IEEE IEC 63260-2020 pdf download

IEEE IEC 63260-2020 pdf download.Guide for incorporating human reliability analysis into probabilistic risk assessments for nuclear power generating stations and other nuclear facilities.
The focus of this guide is restricted to the incorporation of the HRA integrally into a PRA. This includes the following issues:
a) The compatibility ofan HRA with the PRA of which it is a part;
b) The relationship between the way in which an HRA is performed, its philosophy, and the results or insights that may be obtained;
c) Matching the best suited HRA method to the analysis requirements; and
d) The limits ofan LIRA or its results.
3.2.1 PRA compatibility
The HRA process proposed is suitable to all levels of a PRA given defined human failure events. If these are not defined, then this guidance cannot be applied successfully. The risk focus of a PRA requires the quantitative results of an IIRA to be probabilistic in nature. Applications of PRAs to risk management efforts require that the IIRA documents in sufficient detail the analyst’s human factors considerations for the human failure events. The PRA can have a diverse range of applications, the objectives of which may not be completely identified prior to the assessment. The HRA process should be flexible enough to anticipate some of the likely applications of the results of the IIRA. For example, this may include design changes, procedure changes, training development, safety evaluations, or technical specification modification.
3.2.2 Qualitative HRA
While the approach identified in this guide supports I IRA quantification as part of the PRA, it should be noted that there is an increasing emphasis on the importance of qualitative I IRA [13 15], i.e., I IRA that does not produce a human error probability, but rather insights into the human’s role and contribution to overall system performance. The HRA approach in this guide supports both qualitative and quantitative aspects of HRA. For PRA, the quantitative approach should be adopted. For non-PRA applications of IIRA, steps relevant to ciuantification should be omitted as appropriate.
3.2.3 The relationship of approach to results
Assumptions made by human reliability analysts about the relative importance of various human activities will influence the breadth and detail of’ models developed for the IIRA. The data and chosen method of quantifying human interactions will influence the specific estimates or ranges of uncertainty obtained, although there is generally good agreement between HRA methods. If results point to the need to improve the reliability of selected systems and accompanying human interactions, these improvements should either be readily identifiable from the documented HRA or should be the subject of’ further or different analytical methods that will allow improvements to be identified as described in method-specific documents. In addition to method-specific guidance, general guidance on selection of appropriate IIRA approaches can be found in cross-method overview documents such as [1321, [133], and [1314]. The IIRA analyst should be mindful of this when considering the specific approach to be taken.
3.2.4 Matching the method to the application
Various HRA-related methods are available and being developed (e.g., cognitive approaches to human error or approaches that address errors of commission). I IRAs should be flexible enough to accommodate new findings and model dcvclopments, while structured enough to be repeatable and traceable. HRA methods were developed for different purposes, and they feature different strengths [B 14]. One emerging practice is that multiple IIRA methods may be used within a single analysis to reflect the strengths of those approaches and the needs of the analysis [B7]. This guide remains method-neutral but encourages analysts to be flexible in considering the best HRA methods for particular applications.
3.2.5 Limits
To be effectively incoiporated into a IRA an I IRA should provide a realistic-as-possible interpretation of the role of plant personnel in accident prevention and mitigation. Accordingly, the results of an HRA should be documented in a format such that the basic assumptions models, and data sources are clearly documented and the limitations of the analysis are understandable to the user (e.g., PRA analyst).