| Part/Section | Technical Element | Section | Index No | Issue | Position | Resolution |
|---|---|---|---|---|---|---|
| Part 5 - Seismic | No Technical Element | Section 5-1 | 5-1.1 to 5-1.2 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | No Technical Element | Section 5-1 | 5-1.3 | The last paragraph of the section states that the internal events PRA model is the starting point “…to which must be added a number of structures, systems, and components (SSCs) not included in the model but that could fail due to the external hazard.” Failure modes caused by the external hazard for SSCs existing in the internal events PRA should also be included. | Clarification | The approach to any external hazard PRA typically uses as its starting point the internal events PRA model “to which must be added a number of structures, systems, and components (SSCs) not included in the model but that could fail due to the external hazard and new failure modes caused by the external hazard for SSCs already present in the model.” Both the part of the internal events model dealing with CDF and the part dealing with LERF are used as starting points. |
| Part 5 - Seismic | No Technical Element | Section 5-1 | Eliminated Sections 5‑1.4 and 5-1.5 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | No Technical Element | Section 5-1 | Eliminated Section 5‑1.6 | The Part 5 Code Case does not include the language from Section 5‑1.6 in ASME/ANS RA‑Sb‑2013, which discussed the usage of generic fragility information. Section 5‑1.6 in ASME/ANS RA‑Sb‑2013 indicates that “(a) Analysts should apply caution in the use of generic fragilities and provide justification that the generic fragilities are applicable, and (b) Peer reviews should focus on the use of generic fragilities to ensure that their use is appropriate and justified.” These statements are important because they appropriately identify the scope of interest with respect to generic fragility for both the analysts and the peer reviewers. | Clarification | Include in the nonmandatory appendix (NMA) language on the use of generic fragility information as in Section 5-1.6 in ASME/ANS RA-Sb-2013 as follows: (a) Analysts should apply caution in the use of generic fragilities and provide justification that the generic fragilities are applicable, and (b) Peer reviews should focus on the use of generic fragilities to ensure that their use is appropriate and justified. |
| Part 5 - Seismic | No Technical Element | Section 5-2 | Introductory text | Text was removed from Section 5-2 that helps set the context for the standard requirements. | Clarification | Seismic PRA is an integrated activity requiring close interactions among specialists from different fields (e.g., seismic hazard analysis, systems analysis, fragility evaluation). For this reason, it is important that all members of the seismic PRA team be cognizant of all of the supporting requirements (SRs) in this part, not just those in their area of expertise, and understand the interactions required between the elements. The analysis requires judgment and extrapolation beyond observed data. Therefore, the analyst is strongly urged to review published seismic PRA reports and to compare his/her plant-specific seismic PRA to the published studies of similar reactor types and system designs. This understanding of the standard and other seismic PRAs will promote consistency among similar PRAs and risk-informed applications and will also promote reasonableness in the numerical results and risk insights. The peer review is also directed in part toward this same objective of reasonableness in the numerical results and risk insights. |
| Part 5 - Seismic | No Technical Element | Section 5-2.1 | Introductory text | The first full paragraph of Section 5-2.1 states in part, “The requirements described in Part 5-2.1 address these objectives in detail. A probabilistic seismic hazard analysis (PSHA), which may directly incorporate site response analyses, is used to assess horizontal ground motions at the site.” It does not seem appropriate to highlight a specific aspect of the PSHA, particularly in such an ambiguous manner. | Clarification | The requirements described in Part 5‑2.1 address these objectives in detail. A probabilistic seismic hazard analysis (PSHA) |
| Part 5 - Seismic | No Technical Element | Section 5-2.1 | General comments on the SHA Technical Element | The Code Case proposes definitions for the terms “primary hazard” and “secondary hazard.” However, the Code Case only uses the term “primary hazard” in the definition of the term “secondary hazard,” which may not prompt a need to define the term “primary hazard.” The primary hazard described by the objectives in Section 5-2.1 seems to be the vibratory ground motion. However, in many instances, but not all, the text refers to secondary hazards from vibratory ground motions. It is unclear whether there is a difference between the way vibratory ground motion is referred to in primary and secondary hazards or if these are intended to be synonymous. Consideration should be given to whether the definition be made more precise to the hazards, primary or secondary, that the Code Case intends to