Aircraft Impact Analysis for APR1400 Reactor Containment Building

  • Fatema AlMuhairi

Student thesis: Master's Thesis

Abstract

Aircraft impact on nuclear power plant structures is an issue of global concern, since the consequences of such an impact can be severe and may lead to release of radioactive material to the environment. The reactor containment buildings (RCBs) are the last barrier of protection in a nuclear power plant, where it protects the plant from external incidents, prevents the release of radioactive materials during normal operation or accidents and provides radiation shield. Moreover, with the materials degradation of the RCB by aging, the load bearing capacity can be compromised, and in the event of an aircraft impact on an aged RCB, the structural integrity might be lost. An impact of a commercial aircraft (Airbus A320) on the RCB of the APR 1400 design was investigated using finite element analysis (FEA). A new modeling approach was developed in this study for the purpose of determining the impact pressure of the aircraft, taking into account the change of the aircraft's cross section during crushing and divides the impact into three stages. The impact force of the aircraft on the containment building was calculated using the classical Riera approach, and the obtained force vs. time history was then converted into an appropriate dynamic pressure load for each stage of loading. The calculated pressure vs. time history was then applied to an RCB model developed using the commercial FE code ABAQUS, and the dynamic response was calculated. Compared to previous studies in this field, this work goes a step further in the analysis by analyzing the effect of aging on the impact response of an APR1400 RCB. Three degradation mechanisms were considered in modeling the aging of the containment, namely liner corrosion, rebar corrosion and pre-stress loss of tendons. It was found that the unaged APR1400 RCB is able to withstand the impact load of an Airbus A320 aircraft without liner or rebar failure for impact velocities as great as 300 m/s. While aging of the RCB caused the plastic liner and rebar strains to increase, the structural integrity of the RCB was maintained for most cases considered. Full penetration of the RCB was reported only for the unlikely event of an A320 impacting a highly degraded RCB (all Aircraft Impact Analysis for APR1400 Reactor Containment Building degradation mechanism applied simultaneously) at a velocity of 300 m/s, a scenario that is judged very unlikely to occur during the design life of 60 years.
Date of AwardJun 2019
Original languageAmerican English

Keywords

  • Reactor containment building
  • aircraft impact
  • aging
  • finite element analysis

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