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ASME 58.22-2014 pdf download

ASME 58.22-2014 pdf download.Requirements for Low Power and Shutdown Probabilistic Risk Assessment.
(d) Fragility analysis. This is the analysis of the fragility (probability of “damage” vs. “size” of hazard) for each SSC on the list from (c) above. This work must include the analysis of correlated damage, if appropriate (such as for groups of SSCs affected by the same flooding in a room.) Relation to Technical Requirements in the ASME/ANS PRA Standard [1]: The fragility analysis work is conceptually identical to that for full power operation, although the scope of the analysis of course must be tailored to the POS and its configuration. The relevant HLRs and SRs are in the ASME/ANS PRA Standard [1], as discussed in detail for earthquakes in Section 5-2 (designated as SFR), for high winds in Section 7-2 (designated as WFR), for external floods in Section 8-2 (designated as XFFR), and for other external hazards in Section 9-2 (designated as XFR). (e) Identification of the character of the “hazard-induced initial damage states” caused by the hazard. This identification needs to be done as a function of hazard “size” and of the POS. Here, a “hazard-induced initial damage state” is intended to mean a set of specified initial damage or other effects on the plant such as “loss of system X, combined with failure of shear wall Y.” This explicitly involves addressing each POS (or group of POSs) separately, because the combination of failures or problems resulting from the hazard may be unique to that POS. Relation to Technical Requirements in the ASME/ANS PRA Standard [1]: HLRs and SRs for the work of identifying the character of all “initiating events” caused by the external hazard during LPSD states are already in the ASME/ANS PRA Standard [1]; they are discussed in detail for earthquakes in Section 5-2 (designated as SPR), for high winds in Section 7-2 (designated as WPR-A), for external floods in Section 8-2 (designated as XFPR-A), and for other external hazards in Section 9.2 (designated as XPR-A). The analyst needs to account not only for the POS, but also for any special effects of the given external hazard such as damage that might be caused by the external hazard that would not otherwise be modeled in the LPSD PRA along with any special activities or configurations such as whether the reactor vessel head is off or whether crane use involving heavy-loads could be affected by an earthquake or high winds. (f) Systems analysis. This is the development of initiating-event systems analysis and event- tree/fault-tree systems analysis, accounting for any special analysis features as needed. These special analysis features are likely to differ in many POSs from the models for internal events analysis and might include special effects of the external hazard on the structure of the systems analysis or special types of initiating events that would need tailored treatment in the analysis. Relation to Technical Requirements in the ASME/ANS PRA Standard [1]: The systems analysis work is similar to that for external hazards PRA for full power operation. It must be addressed separately for each POS (or group of POSs). The relevant HLRs and SRs for this element are in the ASME/ANS PRA Standard [1], as discussed in detail for earthquakes in Section 5-2 (designated as SPR), for high winds in Section 7-2 (designated as WPR-A), for external floods in Section 8-2 (designated as XFPR-A), and for other external hazards in Section 9-2 (designated as XPR-A).
(g) Integration of hazard analysis with SSC fragility analysis and with systems analysis to quantify CDF and LERF. This portion of the analysis consists of integrating the intermediate results of the earlier phases to quantify CDF and LERF values. Relation to Technical Requirements in the ASME/ANS PRA Standard [1]: The integration work is identical to that for external hazards PRA for full power operation. The HLRs and SRs for this element are in the ASME/ANS PRA Standard [1]; they are discussed in detail for earthquakes in Section 5-2 (designated as SPR-E), for high winds in Section 7-2 (designated as WPR-B), for external floods in Section 8-2 (designated as XFPR-B), and for other external hazards in Section 9-2 (designated as XPR-B). In addition to the technical elements above, an additional and vital task is the documentation of the work. Requirements for documentation are also included throughout this standard. 1.1.8.4 High Winds PRA and External Flooding, LPSD PRA The ASME/ANS PRA Standard [1] contains separate sections with technical requirements for high winds PRA (Part 7) and external flooding PRA (Part 8). It also contains guidance that permits the analyst to use either the requirements in these specific sections or the more general requirements that cover any other external hazard, found in Part 9 of that standard. As noted just above in Section 1.1.8.2, this approach is also followed here. 1.1.8.5 High Level Requirements for a Specific External Hazard for Each POS Separately All of the requirements in Parts 5 through 9 are to be carried out separately for each POS (or set of POSs) identified as relevant. 1.2 Acronyms and Definitions The list of acronyms and definitions from Reference [1] is adopted for this standard by reference. Additional acronyms and definitions are provided in this section to ensure the understanding of terms as they are used in this standard.

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