address. For example, does it intend to address tsunamis and seiches? If not, it should not be mentioned. | Clarification | Ensure consistent use of the term “secondary hazard” with the definition. To the extent possible express which secondary seismic hazards are included or, alternatively, which are not. |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-1 | HLR-SHA-A | The language of the high‑level requirement (HLR) HLR-SHA-A states, “The frequency of seismic ground motion at the site shall be based on a site-specific PSHA that represents the center, body, and range of the technically defensible interpretations. The level of analysis, as well as the level of updates when an existing study is the initial basis for the site-specific PSHA, shall be determined based on the intended application and on the technical viability of existing PSHA models.” This language is too vague. In particular, the frequency of the ground motion is a natural process. It is the frequency of the ground motion calculation that is based on a PSHA. | Clarification | The basis for the calculation of |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-1 | HLR-SHA-B through HLR‑SHA‑J | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-2 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-2 | SHA‑A1 through SHA‑A4 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-2 | SHA-A5 | Regarding supporting requirement SHA-A5 in Table 5-2.1-2, the NRC staff has discouraged use of the damage parameter cumulative absolute velocity (CAV) filter in place of a lower bound magnitude for the PSHA. Use of CAV has often been misapplied in PSHAs to improperly filter out larger magnitude events at larger source‑to‑site distances. Recently completed PSHAs for Fukushima Near‑Term Task Force (NTTF) Recommendation 2.1 and combined operating license (COL) and early site permit (ESP) applications no longer use the CAV damage parameter in place of a lower bound magnitude. The NRC staff’s related letter pursuant to Title 10 of the Code of Federal Regulations (10 CFR) Section 50.54(f) specified use of M5 (moment magnitude 5) as an appropriate lower bound magnitude. | Clarification | JUSTIFY the specified lower-bound magnitude |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-2 | SHA-A6 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-2 | Note (1), Issue 1 | Note (1) of Table 5-2.1-2 states, in part, “The appropriate level of the hazard analysis will depend on project‑specific factors and should include considerations such as the safety significance of the nuclear power plant, the technical complexity and uncertainties in hazard inputs, regulatory oversight and requirements, and the availability of resources.” Although it is a note and not a requirement, citing the availability of resources as a means of determining the appropriate level of hazard analysis may be misconstrued as a justification for excluding consideration of a safety issue. | Clarification | The appropriate level of the hazard analysis will depend on project-specific factors and should include considerations such as the |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-2 | Note (1), Issue 2 | Note (1) of Table 5-2.1-2 refers to RG 1.208, “A Performance-Based Approach to Define the Site-Specific Earthquake Ground Motion,” as providing an acceptable approach to establishing a lower-bound magnitude for use in the hazard analysis. However, as discussed above with regard to SHA-A5, the NRC staff has discouraged use of the damage parameter CAV filter in place of a lower bound magnitude for the PSHA. Use of CAV has often been misapplied in PSHAs to improperly filter out larger magnitude events at larger source‑to‑site distances. Recently completed PSHAs for NTTF Recommendation 2.1 and COL and ESP applications no longer use the CAV damage parameter in place of a lower bound magnitude. The NRC staff’s related letter pursuant to 10 CFR 50.54(f) specified use of M5 (moment magnitude 5) as an appropriate lower-bound magnitude. | Clarification | Remove the following language in Note (1) of Table 5-2.1-2: |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-3 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-3 | SHA-B1, SHA‑B2 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-3 | SHA-B3 | Sole use of term “attenuation” in conjunction with modeling ground motions is unnecessarily limiting. | Clarification | ENSURE that the data and information are sufficient to characterize attributes important for modeling both regional propagation |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-3 | SHA-B4 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-3 | SHA-B5 | The current language requires a demonstration that the updated earthquake catalog has been reviewed if an existing PSHA is used. However, this does not include accounting for the impact of the updated earthquake catalog on the existing PSHA. | Clarification | If an existing PSHA is used, DEMONSTRATE that an updated catalog of earthquakes |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-3 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-4 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-4 | SHA-C1 through SHA‑C4 