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Numerical Experiment on Two-Sided Tolerance Limit for Safety Analysis of Energy Generation Systems
Seola Han1, Taew N Kim2

1Seola Han, Department of Safety Engineering, Incheon National University, South Korea, East Asian.

2Taew N Kim, Department of Safety Engineering, Incheon National University, South Korea, East Asian.

Manuscript received on 05 June 2019 | Revised Manuscript received on 12 June 2019 | Manuscript Published on 19 June 2019 | PP: 119-122 | Volume-8 Issue-8S June 2019 | Retrieval Number: H10220688S19/19©BEIESP

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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open-access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: It is necessary to quantify the uncertainty in the safe-ty assessment when the protection characteristics of energy gen-eration systems are tested through first-class-estimate methodol-ogies. Especially, the tolerance restriction for licensing must be carefully predicted taking into account the uncertainty within the protection analysis results. The tolerance limits are usually pre-dicted as values with a probability of 95% and a confidence level of 95% for general industrial applications. Various statistical techniques were applied a good way to estimate the tolerance restriction of the great-predicted results and a methodology based totally on non-parametric facts is one of these methods which lets in to estimate the tolerance limit with reasonable attempt. Among non-parametric methodologies, a method primarily based on order statics has been broadly used to decide the tolerance restriction for energy structures including nuclear structures. This method has benefits wherein the quantity of simulations is inde-pendent of the number of uncertainty parameters and the inter-pretation of the results has not anything to do with the distribu-tion of the outcomes from uncertainty evaluation. In this tech-nique, the quantity of simulations is determined by a formula recommended by Wilks but it is recently found that the quantity of simulation decided by Wilks’ formula should be revised consi-dering the symmetric nature of the tolerance limits in case of two-sided approach, namely centered two-sided formula. In this study, the results from methods based on Wilks’ formula and centered two-sided formula are compared for three different trial output distributions. The comparison indicates that the tolerance limits estimated on the basis of Wilks’ formula shows lower con-fidence level, 80%, whereas the centered two-sided formula re-sults in a proper confidence level of 95%. In addition, the distri-bution-free and order-free characteristics of non-parametric methodology have been demonstrated on the basis of the analysis results. The results indicate that the lower order formula tends to produce more conservative results. Thus, it is recommended for regulators to use the lower order formula for safety audit analysis for energy generation systems to secure higher safety.

Keywords: Wilks’ Formula, Tolerance Limit, Best-Estimate Analysis, Non-Parametric Method, Centered Two-Sided Tolerance Limit.
Scope of the Article: Analysis of Algorithms and Computational Complexity