Surveillance Programme for WWER-440/Type 213 Reactor Pressure Vessels- Standard Programme, Re-Evaluation of Results, Supplementary Programme

Abstract

Irradiation embrittlement of the reactor pressure vessel beltline materials of WWER-440/Type 213 reactors is monitored by a material irradiation surveillance programme. Due to the high lead factor, the duration of the standard surveillance programme is only five years, after which no further surveillance samples remain in the reactor. The large variation and uncertaintity in neutron flux over the irradiated materials produce significant scatter in mechanical properties and necessitate a re-evaluation of results using gamma scanning, specimen reconstitution and recalculation. In order to provide information on the impact of changes in plant operation during later years a supplementary surveillance programme has been devised.

Fracture mechanics characterisation of the WWER-440 reactor pressure vessel beltline welding seam

“…Test specimens of the WWER-440/V-213 surveillance programme were manufactured from the following RPV materials [7][8][9]: base metal (RPV steel 15Kh2MFAA from the beltline ring 0.3.1), weld metal (submerged arc weld Sv-10KhMFTU) from a welding coupon representing the beltline weld SN0.1.4. and heat affected zone from the welding coupon.…”