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-4 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-5 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-5 | SHA-D1 | The ground motion characterization model needs to include the interface with the site response analysis in terms of a reference soil or rock horizon, as defined by shear wave velocity, density, and damping values. | Clarification | In the ground motion characterization model that determines the range of seismic vibratory ground motion that can occur at a site, INCLUDE (a) credible mechanisms governing estimates of vibratory ground motion that can occur at a site, (b) a review of available historical and instrumental seismicity data (including strong motion data) to assess and calibrate the model, and (c) applicable (existing and/or newly developed) ground motion prediction equations for the ground motion estimates, and (d) reference soil or rock horizon (defined by shear wave velocity, density, and damping values). |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-5 | SHA-D2 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-5 | SHA-D3 | The ground motion characterization model should include ground motion prediction equations (GMPEs) with alternative distance and magnitude scaling behaviors, not just a range of amplitudes. | Clarification | ENSURE that uncertainties are included in the model that determine the range of seismic vibratory ground motion that can occur at a site as well as alternative magnitude and distance scaling |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-5 | SHA-D4 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-5 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-6 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-6 | SHA-E1, SHA‑E2 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-6 | SHA-E3 | The term “ENSURE” is not the appropriate action verb. | Clarification | JUSTIFY |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-7 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-7 | SHA-F1 through SHA‑F3 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-7 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-8 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-8 | SHA-G1, SHA‑G2 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-8 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-9 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-9 | SHA-H1, SHA‑H2 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-9 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-10 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-10 | SHA-I1 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-10 | SHA-I2 | The supporting requirement uses the terms “hazards” and “secondary hazard” interchangeably, which is potentially confusing. | Clarification | For those secondary hazards that are not screened out, INCLUDE their effect through assessment of the frequency of |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-10 | Note 2 | The last sentence of Note (2) in Table 5‑2.1‑10 is vague and unnecessary. | Clarification | The appropriate approach used to justify the basis and methodology used for screening out secondary hazards is hazard- and site-specific. |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-11 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-11 | SHA-J1, SHA‑J2 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SHA - Seismic Hazard Analysis | Table 5-2.1-11 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Section 5-2.2 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-1 | HLR-SFR-A through HLR‑SFR-F | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-2 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-2 | SFR-A1 | The intent of supporting requirement SFR-A1 needs additional clarification. | Clarification | The NMA already discusses the overall intent of SFR-A1 and distinguishes between failure mechanism and failure mode. Include in the NMA a discussion such as the following: The intent of SFR-A1 is to ensure that the fragility analyst provides fragility assessments for the SSCs defined by the systems analyst in the plant’s SEL and for the relevant failure modes associated with the basic PRA events. The understanding is that fragility assessments relate to failure mechanisms, which, in turn, relate to failure modes defined by the systems analyst. |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-2 | SFR-A2 | The information to be included should be such that it can justify the modeling of SSCs as correlated from a fragility perspective and not simply be relevant. Justification, more than the examples provided, will be necessary for any correlation other than 0 and 1. Additionally, the phrase “fragility correlation” should be replaced with “fragility dependence.” Dependence between random variables characterizes their interrelationship. Correlation (coefficient) is used to define the dependence structure between random variables. It is also lacking criteria for determining the acceptability of a correlation model. |
