Integrity analysis of a reactor pressure vessel subjected to pressurized thermal shocks by considering constraint effect

摘要: The integrity analysis of a reactor pressure vessel subjected to pressurized thermal shocks is performed. Linear elastic leads more conservative result than the elastic– plastic if warm prestressing effect not considered. stress intensity factor for deepest point surface crack front always larger that point, indicating both and points should be safety margin based on K–T approach only K approach. Reactor vessels (RPVs) nuclear power plants are exposed neutron irradiation, which causes embrittlement ferritic steel makes material susceptible brittle fracture. This has negative consequences RPV integrity, especially in case unforeseen extreme loading conditions. One potential challenge water posed by shock (PTS), associated with severe cooling core together or followed repressurization RPV. PTS transients arisen number abnormal events postulated accidents including pipe break primary circuit, stuck-open valve circuit later re-closes, main steamline. lead high tensile circumferential axial stresses wall. If (SIF) too large this may initiation worst even failure Thus, assessed against cleavage fracture [1–7]. involves comparison KI KIc whole PTS. Calculation generally linear mechanics (LEFM) simplification reasons. along will yield due vicinity front. (EPFM) shall used nonlinear analysis. For modeling KIc, an important aspect constraint effect, different strains at tip between components tested specimens under same driving force (KI J). Fracture toughness testing standards use highly constrained deep cracks guarantee data. effective deeper (high constraint) lower shallow (low higher hydrostatic tip. data from directly structure low constraint, it over results early decommissioning structures [8–10]. However, significant