A novel approach for software reliability analysis of digital instrumentation and control systems in nuclear power plants

An Integrated Framework for Risk Assessment of High Safety Significant Safety-related Digital Instrumentation and Control Systems in Nuclear Power Plants: Methodology and Demonstration

“…ORCAS only partially addresses this issue. When testing completeness is sufficient, but failure data is insufficient (i.e., all triggers are considered but no defects were discovered), ORCAS defers to a different methodology, which is known as BAHAMAS [18] that will be introduced in next section. The qualitative evidence derived from ORCAS can also be used to support BAHAMAS.…”

“…The second part in risk analysis is reliability analysis with the tasks of (1) quantifying the probabilities of basic events of the integrated FT from the hazard analysis; (2) estimating the probabilities of the consequences of digital system failures. In the proposed framework, two methods have been developed for different application conditions: the Bayesian and human-reliability-analysis-aided method for the reliability analysis of software (BAHAMAS) [18] for limited-data conditions and orthogonaldefect classification for assessing software reliability (ORCAS) for data-rich analysis. Finally, consequence analysis is conducted to quantitatively evaluate the consequence impact of digital failures on plant behaviors and responses.…”

“…Control algorithms specify how control actions are determined based on the controller's process model, inputs, and feedbacks from previous control processes and intermediate modules. In [18], a process model is thought as the diagnosis portion of a controller, whereas the control algorithm provides actions based on the model's diagnosis. Figure 6.…”

“…The next step is to estimate the failure probability of UCAs/UIFs identified in RESHA. Two methods have been developed for different application conditions: BAHAMAS [18] for limited-data conditions and ORCAS for data-rich analysis.…”

Peak-Load-Regulation Nuclear Power Unit Fault Diagnosis Using Thermal Sensors Combined with Improved ICA-RF Algorithm

“…Zhang et al [8] studied the nuclear power market in North America and proposed a rapid method for the calculation of nuclear power performance, which can also analyze the evaluation index of the nuclear power market. Shorthill et al [9] put forth the Bayesian and HRA-Aided Method for the Reliability Analysis of Software (Bahamas) for analyzing nuclear power in North America. Based on human reliability analysis (HRA), and common cause failure (CCF), the algorithm can diagnose the vibration failure and human factor faults of nuclear power.…”