Clarification | INCLUDE information |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-3 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-3 | SFR-B1, through SFR‑B3 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-3 | SFR-B4 | The action verb ESTIMATE implies using judgement or qualitative measures, which are inconsistent with the intent of the SR. The action verb CALCULATE involves a mathematical process, whereas the action verb ESTIMATE does not necessarily involve a calculation (e.g., quantification of a probability or frequency) and can be derived qualitatively. | Qualification | If median-centered response analysis is performed, CALCULATE |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-3 | SFR-B5 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-3 | SFR-B6 | In the 2009 revision (SFR-C2), part of the SR asked one to ACCOUNT for the entire spectrum of input ground motion levels displayed in the seismic hazard curves. This sentence is removed in the Code Case. However, this sentence also ensures the quality of the results of the probabilistic response analysis. | Qualification | If probabilistic response analysis is performed to calculate structural loads and floor response spectra, ENSURE that the number of simulations done (e.g., Monte Carlo simulation or Latin Hypercube Sampling) is large enough to calculate stable responses. ACCOUNT for the entire spectrum of input ground motion levels displayed in the seismic hazard curves. |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-4 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-4 | SFR-C1 | The intent is to provide the basis and methodology to justify that the capacity of the SSC exceeds the screening level. | Clarification | SPECIFY the basis and methodologies established for the capacity-based screening for the level defined in SPR-B5 (e.g., use of simplified fragility analysis, use of applicable generic fragility or qualification data or earthquake experience, and use and applicability of EPRI fragility screening guidance are examples). |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-4 | SFR-C2 | In ASME/ANS RA-Sa-2009, Note (2) of the corresponding supporting requirement (i.e., SFR‑B2) indicates that the screening criteria do not apply to high-seismic regions such as coastal California. However, SFR-C2 in the Code Case does not discuss this note. | Qualification | |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-5 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-5 | SFR-D1, SFR‑D2 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-5 | SFR-D3 | For Capability Category (CC) I: In general, the walkdown AND the fragility evaluation provide the assurance. This requirement supports that assurance but may not always ensure. Also, “vulnerability” needs to be defined. | Clarification | IDENTIFY |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-5 | SFR-D3 | For CC II: The current language implies realistic and plant‑specific fragilities for all vulnerabilities, which is inconsistent with SFR-E3 and established practice. | Clarification | IDENTIFY seismic vulnerabilities to ensure |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-5 | SFR-D4 | The walkdown should also focus on operator pathways and potential unavailability of those pathways. SFR-D7 seems to refer to consequences of failure of one SSC on the performance of another SSC, including inoperability of the SSC by an operator action. However, the words added here refer to pathways for ex-control room actions. |
Clarification | FOCUS on potential functional and structural failure modes, equipment anchorage, |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-5 | SFR-D5 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-5 | SFR-D6 | In ASME/ANS RA‑Sa‑2009, SFR-E3 indicates that if a component is screened out during or following the walkdowns, document the anchorage calculation and provide the basis. However, this statement is removed in the Code Case, and it is not clear whether screening out equipment during walkdowns is allowed. | Qualification | Add the following or equivalent as a new SFR-D6: IDENTIFY credible seismic-induced failure for the fire sources provided in SPR-C4. If components are screened out during or following the walkdown, PROVIDE the basis justifying such a screening. |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-5 | SFR-D7 | This supporting requirement appears to prejudge which seismic interactions have the potential to be “risk‑significant” prior to the walkdown. If the intent is that such information will be provided to the walkdown team by the plant-systems analyst, it appears to be premature to expect such information to be available at the time of walkdown. Further, such an intent or appearance of intent can lead to an argument for excluding the plant-systems analyst from the walkdown. The second part of the SR starting with “EVALUATE the consequences…” is expected to capture the “risk-importance” of the identified interactions. | Clarification | IDENTIFY |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-6 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-6 | SFR-E1 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-6 | SFR-E2 | For CC I: The intent of the requirements should be to identify relevant failure mechanisms. In CCI conservative assumptions