Investigation of temperature-dependent high consequence system with weak and strong links based on probability of loss of assured safety

Abstract

Strong link and weak link systems are the critical safety design of high consequence system. The probability of loss of assured safety (PLOAS) which is the likelihood that weak link system will fail to deactivate the high consequence system before strong link system fails is used to assess the system assured safety. In this paper, a novel method based on PLOAS is proposed to estimate the mean and standard deviation of failure temperature or the minimum failure temperature of strong link for temperature-dependent high consequence system when given the failure temperature density function of weak link and the PLOAS. Four test problems are studied to verify the correctness of the proposed method. The corresponding L1-norm minimization problems are solved using gradient descend method. Based on the results of test problems, it concludes that this new method can provide a clear and quantitative “guide line” for critical safety component design. Moreover, the influences of the rates of temperature increase of strong link and weak link systems on required ability to bear abnormal heat environment are discussed and the safety index assignment is finally introduced.