; Mudronja, Vedran ; Zadro, Vladimir ; Bezlaj, Hrvoje ; Petkov, Miladin ; Gledatchev, Jonko ; Radomirski, Stefan ; Ribarska, Teodara ; Kroes, Bert

Izvornik
Nuclear Engineering and Design (0029-5493) 191 (1999), 3; 293-312

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
reactor pressure vessel weld; inservice inspection

Sažetak
The paper deals with reactor pressure vessel (RPV) boat sampling performed at Kozloduy Nuclear Power Plant, Unit 1, from August to November 1996. Kozloduy NPP, Unit 1 has no reactor vessel material surveillance program. Changes in material fracture toughness resulting from the fast neutron irradiation which cannot be monitored without removal of the vessel material. Therefore, the main objective of the project was to cut out samples from PRV wall in order to obtain samples of the RPV material for further analyses. The most critical area, i.e. weld No. 4 was determined as a location for boat sampling. Replication technique was applied in order to obtain precise determination of the weld geometry necessary for positioning of the cutting tool prior to boat sampling, and determination of divot depth left after boat sampling and grinding of sample sites. Boat sampling was performed by electrical discharge machining (EDM). Grinding of sample sites was implemented to minimize stress concentration effects on sample sites, to eliminate surface irregularities resulting from EDM process, and to eliminate recast layer on the surface of the EDM cut. Ultrasonic, liquid penetrant, magnetic particles, and visual examinations were performed after grinding to establish baseline data in the boat sampling area.

Izvorni jezik
Engleski

Znanstvena područja
Strojarstvo

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