and data may be used. | Qualification | For SSCs identified in |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-6 | SFR-E2 | For CC II: The examples listed in the requirement confuse the differences between CC I and CC II. The only real difference is that CC I states “conservatively IDENTIFY relevant” while CC II says “IDENTIFY relevant and realistic”. This SR references SPR-C4 but should reference SPR-C6. | Clarification | For those SSCs identified in |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-6 | SFR-E3 | For CC I: Seismic fragility estimates should be conservative. Ensuring the fragility estimate is conservative may require the development of a more realistic estimate to compare against, which arguably makes the CC I requirement more of a CC II requirement and effectively defeats the purpose of establishing a CC I requirement. Therefore, besides the action verb, the main distinction between CC I and CC II should be the “refinement” of fragilities (conservative or bounding for CC I and realistic for CC II). | Qualification | ESTIMATE conservative seismic fragilities for the failure modes of interest identified in SFR-E2 using plant-specific data, |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-6 | SFR-E3 | For CC II: Calculated seismic fragility should be realistic. The requirement to ensure is unnecessary as this effectively is a function of a peer review. The addition of showing no difference in insights or masking of risk helps ensure the use of generic fragility or conservative assumptions is acceptable for CC II. | Qualification | CALCULATE realistic seismic fragilities for the failure modes of interest identified in SFR-E2 using plant-specific data, |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-6 | SFR‑E4 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-6 | SFR-E5 | The SR (CC I and II) refers to SPR-B6 for identification purposes. SPR-B6 discusses “relay or other similar devices.” To capture these items, this SR also needs to apply to “other similar devices” to prevent any implication that “other similar devices” need not be considered here. Additionally, the action verb for the second part of the CC II requirements needs to be capitalized to identify it. | Clarification | For CCI: ESTIMATE contact-chatter seismic fragilities for relays or other similar devices that are identified in the systems analysis. (See SPR-B6.) For CCII: CALCULATE contact-chatter seismic fragilities for relays or other similar devices that are identified in the systems analysis (see SPR-B6) that significantly contribute to seismic core damage frequency and/or seismic large early release frequency. |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-6 | SFR-E6 | For CC II: The action verb for the second part of the CC II requirements needs to be capitalized to identify it. “Calculate” is the appropriate action verb to be used for this supporting requirement. | Qualification | CALCULATE seismic fragilities for credible seismic-induced flood sources (see SFR-D5) and seismic-induced fire sources (see SFR-D6) that significantly contribute to seismic core damage frequency and/or seismic large early release frequency. For those flood and fire sources that do not significantly contribute to seismic core damage frequency and/or seismic large early release frequency, |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-7 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-7 | SFR-F1 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-7 | SFR-F2 | Related Table 5-2.2-6 that provides supporting requirements associated with the calculation of seismic-fragility parameters use distinct action verbs ESTIMATE and CALCULATE, respectively, for CC I and CC II. However, the related supporting requirement SFR-F2, item (i), associated with documentation of fragility parameter values only uses the word “estimation” but not “calculation.” Therefore, the documentation supporting requirement item (i) is partly inconsistent with other related supporting requirements. | Clarification | Regarding list item (i) in SFR-F2: (i) estimation or calculation of fragility parameter values for each SSC modeled (median capacity, logarithmic standard deviation reflecting the randomness in median capacity, and logarithmic standard deviation representing the uncertainty in median capacity), and |
| Part 5 - Seismic | SFR - Seismic Fragility Analysis | Table 5-2.2-7 | SFR-F3 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Section 5-2.3 | Introductory text, Issue 1 | The seismic PRA depends on both the capability and completeness of the internal events at-power PRA. | Clarification | It is assumed: Relative to the systems-analysis requirements contained herein, the seismic PRA analysis team possesses a full-scope internal events, at-power Level 1 and Level 2 LERF PRA, developed either before or concurrently with the seismic PRA. The internal-events PRA is then used as the basis for the seismic PRA systems analysis. It is recognized that the capability and completeness of the seismic PRA is a function of the capability and completeness of the internal events at-power PRA. |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Section 5-2.3 | Introductory text, Issue 2 | The sentence reads like a “how to,” which is not the intent of the standard. Further, none of the references cited in the section are endorsed by the staff. Such references should be moved to the NMA portion of the standard. | Clarification | |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Section 5-2.3 | Introductory text, Issue 3 | - It needs to be ensured that cross‑references in SFR SRs to SPR SRs are also cross-referenced in the related SPR SRs. For example: SPR-B4 includes the reference to SFR-A2. SPR-B5 includes the reference to SFR-C1. SPR-C4 does not cross-reference SFR‑D6. SPR-D does not cross‑reference SFR‑D7. |
