A Novel Safety Assessment Approach Based on Evolutionary Clustering Learning

In the effort to quantify Automatic Dependent Surveillance Broadcast (ADS-B) system safety, the authors have identified potential ADS-B failure modes in Syd Ali et al. (2014). Based on the findings, six potential hazards of ADS-B are identified in this paper. The authors then applied the Probabilistic Safety Assessment approach which includes Fault Tree Analysis (FTA) and Importance Analysis methods to quantify the system safety. FTA is applied to measure ADS-B system availability for each identified hazard while Importance Analysis is conducted to identify the most significant failure modes that may lead to the occurrence of the hazards. In addition, risk significance and safety significance of each failure mode are also identified. The result shows that the availability for the ADS-B system as a sole surveillance means is low at 0·898 in comparison to the availability of ADS-B system as supplemental or as primary means of surveillance at 0·95 and 0·999 respectively. The latter availability values are obtained from Minimum Aviation System Performance Standards (MASPS) for Automatic Dependent Surveillance-Broadcast (DO-242A).

Download Full-text

Safety Assessment of Casting Workshop by Cloud Model and Cause and Effect–LOPA to Protect Employee Health

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17072555 ◽

2020 ◽

Vol 17 (7) ◽

pp. 2555 ◽

Cited By ~ 1

Author(s):

Qingwei Xu ◽

Kaili Xu ◽

Fang Zhou

Keyword(s):

Safety Assessment ◽

Cloud Model ◽

Least Square Method ◽

Assessment Method ◽

Employee Health ◽

Least Square ◽

Entropy Weight ◽

Safety Level ◽

Cause And Effect ◽

Assessment Approach

Safety assessment of a casting workshop will provide a clearer understanding of the important safety level required for a foundry. The main purpose of this study was to construct a composite safety assessment method to protect employee health using the cloud model and cause and effect–Layer of Protection Analysis (LOPA). In this study, the weights of evaluation indicators were determined using the subjective analytic hierarchy process and objective entropy weight method respectively. Then, to obtain the preference coefficient of the integrated weight more precisely, a new algorithm was proposed based on the least square method. Next, the safety level of the casting workshop was presented based on the qualitative and quantitative analysis of the cloud model, which realized the uncertainty conversion between qualitative concepts and their corresponding quantitative values, as well as taking the fuzziness and randomness into account; the validity of cloud model evaluation was validated by grey relational analysis. In addition, cause and effect was used to proactively identify factors that may lead to accidents. LOPA was used to correlate corresponding safety measures to the identified risk factors. 6 causes and 19 sub-causes that may contribute to accidents were identified, and 18 potential remedies, or independent protection layers (IPLs), were described as ways to protect employee health in foundry operations. A mechanical manufacturing business in Hunan, China was considered as a case study to demonstrate the applicability and benefits of the proposed safety assessment approach.

Download Full-text

Engineering Assessment Approach for the Leningrad Nuclear Power Plant In-Depth Safety Assessment

10.1115/imece2000-1037 ◽

2000 ◽

Author(s):

Garill Coles ◽

Sam McKay ◽

Jon Young ◽

Yuri Skok

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Nuclear Power ◽

Safety Assessment ◽

Safety Analysis ◽

Regulatory Compliance ◽

Regulatory Requirements ◽

Related Function ◽

Assessment Approach ◽

Leningrad Nuclear Power Plant

Abstract Engineering assessment that supports the safety basis for a reactor plant operating license is defined as: “An assessment of a system to determine its adequacy to successfully perform its safety-related function(s) when required.” The approach to engineering assessment of systems at the Leningrad Nuclear Power Plant (LNPP), as part of its in-depth safety assessment (ISA), is unique. The content and format of engineering assessments for western Safety Analysis Reports (SARs) have evolved over time and current requirements are somewhat scattered in the governing documents (USNRC, 1978). Many regulatory guides and requirements (western or eastern) have not kept up with changes in safety analysis technology. Performance of the ISA for LNPP affords the opportunity to rethink the approach to engineering assessments, and to incorporate current methods and latest technology in safety analysis. As an example, for many systems, information about system reliability obtained from a modem Probabilistic Safety Assessment is more comprehensive than that from a Single Failure Analysis as prescribed in SAR content and format guides. Overall, the engineering assessment of LNPP systems looks at five major assessment elements: 1) assessment of regulatory compliance, 2) assessment of operability, 3) assessment of vulnerability, 4) assessment of environmental qualifications, and 5) assessment of reliability. By reorganizing the approach to meeting regulatory requirements, and by looking at engineering assessment in various ways, information can be obtained that goes beyond simply demonstrating regulatory compliance to more fully supporting the safety basis for a plant operating license.

Download Full-text

Preliminary Study on Risk-Informed LBLOCA of CPR1000

Volume 4: Nuclear Safety, Security, Non-Proliferation and Cyber Security; Risk Management ◽

10.1115/icone25-66201 ◽

2017 ◽

Author(s):

Jianyang Song ◽

Jingquan Liu ◽

Ting Wang ◽

Pingping Liu ◽

Zhikang Lin

Keyword(s):

Nuclear Power ◽

Safety Assessment ◽

Power Plants ◽

Estimation Method ◽

Lessons Learned ◽

Load Spectrum ◽

Analysis Methodology ◽

Assessment Approach ◽

Value Estimation ◽

Probabilistic Sequences

The safety assessment approach of nuclear power plants (NPPs) has been evolved with the technological progress and the lessons learned from the major events. Recently, the risk-informed analysis methodology combined probabilistic safety assessment (PSA) and traditional deterministic methodology has been a hot topic. Following the Risk-Informed Analysis Methodology, the PCT margin of CPR1000 Nuclear Power Plant was re-evaluated in this paper. In the PSA analysis, 162 probabilistic sequences had been identified after LBLOCA occurs. Then 18 probabilistically significant sequences were selected for the deterministic methodology analysis with deterministic realistic method (DRM) for CPR1000 NPP. With calculated PCT of each dominant sequence, a load spectrum of PCT for LBLOCA was generated. Then the risk-informed PCT margin can be evaluated by two different methods, namely the expecting value estimation method and the sequence probability coverage method. In conclusion, it was found that the PCT margin evaluated by the Risk-Informed Analysis Methodology can be greater than that of the deterministic DRM methodology by 16∼34°C.

Download Full-text