Clarification | Include the missing cross-references either in the requirements or the footnotes. |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-1 | HLR-SPR-A through HLR‑SPR‑C | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-1 | HLR-SPR-D | The term “operator performance” can be interpreted in a narrow context to mean only in‑control room actions and performance. However, the HLR and the corresponding SRs are applicable to all human actions included in the seismic PRA. | Clarification | Human actions credited in the seismic PRA shall consider seismic-specific challenges to |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-1 | HLR-SPR-E | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-1 | HLR-SPR-F | This HLR is overly broad, since HLR-SHA-J and HLR-SFR-F already address documentation of the seismic hazard evaluation and the seismic fragility evaluation, respectively. | Clarification | Documentation of the seismic |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-2 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-2 | SPR-A1 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-2 | SPR-A2 | It is unclear whether the SR is seeking to identify all possible initiating events from secondary hazards or if the intent is to identify and screen such initiators for inclusion in the plant‑systems model. | Clarification | Using a systematic process, IDENTIFY credible seismically induced initiating events caused by secondary hazards (e.g., seismically induced internal flooding, external flooding, and fire) including those identified in SHA-I2 for consideration retention in the plant-response analysis and model development process. |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-2 | SPR-A3 | The verb “encompasses” is overly severe and cannot reasonably be achieved in practice. The wording of this SR should be similar to that of IE-A3 and IE-A4. | Clarification | REVIEW plant-specific response to past seismic events, as well as other available seismic risk evaluations for nuclear plants, to ensure that the list of initiating events included in the evaluation |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-2 | SPR-A4 | The plant-response analysis should include all identified events. | Clarification | INCLUDE in the plant-response analysis the events identified in SPR-A1, |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-2 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-3 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-3 | SPR-B1 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-3 | SPR-B2 | Due to the input from the fire and internal flooding PRAs, and possibly other hazard PRAs, in addition to internal events the findings from all relevant PRAs should be appropriately dispositioned. Additionally, it is not clear what is intended by the latter part of this SR (“…does not adversely affect…”). | Qualification | ENSURE that the peer review findings for the internal-events and other hazard PRAs that are relevant to the seismic PRA are resolved and |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-3 | SPR-B3 | Incorrect reference to SPR-C4 instead of SPR‑C6. | Clarification | INCLUDE seismically induced failures representing the failure modes of interest in the seismic PRA plant-response model (e.g., tank rupture, pump failure to start/run, etc.). (See |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-3 | SPR-B4 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-3 | SPR-B5 | The justification for the appropriate capacity‑based screening level needs to be provided. Neither the action verb for this SR nor that used for SFR-C1 achieves that purpose. | Qualification | |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-3 | SPR-B6 | The term “with a significant contributor to CDF or LERF” is not defined. How can one determine the significance without performing the calculation? | Clarification | USE a systematic approach to INCLUDE in the system analysis the effects of those relays or similar devices susceptible to contact chatter whose contact chatter results in the unavailability or spurious actuation of SSCs on the seismic equipment list. |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-3 | SPR-B7 through SPR‑B11 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-3 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-4 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-4 | SPR-C1 through SPR-C6 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-5 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-5 | SPR-D1, SPR‑D2 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-5 | SPR‑D3 | Cue availability as well as dependencies are integral part of human reliability analyses and maybe affected by seismic events. | Clarification | For CC I: CALCULATE the HEPs for all HFEs taking into account relevant seismic‑related effects on control room and ex-control room post-initiator actions in accordance with the SRs for HLR‑HR‑G in Part 2 of this Standard as set forth under Capability Category I. In addressing influencing factors and the timing considerations covered in SRs HR‑G3, HR‑G4, and HR-G5 in Part 2, attention is to be given to how the seismic event alters any previous assessments in non-seismic analyses including: additional workload and stress; effects of the seismic event on mitigation, cue availability, dependencies, required response, timing, accessibility, and potential for physical harm; and seismic-specific job aids and training. For CC II: CALCULATE the HEPs for all HFEs taking into account relevant seismic‑related effects on control room and ex-control room post-initiator actions in accordance with the SRs for HLR‑HR‑G in Part 2 of this Standard as set forth under Capability Category II. In addressing influencing factors and the timing considerations covered in SRs HR‑G3, HR‑G4, and HR-G5 in Part 2, attention is to be given to how the seismic event alters any previous assessments in non-seismic analyses including: additional workload and stress; effects of the seismic event on mitigation, cue availability, dependencies, required response, timing, accessibility, and potential for physical harm; and seismic-specific job aids and training. |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-5 | SPR‑D4 | The action verb ESTIMATE implies using judgement or qualitative measures only, which is inconsistent with the intent of the SR. Some of the examples of approaches provide more information than an estimate. | Qualification | For significant HFEs, (a) Walk-throughs or talk-throughs of procedures with plant operations or training personnel (b) Simulator observations (c) Plant-specific thermal-hydraulic analyses (d) Realistic and applicable generic or similar plant thermal-hydraulic analyses. Based on a review of procedures with plant operations or training personnel and recognizing the sequence of events and expected seismic conditions, CONFIRM for nonsignificant HFEs the timing aspects of the response actions. |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-5 | SPR‑D5 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-5 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-6 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-6 | SPR-E1 through SPR‑E3 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-6 | SPR-E4 | The phrase “dominant sequence insights” is not defined in either Addendum A or Addendum B. The term “dominant” was intentionally not used anywhere in the standard. | Clarification | USE the quantification process to ensure that the components screened out, based on the screening level defined in SPR-B5, do not become a significant contributor or do not invalidate the |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-6 | SPR-E5 | For CC II: It is not possible or necessary to quantify all uncertainties. | Clarification | For CC II: QUANTIFY the mean core damage frequency and large early release frequency and propagate the parameter uncertainty that results from each input (i.e., the seismic hazard, the seismic fragilities, and the systems analysis). |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-6 | SPR-E6 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-6 | SPR-E7 | For CC II: The reference to Part 2 is missing for HLR-QU-E for CC II. | Clarification | For CC II: PERFORM the uncertainty analysis consistent with HLR-QU-E of Part 2 addressing key assumptions in the hazard analysis (see SHA-J2), fragility analysis (see SFR-F3), and system modeling for Capability Category II. |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-6 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-7 | Introductory text | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-7 | SPR-F1 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-7 | SPR-F2 | The Code Case needs to specify the type of documentation to be provided, rather than relying on the discretion of the user. | Clarification | DOCUMENT the process used in the seismic plant-response analysis and quantification, including. |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-7 | SPR-F3 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | SPR - Seismic Plant Response Analysis | Table 5-2.3-7 | Notes | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | No Technical Element | Section 5-3 | Section 5-3 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | No Technical Element | Section 5-4 | Section 5-4 | -------------------- | No objection | -------------------- |
| Part 5 - Seismic | No Technical Element | Nonmandatory Appendix 5-A | Nonmandatory Appendix 5-A | -------------------- | No objection | -------------------- |
| Part/Section | Technical Element | Section | Index No | Issue | Position | Resolution |